When I read "nature prefers" and the author admits the data's sample size is less than a drop in an ocean (we found < 1000 solar systems), I just have to stop reading.
Our Solar System Isn't Normal
101–107 of 107 posts
Re: Our Solar System Isn't Normal
#102Earlier quoted context omitted.
I was very surprised that the article made no mention of such a bias. It was my first thought, too. I'm not terribly up-to-date on how Kepler has been detecting planets, but isn't it due to the 'wobble' of the stars? Surely they'll find planets that orbit faster (and wobble their stars faster) first. It'll take many many years of very consistent observations (or one very lucky day) to see a wobble (or occlusion) from…
Most exoplanets are discovered by the radial velocity method, (tracking the doppler shifts in the spectrographic lines in the light emitted by the star) but the best data is produced by Kepler, which uses occlusion and thus can tell you how big the planet is, by how much the star dims. Both methods are biased towards finding big planets (which produce clear, easy to detect spikes) that are close to their star. (so yo…
That's a very interesting point. I knew about this method but didn't connect it to the article. it would be interesting to have some stats on the number of stars that were probed and that were found to have exoplanets.
I have no idea of what the actual numbers are, but if we need to probe 100000 stars to find one that has an exo planet, it means that the radial velocity method might not be that efficient.
Re: Our Solar System Isn't Normal
#103Earlier quoted context omitted.
For pete's sake, can't someone wax poetic on a slightly related subject of interest without it having to be taken as a polarizing direct criticism of the article? My bad, move along.
You're surprised that people assume your comments are on-topic? I'm surprised by your surprise. In general, when everybody is talking about a topic and you add something to that discussion, they will try to interpret it in a light that makes it relevant. That's just how our brains process communication. If you intentionally mean to go off-topic (which you usually shouldn't, but we'll assume you have something really…
Can't a guy just pull at some straws and try to save face when he's clearly in the wrong? (Sorry)
Re: Our Solar System Isn't Normal
#104Does anyone know how far away we are from being able to confirm the presence of planets as we might on a photograph? Or the obstacles we face getting to a high enough resolution?
Minus five years? See this HST image from 2008: http://hubblesite.org/newscenter/archive/releases/2008/39/im...
Re: Our Solar System Isn't Normal
#105Earlier quoted context omitted.
Yeah, that was my first thought too. Sample bias all the way. 1) Things which orbit rapidly are easy to spot as we get lots of observations from occlusion and wobble. You can identify a planet over the course of a few weeks if it has a period measured in days. 2) Things which are massive are easy to detect using wobble methods. The closer in they are, the more wobble there is. GMm/r^2 and all that. 3) Massive close-i…
I think sampling bias is definitely the most likely reason we haven't seen any solar systems like ours, but... Even with sampling bias, we could still be seeing something legitimately weird. We expect to detect some certain number of exo-planets with a certain range of characteristics with our current technology. We don't think this set of exo-planets is necessarily representative of the average exo-planet in the gal…
I think there's a meta argument encoded in the sampling bias discussion. That being: some people want to expose NPR as just another media center that produces watered down content labeled as science with a complete lack of journalistic integrity. Other people want to believe NPR and perhaps a few other select content producers are publishing articles such as this with the utmost respect to the material. I.e. Things like page views are not considered when it comes to telling a somewhat complete version of the story.
I think this case falls under the lack of journalistic integrity, regardless of whether the overall claim is right or wrong. My view is that when a science article wants introduce the idea that reality may be different than conventionally believed, the goal should be to write an (at least mildly) well rounded, informative piece, not a strictly persuasive piece. When the first response in hundreds of armchair physicists' minds around the world is surprise that selection bias wasn't even mentioned (mine included), I think it's fair to say the article falls more into the persuasive category.
Re: Our Solar System Isn't Normal
#106Re: Our Solar System Isn't Normal
#107I had no idea that: "Or maybe it got ejected — astronomers are finding emigrant planets, lonely orbs that wander the universe with no star, just drifting. Maybe one of those used to live here." There are planets not orbiting stars? I searched Google for "emigrant planets" and the npr article is the number 1 result for that. I think he invented the term. What are these called if I wanted to find more information about…
They are more commonly called rouge planets. http://en.wikipedia.org/wiki/Rogue_planet
I bet johngalt's spell czech is on. ;-)