Planck Telescope Is Coolest Spacecraft Ever 196
Hugh Pickens writes "Launched in May, BBC reports that Europe's Planck observatory has reached its operating temperature, a staggering minus 273.05C — just a tenth of a degree above what scientists term "absolute zero." and although laboratory set-ups have got closer to absolute zero than Planck, researchers say it is unlikely there is anywhere in space currently that is colder than their astronomical satellite. This frigidity should ensure the bolometers will be at their most sensitive as they look for variations in the temperature of the Cosmic Microwave Background (CMB) that are about a million times smaller than one degree — comparable to measuring from Earth the heat produced by a rabbit sitting on the Moon. Planck has been sent to an observation position around the second Lagrange point of the Sun-Earth system, L2, some 1.5 million km from Earth and Planck will help provide answers to one of the most important sets of questions asked in modern science — how did the Universe begin, how did it evolve to the state we observe today, and how will it continue to evolve in the future. Planck's objectives include mapping of Cosmic Microwave Background anisotropies with improved sensitivity and angular resolution, determination of the Hubble constant, testing inflationary models of the early Universe, and measuring amplitude of structures in Cosmic Microwave Background. 'We will be probing regimes that have never been studied before where the physics is very, very uncertain,' says Planck investigator Professor George Efstathiou from Cambridge University. 'It's possible we could find a signature from before the Big Bang; or it's possible we could find the signature of another Universe and then we'd have experimental evidence that we are part of a multi-verse.'"
Re:NPOV (Score:3, Interesting)
Re:Don't think so. (Score:5, Interesting)
Neat idea, taken a little farther. An advanced civilization prevents a more primitive one from developing advanced physics by making astrophysical observations look funny locally. The primitives assume the weak anthropic principle holds, come up with all these really strange theories about cosmic strings, dark energy and such, and never become competition.
Re:rabit from the moon (Score:3, Interesting)
MUAD'DIB: the adapted kangaroo mouse of Arrakis, a creature associated in the Fremen earth-spirit mythology with a design visible on the planet's second moon. This creature is admired by Fremen for its ability to survive in the open desert. [1]
[1] Herbert, Frank. Dune. 1965.
Re:Why is it so hard for people to understand? (Score:0, Interesting)
"It is something that should be true or false by definition."
I don't know anything about the definition of Big Bang including the idea that time began with it. As far as I know Big Bang is the name for the explosive expansion of all matter in the universe at some point in the past from a primeval dense condition.
That time originated there as well is just a theory, nothing definitional about it as far as I know.
Well, he's wrong in that the big bang is by definition true or false. There are many different aspects of the theory that do indeed require testing and as to the how do we test these things, that's a very good question on your part.
You did, however, made me cringe when you used the "just a theory" line. It implies you don't understand the meaning of "theory" in science. It's not the same as the meaning of the word outside scientific circles. In science, a "theory" is basically as close to truth that you can get apart from direct observation. We accept the fact that nothing can ever be proven to be true beyond the shadow of a doubt, but if a theory gives accurate predictions, is falsifiable but has not been falsified, then it can't get better than that until you come across something that the theory does not explain. That's not a bad thing, that's a great thing: it allows us to learn more about the universe, refine the theory, and come up with something that is even closer to the truth.
The big bang is not the explosive expansion of all matter in the universe from a point. It's the explosive expansion of all spacetime. Don't think of it as matter shooting off from a single point in the universe into already existing space. Think of it as the space between particles growing. The universe used to be infinitely small (and thus infinitely dense)--as in, there was no volume, no place for matter to go into. Then there was more space. The center of the big bang is right where you are standing now. Right where I'm standing now. Everywhere is the center of the big bang, the dimensions of the universe just got bigger...and that includes time. So, the grandparent is right that, in a way, it does not make sense to talk about "before the big bang." However, the term "before the big bang" is usually how scientists refer to conditions upon which a big bang occurs. There's a theory that we are not the only universe, that big bangs happen all the time, and this environment where big bangs occur is what these scientists typically mean when they say "before the big bang."
So yes, the definition of the Big Bang does include the idea that time began with it, and although being the currently accepted theory means quite a lot more than "just a theory" would imply, it doesn't mean we shouldn't test the hell out of it. Look this stuff up. Plenty of material available, and it's all interesting stuff.