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Comment: Quote (Score 1) 81

by Rei (#49363093) Attached to: Russia Wants To Work With NASA On a New Space Station

"We are pleased Roscomos wants to continue full use of the International Space Station through 2024 -- a priority of ours -- and expressed interest in continuing international cooperation for human space exploration beyond that. The United States is planning to lead a human mission to Mars in the 2030s, and we have advanced that effort farther than at any point in NASA's history. We welcome international support for this ambitious undertaking.

Yeah, that's basically "Go F* yourselves" in diplomatic speech.

And as it should be.

Comment: Re:what if... (Score 1) 204

by mbone (#49362193) Attached to: Dark Matter Is Even More of a Mystery Than Expected

There have been several theories built on that assumption, most prominently one called MOND (MOdified Newtonian Dynamics), but more recently one that builds on relativity rather than Newtonian gravity/dynamics.

But none of these theories (hypotheses?) have gained much acceptance from the physics community, as far as I know.

Yes, and one reason is that they find it hard to model these kinds of galaxy cluster observations in MOND / TeVeS without assuming there is also some dark matter or some other non-MOND effect involved. Now, that could be (and MOND proponents will point out that standard CMD also has its problems, e.g., with the core/cusp problem, and we don't throw out CDM every time such a problem is encountered), but it certainly takes some of the shine off of the theory.

Comment: Re:WIMPs (Score 1) 204

by mbone (#49362155) Attached to: Dark Matter Is Even More of a Mystery Than Expected

I don't have the article in the mail yet, but I'm guessing that's new. At the very least, Weakly Interacting is now Really Weakly Interacting.

Here you go.

From my perspective, it hardly changes a thing (it lowers the cross section / mass constraint a little, but not even an order of magnitude). But, then, I'm not a WIMP guy.

Comment: Re:WIMPs (Score 1) 204

by mbone (#49362143) Attached to: Dark Matter Is Even More of a Mystery Than Expected

Math proofs are meaningless without physical observations to back them up.

Fully agree. And, as it happens, General Relativity has a massive amount of physical observation backing it up, and no physical observations contradicting* it.

* If you believe in MOND / TeVeS, then the dark matter observations contradict GR. Let's just say that there is not yet consensus around that view.

Comment: Re:WIMPs (Score 1) 204

by mbone (#49361765) Attached to: Dark Matter Is Even More of a Mystery Than Expected

That the thing about dark matter... it has a perfectly reasonable explanation (WIMPs). It's not that weird of a "thing".

I dunno. Usually when a theory requires more and more unseen entities over time it's a sign that it's time to replace the theory. We know General Relativity is incomplete, both because it doesn't take into account quantum effects and because it has internal contradictions - specifically, it assumes a continuous spacetime geometry but predicts non-continuous points (black hole singularities).

That is not thought to be an internal contradiction of General Relativity, as, even though GR does have singularities, thanks to event horizons and cosmological censorship, there are no known cases where you can use these singularities to derive multiple different estimates of the same observational quantity (which is what having an inconsistent physical model means). I don't believe that there are any mathematical proofs of this, but I suspect you would have to come up with a counter-example if you wanted to convince people GR was self-contradictary.

Comment: Re:WIMPs (Score 1) 204

by mbone (#49361719) Attached to: Dark Matter Is Even More of a Mystery Than Expected

Dark energy is just the latest name for the Cosmological Constant

You know, I'm as happy as anyone else that physicists have been able to do so much with their models, but what kind of navel-gazing mathurbation is this?

Dark energy is an observed physical phenomenon.

The cosmological constant is a term in an equation. It's a very good equation, mind you, but a lot of very good equations have later turned out to be wrong or good for only a special class of phenomena. Equations can predict, but they don't prove anything. It's also worth noting that the cosmological constant was supposed to predict a force that would hold the universe together. Dark energy is a force that is tearing the universe apart. Someone clever pointed out that hey, that works if you just flip the sign of the cosmological constant but I'm not sure I'd call that a win.
 

This is physics. Everything is a term in an equation.

The cosmological constant is the only free parameter in Einstein's equations. The. Only. One. And, it fits exactly all of the available data. Unless and until that changes, there is no good reason to believe to believe that we do not live in a de Sitter space.

Comment: Re:WIMPs (Score 1) 204

by mbone (#49361693) Attached to: Dark Matter Is Even More of a Mystery Than Expected

That's exactly backwards.

The WIMP miracle is over; unless the LHC finds success with its Hail Mary pass, interest in WMPs will inevitably decline, and people will look (are looking) at other explanations for Dark Matter.

Dark Energy, on the other hand, is just a cosmological constant. Nothing mysterious (from a General Relativistic standpoint) about it at all.

Comment: Re:WIMPs (Score 1) 204

by Rei (#49360117) Attached to: Dark Matter Is Even More of a Mystery Than Expected

One thing that dark energy can't be is *all* fundamental constants, plus position, velocity, etc scaling up evenly. Because if such was the case then there would be no perceptible change.

If youe saying that for example what is ground state would change too then it seems like you're arguing that things at the quantum level *aren't* moving into higher energy states. But things at the macroscopic level absolutely are moving into a higher energy state. So are you arguing that dark energy doesn't act on the quantum scale? I find that difficult to accept if so.

Comment: Re:WIMPs (Score 4, Interesting) 204

by Rei (#49358535) Attached to: Dark Matter Is Even More of a Mystery Than Expected

That the thing about dark matter... it has a perfectly reasonable explanation (WIMPs). It's not that weird of a "thing".

Dark energy on the other hand, that's just WEIRD ;) It doesn't act like any "energy" as we know it, even though everything is clearly moving into a higher energy state. A question I've had for a while... if space itself is being inflated (or any sort of mathematically equivalent scenario) - everything inflating in all directions at all scales - wouldn't there be some sort of weak radiation signal from electrons expanding into a higher energy state due to dark energy and then collapsing back down? But I have trouble picturing how to reconcile an absolute, varying distance at the atomic scale with quantization of energy states, positions, etc...

It is masked but always present. I don't know who built to it. It came before the first kernel.

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