Forgot your password?
typodupeerror

Comment: Re:Seriously though, why a singularity? (Score 1) 224

by david_thornley (#47534905) Attached to: Black Holes Not Black After All, Theorize Physicists

There is no such force as gravity. There is only Newton's first law in curved spacetime. I am currently on a straight path in spacetime that takes me closer to the center of the earth, and this chair keeps using electromagnetic force to push me out of my path onto another one. Falling is natural. (It's also harmless, although the withdrawal symptoms can be nasty.) Gravity is just as much of a fiction as centrifugal force, and for the same reason.

Comment: Re:wat (Score 1) 224

by david_thornley (#47534799) Attached to: Black Holes Not Black After All, Theorize Physicists

Depends on your point of view. From my point of view, stuff slowly approaches the event horizon and never hits it. From the point of view of a guy falling into one, he's probably already torn apart by the tidal forces, so it's arguable whether he has a point of view at the event horizon. Assuming a sufficiently large black hole, so the tidal force is survivable, I think he just heads in and doesn't necessarily notice the event horizon as anything special.

Unlike what we've seen on Star Trek: Voyager, the event horizon isn't a solid thing that allows Voyager to move around within freely.

Comment: Re:wat (Score 1) 224

by david_thornley (#47534763) Attached to: Black Holes Not Black After All, Theorize Physicists

A lot of infinities and discontinuities are found where the math breaks down for some reason. Any two-dimensional mapping of the Earth is going to have discontinuities, for example, but the planet surface is roughly the same wherever you go. That doesn't mean they all are. There's a lot of thinking that some subatomic particles are points, which means that since they have mass, they would have infinite density.

Comment: Re:Correct: many phenoma in astrophysics are ideas (Score 1) 224

by david_thornley (#47534737) Attached to: Black Holes Not Black After All, Theorize Physicists

Yeah. And we could also be green-skinned with bad eyes. Nothing is scientifically proven, but there's things we're pretty darn sure of.

Dark matter? There's matter there, and we can't detect it by any electromagnetic means. It doesn't interact with photons. That seems pretty definite. Exactly what it is is another question. We don't know that it's the suggested weakly interacting massive particles, but that's where we seem to be looking at the moment.

Speed of light limitation? We actually don't have such a thing in Special Relativity. What we have is an equivalence of FTL and time travel. We do know, by ridiculously large numbers of observations, that you can't get something quite to the speed of light by accelerating it a whole lot. Neutrinos have got to have incredibly low actual mass, since they travel so very close to light speed without all that much energy involved. We are multiplying a really small number (neutron mass) by a really large number (the relativistic factor) and getting something more reasonable.

Big bang? There's a whole lot of evidence for that. The Universe has changed over time, running things backwards seems to result in a big crunch, and there's a lot of things the big bang predicts that we've found.

Comment: Re:wat (Score 1) 224

by david_thornley (#47534669) Attached to: Black Holes Not Black After All, Theorize Physicists

Excuse me, Hilbert's Hotel is infinite. That's it's definition. You want to talk about a finite hotel, you make up TemperedAlchemist's hotel or something, and what you say will be true of that.

That sum you mention is a sum of finitely many numbers. It's numbers from 1 to n, and n is expressed as finite. Therefore, it follows the normal laws of arithmetic, and shows that you can't do this trick at the downtown Hilton without pushing the penthouse occupant off the roof.

Similarly, you have room n and room 2n, where n is a finite number. If the room numbers end at n, it's not Hilbert's Hotel.

The rule is that, for any positive integer you can name, there's a room with that number, and every room has a different integer number. Any given guest is in a room with a finite number on it (or is near one in the hall). There is no last room. You seem to think that the rooms run from 1 to aleph-null, but that's not how it works. You seem to be thinking of aleph-null as a literal value.

For any positive integer n, both n + 1 and 2n are integers. (It follows that n + 2, 2n+1, 2n+2, and 4n are integers, of course.) Therefore, it's possible to move every guest from room n to room n+1, since room n+1 exists, and that leaves room 1 empty. It's also possible to move every guest from room n to room 2n, leaving the odd-numbered rooms empty.

It's true that one kind of infinity doesn't necessarily equal another kind (the number of integers and the number of real numbers are different, for example), but it's also true that no infinity equals something finite, which you were trying to do.

"Here at the Phone Company, we serve all kinds of people; from Presidents and Kings to the scum of the earth ..."

Working...