Author Archives: jtw13

Planck Frequencies as Schelling Points in SETI

Early when I was learning about SETI I was reading about “magic frequencies” and the “Water Hole.”

Back in the early days of radio SETI, instrumental bandwidths were pretty narrow, so Frank Drake and others had to guess what frequencies to observe at to find deliberate signals. One wants a high frequency to avoid interference from the Earth’s ionosphere and background noise from the Galaxy. But one also wants to observe at a high frequency to avoid lots of emission from Earth’s atmosphere.  There is a “sweet spot” between these problems, in the range of 1–10 GHz:

Figure showing background levels as a function of frequency, with a minimum between 1-10 GHz

From seti.net

In this broad minimum are two famous and strong astrophysical emission lines: the spin-flip hyperfine transition due to hydrogen (the “21 cm line”), and the emission from the hydroxyl radical (OH-).  Since these two species combine to form water, and since water is essential to life-as-we-know-it, the region between these two lines is known as the “water hole”. This has a nice pun to it too as a reference to a place where savannah animals (or barflies) gather.  As Barney Oliver put it “Where should we meet? The watering hole!”

Trying to determine exactly which frequency in the Water Hole to search became a game of guessing “magic frequencies” (I think the term is due to Jill Tarter, though I could be wrong) to tune one’s telescope to.

When I was learning about all of this, I was reading the Wikipedia article on the Water Hole and I saw this intriguing link:

Screenshot of the Wikipedia page on the Water Hole showing a link to "Schelling Points"

Clicking on that last link sent me down a nifty rabbit hole and eventually got Schelling points introduced into the SETI literature.

I wrote a while back on Schelling points and their relevance to SETI.  Go there for the full story, but briefly: Thomas Schelling was an economist and game theorist who considered games where players must cooperate (everyone wins or everyone loses) but cannot communicate. His example was finding someone else who is also looking for you in New York City.  The prospects for winning such a game seems hopeless, but Schelling’s insight was that it was actually pretty easy if you could correctly guess the other person’s strategy, since some strategies are clearly bad (a random search) and others are plausibly good (go to a major landmark).

These optimal strategies are characterized by what we now call Schelling points: in New York City, it’s the Empire State Building and noon are good ones.

Amazingly, ABC News Primetime got people to actually play that game and they won! In hours!

When introducing this idea to the world in his book The Strategy of Conflict, Schelling wrote:

[A good example] is meeting on the same radio frequency with whoever may be signaling us from outer space. “At what frequency shall we look? A long spectrum search for a weak signal of unknown frequency is difficult.  But, just in the most favored radio region there lies a unique, objective standard of frequency, which must be known to every observer in the universe: the outstanding radio emission line at 1420 megacycles of neutral hydrogen” (Giuseppe Cocconi and Philip Morrison, Nature, Sep. 19, 1959, pp. 844-846). The reasoning is amplified by John Lear: “Any astronomer on earth would say ‘Why, 1420 megacycles of course! That’s the characteristic radio emission line of neutral hydrogen.  Hydrogen being the most plentiful element beyond the earth, our neighbors would expect it to be looked for even by tyros in astronomy’” (“The Search for Intelligent Life on Other Planets,” Saturday Review, Jan. 2, 1960, pp. 39-43). What signal to look for? Cocconi and Morrison suggest a sequence of small prime numbers of pulses, or simple arithmetic sums.

So the water hole is a Schelling point!  Or it could be—we need to guess the mind of ET and ask: what frequencies would they guess we would guess, and perhaps water and ionospheres and radio just aren’t their thing?  Schelling’s players can win the game only because they have a common cultural heritage and know about the Empire State Building being famous. If we played that game with aliens, we’d probably lose.

So what do we know we have in common with aliens?  Max Planck had an idea.

Image of Max Planck

Max Planck

Max Planck is one of the most important figures in modern physics, famous for many key insights but among them his constant, h, and his eponymous “natural units.”  Planck realized that there is a fundamental length scale of the universe, set by the nature of space and time, gravity, and quantum mechanics. We call it the “Planck length” and it is given by:

Planck Length formula

Very roughly and heuristically, it is the wavelength of a photon so energetic that its wavelength is equal to its Schwartzchild radius (that is, a photon so dense with energy that it would be a black hole).  Today, we recognize this as the scale on which quantum mechanics and General Relativity give different answers or become mutually incompatible.  Dividing by the speed of light, one defines a fundamental timescale of the universe, which could be interpreted as an observing frequency.

In his famous paper on the topic written in 1900, he wrote:

It is interesting to note that with the help of the [above constants] it is possible to introduce units…which…remain meaningful for all times and also for extraterrestrial and non-human cultures, and therefore can be understood as ’natural units’

and that

…these units keep their values as long as the laws of gravitation, the speed of light in vacuum, and the two laws of thermodynamics hold; therefore they must, when measured by other intelligences with different methods, always yield the same.

So he imagined that these units would be known to extraterrestrial physicists, unlike, say, kilograms and seconds which are completely arbitrary and anthropocentric. Since what we’re looking for is a frequency that we know they would know that we know, this seems like a good Schelling point!

The problem is that the Planck time is way way too short—photons at those frequencies are little black holes (or something—we don’t have physics for it) so don’t exist (or can’t be produced, anyway.)  So how could we use them?

Well, there is another fundamental physics constant, another fundamental unit in nature, which is the fundamental unit of charge. Aliens would have to know that!  Combining the charge of the electron with the speed of light and Planck’s constant h one gets the fine structure constant:

Formula for the fine structure constant

which has a value near 1/137 and is dimensionless.  This is a constant of nature that we do not have a way to calculate purely mathematically or from first principles—it measures the degree to which electrons “couple” to photons, and so governs how all of electromagnetism and light works.

So, can we get another frequency if we multiply the inverse of the Planck time by the fine structure constant. That frequency turns out to still be too high to observe, but there’s no reason we couldn’t keep multiplying by the fine structure constant until we get a useful frequency. This process would actually generate a large number of frequencies—a frequency “comb” with many “teeth.”  Some of the frequencies generated this way are at interesting frequencies: 610.3 nm in the optical, and 26.16 GHz in the microwave, for instance, are both easily observed from Earth and in fact the sorts of frequencies we might use for communication.  These are Planck’s Schelling points!

But there are some caveats here.  Are Planck’s units really that universal?  Look at those equations above: they both have a factor of 2π in them.  Where did that come from?

Well, Planck liked to define things in terms of angular frequency, meaning the time it takes the phase of an oscillator to change by 1 radian. The 2π goes away if you choose to define frequency in terms of cycles per unit time (as astronomers do for light or engineers do for AC electricity).  It’s arbitrary!  So, we could also define both constants without the 2π. Maybe aliens like it better that way?  So we can build a frequency comb that way, and that’s another potential Schelling point.

Also, maybe we’re overcomplicating things.  If we’re going to choose a base to raise to a power then maybe the fine structure constant isn’t the natural one to use—any mathematician will tell you that the natural base to use is the base of the natural logarithm, e! (Different e from the one above, though). Then you can do it all with only 3 physical constants instead of 4, so maybe more obvious? So that’s another potential Schelling point.

Or maybe you want to make sure the frequencies have physical meaning akin to the 21 cm line Shelling mentioned, and as long as you’re thinking about light you might like to use the mass of the electron instead of the gravitational constant G.  In that case you could define your base unit of energy as half of its rest energy of the electron and use the fine structure constant to make your comb.  Seems a bit arbitrary, at first, but the energies defined by that comb are

(m_e c^2)/2 \alpha^n

and when n=2 we have an important unit in physics, the Rydberg, equal to the energy it takes to ionize a ground state atom with only one electron (in reality there’s a small correction factor, but this is the fundamental unit).  This unit was known even to classical physics and so is a very “natural” way to define a universal energy or frequency.  So there’s yet another frequency comb.

We could surely define more. The truth is, Planck’s insight isn’t all that helpful for guessing exactly which frequencies we should look at because we still need to make lots of choices and we don’t have any guide beyond what seems natural.

But still, it’s a useful illustrations of both the power and limitations of Schelling’s idea. Also, we can add the frequencies that appear in these frequency combs to the lists of “magic frequencies” we check for—more ideas about places to look can’t hurt, because today modern radio observatories can search billions of frequencies at once, so it costs nothing to check a few more more that they observed.

But there may be another insight here: these frequency combs generate multiple frequencies, and perhaps we should look for signals at all of them.  After all, unlike looking for someone in New York, there is little preventing us from looking in more than one channel at once, or from their signals being at more than one frequency at once.  Perhaps we should be looking for combs of signals, or at multiple wavelengths simultaneously!

Anyway, this idea of Schelling points has gained a lot of traction since I made passing reference to it in a review article a while back, but it has no proper, refereed citation in a SETI context (beyond Schelling’s offhand remark in his book).  So I’ve written up the idea formally, including the Planck Frequency Comb as a case study, in a new paper for the International Journal of Astrobiology. You can read it on the arXiv here.

 

Thanks to Sabine Hossenfelder and Michael Hippke for these translations of Planck’s 1900 paper.

Is SETI dangerous?

Interdisciplinarity in science can be wonderful: combining expertise across disciplines leads to new insights and progress because it’s only when people from those disciplines communicate about a particular problem that progress is made, and that happens much more rarely than communications among members of a single discipline.

It’s important, though, when working across disciplines to actually engage experts in those other fields. There’s a particular kind of arrogance, common among physicists, that a very good scientist can wander into another discipline, learn about it by reading some papers, and start making important contributions right away. xkcd nailed it:

xkcd comic. A physicist is lecturing an annoyed person who has beer working at a blackboard and laptop with notes strewn about. "You're trying to predict the behavior of <complicated system>? Just model it as a <simple object>, and then add some secondary terms to account for <complications I just thought of>. Easy, right? So, why does <your field> need a whole journal, anyway? Caption: Liberal arts majors may be annoying sometimes, but there's nothing more obnoxious than a physicist first encountering a new subject.And my favorite takedown of the type is from SMBC (go read it!)

There’s a new paper about the dangers of SETI out by Kenneth W. Wisian and John W. Traphagan in Space Policy, described here on Centauri Dreams. In it, they describe the worldwide “arms” race, similar to the one in the film Arrival, to communicate with ETIs once contact is established. They say this is an unappreciated aspect of SETI and that SETI facilities should take precautions similar to those at nuclear power plants.  Specifically, they write:

In the vigorous academic debate over the risks of the Search for ExtraTerrestrial Intelligence (SETI) and active Messaging ExtraTerrestrial Intelligence (ETI) (METI), a significant factor has been largely over- looked. Specifically, the risk of merely detecting an alien signal from passive SETI activity is usually considered to be negligible. The history of international relations viewed through the lens of the realpolitik tradition of realist political thought suggests, however, that there is a measurable risk of conflict over the perceived benefit of monopoly access to ETI communication channels. This possibility needs to be considered when analyzing the potential risks and benefits of contact with ETI.

I have major issues with their “realpolitik” analysis, but I’m not an expert in global politics, international affairs, or risk aversion so I’m not going to critique that part here. Instead, I’ll stick to my expertise and point out that the article would be much stronger if the authors had consulted some SETI experts, because it is based on some very dubious assumptions about the nature of contact.

The authors seems to think it is clear that once a signal is identified:

  1. Only around “a dozen” facilities in the world will be able to receive the signal, and that states will be able to somehow restrict this capability from other states. The authors think this covers both laser and radio.
  2. That it will be possible to send a signal to the ETI transmitter, and that this capability will have perceived advantages to states.

While there are some contact scenarios where these assumptions are valid, they are rather narrow.

First, modern radio telescopes are large and expensive because they are general purpose instruments. They can often point in any direction, and have a suite of specialized instrumentation designed to operate over a huge range of frequencies.

But once a signal is discovered, the requirements to pick it up shrink dramatically. Only a single receiver is required, and its bandwidth need be no wider than the signal itself. The telescope need only point at the parts of the sky where the signal comes from, so it need only have a single drive motor. And the size of the dish need not be enormous, unless the signal just happens to be of a strength that large telescopes can decode it but small ones cannot, which is possible but a priori unlikely.

Indeed, there are an enormous number of radio dishes designed to communicate with Earth satellites that could easily be repurposed for such an effort, and can even be combined to achieve sensitivities similar to a single very large telescope, if signal strength is an issue. And there is no shortage of radio engineers and communications experts around the world that can solve the problem quickly and easily. The scale of such a project is probably of order tens of thousands to millions of dollars, depending on the strength and kind of signal involved. The number of actors that could do this worldwide is huge. Also, such efforts would be indistinguishable from normal radio astronomy or satellite communications, so very hard to curtail without ending those industries.

The situation is similar for a laser signal: if it is a laser “flash” then the difficulty is primarily in very fast detectors that can pick it up. Here, the technology is not as mature, and if the flashes are *extremely* fast it is possible that the necessary technology could be controlled but, again, this assumes a very particular kind of laser signal. And, again, there are an enormous number of optical telescopes which will have similar sensitivity to optical flashes as existing optical SETI experiments (which, again, are only expensive because they search a huge fraction of the sky for signals of unknown duration).

Finally, there is the issue of two-way communication: unless the signal is coming from within the solar system or the very closest stars, the “ping time” back and forth is at least a decade, and likely much longer. There is no “conversation” in this case: the first response to our communications would be ten years down the line! So the real dangers are transmitters within the solar system or signals that contain useful information without the need for us to send signals.

In summary, the concerns expressed in this article apply to a narrow range of contact scenarios in which the signal is, somehow, only accessible to those with highly specialized equipment or from a transmitter within the solar system. The first seems highly unlikely; I do not know to evaluate the second, but note that such signals are not searched for routinely in the radio, anyway.

I’d be happy to engage with experts in space law on a paper on the topic, if I know any?

Science is not logical

OK, time for some armchair philosophy of science!

You often hear about how logic and deductive reasoning are at the heart of science, or expressions that science is a formal, logical system for uncovering truth. Many scientists have heard definitions of science that include statements like “science never proves anything, it only disproves things” or “only testable hypotheses are scientific.” But these are not actually reflective of how science is done. They are not even ideals we aspire to!

You might think that logic is the foundation of scientific reasoning, and indeed it plays an essential role. But logic often leads to conclusions at odds with the scientific method.  Take, for instance, the “Raven Paradox”, expertly explained here by Sabine Hossenfelder:

Sabine offers the “Bayesian” solution to the paradox, but also nods to the fact that philosophers of science have managed to punch a bunch of holes into it. Even if you accept that solution, the paradox is still there, insisting that in principle the scientific method allows you to study the color of ravens by examining the color of everything in the universe except ravens.

I think part of the problem is that the statement “All ravens are black” sounds like a scientific statement or hypothesis, but when we actually make a scientific statement like “all ravens are black” we mean it in something closer to the vernacular sense than the logical one. For instance:

  • “Ravens” is not really well defined. Which subspecies? Where is the boundary between past (and future!) species in its evolutionary descent?
  • “Black” is not well defined.  How black? Does very dark blue count?
  • “Are” is not well defined. Ravens’ eyes are not black. Their blood is not black.

Also, logically, “all ravens are black” is strictly true even if no ravens exist! (Because “all non-black things are not ravens” is an equivalent statement and trivially true in that case). Weirdly, “all ravens are red” is strictly true in that case, as well! This is not really consistent with what scientists mean when we say something like “all ravens are black”, which presumes the existence of ravens. We would argue that a statement like that in a universe that contains no ravens is basically meaningless (having no truth value) and actually misleading, not trivially true, as logic insists.

So the logical statement “all ravens are black” is supposed to be very precise, but that is very different from our mental conception of its implications when we hear the sentence, which are squishier. We understand we’re not to take it strictly literally, but that is exactly what logic demands we do!  And if we don’t take it in exactly the strict logical sense, then we cannot apply the rules of formal logic to it. This means that the logical conclusion that observing a blue sock is support for “all ravens is black” does not reflect the actual scientific method.

You might argue that “black” and “raven” are just examples, and that in science we can be more precise about what we mean and recover a logical statement, but really almost everything we do in science is ultimately subject to the same squishiness at some level.

Also, and more damningly:

If we were to see a non-white raven—one that has been painted white, an albino, or one with a fungal infection of its wings— we would not necessarily consider it evidence against “all ravens are black”!  We understand that “all ravens are black” is a general rule with all kinds of technical exceptions. Indeed, a cardinal rule in science is that all laws admit exceptions! Logically, this is very close to the “no true Scotsman fallacy,” but it is actually great strength of science, that we do not reach for universal laws from evidence limited in scope, only trends and general understandings. After all, even GR must fail at the Planck length. 

So even the word “all” does not have the same meaning in science as it does in logic!

More generally, in science we follow inductive reasoning. This means that seeing a black raven supports our hypothesis that all ravens are black. But in logic there is no “support” or “probability,” there is only truth and falsity. On the other hand, in science there are broad, essential classes of statements for which we never have truth, only hypotheses, credence, guesses, and suppositions. Philosophers have struggled for years to put inductive reasoning on firm logical footing, but the Raven Paradox shows how hard it is, and how it leads to counter-intuitive results.

I would go further and argue that strictly logical conclusions like those of the Raven Paradox are inconsistent with the scientific method. I would simply give up and admit: the scientific method is not actually logical!

After all, science is a human endeavor, and humans are not Vulcans. Logic is a tool we use, a model of how we reason about things, and that’s OK: “All models are wrong, but some are useful.”  Modeling the Earth as a sphere (or an oblate spheroid, or higher levels of approximation) is how we do any science that requires knowledge of its shape but it’s not true. Newton’s laws are an incredibly useful model for how all things move in the universe, but they are not true (if nothing else, they fail in the relativistic limit).

Similarly, logic is a very useful and essential model for scientific reasoning, and the philosophy of science is a good way to interrogate how useful it is. But we should not pretend that scientists follow strict adherence to logic or that the scientific method is well defined as a logical enterprise—I’m not even sure that’s possible in principle!

The astrophysical sources of RV jitter

A big day for our understanding of RV jitter!
 
Penn State graduate student Jacob Luhn has just posted two important papers to the arXiv. You can read his excellent writeup of the first of them here:
 
It took Jacob a HUGE amount of work to determine the *empirical* RV jitter of hundreds of stars from decades of observations from Keck/HIRES. These are “hand crafted” jitter values, free of planets, containing only the HIRES instrumental jitter plus astrophysical jitter.
(Along the way, we wondered how to put error bars on jitter, which is itself a deviation. What’s the standard deviation of a standard deviation? Jacob found the formula—it’s in the paper if you’d like to see how it’s done (you have to use the kurtosis). )
You may have seen Jacob’s work at various meetings: young stars and evolved have high jitter, so there is a “jitter minimum” where they are quietest.
But this paper has more! It turns out the location of the jitter minimum depends in a predictable way on a star’s mass.
Figure from Jacob's paper illustrating the dependence of jitter on log(g) and mass.
 
The second paper describes the properties of F stars with low jitter.
 
But don’t F stars all have high jitter?
 
Nope. Jacob has found many stars in the “jitter minimum” are F stars with < 5 m/s of RV jitter. This has important implications for following up transiting planets.
 
My favorite consequence of this work is that we will be able to now *predict* the RV jitter of a star from its mass, R’HK, and log(g) *empirically*, incorporating *all* sources of RV noise . Right now, such predictions are only good to ~factor of 2. Jacob can predict it to <25%!
 
But predicting RV jitter is a story for another paper, coming soon. For now, enjoy these papers at AJ and on @jacobkluhn’s blog:
https://iopscience.iop.org/article/10.3847/1538-3881/ab855a
https://iopscience.iop.org/article/10.3847/1538-3881/ab775c

On Meeting Your Heroes

Freeman Dyson died on Friday. He was a giant in science, possibly the most accomplished and foundational living physicist without a Nobel Prize. He was 96.

Tania/Contrasto, via Redux

He had a big influence on my turn to SETI. I’ve written about him several times on this blog, including about his “First Law of SETI Investigations”, his role in the development of adaptive optics, how that intersected with Project Orion and General Atomic, and of course his eponymous spheres that I’ve spent some time looking for.

I got to meet him twice. Once was when Franck Marchis invited him, Jill Tarter, Matt Povich, and me to talk about Dyson spheres on a Google Hangout for the SETI Institute:

The second time was a at UC San Diego. I was there to give a talk, and walking down the hallway of the astronomy part of the physics department I saw “F. Dyson” on one of the doors. I asked, and was surprised to learn that he spent his winters in San Diego where his grandchildren lived, and that he had an office in the department.

And he was there that day.

And he’d be at my talk.

About Dyson spheres.

Indeed, his face was on the second slide.

The talk went well and afterwords he invited me to lunch to discuss it. He asked if I was free. I looked at my schedule: of course I had a lunch appointment. “Yes, it looks like I’m free!” I said, then briefly excused myself to explain the change to my host.

Freeman Dyson and me after my talk at UCSD

Freeman Dyson and me after my talk at UCSD

I asked where we should go and he said “I like Burger King.” So he walked me to the student union where he got a hotdog, and we sat at a table for four, next to a slightly annoyed undergraduate looking at his phone.  We talked about Dyson spheres and SETI, I’m sure. I also could not resist and asked embarrassingly naïve questions about experimental tests of the vacuum energy and the like. “I don’t think that’s a promising line of research” he politely deflected.


I have a list of bands I’ll see if they come to town, and a shorter list of bands I’ll see if they come within driving distance. It’s not a list of my favorite bands, it’s a list of bands that might be on their last tour that I want to have seen at least once. I’ve seen Dylan (twice!), Springsteen (twice!), The Who (Quandrophenia in Philadelphia), Bob Seeger, Rod Stewart, Elton John, Metallica (twice!), the Rolling Stones, Paul McCartney, and more. Cher caught a cold and so they canceled the State College show (I really bought the tickets for Pat Benitar’s opening act, though).

I missed Prince. You never know.

I’ve twice missed talking to my heroes because they were old and I dallied. I invited Nikolai Kardashev to this summer’s SETI Symposium, but I got a decline from someone managing his email account, and then we learned last August that he had passed away at 87.

When I was organizing the letter writing campaign for a prize from the AAS for Frank Kameny, I got his contact information (the phone number at his house). I wanted to call him to tell him what we were doing, but I decided to wait until the prize was official so I could tell him the good news. On August 1, 2011 I learned the AAS was officially going to consider the prize. On October 12, Kameny passed away at 86. On October 15, the AAS announced the prize, which had to be posthumous.

I never called. I’m not sure Frank knew about the effort at all, that his old professional society was finally honoring him.


I’m glad I met Freeman. I’m sad I won’t get his feedback on the big review article on Dyson Spheres that I’ve written that will be published this summer. I probably should have sent it to him earlier.

Battling the Email Monster

Sometimes when people ask what I do for a living, I tell them I write and answer email.  It certainly is a big part of my day!

That said, I have a pretty good relationship with email. I have a well-managed inbox and occasionally even hit inbox zero, despite getting a lot of emails every day and juggling a lot of responsibilities.

There are a lot of guides out there about how to do this, including this nice Harvard Business Review article on how to have an efficient email session, the “touch it once” philosophy that apparently got its start in the pre-email days, and the original “inbox zero” philosophy that leverages a lot of Gmail features.  My own philosophy borrows a lot from all of these, especially the idea that when you encounter an email you should dispose of it quickly in a way that either gets it off of your desk or puts it where it needs to be for you to act on it.

I know many people with tens of thousands of unread emails, and it’s probably not practical for them to go through and dispose of them all.  For them, I might recommend email bankruptcy: file everything away, start from an empty inbox, and this time don’t let it build up.

I got to this state by building up a lot of good email habits including, counterintuitively, sending myself lots of emails.  Here they are, in case you’d like to try it:

  1. Get GMail. It has good filtering, enough storage space for all of your email, a snooze feature, and (and this is key): such good search capabilities that you don’t have to file anything. It has good support for mobile devices, you can configure it for offline use, and the cloud storage means you don’t have to worry too much about backups.
  2. Use hotkeys. They save a second per email which really adds up. Have one for archiving, one for spam, one for responding, and one for responding to all.
  3. Think of your inbox as your to-do list.  If it’s in your inbox, it’s a short- to medium-term action item. Every email is an item. If you’re not going to do something with it soon, it should not be in your inbox. Keep your list of big and/or long-term projects you’re working on somewhere else.
  4. Archive emails immediately after dealing with them. This is how you cross the item off of your to-do list. GMail is also spooky good at giving “nudges” about emails you sent that never got answered, helping you to not lose track of important threads when they leave your inbox.
  5. Use snooze a lot. If you don’t need to work on it soon, snooze it until you do need to work on it. That final report due in December? Snooze until late November.  That speaker you need to arrange visits for? Snooze the “yes I can host” email you sent until the week before they arrive. That thing you’re going to buy this weekend? Snooze until Friday afternoon. Don’t have things in your inbox that aren’t potential action items today or very soon.
  6. Battle the email monster often and efficiently. I “weed” my inbox many times per day. It’s a constant triage, with every email getting one of three dispositions every time I see it:

    1) deal with it and archive it forever,
    2)
    snooze it for later, or
    3)
    decide you’ll deal with it very soon.
    It’s a good way to spend those odd bits of time between meetings or on a bus where you don’t have time to dig into a big project.

  7. Send yourself emails. If you have an ongoing thing that you need to have on your to-do list (i.e. in your inbox) and there is no associated email for the next short-term task, make one by sending yourself an email with the task as the subject.
  8. Get used to saying “send me an email”. If I’m in a conversation and we generate an action item for me, I make sure there is an email to go with it. You might send it to yourself, you might summarize the conversation at the end in an email to them and you, or (if appropriate) just ask them to send you an email asking for that thing. Now it’s on your to-do list.
  9. Expect that you will archive everything. Plan that every single email will eventually get stored away, the sooner the better. It’s not gone; you’ll find it again because you have Google search. If it’s not on your to-do list, archive it.
    [If you really really can’t not file things because you need that level of organization in your mail: use a label+archive hotkey.  Choose a small number of labels (they’re like folders) and file the emails you’re worried you’ll lose appropriately as you archive them. But: you don’t have to label everything.]
  10. Learn to use the GMail search bar. You can find emails very quickly if you know how to search on sender, dates, and other nifty keywords. This is key: you need to always be able to find any email without spending a lot of time filing them.
  11. Unsubscribe aggressively.  Spam is not to be immediately deleted! Each one is an action item: unsubscribe (if it’s true spam and not just normal marketing you can hit GMail’s “spam” button and better train the AI to keep these out of your inbox in the first place).  Between unsubscribing aggressively and GMail’s spam filter I get very little unwanted mail, which is essential for a well-managed inbox.
  12. Filter out the noise. There are emails you need to have and maybe want to read in batches but don’t really need to read every time they arrive. You can filter them to archive and get a label before they ever hit your inbox. When you want to catch up, go to the label and read them at your leisure, but don’t waste a tiny part of each day acting on them. If you’re worried you’ll never get around to reading them if they’re out of sight, send yourself an email to read them! Now they’re just a single line in your inbox, not many.
  13. Keep it on the first page. If your inbox exceeds your first page (50 or so) you need to sit down and deal with it. This will make you more productive and help with the feeling of doom that comes from having too many emails. Find what is not important to do this week and snooze it. Archive the stuff you just aren’t ever going to get to (maybe send a “sorry I won’t get to this” email first).  Be realistic about what you’re going to do. Don’t guilt pack emails in your inbox!

That’s how it works for me. I know it’s not for everybody, but hopefully there are some nuggets in there you can use.

Technosignatures White Papers

Here, in one place, are the white papers submitted last year to the Astronomy & Astrophysics decadal survey panels:

  1. “Searching for Technosignatures: Implications of Detection and Non-Detection” Haqq-Misra et al. (pdf, ADS)
  2. “The Promise of Data Science for the Technosignatures Field” Berea et al. (pdf, ADS)
  3. “A Technosignature Carrying a Message Will Likely Inform us of Crucial Biological Details of Life Outside our Solar System” Lesyna (pdf, ADS)
  4. “The radio search for technosignatures in the decade 2020—2030” Margot et al. (pdf, ADS)
  5. ” Technosignatures in Transit” Wright et al. (pdf, ADS)
  6. “Technosignatures in the Thermal Infrared” Wright et al. (pdf, ADS)
  7. “Searches for Technosignatures in Astronomy and Astrophysics” Wright  (pdf, ADS)
  8. “Observing the Earth as a Communicating Exoplanet” DeMarines et al. (pdf, ADS)
  9. ” Searches for Technosignatures: The State of the Profession” Wright et al. (pdf, ADS)

And, because it’s relevant and salient: the Houston Workshop report to NASA by the technosignatures community:

“NASA and the Search for Technosignatures: A Report from the NASA Technosignatures Workshop” (Gelino & Wright, eds.)  (pdf, arXiv)

On Watching the Sound of Music as an Adult

As a child, I watched the first two hours of The Sound of Music countless times. We had recorded it off of TV on a VHS top set to short-play mode, and so we only caught the first two hours.  For me, the movie ends with the von Trapps pushing their car away from the house to begin their escape from the Nazis.  I’ve only seen the rest of the movie a few times, as an adult.

As kids, we loved most of the music, we loved the scenes with the kids, we loved “Uncle Max,” and of course we loved Maria.  We generally skipped past the “boring parts” where the adults were talking and “Climb Every Mountain.”  We wanted to see “Do Re Mi” and “Lonely Goatherd”.

My kids have seen it a few times now (2-day rental at the public library) and they love it, too, for the same reasons I did.  But now I love it for different reasons—it’s a rich and brilliant film with lots to offer, much of it contradictory to the reasons I loved it as a child.

Some observations from an adult perspective:

    1. The movie downplays the evil of Nazism.
      As a kid, the Nazis are bad because Georg doesn’t like them and they want him to go to Berlin. In real life, the Nazis were evil because they were genocidal. It’s great to teach kids that “Nazis are bad” but watching as an adult you can’t help but think that the the von Trapps’ troubles are trivial compared to what was actually going on.
    2. “Climb Every Mountain” is great.
      The abbess his some pipes.
    3. Christopher Plummer was a dish.
      We understand Maria’s attraction to him because of the way the camera treats him as a sex object (for instance using soft focus) in a way modern movies usually reserve for women.
    4. Uncle Max is not a good man.
      He makes it clear he’s perfectly happy to collaborate with the Nazis, especially if he’ll make money doing it. The children (in the movie and those watching) love him because he’s so gregarious, but it is only his love for the von Trapps, their money, and Georg’s shaming that makes him help them escape. He doesn’t really deserve the hero status the movie gives him.
      Max
    5. Baroness Schraeder is not a villain.
      As kids we see only see her as an antagonist because she stands in between Georg and Maria’s love, and we dislike her because we see her scheming with Max about money, because she doesn’t like to play ball, and because she dreams of of putting the kids in boarding school.But as an adult I find her to be a sympathetic character, remarkable for her strength and maturity.

      A widow, she finds love in Georg, a good and handsome man who loves her for who she is, not for her money. She is desperate for him to marry her, but this is hardly a character flaw for a single, rich, middle-aged European woman in the 1930s. Georg promises the safety, stability, and love we all seek in life.

      She schemes to get Maria out of the house, yes, but wouldn’t we all in her position? And her schemes are all honest: at end of Act I she truthfully tells Maria Georg is falling in love with her, and Maria follows her calling and leaves the house to pursue her vows. It’s what Maria thinks she wants!

      And when it all falls apart and Georg is clearly conflicted, she doesn’t fight to the end. She knows when she’s been beaten, and she saves face by ending the relationship before he can say anything, telling him to follow his heart. Georg’s smile as she breaks it off is one of admiration, respect, appreciation, and love. It’s a brilliantly done scene, and as an adult that has loved and lost I find it remarkably moving.
      Richard Dreyfuss GIF

    6. Julie Andrews is brilliant.
      Especially thinking about the range revealed by her later roles as mature, stern characters, her innocent, effervescent Maria is just a delight to behold.

  1. Julie Andrews and Christopher Plummer’s onscreen chemistry is fantastic

  1. Except for Leisl, the kids aren’t actually in this movie much
    They hardly get any actual lines, and are mostly just caricatures. The exception is Leisl’s hard lesson in love with Rolf, which is really well done.

  1. “I am Sixteen Going on Seventeen” doesn’t hold up.
    It’s a great song, and a beautifully choreographed sequence that wonderfully captures the unstable mix of love and lust that saturates teenagers, but the sexual politics are so retrograde it’s painful to watch.

  1. Mrs. von Trapp looms over the movie
    The children’s mother is rarely mentioned and we learn almost nothing about her except that she loved music and sang to the children with Georg (“I remember, father,” says Leisl, with aching innocence to the pain Georg is in at those words.).

    As adults and parents we are fascinated: Georg’s retreat into a stern taskmaster is clearly a defense against the pain of his loss; Maria’s music and exuberance clearly reminds him of her. We would understand Georg so much better if we could meet her; instead we barely know of her.

  2. Georg is a remarkable man, perfectly portrayed by Plummer
    His fierce morality, unshakable patriotism, strength, and sensitivity shine through the screen. I first saw the “Eidelwiess” scene as an adult, and Plummer nails it, with Georg unable to finish the song until Maria, his children, and the people of Salzburg give him the strength. For me, it’s a highlight of the movie.

The Little Principle

It it ethical to be good to your family?

Since the Renaissance, ethics has been a core subject in the humanities, but it has fallen out of the usual core curriculum at liberal arts schools, but Penn State is reviving the tradition. Many faculty at Penn State have taken ethics training via Penn State’s Rock Ethics Institute, which provides a week-long crash course in the basics and helps us integrate ethics into the curriculum.  The aspiration is that all faculty will be trained and all courses will have an ethics component. I think it’s a great project.

This means that I have just enough training in formal ethics to think about the topic as a sort of educated layperson or hobbyist. I find ethics to be a great way to think through problems and interrogate our motives, but not necessarily a way to arrive at the “right” answer to a dilemma: different ethical frameworks can yield different conclusions, as can bringing different values to the problem (but when all frameworks point to the same conclusion, you know you’ve got a robust answer). Some ethical reasoning is also about justifying our guts’ impulses formally, codifying, explaining, and refining peoples’ collective moral compass.

One paradox I struggle with is between our deep, instinctual tendency to treat our friends and loved ones better than others, and the bedrock principles of fairness that underlie most ethical frameworks. Put simply: there are things I would do for my family I would not do for a stranger, and things I’d do for a stranger I would not do for an enemy. How does that fit in with ethical analysis?

When thinking about this, I call it “The Little Principle,” and I consider it axiomatic. Here it is:

It is appropriate to treat some people better than others. Specifically, one should prioritize those to whom one has an emotional bond over others.

or, more simply: “Je suis responsable de ma rose.”

The name comes from The Little Prince, the classic children’s(?) book by Antoine Saint-Exupéry. It is a primary theme of the book, and is captured best in the lesson the fox teaches the little prince:

So the little prince tamed the fox. And when the hour of his departure drew near—

“Ah,” said the fox, “I shall cry.”

“It is your own fault,” said the little prince. “I never wished you any sort of harm; but you wanted me to tame you…”

“Yes, that is so,” said the fox.

“But now you are going to cry!” said the little prince.

“Yes, that is so,” said the fox.

“Then it has done you no good at all!”

“It has done me good,” said the fox, “because of the color of the wheat fields.” And then he added:

“Go and look again at the roses. You will understand now that yours is unique in all the world. Then come back to say goodbye to me, and I will make you a present of a secret.”


The little prince went away, to look again at the roses.

“You are not at all like my rose,” he said. “As yet you are nothing. No one has tamed you, and you have tamed no one. You are like my fox when I first knew him. He was only a fox like a hundred thousand other foxes. But I have made him my friend, and now he is unique in all the world.”

And the roses were very much embarrassed.

“You are beautiful, but you are empty,” he went on. “One could not die for you. To be sure, an ordinary passerby would think that my rose looked just like you—the rose that belongs to me. But in herself alone she is more important than all the hundreds of you other roses: because it is she that I have watered; because it is she that I have put under the glass globe; because it is she that I have sheltered behind the screen; because it is for her that I have killed the caterpillars (except the two or three that we saved to become butterflies); because it is she that I have listened to, when she grumbled, or boasted, or even sometimes when she said nothing. Because she is my rose.


And he went back to meet the fox.

“Goodbye,” he said.

“Goodbye,” said the fox. “And now here is my secret, a very simple secret: It is only with the heart that one can see rightly; what is essential is invisible to the eye.”

“What is essential is invisible to the eye,” the little prince repeated, so that he would be sure to remember.

“It is the time you have wasted for your rose that makes your rose so important.”

“It is the time I have wasted for my rose—” said the little prince, so that he would be sure to remember.

“Men have forgotten this truth,” said the fox. “But you must not forget it. You become responsible, forever, for what you have tamed. You are responsible for your rose…”

“I am responsible for my rose,” the little prince repeated, so that he would be sure to remember.

The book is elliptical and has some odd moral dimensions, but with this theme it nails something important on the head, something both profound and trivial: you treat those you care about better than those you have never met.

It’s easy to get carried away with individual ethical principles, to take your morality to extremes. I’ve written before about the great evil that comes from following your ideas to their logical conclusions (and also about the importance of radicalism to positive political change). Clearly, taking The Little Principle to its extreme leads to a sort of puerile selfishness, where all of our actions are centered around helping ourselves and those in our in-group, at whatever expense to others. Depending on whom we identify with, this can lead to great evils like genocide, and is contrary to the egalitarian principles of law and democracy. The Little Principle needs to sit next to another principle that all humans (and, I’d argue, much life) is entitled to a minimum level of moral standing. The Little Principle is not license to treat others badly.

But the other extreme—that we owe nothing special to our friends and loved ones—is fundamentally contrary to who we are as humans. Indeed, we don’t even restrict this instinct to other people, but it extends to our pets, our environment, and even whole classes of beings we’ve never met (“Save the Whales!”). The Little Principle states that any useful moral framework acknowledges that individuals can prioritize which others they help and care for.

I think one way to thread the needle is to acknowledge that this prioritization is personal, not universal. I treat my children better than yours, but I also expect you to treat yours better than mine. We do have universal moral responsibilities, but we also have relative ones that depend on who we care about. We can build universal legal and moral structures that themselves eschew the Little Principle, while enshrining it at the individual level. We are “a nation of laws, not of men.” A court will impartially defend the rights of any parent to care for their own children.

It’s an interesting and nuanced issue!

Background to the 2019 Nobel Prize in Physics

Fifty percent of the 2019 Nobel Prize in Physics goes to Michel Mayor and Didier Queloz for the discovery of 51 Pegasi b!  I had a tweet thread on the topic go viral, so I thought I’d formalize it here (and correct some of the goofs I made in the original).

A hearty congratulations to Michel Mayor & Didier Queloz, for kickstarting the field that I’ve built my career in! Their discovery of 51 Peg b happened in my senior year of high school, and I started working in exoplanets in 2000, when ~20 were known.

A thread:

The Nobels serve a funny place in science: they are wonderful public outreach tools, and a chance for us all to reflect on the discoveries that shape science. The discussions they engender are, IMO, priceless.

They also have their flaws: because they are only be awarded to 3 at a time, they inevitably celebrate the people instead of the discovery.

(This technically a requirement from Alfred Nobel’s will, but there are other requirements, like that the discovery be in the past year, that the committee ignores. Also, the Peace Prize is regularly awarded to teams, but the science prizes have never followed suit.)

Anyway, many of the discoveries awarded Nobels are from those who saw farther because they “stood on the shoulders of giants.” The “pre-history” of exoplanets is a hobby of mine, so below is a thread explaining the caveats to 51 Peg b being the “first” exoplanet discovered.

The first exoplanet discovered was HD 114762b by David Latham et al. (where “al.” includes Mayor!) in 1989. It is a super-Jupiter orbiting a late F dwarf (so, a “sun like star” for my money), published in Nature:

https://www.nature.com/articles/339038a0

Dave is a conservative and careful scientist. At the time there were no known exoplanets *or* brown dwarfs, and they only knew the *minimum* mass of the object, so there was a *tiny* chance it could have been a star. He hedged in the title, calling it “a probable brown dwarf”.

I wonder: if Dave had been more cavalier and declared it a planet, would *that* have kickstarted the exoplanet revolution? Would he be going to Stockholm in a few months?

Meanwhile, Gordon Walker, Bruce Campbell, and Stephenson Yang were using a hydrogen fluoride cell to calibrate their spectrograph. In 1988 they published the detection of gamma Cephei Ab, a giant planet around a red giant star:

https://ui.adsabs.harvard.edu/abs/1988ApJ…331..902C/abstract

They were also very careful. At least four of the other signals reported there turned out to be spurious. They did not claim they had discovered any planets, just noted the intriguing signals. In follow up papers they decided the gamma Cep signal was spurious. Turns out it was actually correct!

Again, what if they had trumpeted these weak signals as planets and parlayed that into more funding to continue their work? Would they have confirmed them and moved on to stars with stronger signals? Would they be headed to Stockholm?

Moving on: in 1993 Artie Hatzes and Bill Cochran announced a signal indicative of a giant planet around the giant star beta Gem (aka Pollux, one of the twin stars in Gemini).

Like gamma Cep A, the signal was weak. Like Campbell Walker & Yang, they hedged about its reality. But again, it turns out it’s real!

https://ui.adsabs.harvard.edu/abs/1993ApJ…413..339H/abstract

Then, in 1991 Matthew Bailes and Andrew Lyne announced they had discovered an 10 Earth-mass planet around a *pulsar*. This was big news! Totally unexpected! What was going on!? They planned to discuss in more detail in a talk at the AAS that January.

But when the big moment came, Bailes retracted: they had made a mistake in their calculation of the Earth’s motion. There was no planet, after all. That made more sense. He got a standing ovation for his candor.

But in the VERY NEXT TALK Alex Wolszczan got up and announced that he and Dale Frail had discovered *two* Earth-massed planets around a different pulsar! They would later announce a third, and that remains the lowest mass planet known.

Some wondered: Was this one really right? Had they done their barycentric correction properly? It held up. The first rocky exoplanets ever discovered, and the last to be discovered for *20 years*.

And there would be more. In 1993 Stein Sigurdsson and Don Backer interpreted the anomalous period second derivative of binary millisecond pulsar PSR 1620-26 as being due to a giant planet. This, too held up.

https://ui.adsabs.harvard.edu/abs/1993ApJ…415L..43S/abstract
https://ui.adsabs.harvard.edu/abs/1993Natur.365..817B/abstract

Meanwhile, in a famous “near miss”, Marcy & Butler were slogging through their iodine work. They actually had the data of multiple exoplanets on disk when Mayor & Queloz announced 51 Peg b, but not the computing power to analyze it.

If you’re interested in more detail, you can read this “pre-history” in section 4 of my review article with Scott Gaudi here:

https://arxiv.org/abs/1210.2471

None of this, BTW, is meant to detract from Michel & Didier’s big day. 51 Peg b was the first exoplanet with the right combination of minimum mass, strength of detection, and host star characteristics to electrify the entire astronomy community and mark the exoplanet epoch. As I wrote above, they kickstarted the exoplanet revolution. It makes sense that Mayor & Queloz got the prize!

This is to make sure that the Nobel serves its best purpose: educating, and promoting and celebrating scientific discovery.

Observers and Theorists Being Wrong

Once upon in time, probably in graduate school, someone told me an aphorism, which went something like this:

A theorist only has to be right once to garner a reputation as a good scientist, but an observer only has to be wrong once to ruin theirs.

Alex Filippenko—spreader of the aphorism

I asked about it on Twitter and Facebook, and multiple people pointed to Alex Filippenko as the originator (which may also be where I heard it, when I TA’d for him at Berkeley). I asked Alex, and he wrote that he heard it from other grad students at Caltech, perhaps Richard Wade. I asked Richard, and he wrote “I think it was a fairly common expression around Caltech when I was a grad student, so Alex could heard it from me. I probably heard it from other grads.”

So, I’m not sure where it comes from, but it’s a great quote!

Some of Facebook and Twitter objected to the sentiment it expresses— ” I’d say it’s best forgotten. No good comes from playing it safe the whole damn time… 😉” quipped David Kipping. Brian Metzger writes “I think one has to make an important distinction: theory that in principle is well-motivated and has a sound physical basis but just turns out to be the wrong explanation (but might still lead to progress by posing new questions), versus theory that e.g. employs bad physics or already disproven assumptions and couldn’t in principle have been correct. ”

But I think it’s got a kernel of truth worth discussing.

As I’ve drifted into theory from observation I’ve been struck by how much more comfortable theorists are being wrong than observers (sometimes I call this Steinn’s bad influence on me ;).

But it makes sense. Theorists are expected to work on hypotheses that might turn out to be wrong, and there is no discredit in one’s theory turning out to be wrong if it was interesting and spurred work that eventually turned up the right answer. There’s no real reason for an equivalent “you’re doing a good job even if you’re wrong” land for observers.

I think David Kipping and Alex Teachey’s laudable and cautious approach to their exomoon candidate illustrates the divide. As an observation project, especially a high profile one, they must be extra careful not to overstate the evidence, careful to call things “candidates” and not “discoveries”, and careful to emphasize the uncertainty inherent in the problem. Their peers, journalists, and the public will scrutinize their verbiage and they will get blowback if it turns out to not be an exomoon and their presentation of the evidence, in retrospect, was overstated.

But a theoretical analysis of the abundance of exomoons (or exoplanets!) that turns out to be off by orders of magnitude can still get cited favorably a decade later if it included novel and important components. After all, everyone understands that theory is hard and that we build theories up piece by piece, and so we’ll get it wrong many times before we get it right. And so such work rarely includes the careful hedging that Kipping and Teachey used in their work.

Or, to give a more dramatic example: If inflation turns out to be completely wrong, the theorists who dedicated their careers to it will still be considered good theorists, but the BICEP2 team that got a subtle issue with dust wrong have a whole book about the very public and embarrassing debacle that followed their (incorrect) detection of sign of inflation in the CMB.

I’m not saying this dichotomy in unfair or inappropriate—on the contrary, I think it’s appropriate!—I’m just pointing out how the aphorism resonates because it identifies something real and tacit about the way we judge science.

Freeman Dyson’s First Law of SETI Investigations

It’s come up a few times, so let me state here for the record the origin of Freeman Dyson’s First Law of SETI Investigations:

It’s from an email he sent me. We were discussing a paper of mine in anticipation of an outreach event we were planning:

and he remarked of the Ĝ strategy:

I am happy to see that your plan is consistent with the First Law of SETI investigations: every search for alien civilizations should be planned to give interesting results even when no aliens are discovered.

I asked permission to repeat this, and he agreed. It’s consistent with his general approach about SETI, searching for the physical limits of technology in a way that also generates ancillary science and makes minimal assumptions about agency.

I think Freeman himself means this as a counterpoint to radio or laser SETI, which has the benefit of working against low natural background but this apparent disadvantage that they are unlikely to discover new natural phenomena in the course of their searches. I think this perspective is often overstated—radio SETI is closely aligned with pulsar and FRB astrophysics, and generates great science along the way, and there are natural sources of very brief optical flashes, too.

Justifying Science Funding in an Unjust World

I was asked recently a stock question by interviewers about how to justify spending SETI when “some people would say” that we have so many problems needing solving , so many better places to spend the money.

There are a few answers to this.

One is that it’s a false choice: certainly if I had to choose between NSF funding for basic research, including SETI, and feeding starving people, I choose feeding the starving people every time. But that is not the choice we face: humanity produces more than enough food to feed the planet and cutting the NSF budget won’t feed any starving people.

Similarly, if I had to choose, I’d rather our government guarantee all people the basics of modern life—shelter, health care, safety, clean water and nutritious food, life, liberty, and the pursuit of happiness, and all that—than search the skies for technosignatures. But that’s not the choice Congress makes every year when it makes up its budget—we can easily afford all of those things.

Another answer is beautifully illustrated by classic Congressional testimony by R. R. Wilson, director of Fermilab, justifying building the lab’s first accelerator in a time when the national defense dominated the budget conversation:

R. R. Wilson

SENATOR PASTORE. Is there anything connected in the hopes of this accelerator that in any way involves the security of the country?

DR. WILSON. No, sir; I do not believe so.

SENATOR PASTORE. Nothing at all?

DR. WILSON. Nothing at all.

SENATOR PASTORE. It has no value in that respect?

DR. WILSON. It only has to do with the respect with which we regard one another, the dignity of men, our love of culture. It has to do with those things.

It has nothing to do with the military. I am sorry.

SENATOR PASTORE. Don’t be sorry for it.

DR. WILSON. I am not, but I cannot in honesty say it has any such application.

Senator John Pastore, dunkee

SENATOR PASTORE. Is there anything here that projects us in a position of being competitive with the Russians, with regard to this race?

DR. WILSON. Only from a long-range point of view, of a developing technology. Otherwise, it has to do with: Are we good painters, good sculptors, great poets? I mean all the things that we really venerate and honor in our country and are patriotic about.

In that sense, this new knowledge has all to do with honor and country but it has nothing to do directly with defending our country except to help make it worth defending.

“It helps make [America] worth defending”—quite the rhetorical dunk there.

But more broadly, basic science is an essential part of culture, civilizations, and humanity. We have more than enough labor and wealth to do SETI and be safe. Indeed, we spend hundreds of billions per year on national security—a future that President Eisenhower warned us against—and against this, basic science expenditures are a rounding error.

The third answer is: because we can easily afford it.

I once heard a figure that America spends more on doggie treats than on publicly funded science.  I threw this figure out in that interview, but worried I had it wrong.  So I looked it up.

The US pet food and treat market is almost $30 billion. Of this, dog and cat “treat” sales reached $4.39 billion in 2017. The FY17 appropriation for NASA’s science mission directorate was $5.76  billion.

So, I was wrong: NASA spent 30% more on science in 2019 than America did on dog and cat treats than. But we spend far more on dog and cat food.

But looking at some other points of comparison:

Since America spends over $2.5 billion on dog treats each year, its probably safe to say that Americans spend about twice as much on doggie treats than their federal taxes do on astronomy.

The point, obviously, is not that we spend too much on doggie treats or that there is some obviously more correct ratio between these two expenditures—it’s that America is a very, very rich country (even ignoring the “1%” that doesn’t spend much on pet treats) and the amount we spend on things as important to culture as basic science is actually quite small, comparable to niche consumer markets like pet treats.

I’m not arguing we should spend less on basic human needs, pet treats, or any of these other things that define modern life. Regardless of whether we fund science with new taxes or by cutting other expenditures like the military budget, we can easily afford to spend a lot more on a lot of those things, including SETI.

 

The hats astronomers wear

Once upon a time science departments in universities often had draftsmen on staff that would produce figures for scientific publications. Today, those positions are much rarer (and called “graphic designers”) except in very large institutions because scientists themselves are expected to do much of that work. Other work routinely done by administrative staff in the past—like travel reimbursements—are now done by faculty themselves.

Part of this is that computerization and other technologies have made these tasks easier and so it’s not unreasonable to expect a typical scientist to do the job quickly and competently. But it also means that the modern astronomer (queue Gilbert & Sullivan “I am the very model of a…”) has to do a wide variety of tasks outside of their training.

Today in group meeting we tried to make a list. This whole exercise was inspired by this Jonathan Fortney tweet thread about “scientists” vs. “engineers”:

and about giving yourself permission to not be interested in certain parts of the job of scientist that other people find endlessly fascinating

My punchline is that it’s fine to love and get really good at a few of the aspects of being a scientist, and that it’s OK to not be good at or enjoy other aspects.

Indeed, I sometimes chafe when people say things like “every scientist has an obligation to communicate their science to the public” or “all astronomers should learn Python” and such. I think its fine and good that astronomers specialize in different parts of the job, and that collaborations consist of a group of people that, together, have all the pieces needed to do great science.

Also, part of my definition of a good job is one where you spend most of your time doing things you both like and are good at, and a minimum of time doing things you dislike and are bad at. Enumerating the parts of the job can help you find the job you like (or turn your current job into that). So it’s OK not to be good at everything.

Here’s the list of “hats” astronomers wear that we came up with.  What did we miss?

  • Teacher / instructor
  • Science popularizer
  • Public ambassador of science
  • Salesperson
  • Writer
    •  proposals
    • research articles
    • emails
    • popular materials
    • journalism (e.g. press releases)
  • Copyeditor
  • Graphic(s) designer
  • Examiner (tests, defenses)
  • Peer reviewer
  • Mentor
  • Research adviser
  • Manager
  • Administrator
    • Travel
    • Grants administration
    • Budgeting
  • Computer programmer
    • Team coding
    • Public code
    • “Private” code
  • Computer systems administrator
  • Web developer
  • Marketer
  • Engineer
  • Physicist
  • Theorist
  • Observer
  • Data analyst
  • Statistician
  • Philosopher of Science
  • Ethicist

[Update: good suggestions from Twitter:

Counselor

Advocate

Legislator

Atmospheric scientist and meteorologist

]

A Second Pleiades in the Sky

Astronomers have discovered a second Pleiades in the sky.

Wait, what?  The Pleiades are an obvious feature of the night sky, known to ancient peoples around the world and a common test of visual acuity.  In a telescope they look like this:

The Pleiades

Four or five bright stars make them obvious in even a moderately dark sky, and the nebulosity adds a nice touch that makes them interesting. Astronomers like them because they were all formed from the same birth cloud, so they share composition, age, and distance. This makes for a great stellar laboratory, since it lets us isolate and focus on the few differences among the stars, like their mass and whether they have binary companions.

So if these are so obvious, how could there be another one?  Answer: if they’re so spread out across the sky that no one noticed they were related!  Back in February Meingast et al. announced that they had spotted a group of hundreds of stars all moving in the same direction—but they were spread all out against the sky.  If you plot most of the sky out flat, here’s what they look like (in red):

The Pisces-Eridanus Stream. The Milky Way, which spans 360 degrees of the sky, appears as a circle in this projection. The stream is over 120 degrees across.

Co-moving stars like this are like clusters but more spread out. It took the precise measurements recently announced by the Gaia team to notice that these stars were all moving in the same direction.

Many of these stars, like the Pleiades are bright enough to see with the naked eye:

When Meingast et al. published, I got excited because they guessed that the stream was 1 billion years old—if correct, that would make it one of the closest older clusters in the sky. Jason Curtis had spent a whole PhD dissertation and more proving Ruprecht 147 was a true cluster, 3 billions years old and only 300 parsecs away. Eunkyu Han worked hard to check out another claimed nearby old cluster, Lodén 1.  Here was one 3 times younger and 3 times closer: another important discovery! I got excited and tweeted at Jason about it.

We started wondering what to call it, and also getting suspicious of the reported age. So we pulled in the expert on “moving groups” and stellar ages, Eric Mamajek:

Jason, Eric, and I then took the conversation offline. First, it needed a name.  Eric came up with the “right” answer:

Next, the stream seemed like it had to be younger than 1 billion years to us, but how old was it?  Then Jason Curtis went to town with TESS, the all-sky planet hunting telescope. It had already hunted for planets around many of the stream’s stars, and Jason was able to quickly measure the stars’ rotation periods.  He tells the story here:

I encourage you to read the whole tweet thread!

Basically, Jason was able to show that the stars in the stream are spinning way too fast to be 1 billion years old. In fact they were spinning just as fast as the Pleiades—so they are probably almost exactly the same age.  They’re also the same distance, and there are just as many of them!

I was actually kind of disappointed:

Chris Lintott was grumpy at my framing of the cluster as a “second Pleiades” because the public would understand that to mean “another thing I can see with my eyes in the sky that wasn’t there before”, which is misleading:

His point is well taken, but Heidi Hammel would say that good science communication means linking to things people know about.  Eric explained well what I meant and why the discovery is a big deal:

This discovery came very fast, and was only possible because of the hard work of the teams that made Gaia, Kepler, and TESS possible.  Because those are all-sky surveys committed to making data public as fast as possible, unexpected gems like this can go from tweets to papers in a matter of weeks.  Jason Curtis pointed out that most of the actual science only took him hours:

It’s a new era of stellar astronomy. So exciting!

In Defense of Magnitudes

Astronomical magnitudes get a bad rap.

Hipparchos 1.jpeg

Hipparchus, supposedly

The Greek astronomer Hipparchus famously mapped the sky and assigned each star a “magnitude” (or size) based on its apparent brightness.  The human eye is a surprisingly precise photometer (you can with just a little effort estimate brightnesses differentially to about 0.1 magnitude; I’m sure dedicated amateurs can do better) So Hipparchus could have been thorough about this, but he was actually quite general: he just lumped them into 6 categories: “stars of the first magnitude” (the brightest), “stars of the second magnitude” and so on.

But while the human eye is precise it’s not linear: it’s actually closer to being a logarithmic detector. This gives it a great dynamic range but it means that what seems to be “twice as bright” is actually much, much brighter than that.

In 1856 Norman Pogson formalized this in modern scientific terms by proposing that one magnitude be equal to a change in brightness of the fifth root of 100, with a zero point that roughly aligned with Hipparcus’s rankings so that “first magnitude stars” would have values around 1. This captured the logarithmic scale and spirit of the original system, and has frustrated astronomers ever since.

Astronomers regularly complain about this archaic system. A lot of this comes from trying to explain it in Astronomy 101 or even Astronomy 201 where our students expect a number attached to brightness to increase for brighter objects, and where we have to teach them a system literally no other discipline uses. Especially at the Astronomy 101 level, where we are loathe to use logarithms, we often skip the topic altogether.

But I think astronomers don’t realize how good we have it.

First of all, the scale increases in the direction of discovery: there are very few objects with negative magnitudes (the Sun and Moon, sometimes Venus, a few stars in certain bands) but lots of objects up in the 20’s where the biggest telescopes are discovering new things. Big numbers = bigger achievements is much better than “we’re down to -10 now!”, in my opinion.

Secondly, the numbers have a nice span. The difference between 6 and 7 is just enough to be worth another number. This is because the fifth root of 100 is only 8% larger than the natural logarithmic base e, which is the closest thing we have to a mathematically rigorous answer to the question “how much is a lot?”.

But most importantly, the system is a beautiful compromise between simplicity and precision that allows for very fast mental math and approximations for any magnitude gap.

This is because we long ago settled on base-10 for our mathematics, and the magnitude system is naturally in base 10. 15 magnitudes is a factor of 100,000, because every 5 magnitudes is exactly 100.  2.5 magnitudes is a factor of exactly 10.

It doesn’t take much practice to get very fast at this. If we used, say, e as the base instead, the 8% difference would compound with each magnitude.  exp(15) is 3.6 times larger than 100,000.

Finally, and most importantly IMO, because this interval is very close to a factor of e, we get the lovely fact that very small magnitude differences translate pretty well to fractional differences.  So, a change of 0.01 magnitudes is almost exactly 1% (only 8% off, actually). That’s so useful when trying to do quick mental estimates.  For instance: a transiting planet with a 10 mmag depth covers 1% of the star, so it has 10% of the star’s radius (since sqrt(0.01) = 0.1). A 1 mmag transit therefore corresponds to 10x less surface covered, so it has 3% of the star’s radius. Easy!

I think of it as akin to the twelfth-root-of-two intervals on an equal-tempered instrument. No interval on such an instrument produces the mathematically perfect 3:2, 4:3, or 5:4 harmonic, but they’re all close enough and in exchange you can transpose music and shift keys with ease and without loss of musical fidelity. The pedants may complain, but it’s worked great for centuries.

Do NASA and the NSF support SETI?

Does the federal government support SETI?  We usually say it does not, but in the 2019 audit of the SETI Institute, there is a letter from NASA protesting this characterization.  It contains this language:

The OIG’s statement on the absence of NASA’s funding for SETI research is misleading and the finding incorrect.1 NASA has funded the development of several instruments that enable such searches

Michael New made a similar point at the Houston NASA Technosignatures workshop: NASA has funded some SETI work since 1993 (including that workshop itself).

The footnote in the text above mentions 3 grants explicitly, but I think they missed one. Working with Jill Tarter and others I’ve tried to count every NASA and NSF grant for SETI work since 1993. I don’t know of any from the ’90’s, but, as the report states, there are some in the past 15 years.

Here’s my list:

NASA:

  • “A 2 Billion Channel Multibeam Spectrometer for SETI” 2 years, $398,040 (PI: Marcy, NRA-01-OSS-01-ASTID)
  • “Arecibo Multibeam Sky Survey for Direct Detection of Inhabited Planets,” 4 years, $485,642   (PI: Korpella, Exobiology 2008 NNH08ZDA001N-EXOB) Money funded running the SERENDIP IV survey and SETI@Home
  • “Detection of Complex Electromagnetic Markers of Technology,” 3 years (+ 1 year no-cost extension), $660,079 (PI: Jill Tarter NRA-OSS-01-ASTID). Money funded studies by Cullers, Stauduhar, Harp, Messerschmitt, and Morrison on using autocorrelation and other methods for detecting broadband SETI signals.
  • “Instrumentation for the Search for Extraterrestrial Intelligence,” 3 years, $590,589 (PI: Werthheimer, ASTID 2011 NNH11ZDA001N-ASTID) Money funded building an instrument at Arecibo/GBT.

NSF:

  • AST-0808175 :  Radio Transient and SETI Sky Surveys Using the Arecibo L-Band Feed Array  $362,624.00 (PI: Wertheimer, NSF-AST 2008 )
  • AST-0838262:  Collaborative Research: The Allen Telescope Array: Science Operations
    $310,000.00 (PI: Tarter, NSF-AST 2008 )
  • AST-0540599:  Collaborative Proposal: Science with the Allen Telescope Array
    $300,000 (PI: Tarter, NSF-AST 2005)
  • AST-0243040 :  Multipurpose Spectrometer Instrumentation for SETI and Radio Astronomy
    $704,080.00 (PI: Marcy, NSF-AST 2002)
  • OAC-0221529:  Research and Infrastructure Development for Public-Resource Scientific Computing
    $911,264.00 (PI: Anderson, NSF-OAC 2001)

Total since 1993: $2,587,968 (NASA) + $2,134,350 (NSF) = $4,722,318

Wow! $4.7 million!  That’s a lot, right?

Well, not really. That means that since 1993, the entirety of federal grant spending on the topic is about $180,000/yr, which, after indirect costs, supports 1-ish FTE (i.e. one scientist/engineer).  So one person at a time.

Now maybe that’s not fair, and we should count from 2001, when the first of these grants began.  Then it’s $262,000/yr, so we’re up to maybe 1.5 FTEs.

So, while it’s technically true that NASA has supported SETI for decades, the amount we’re talking about is so small that it’s not really a rebuttal to the reality of the situation, which is that the government doesn’t adequately fund SETI.  Why not?  The letter in the audit gives a reason:

NASA sets its priorities by following the recommendations of the National Academies of Science, Engineering, and Medicine while simultaneously implementing national priorities established by the President and Congress. SMD will continue to evaluate technosignatures research in the context of the Directorate’s overall portfolio through its standard scientific prioritization process.

This is mealy-mouthed, but the bottom line is that SETI funding is not a high priority in the NASA authorization bills or in the 2000 or 2010 Decadal reviews, so NASA doesn’t feel that it needs to fund it.

Now, this isn’t really a great excuse—the Decadal reviews do say that SETI is good and worth pursuing (even if they don’t recommend funding), and there’s nothing preventing NASA from including SETI under the astrobiology umbrella (which is a field it’s required to pursue).

Indeed, NASA is very inconsistent about whether SETI is allowed to be funded via grants—contrast its protest above that yes it does too fund SETI with Jill Tarter’s exploration of how SETI is/isn’t allowed in various NASA calls through the years here.

The bottom line is that what SETI needs is an explicit recommendation for funding in this upcoming Decadal process and/or explicit mention of technosignatures as an authorized expenditure for NASA and the NSF by Congress.  Here’s hoping that the winds really are changes and that we’ll get both in the next couple of years!

Cape Cod Light

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Michael loved Cape Cod. It lighted his life and his poetry, and it was there that he felt most connected to the natural world from which we come and to which we ultimately return.

His will told us to

Cremate me, scatter a bit in the garden, and put the rest of me in the dunes and the sea.

The final poem in Cape Cod Light is the book’s eponym.


Cape Cod Light

Dawn: earth is grey.
Overhead, a seagull catches the sun,
Flames bronze, and dives behind scrub pines.
It will glide low over swamp rushes,
Bank across the dune, and settle at the water’s edge.
Crabs wait, pursed muscles and clams,
To whom the golden seagull feels like death,
A conduit from sea to soil.
It becomes something new with each motion,
Plunging out of the sky.

It is a day to rise and go out to the Cape Cod Light
To watch the water work its will on the land.
We were all led down as children to the beach,
And bound, by a mutual gesture, to the sea.
Our awe: the miracle of light,
Plant light, sand light, bark bush and fire light,
Light on the several blues, greens, and whites of the sea.

Events intervened.
Grey dune shacks crumble into the sand
And more are built, the same. The stubby sandgrass
Creeps from green through yellow into August.
We can descend the dunes only by jumping,
Printing accidental angels in the sand.
By the shore, souls claimed by ocean
Reach up through the waves to take the hands
Of the living, not at all like dead things,
More fluid than bones picked white.
We brush them aside, proceed, do their will.
We inherit what our parents didn’t know.

It grows cool at sunset in August.
The sea blows hot and cold. The stars
That glint in the corners of your eyes
Evaporate looked at straight. Still,
You can chart a true course from them.

When storms spark
And the sky shakes itself like an angry old head,
When fog rolls in over the implacable light,
We calculate our position, and chart an according way.
In time, the full night sky will be lacerated with stars.
The sea will despoil itself on the white shore.
The enormous sandbar will hook around ahead
Into a harbor, where the fishing boats rise and fall.

The cries of the dead are stirring in the surf.
Anger keeps them here, each others’ audience,
Wearing, from time to time, the bodies of the living.
Waves crack and slither on the shore,
Black, white and black. Dunes hunch,
Dark shoulders of earth in the night.
One by one, and graves slide into the sea.
The fat orange moon spills across the water
And the dead are assumed, the unbroken line of them
Moving solemnly as kings to a miracle. They remind us
How we are falling into the future, falling.

Provincetown Harbor by Bret Duback


 

 

Bournemouth, England

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

Michael moved around a lot as a child and spent time in England, Germany and the US among other places. After the Korean War, his father’s army obligations stopped moving them around so much, my mother was born, and they eventually settled into suburban life in Connecticut.

The “army brat” life helped shape Michael, especially his relationship with his mother. He liked to tell a story about his strict German piano teacher, a professional musician indignant at having been reduced after the war to teaching American children scales.

Michael, Nessa, and my mother.

The thirty-first poem in Cape Cod Light is Bournemouth, England, about his early childhood memories of living in his mother’s hometown during his itinerant period.

Michael’s mother Valerie in the basement of the Connecticut house, listening to the kids’ music.


Bournemouth, England

Small things open to the rain
With the grace of a child
Who doesn’t know his parents watch
And absorbs a playmate’s hand into his heart.

Then I had a tail, like my water bottle, Miss Tibby,
Whom I carried each night with a candle up the dark stairs.
Inside, I draped it over my arm
Delicately, something entrusted to me for a short time.

In the garden, it reminded me of my connection to the earth
As I walked more gravely down the stepping stones to the hedge.
It worked when I climbed the apple tree
And sat tightly bound to the branch like a wise beast.

The carnival of birds
Acknowledged our kinship and ignored me at the bath
As they scattered water with their wings, wanton.
These memories work powerfully as flying swans in my dreams.


The next poem is here.

America’s Edge: Herring Cove

[This year is the 20th anniversary of Cape Cod Light by Michael Hattersley. The other parts of this series are here.]

A version of thirtieth poem in Cape Cod Light, America’s Edge: Herring Cove, first appeared in Squid with the date December, 1993 (I note the changes to the Cape Cod Light version, below).

America’s Edge is the longest poem in the book, and the most ambitious. Michael’s erudition is in full force here, connecting the full historical arc of Homo sapiens to the ancient cycles of life in the natural world; the fall of empire to the indignities of childhood discipline.

Michael was always a student, of history, of politics, of America’s place in the the world. In college his team won the College Bowl; when I knew him he was a bottomless font of facts. He delighted in the book 1,000 Years,1,000 People: Ranking the Men and Women Who Shaped the Millennium because it let him riff on the author’s choices, quibble over who deserved to be there, speculate on who would remain on the list if you expanded it back another 1,000 years. He loved to champion unjustly-forgotten historical figures, and outré ideas like the historical basis of Pope Joan or the ancient provenance of Kennewick Man and the Ainu.

Michael and the rest of the winning College Bowl team from Swarthmore. Their captain was Nancy Bekavac, who would go on to be the sixth president of Scripps College.

The action in the poem moves around, from the shores of the cove to the deck of the house, from night to morning. Michael added the subtitle Herring Cove to the poem after it appeared in Squid, emphasizing the way the poem is grounded in Provincetown. From the edge of the continent Michael looks out across the ocean, to Europe’s past.

Michael is probably using the phrase beautiful conqueror generically, but knowing him he probably had Alexander the Great in mind. Michael loved the story of Alexander, and it suited him: the brilliant, beautiful, gay, doomed and fierce general and emperor, who conquered half of Eurasia, defied convention, burned brighter than anyone before him, and died young.


America’s Edge: Herring Cove

Last night, the full moon insisted on breaking through.
It spackled the bay like jungle animal
Yearning to turn teeth on its hosts in a sea of blood;
Behind it, the slow blizzard of falling stars.

The predictable glory of a mid-summer sunrise
Rouses us from a bad dream, and the television under your hand
Crackles into anthems and Rothko paintings.
From the deck we watch the birds, and subtler animals slung to the ground,
More acute in their indifference to forging beauty,
Shake, find the first meal, and steel themselves;
They remember the safe spots.

Gradually, the insides and outsides blend
Into a language invented for today.
Scores replicate
In patterns of dried moss scriven on beech limbs.

Morning thunder
Means the life or death of tropical weather
As recent cuttings ripple across the asphalt and into the sand.
The whole world can sing;
Watch the choke cherries throw down their hair in shades of green and yellow,
Becoming, against their wills, the stalks of another summer.

When the old words change their meanings,
We adjust, in the face of grandmothers and grammarians.
Even the ancient capitals submitted
To the syllables of a beautiful conqueror, more arbitrary
Than the barriers thrown down by rivers, oceans, deserts, or mountains.
Membranes strain around every sound:
“I, too, have come further than expected”
Like the markings of Napoleon’s soldiers in Egypt,
“I’ve crossed into a new province, and forced
Guidelines down from the sky.” These dot
Our memories like heroic statues or megaliths.

Places are made sacred by work:
The work that builds a relationship or rears a home out of the dirt,
The work of a prophet against disease, or a king who secures new borders.
These are all written down into verses or laws, and result in trials,
Just as Neanderthals brooded over the end of the Ice Age,
Regretting what they had taught us, and worrying about their children,
But proud in their dying that they had never succumbed to words.

Insects in amber, reconstituted skeletons
Explain how to live in the present. They say:
Walk back into that argument with your loved one,
Muscles rigid with the knowledge that you were right,
Try the whole truth; eventually anyway,
It will erupt out of the flesh.

Nevermind. I’ve decided to confess
Memories of three decades ago: parental extortions,
Denials, dead animals, love and hatreds. All
Crossed into new territory named for the suffering conquerors.

We were supposed to forget
Dislocations, reprimands, unapproved influences;
Only then could we turn them into anger and use them.
So too the misguided affections of adolescence:

Some of the music, all of the friends,
A late dawn, even the horror movies
When the child walked out and sat trembling on the steps, believing.
We did forget, for a generation,
Until our lives became as boring as suburban lawns.

Children are right
In their urgency to get on to the next thing
Like generous puppies with their noses to the ground
Or eunuchs helping the monarch to appreciate a new toy.
Left to itself,
The living fabric will try everything.

The more willing, the more willing to believe,
A mammal, twitching on the edge of the road,
Sticking to its ideology till it dies.
In the end, the corpse cracks, and forms tiny splinters, like dust.
It’s the need to restore things to how they were.

This is the time to inhabit the village,
As if watching it made all the same world.

At the ocean, Permian remnants
Swirl around the feet of the children
Like an alphabet scrawled on the tideline.
Plenty or lack gets recorded in the ancient language.
Every interpreter has its own reading
Of how neutral the ocean can be
In its retreats and assaults,
How brutally alive the slipping of the fierce lines.


Herring Cove Tide by Bret Duback


The next poem is here.

The version in Cape Cod Light differs from the version in Squid, with many additions and some line break changes. I have corrected the lowercase i that begins the fourth line in the second to last stanza; other than than I have deferred to the Cape Cod Light version.