Jargon update: “dispositive null”

Back when Sharon Wang published her first paper with me, we struggled to title it. A big result in the paper was that our team had shown that the planet did not transit: that is, we had ruled out transits.

But calling this a “null detection” of a planet seemed to send the wrong message: we had not failed to find a transit, we had succeeded in showing that the planet had failed to transit! I mulled over this in this space here and here.

Eventually, we coined some jargon in the paper: “dispositive null detection”.  Such a result “disposes” of the question of whether an effect exists. You use it when you are ruling out an effect with a known minimum amplitude (like non-grazing transits of a giant planet, or the effects of the ether in the Michelson-Morley experiment) and you do so definitively.  You don’t use it when you don’t find anything, but there could still be something beneath your detection threshold: that’s an ordinary “null detection”.

I wondered if it would catch on.  So far, I count six additional instances of its use, only 3 of which are my own uses of the term!

  1. Greg Henry used the term in text I contributed to his paper on HD 38529.
  2. I used it in our first Ĝ paper.
  3. Natalie Hinkel, at my suggestion, included it in the abstract of our paper on HD 130322.
  4. Natalie later included the term in the body of her paper on HD 6434.
  5. Danielle Piscorz and Heather Knutson defined and used the term in their “Cold Friends of Hot Jupiters” series.
  6. And just last month Andrew Howard and BJ Fulton used the term in their big RV limits paper.

So it hasn’t exactly taken off, but it is getting more use than I thought it would.  We’ll see!

1 thought on “Jargon update: “dispositive null”

  1. Harry R Ray

    Is this opposed to a “presumptive null detection” where there is a “candidate transit signal that is ruled most likely a “false positive” fro other data. Case in point: “candidate C ” in Kipping’s MOST Proxima b transit search?

Leave a Reply

Your email address will not be published. Required fields are marked *