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Examining the Expected Effects of Dark Matter On the Solar System
First time accepted submitter LiavK writes "Ethan Siegel recently wrote a great post for ScienceBlogs discussing the expected total mass of dark matter in the solar system. As far as we can tell, dark matter only interacts weakly, via gravity, both with itself and normal matter. So, it can't collide with itself, meaning that it has no way of getting hotter and radiating away energy and momentum. This means that it remains a diffuse mess, with a density that is ridiculously low, to the point where detecting its local effects is likely to remain... challenging for the foreseeable future."
As opposed to the ether of the 19th century, quantum fields, which are what we currently use to explain everything?
Michelson and Morley found that the hypothetical ether had no detectable effects.
In contrast, scientists started by measuring orbital velocities and could only explain them with dark matter.
The problem with dark matter observation in this case is that science is based on empirical observation. If you can't see it, can't measure it, and can't even draw inferences from what you can see and measure to detect something indirectly... it's not science. What this is saying is that the effects are so miniscule that there is no equipment presently capable of separating an actual effect or observation from systemic inaccuracy in the equipment itself. That is, you can't tell whether it's just random 'noise' or an actual signal.
As I understand it, there's a big empty space in most of our theories and observations that says something should be filling it up, but we have very little in the way of actual data of what exists within this hole. We can infer something is needed to balance out our observations, but we haven't actually seen the 'something'. It's like a shy cat in an apartment. You won't see that cat again, and an exhaustive search of most of the rooms in the apartment comes up empty, but something keeps eating the cat food. Thus, we have concluded there's a cat in the apartment... but nobody has actually ever seen the cat.
#fuckbeta #iamslashdot #dicemustdie
Rebuttal: Bullet cluster.
Dark matter, the Ether of the 21st century.
Right you are, mate. I mean, have you tried sniffing that shit? That will get you tall faster than you can say Patrick Moore.
Ezekiel 23:20
My bet is that the need for dark matter will disappear when relativistic effects are properly taken into account.
And I bet that at some point during the last few decades of thousands of observations, theories, and calculations by thousands of astronomers, physicists, and mathematicians (some with Nobel prizes, no less), someone would have already thought of this if it was an issue.
systemd is Roko's Basilisk.
Or you could say space has a property of localized time. Which means time doesn't scale or progress uniformly throughout the universe. If you've got enough gravity, it's going to make things appear even more massive then they are because of time dilation. The relationship of gravity vs. time also means c should be treated as a coefficient rather than a constant. (The effective value of c still remains fixed, but that's because relationship of distance vs. time has both parts as variables. Time effectively rescales itself at higher energies to maintain c for a given distance traveled by a particle, but if you don't account for that, the extra momentum approaching or exceeding c looks like a gain in mass.)
Somebody with better math skills than myself could probably re-jigger Special Relativity in this regard and account for missing mass. It may even show a cumulative effect with gravitational time dilation when you have a system of multiple orbiting objects. But you might also have to toss the idea of a "Big Bang" out the window. (Makes "age" of things in the universe fairly irrelevant when a localized second is defined by the gravitational or acceleration field it's being measured under. Not to mention under certain conditions the typical light-year measuring stick astronomers like to use will also look about as uniform as a funhouse mirror. The funny-sounding Dr. Who sci-fi explanation of time being "Wibbly wobbly" may have some real logic to it.)
Of course it sounds nutty, because it opens up a lot of loopholes. Probably explains why Einstein was uncomfortable with some things, even if it provided the template for a more accurate model than some later revisions.
It's an energy field created by all living things. It surrounds us, penetrates us, it binds the galaxy together.
Actually, it doesn't really in any way. Unless you think the only relevant property of the ether was that it permeated all space, in which case there is a bunch of stuff in science, past and present, that fits that description, anywhere from various potentials to other various fields. Might as well complain heliocentricism sounds just like geocentricism because they both involved spinning things.
This is probably a dumb question, but I've been wondering about it for something like a decade, and I never see it referenced (even to debunk it) in legitimate science discussions.
A mysterious effect which looks like matter, but is invisible except for its gravitational effect. A second mysterious effect which causes the rate-of-expansion of the universe to increase.
I grow more and more skeptical of string theory and its relations every year, but the first of those definitely sounds to me like matter that's in another brane. The second one seems (to my non-physicist mind) like it could also be explained by the same thing, just a different set of matter in a different position relative to the first.
If our universe really is a 3D brane in a hyperdimensional space with others, isn't this exactly the sort of thing we'd expect to see? Further, wouldn't we see related effects like neutron stars unexpectedly flashing into black holes when they come into close-enough contact with dense clumps of matter in adjacent branes (IOW, when there's not enough observed mass in our own to explain the change to a black hole)?
"...always new atoms but always doing the same dance, remembering what the dance was yesterday." -Richard Feynman
The Higgs field is just the latest one. Quantum field theory (what people mean today when they say "quantum mechanics") includes a field for every fundamental particle. Yes, the ether won.
Don't make the mistake of thinking there was just one ether theory. There were lots of them, many quite compatible with special relativity. Quite a few that sound like 1890s versions of quantum electrodynamics.
Are you describing tentacle porn?
Learn to love Alaska
That's because when you say things like that you check off quite a few boxes on the crackpot criteria.
It's not a religion. Lots of different dark matter theories and alternatives have been proposed and tested. The problem is that when some random Slashdotter comes along and says "dude, it must be something else!" the actual astronomers, and the amateurs who can read, roll their eyes. When the same Slashdotter then says "dude, you're not taking me seriously because you can't get past your religious dogma!" said astronomers and literate amateurs roll their eyes harder.
This is a sig I've seen someone use on /. the article says to me dark matter was here, then nothing exploded.
The 2dF Galaxy Redshift Survey http://scienceblogs.com/startswithabang/files/2013/07/kozm_LSS.jpg
shows stuff coming towards us. I've heard so many space programs say everywhere you look everything is moving away from us,
You've got a bit mixed up here. The entire idea of dark matter is because we can measure something we can't see - there are gravitational effects but not electromagnetic ones that have been seen yet.
It's more like stepping on a black cat in the dark. You've felt it underfoot for an instant and it's run off somewhere, so while you don't know what it is or where it is you do have empirical evidence that you've stood on something.
So who is it you're accusing of the religion of dark matter? The astrophysicists who've spent the last twenty years thinking up all sorts of crazy ideas for what it might be and then testing those ideas?
Ah, I understand. You're talking about people who are skeptical of your favourite off the wall theory. That's not religion. As the thread before your post said, when Slashdotter 214243 comes along with some theory from left field, along with an assertion that the experts (some of whom have Nobel prizes), who have put careers into looking into this question, are wrong (or religious), he better have some good evidence to support it. Every time I've seen it that "evidence" boiled down to a vague, usually incorrect understanding, usually with a healthy dose of conspiracy theory.
Maybe you've seen something a little more solid? Care to share?
Let me know when they find supporting evidence [of dark matter]
You mean like the rotational curves of galaxies, the velocity dispersion of stars in galaxies (including observations of globular clusters with very little dark matter, leaving MOND with even more problems), gravitational lensing (including the bullet cluster), fluctuations in the cosmic microwave background etc.?
Mind you, I can't forward a better theory to explain why things have mass
Dark matter has nothing to do with why things have mass. That would be the Higgs field (or, rather, why fundamental particles have mass. Most of the mass of normal matter has another explanation).