The case for, and against, the still-unseen Planet 9
astronomynow.com
astronomynow.com
(Re 'is glass a fluid', my condensed matter professor said something like 'if it is, it flows too slowly to observe significant movement in the lifetime of the universe'.)
How did you turn the camera?
You could have turned it towards you by turning it bottom over top and then you would have to vertically flip the image, but you probably would have never even thought to do it.
So instead you chose to turn it left to right so to get a mirror image you have to flip the pixels left to right.
You’re human so flipping a camera upside down seems quite silly but that’s just an artifact of your environment.
As you can see, the mirror is reversing up and down, not left and right.
Well, a mirror gives you a different picture than a webcam and a computer screen (unless the webcam software flips the picture along the x axis).
Now why is that, that the software needs to flip along the x axis? It is actually because a mirror mirrors around the the z axis, so it switches front and back.
That is exactly what happens if I open Facetime on my Mac and hold something in the camera.
To be a bit more precise: There are two streams generated. One is shown to yourself, and this one works like a mirror. The other one is shown to remote participants and this one is not flipped.
I'm not really sure how it's debatable, either their evidence was correct or not. Surely a respectable third person can look and tell us? The mathematics has been out for 6 weeks.
> “It is important to note that our work does not explicitly rule out Planet X/Planet 9"
I find this annoying. If it disproves their evidence, which I assume was the only known evidence for a 9th planet, then it does.
Add to this "Planet X" is tied to the original article, so if this kills all their evidence they also lose naming rights.
It looks like there are two things going on:
- With the current set of observations, the evidence for clustering is fairly strong, but well short of strong enough that it can't just be chance.
- The new survey was including one data point (which doesn't fit in the 'cluster') that Mike Brown doesn't think counts [1]. With the numbers involved, it seems to me that one additional data point is likely to be making a big difference.
[1] « there is one additional object that Napier et al. include that was never reported to the Minor Planet Center; we restrict our analysis to objects whose detection history we can track; that one unreported object is down in the lower left of the lefthand plot »
It addresses the above a bit and its interesting in its own right talking about Kuiper belt stuff.
Pluto's number would also depend on the current location of at least Quaoar, Haumea and Makemake, since I know their orbits cross inside Pluto's. Pluto may also swap numbers over time with others, like Sedna, Eris, Gonggong, Orcus, Salacia, Varda, Ixion, 2003 AZ84, 2002 MS4, 2002 AW197, etc. since they have quite low perihelia (30 to 40 AU) so may also cross inside Pluto's orbit.
Dwarf planets seem to be lucrative business for those who sell wall posters of the solar system. I would hate having to learn all of their relative locations and interactions in school!
- Eris is more massive than Pluto (1.6e22kg versus Pluto's 1.3e22kg)
- Eris is only slightly smaller than Pluto, at 2326km diameter (more than your arbitrary 2000km cutoff)
- The orbit of Eris crosses Pluto's, so it may be closer to the Sun part of the time https://solarstory.net/img/articles/big/orbit-of-eris.jpg
On reread that probably wasn't clear, since I still think of Pluto as a planet.
That seems to have been the main reason the majority in the IAU voted to make dwarf planets not considered actual planets. Can't really say I agree with the mindset - it overly simplifies our solar system, as well as making the rocky planets appear more similar to the gas giants than they actually are (a problem in a lot of images of the solar system as well).
It's funny to see the number of people who believe the definition was just following scientific facts, when the vote came down to personal preferences over nomenclature. It's one of the more common examples you run into where modern day scientism has trouble distinguishing what is and what isn't science.