Interesting, but astronomical errors back then were plenty, so it was just possible that the measurements weren’t great. Definitive evidence for dark matter came a little later.
-
Show this thread
-
Vera Rubin, working with Kent Ford, was studying velocities of stars in spiral galaxies, as a function of their distance from the galaxy center. You can probably see where this is going.
1 reply 1 retweet 0 likesShow this thread -
You would naively expect, like with Zwicky’s galaxy cluster problem, that the stars further out from the galaxy would be moving slower. The resulting plot should look something like this.pic.twitter.com/daOn75N3v1
1 reply 0 retweets 0 likesShow this thread -
Instead, they found a very peculiar result. Instead of seeing the velocity fall off (A), it leveled off and remained constant (B). This phenomenon has been observed in practically every galaxy studied since.pic.twitter.com/8DYUuBe45N
1 reply 0 retweets 0 likesShow this thread -
And again, like with the galaxy cluster, the simplest explanation is that there is a lot of mass that’s ‘dark’ and undetectable. And also that this mysterious mass extends far beyond the edges of the galaxies that we can see.
1 reply 0 retweets 0 likesShow this thread -
And in a nutshell, that is pretty much the story of dark matter. Now, you might be wondering, if we can’t detect it, how do we know that it’s there? What if something weird is happening on large scales of the sizes of galaxies that’s causing these phenomena.
1 reply 0 retweets 0 likesShow this thread -
Well, almost everyone’s considered that at some point, but we can’t find a simpler explanation than ‘weird undetectable matter that somehow makes up most of matter but we still can’t see it.’ That doesn’t seem very convincing, but it is what it is.
1 reply 0 retweets 0 likesShow this thread -
There are people out there who advocate for a theory which claims that the force of gravity changes on large scales, and that in fact no extra mass is needed. The majority of the physics community however, are not convinced.
1 reply 0 retweets 0 likesShow this thread -
So if we’re sticking to the theory of dark matter, then do we at least have any clues as to what it may be, and why it’s hiding so well? Well, the good news is that we do ( and we probably have way too many ideas about this than we should)..
1 reply 0 retweets 0 likesShow this thread -
One obvious answer would be: black holes! black holes are dark, are they not? Maybe black holes are dark matter. We wouldn’t be able to see them, after all. Although it would be really cool, dark matter probably isn’t made of tiny black holes.
2 replies 0 retweets 0 likesShow this thread
what if everything is made of tiny black holes
-
-
Replying to @Plinz
I believe there are people out there trying to find evidence for tiny black hole, but so far nothing.
1 reply 0 retweets 0 likes -
- 2 more replies
New conversation -
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.