The Anthropomorphization of Nature (is not SETI)

I shall not be talking about the article Carlotto 1988, in particular but a general overview of the topic. The subject in question here is the controversy surrounding the image taken by the Viking martian orbiter in the 1970s in the Cydonia region on Mars(described here).  The image is shown below in Figure 1 –

Figure 1 : Image taken by Viking showing the region where the ‘FACE’ is seen. Image Credit: NASA JPL

This 1988 article discusses the analysis of this image and his attempt to reconstruct the image in 3 dimensions.  It does this using FOUR images where the ‘FACE’ can be seen. As can be seen in Figure 1, half of this structure is in a shadow and hence the author of the article – Mark Carlotto attempts to use image processing techniques to generate images of the face in varying degrees of illumination.

In 1997 in an article titled ‘Evidence in Support of the Hypothesis that Certain Objects on Mars are Artificial in Origin’ , he presents the following images with the presence of the ‘FACE’ , a pyramid and a city indicated.

Fig 2a and 2b: Mosaic of Viking images (Carlotto 1997)

Interestingly, the concept is taken a step further. This city on Mars, has not only a Pyramid and a trapzeoidal Fortress, but also a City Square! In the same article the author moves on to present evidences for the FACE being artificial. Since no human has ever walked on Mars, let alone inhabited or formed a city there, the suggestion of artificiality implies that it is Extra Terrestrial in origin and nature. Somewhat ironically the author talks about the human tendency to see humanoid structures and facial forms in nature. However for the FACE this is ruled out due to a number of reasons; among others, some of them are – the symmetry of the shape, the semblance of teeth and eyeballs.

He even performs a fractal analysis (discussed here) on the object. The fact that it does not seem to be a fractal object suggests that it is “least natural object” in that Viking frame. There is further talk about the orientation, geometry and supposed hollowness of the pyramid.

It gets better. He then performs Bayesian analysis to determine the probability given the evidence (the pictures) that the hypothesis of its artificial origin is correct. I think that this is a prime example of how statistical inference techniques can be misused or led to produce results at will if the theory behind them is not understood.

To conclude this discussion, here is a comparative image showing the original face and more recent snapshots.

Fig 3a : Viking in ’76, and then follow up by the Mars Global Surveyor (MGS) in ’98 and ’01. 3b: Taken by the Mars Reconnaissance Orbiter showing the absence of teeth or eyeballs on this Martian terrain.

 

I think it is also worthy to note that this study by Carlotto was cited in 1988   as how though our eyes are great at finding patterns, they often get fooled into finding structure where this none.

Such kinds of ‘studies’ have contributed to the giggle factor associated with SETI, and the subsequent grandstanding by the venerable politicians at Capitol Hill (see here). I believe it is important to decouple such efforts from those being led in a scientific manner to find evidence of Intelligent life outside Earth, as it dilutes the importance of the search.

Interstellar Semaphores?

This article by Luc Arnold (2005) explores light curves from aspherical transiting objects – namely a triangle, two screen, and a six screen. By analyzing the resultant light curve and its deviation from a standard light curve (due to a spherical object), it argues  that these can be potential signatures of Extra Terrestrial Intelligence (ETI) and even as a means of interstellar communication .

Louver like six screen object

Arnold first establishes the premise for the detectability by space based telescopes of such irregular shaped objects (shown above), and then the ability to distinguish these asymmetric shapes from spherical planets. He then considers not one such object, but a series of objects of different sizes and spacing (gaps). These objects could encode a pattern (say prime numbers) to be used as a means of transmitting information. This is reminiscent of late 18th century communication during the Anglo – Franco wars using optical telegraphs and semaphores (as shown below).

Here, they used various ON and OFF positions of the shutter to transfer 6 bits of information – 2^6 – 1 = 63.

 

Murray’s 6 shutter telegraph 

 

A similar concept is hypothesized by Arnold, as a means of interstellar information transfer. The variations in the light curve will be akin to the shutters in the telegraph changing state. He then compares the data transfer rate per steradian of this method with that of laser beacons. Though they have a higher transfer rate if focussed on one star due to their small cone angle, if one aims to transmit over a greater area, then the interstellar semaphores are faster.

I think it is a very novel method for communication that has parallels with techniques used by humanity a few centuries ago. Further, using this technique we may communicate with civilizations which are not in the Earth Transit Zone by giant sails and solar panels in polar orbits of the Sun, perhaps a viable alternative to energy intensive beamed transmission?

 

 

Do Kardashev Type III civilizations really exist? (Annis 1999)

In this blogpost I shall review and briefly summarize the article by James Annis (1999) which is the first published work on the search for Kardashev Type III civilizations.

The 1964 work by Nikolai Kardashev established a scale for the technological development of intelligent civilizations based on their energy consumption. A Type III entity was posited to have the technological prowess to harness the energy of its entire galaxy. This would mean that it could capture energy from most of the stars in the galaxy and / or the supermassive black hole at the center of the galaxy. Potentially even Dark Matter and Dark Energy?

Annis theorizes that the if a entity could capture energy from most of the stars in its galaxy, it would give off signatures that should be observable by us. From the fundamental concepts of gravitation and thermodynamics he establishes relations between the observed intensity and the temperature of the galaxy.  These relations should hold true for naturally occurring signals from galaxies. Therefore a potential way to find these ET civilizations is to look for outliers.

The cultivation of energy from stellar sources would lead to a dip in the stellar flux at the peak of its black body and increased emission at about 300 K since the absorbing objects would emit in the thermal region. Using the Tully Fisher relationship they plot the Luminosity vs Rotation Velocity (proxy for temperature) of the galaxies and try to find outliers or deviations from the trend. Doing this for a sample of about 130 Spiral and Elliptical galaxies they do not find any signals which can potentially be attributed to a Type III civilization.

Citing the results of his work, and the fact that we see that our (and our closest) galaxy/ies do not show such an anomaly, he tries to put constraints on the incidence rates for such a civilization. The upper limit on this rate is calculated to be about 300 Gyrs, which effectively means that such civilizations do not currently exist. However, an interesting point raised is the possibility of observer’s bias in the sample collected, and the fact that the outliers in the trend might have been excluded earlier on.

Further, if their technologies have evolved beyond stellar energy to more advanced forms such as exploiting the black hole at the center of the galaxy or generating energy from dark energy or dark matter then this technique would fail.  This is further discussed in Wright et al. 2014b.

 

Kardashev 1964

In his 1964 Nikolai Kardashev (1932 – ) reviews and articulates the basic requirements for interstellar communication using radio waves. Further, it considers the noise sources in the radio and attempts to establish the ideal wavelength range for space communication. Not only this, calculating the energy requirements for such communication he classifies the three types of civilizations (now known as Kardashev civilizations) based on their energy harnessing capacities.

He starts off by stating that the 1 GHz – 100 GHz frequency space should be ideal for interstellar communication since the absorption due to the interstellar medium is minimum at these frequencies. The limiting factor for communication within the galaxy is the background from the galactic disk. However for intergalactic communication we also need to start worrying about radiation from the halo of the galaxy. Considering both these cases for communication, Kardashev again states that the 1 – 10 cm  wavelength range (~ 1 GHz) would be the optimum band since the noise background reduces.

He then talks about the information content of the signal and the minimum power that would be required to establish a signal of appreciable statistical significance over the noise.  To consider the maximum power of which a signal a civilization can transfer, he classifies levels of civilization and technological advancement.

As shown in the Figure below, a Type I civilization can garner all the energy incident on a planet from its host star.

Type II civilizations can utilize all of the energy of the star. As discussed in Dyson (1960), a potential way to do this by using a (now called) Dyson sphere or Dyson swarm, an artificial cloud of material to enshroud the star and absorb all of its energy output.  There are also hypothetical scenarios proposed by Roger Penrose (1931 – ) where the the civilization can feed its star into a black hole and utilize the waste heat produced by the accretion disk.

Type III civilizations are those which can harness the entire energy output of their galaxy, potentially the supermassive black holes at the center and even quasars.

Humanity in its current era, is more of a 0.7 on this scale. Michio Kaku posits that it would take humanity another century or two to reach a type I stage.

 Kardashev civilizations

It is interesting to note that one of the potential extraterrestrial sources he mentions in this paper (CTA-102) was later discovered to be a quasar.

Also the fact that he posits the development of radio telescopes 100,000 m^2 in area, the same year that the construction for Arecibo began. Arecibo has an area of about 70,000 m^2.

I think this paper is of historical significance as the first mention of the Types of civilizations which are now famous as Kardashev civilizations. Not only that, but also the fact that it takes the idea of the Dyson sphere and provides it with a much broader framework  as to its significance for an advancing civilization.

I believe it is also important in the context of Science Fiction, the possibility of a realm where a single civilization can harness the energy of the entire galaxy. The concept seems to be too far fetched to humanity in the present, but it provides fodder for the imagination of authors and Sci-Fi creators to run wild with possible technologies of the future which can achieve this. Technologies and achievements which could potentially be realized in the future.

 

 

Direct Dark Matter detection is NOT analogous to SETI

In this post I seek to address and contradict the Appendix of Wright and Oman-Reagan 2017. I shall not delve into the main contents of the paper, which I wholeheartedly agree with. Before delving into criticism of the analogy stated in the Appendix, I must say that I do agree with the basic premise of the argument. Just not the example used.

Dark Matter  was first evidenced by Fritz Zwicky (1898-1974) (yes the same one who shot through a rifle along the telescope line of sight to clear the atmosphere) in the 1930s. Initially believed by no one, he used this hitherto unknown form of matter to explain the velocity dispersion of the galaxies in the Coma Berenices cluster. Similar results were then found in the Virgo cluster.  A hypothesis that was not accepted till much later, when in the 70s  Vera Rubin (1928 – 2016) and Kent Ford (1931 – ) studied the rotation curve for Andromeda to find an anomaly in the velocity distribution as a function of distance from the center.


Fritz Zwicky explaining dunkle Materie ?

 

Evidence for Dark Matter has also been found in the power spectrum of the Cosmic Microwave Background radiation (CMB). Further, any discussion regarding the discovery of dark matter is incomplete without a reference (albeit passing) to the Bullet Cluster (below).

 

Dark Matter: From shooting bullets, to the bullet cluster. Credit: Clowe 2006

Even though direct detection of the dark matter particles (WIMP, MaCHOs, Axions)  still eludes us, there is substantial evidence which supports the existence of dark matter. Therefore I feel it is unfair to call direct dark matter detection – a speculative field. The exact nature of the dark matter particle remains uncertain, however its existence cannot be questioned.

Extraterrestrial intelligence, on the other hand is a concept until proven otherwise. Despite the doltish nature of anthropocentric arguments against SETI, and my personal distaste for them, till we do not find some evidence for extraterrestrial intelligence we cannot be sure of their existence. There is no observational evidence which supports its existence apart from philosophy, motivated arguments and calculations. As Sagan said “ the only significant test of the existence of extraterrestrial intelligence is an experimental one. No a priori arguments on this subject can be compelling or should be used as a substitute for an observational program.”

For dark matter the evidence already exists, incontrovertible at so. Considering that the search for dark matter particles (direct dark matter search) has a strong theoretical backing, the similitudes for dark matter detection are more with the Higgs Boson or Gravitational Waves than anything else.

As is mentioned in the last paragraph of the Appendix, the analogy is very much an imperfect one. That being said, it cannot be denied that the giggle factor, is very much an affliction for SETI.

However,  we are not the Tralfamadorians from Kurt Vonnegut’s novels, who can see in 4 dimensions; hence being privy to the future as well as of the past. Being as we are without their foresight (hindsight?), we must keep looking till we either find extraterrestrial intelligence or indubitable evidence of the otherwise (however you prove a negative); and so it goes.

Addendum 31st January 2018:

There are certain points which I should have explained better:

  1. The existence of Dark Matter has been proved beyond doubt. The fact that it consists of dark matter particles (or those which can interact with particles from the standard model) has not. It is not 100 % certain. I do not think this is a good analogy with SETI because our existence does not necessarily imply that there DO exist other space faring civilizations. We can only say with 100 % certainty that life CAN exist elsewhere, not that it DOES. Therefore we are searching elsewhere trying to prove the anthropocentric principle wrong.  The fact that dark matter exists, already changes the playing field and erases the similarity to SETI.
  2. Search for the dark matter particle is based on more than just guesses. I believe here an apt comparison to differentiate between the two concepts is to Schelling points in SETI. In SETI, the phase space of possibilities is essentially infinite, however using cultural, biological and physical arguments we make certain assumptions to make the search doable. These arguments are strongly motivated by an anthropocentric bias, but it gives a place to start from.  For Dark Matter particles, these searches are not based on assumptions. There are different branches of theoretical frameworks which match observational evidences and predict different kinds of particle (WIMP, Axions, Supersymmetry etc. ) to fulfill the role of this elusive piece in the puzzle.
  3. The fact that the Standard Model does not include the Dark Matter particle is not a shortcoming of the particle itself, but one of the possible flaws with the Standard Model. Be as it may the most comprehensive theory we have, it has many inconsistencies and things that it cannot explain. Therefore given further research and work on the theoretical aspect, it is possible (albeit not certain) that the Model grows to encompass and address these flaws (supersymmetry , hierarchy problem, neutrino mass, etc.). No theory can ever claim with certainty that ETI exists.

Arecibo 1974 – Interstellar telegram or PR gimmick?

In this article I shall delve into whether Message Extra-Terrestrial Intelligence (METI) is a smart idea or not. I  seek to discuss and question whether the message broadcasted by Arecibo in 1974 was meant to reach out to another civilization, or was it just a PR gimmick?

Arecibo Observatory

The Arecibo Observatory, in Puerto Rico (USA) is a 305 m (1000 ft) radio telescope. It is the most powerful non military radio transmitter that mankind possesses. In 1974, it was used to broadcast a narrow-band signal ( ~ 10 MHz) at  2380 MHz towards the globular cluster Messier 13.  M 13 is a globular cluster in the constellation of Hercules and is at a distance of about 22000 light years. Globular clusters are some of the oldest objects in the known Universe and hence harbour a stable host environment for an intelligent life form to develop, say as opposed to a Star Forming Region.

The message contained 1679 (73 x 23) bits (0s and 1s) and was supposed to be a cheat sheet for alien civilizations to infer our presence and know more about humans and the fundamentals of our existence.  Further, the signal was barycentric corrected (motion of the Earth around the Sun) to ensure that the frequency received is not modulated due to this motion. It contained the following information  (taken from Wikipedia) –

  1. The numbers one (1) to ten (10) (white)
  2. The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA) (purple)
  3. The formulas for the sugars and bases in the nucleotides of DNA (green)
  4. The number of nucleotides in DNA, and a graphic of the double helix structure of DNA (white & blue)
  5. A graphic figure of a human, the dimension (physical height) of an average man, and the human population of Earth (red, blue/white, & white respectively)
  6. A graphic of the Solar System indicating which of the planets the message is coming from (yellow)
  7. A graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish (purple, white, & blue)

The Arecibo message represented pictorially  in a grid of 73 x 23 with colour added for clarity. Courtesy: Wikipedia

 

The intensity of the transmitted signal was such, that is would outshine the Sun by a factor of 10 billion (10^7). The intensity, narrow-band and the prime number factors should be enough to clue in the listener to the signal’s artificial origin. A fact that can be further confirmed by the contents of the signal.

Thus, it seems that the message was formulated and broadcasted to serve as an announcement of our place in the Universe. That being said, as has been clearly articulated at the end of NAIC STAFF, 1974: the target (why not M4, at one third the distance), the frequency (2380 MHz and not the waterhole frequency), and the duration of the message (only 169 seconds) clearly indicate that the message was not meant to initiate interstellar dialogue. Further they also mention that a serious attempt to initiate such a discourse should come from an international consensus of nations and not unilateral action. Rather I believe, that the broadcast was a technology demonstrator for the newly upgraded radio transmitter (funded by the National Science Foundation – NSF) . It was meant to garner public support towards funding scientific pursuit.

 

Considering that it was not really meant as an attempt to initiate interstellar dialogue, is it justified to classify it along with METI (Messaging to ET intelligence) ?

 

 

 

 

 

1420 MHz: The interstellar water[ing] hole?

In this 1979 article, Bernard M. Oliver (1916 – 1995) builds up on the suggestion of Cocconi and Morrison (1959), and the work of the Cyclops study (Oliver and Billingham, 1973) to suggest that the region bound by the Hydrogen and Hydroxl lines (1420 – 1660 MHz) should be the prime frequency band for our search for extra – terrestrial intelligence. This region bounded by the ‘water’ band, has since been called the water hole, an allusion to a watering hole.

  •  Oliver starts off by my making the case for electromagnetic (EM) waves are the most practical (fastest and most energy efficient) way to interact with extra-terrestrial civilizations under the current technological limitations. This is mainly due to their  zero mass, and travel speed (celeritas).
  • Then, estimating the noise contribution from the non thermal background, and the cosmic microwave background (CMB) radiation, and collating that with the absorption features (mainly the water molecules in the atmosphere), he concludes that the ~ 1 GHz to ~ 10 GHz window is the preferred spectrum for us to search for ET signals.
  • Citing the Cyclops study, he concludes that the region between Hydrogen and Hydroxl ions would be the best band to look at it, due to the significance of water for harbouring life.

 

Is this really the best place to look in? 

Unlike Calvin,  Barney Oliver does not think that the optical band is the best place to communicate with extra – terrestrial intelligence.  [Calvin & Hobbes, by Bill Watterson]
He does go on to question whether such an argument is being too ‘chauvinistic’ and anthropomorphic. Considering that life on Earth is the only example we have for life, I feel that this is a reasonable place to start looking in. Due to the above, he strongly recommends that this waterhole must be protected from any terrestrial interference and noise.

I think this paper was assigned to us to understand the details associated with choosing this particular radio band, as the preferred means of communication and search, and its significance. It is important to understand the historical and scientific background for today’s SETI searches looking for extraterrestrial intelligence around this interstellar watering hole.

Search for Extra-Terrestrial Intelligence at Capitol Hill

The paper by Stephen Garber delves into the politics and the history of the funding for Search for Extra Terrestrial Intelligence (SETI) by the National Aeronautics and Space Administration (NASA), and the opposition it has faced in the US Congress.

Garber starts off by reviewing the history of SETI. Its origins in the seminal paper by Cocconi and Morrison (1959), from where it moved on to Project Ozma, the proposed Project Cyclops, Serendip, and the establishment of the non-profit SETI Institute in California.

In the 1970s, NASA began funding SETI under Philip Morrison, and established a SETI branch at Jet Propulsion Laboratory (JPL).  However, 1978 bought along the first roadblock for SETI in the US Congress; where, Senator William Proxmire moved an amendment to stop funding the SETI research, something he viewed as a silly search for aliens. Timely intervention by Carl Sagan made NASA resume the funding in 1983. Come along 1991, and NASA formally endorsed the SETI programme, with the Bush government requesting $12 million in funding. This would have been to start the Microwave Observing Project (MOP). However, the reception given to this proposal at the Capitol Hill was adverse to say the least, an uphill task was at hand.

An affliction of the SETI programme is the ‘giggle factor’, which is how SETI is wrongfully associated with UFOs and Science Fiction. In the light of the budget deficit and this erroneous public (and sometimes Congressional) perception, NASA  restructured the programme as the High Resolution Microwave Survey (HRMS).

This restructuring, along with the efforts by Senator Jake Garn, led to HRMS being allocated $12 million for FY93, in part for a $100 million 10 year program.  However, the very next year the Senate approved a plan to terminate SETI. In the words of Senator Richard Bryan –  “This hopefully will be the end of Martian hunting season at the
taxpayer’s expense”. Starting then, SETI relied on private donors for its funding.

Moving forward 25 years, unfortunately the situation today (2018) is not much more favourable for SETI. As discussed in Wright 2018 , SETI is still not viewed as a part of astrobiology by NASA. Further, budget cuts in the sciences by the new Trump administration have not helped its cause. That being said, on a more optimistic note: SETI has been helped by an infusion of funds from the Breakthrough Listen Initiative. Though private funding of the Sciences is always welcome, it should not be a substitute for reduced funding by the Government in lieu of  buying more F-35s (each one costs about $100 million).

 

Searching for Ozma!

Princess Ozma?
No.   Project Ozma

 

 

 

 

 

 

 

The PSU SETI class with the Project Ozma 85ft telescope.

 

In his 1960 article for Physics Today, Frank Donald Drake (1930 – Now) discusses the rationale for searching for extra-terrestrial (ET) intelligent civilizations using radio surveys, and after doing so describes Project Ozma. Further, he lays the groundwork to quantify the probability of finding intelligent life, which was later formalized as the ‘Drake Equation’.

Project Ozma conducted at Green Bank using the 26 m (85 ft) diameter radio telescope, was one of the first SETI (Search for Extra-Terrestrial Intelligence) experiments to search for intelligent transmissions of ET origin. It included observations of Tau Ceti and Epsilon Eridani, two stars spectrally similar to the Sun. With the exception of a false alarm due to a secret military project, the project did not yield any significant signal from these two stars.

Drake starts off by discussing how later generation stars contain not only Hydrogen and Helium but also metals. These metals (heavier elements) are required to form solid bodies like planets. Further, the formation of planets assuages the angular momentum problem in a cloud of condensing gas. Sun and other stars like the Sun have relatively slow rotational periods. This rotational period does not conserve the initial angular momentum and hence leads to a discrepancy. This can be solved by the introduction of secondary bodies like planets or binary stars, to which the gas cloud transfers angular momentum as it slows down. Drake suggests that as high as 60 percent of stars should harbour planetary systems.

Establishing heuristic arguments for their existence, Drake goes on to hypothesize whether life can arise on these extra solar planetary systems. He then cites the Urey – Miller experiment, which managed to successfully create amino acids in the laboratory using gases like ammonia, methane, hydrogen and water vapour and an electric discharge (simulating the early atmosphere and a lightning discharge). Amino acids are the building blocks of proteins which are the key ingredients for life. Therefore, the oceans were the harbinger of early life, which after about 5 billion years of evolution led to intelligent civilization. Drawing parallels to the origin and evolution of  life on Earth, he postulates the fact that since life would take so long (5 Gyrs) to develop and achieve intelligent civilization one can discount non main – sequence stars and those which have relatively short life spans (stars much larger than the Sun).

Another consequence of the comparison to life on Earth is the hypothesis that life needs liquid water to develop, due to which the planet (if it has water on it), cannot be too cold or too hot. This leads to existence of a narrow band around the star a planet can orbit – The Habitable zone. Being much closer, or much farther would lead to the vapourisation or freezing of water, respectively.

To search for such life on Earth – like planets around Sun – like stars, the use of narrow – band transmission in the radio is suggested. Discovery, and subsequent contact with such a civilization would likely be in the vicinity of the 1420 MHz region of the radio spectrum. This would be because it corresponds to the 21 cm Hydrogen line spin transition in neutral Hydrogen, a spectral feature that should be known to an intelligent life form. Also, in this region the cosmic noise signal is negligible making it easier to transfer signal at cosmic distances. On the other hand, even if we want to actively seek out ET intelligence this would be the appropriate EM region to seek communication in, since there is a greater possibility of such civilization having radio telescopes tuned and actively searching in this region of the spectrum.

Thus Drake lays the justification for Project Ozma where he searches in this radio band around two Sun -like stars (for princess Ozma?) . He concludes by stating the goal (of finding ET  intelligence) justifies the amount of effort required to carry out this work, and with the hope that in the near future, the search will be successful.

The Sagan petition

In this brief one page petition, astronomer Carl Sagan (1934 – 1996) makes the case to begin a world wide coordinated program to search for signals from advanced civilizations.  He mobilizes the support of numerous scientists across nations who have given this issue thought, some of whom have worked on it upwards of 20 years.

This petition seeks to galvanize support and financial assistance for the cause of establishing such a coordinated search. It also lays forth an interesting point about how noise and terrestrial contamination in the radio frequency is a growing problem and with further development of technology this would only worsen. Further, Sagan seeks to rebuke the extrapolation which decries the existence of extraterrestrial intelligence in the Milky Way galaxy due to the apparent absence of any signatures of such origin in the Solar System.

Such a ‘call to arms’ by a prominent astronomer and public scientific figure (Carl Sagan) is significant in its own right, only to be bolstered by the supported it garnered from the leading scientific minds of its time.  I feel an effort such as this is more symbolic, and is meant to lobby for funding from the unsympathetic national funding agencies of the time.