Castle Paradox

[Bagne]

Lol, here's your FTL communication:
http://www.technologyreview.com/blog/arxiv/24759/

But seriously ... what?
Either this media report has twisted this research into something that it isn't ... or we have something big.
I suspect the former.
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Working on rain and cloud formation

[NeoSpade]

[TMC]

[Bob the Hamster]

Unfortunately quantum entanglement cannot be used for FTL or FTC. The article (like most media reports of Quantum Entanglement) does a lousy job of explaining.

An entangled pair can be separated to any distance, and if you measure them both there will be a correlation between the results-- but from each local perspective the results still appear totally random. You can't see the correlation until you have communicated at least one measurement so you can compare them and then the correlation becomes visible.

This idea of teleporting energy basically means that you could extract energy from the B half of the entangled pair, but you would still need to communicate the results from the A half of the pair using slower-than-light communications.

Or to use another analogy, pretend we have a pair of Quantum Entangled Magic Silver Dollars. I take mine on a rocket to Mars, You keep yours here on earth.

Now if you flip heads, mine will flip tails. and if you flip tails mine will flip heads.

At their closest, Earth and Mars are still 182 light seconds apart, so if we both flip our magic quantum coins at the same time, some kind of "spooky action at a distance" must be happening...

...except your coin toss looks completely random to you, and my coin toss seems completely random to me. We can't tell they are entangled until we communicate with each other over that 182 light second distance so we can compare our coin toss results and discoverer "Hey! Wow!" We always get the exact opposite results!

@Philadelphia Experiment: Has anybody seen the campy 1984 Sci Fi film based on this? It has been on my "Bad Films To Watch" list forever, but I have never got around to finding a copy of it.

[Bagne]

@ James - right, that's my understanding too: the collapse of a wave function is instantaneous (a.k.a. non-local), but special relativity doesn't care because there is no transfer of information.
Er ... at least, that's true for a conventional non-deterministic interpretation of QM.

Apparently there exists some deterministic non-local theories to explain the results of QM (a.k.a. hidden variable theories). They're supposedly legit, although they don't seem to receive much attention. I'm not sure how they sort out the whole "information traveling faster than light" business.

[Bagne]

Here is a reason to be sort of sad:
http://www.theregister.co.uk/2010/02/17/star_trek_scuppered/
There's gotta be another way, even if it means making and dragging worm-hole openings across the universe.

I bet once we get a better idea of what this dark energy stuff is, physics will take a bizarre left turn. There's nothing to say that we don't have a completely new fundamental force of physics on our hands... is there? So far, we only have an idea of the (anti) gravitational properties of dark energy - something completely unlike anything we have ever seen anywhere else.
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Working on rain and cloud formation

[Bob the Hamster]

I am betting that dark energy, like gravity, will turn out to be a curvature of space like gravity, rather than a force like electromagnetism.

(Although the difference between forces and space curvatures will probably be mooted by any Grand Unified theory, should one come into fruition.)

Another type of interstellar travel to talk about is generations ships. Assuming a civilization gives up on FTL travel, but they still want to travel to other stars, they need to build a self-sufficient traveling space-station. The original travelers won't make it to the destination, but their great great great great grandchildren might.

[Bagne]

I recently read a really cool paper - it was proposing that gravity wasn't a fundamental force, and instead was an entropic force (Entropy! Of course!).

If I understand correctly, an entropic force is basically some kind of directed movement that's favoured by increasing entropy.
If you stretch out a polymer, it will recoil back into a knotty blob because there is less entropy in the system when all the polymer units lined up in a row. Apparently you can treat this polymer like a spring and even get an F = kx kind of behavior out of it. Bear in mind that the polymer isn't moving itself though, Brownian motion in the environment is.

So this paper worked a bunch of magic that I didn't understand: holographic universes and information theory ... but apparently a lot of the assumptions they used have been applied successfully in the past.
Anyways, from a set of 3-4 assumptions, they recreated Newton's Law of gravity (!!!) and Newton's Laws of Motion (!!!!!!!!!) and then went on to formulate equations from special relativity (!!!!!!!!!!!!!!!!!!!!).

I'll see if I can find a link for yous ...

EDIT:
Maybe we should just break down and make a "Geek out about cool science things" thread.
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Working on rain and cloud formation

[Bagne]

A while ago there was some discussion about the probability of life spontaneously taking form as fully functional single cell.
It was mentioned (and I agree) that this isn't what scientists believed to have happened. Here's some experiments which support the notion that cellular life could have evolved from simpler chemical reactions (which in turn evolved from even simpler chemistry ... etc )
http://www.cosmosmagazine.com/news/3325/life-evolution-a-test-tube
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Working on rain and cloud formation