The Littlest Big Bang

Scientists are building ultra-cold systems that mimic the most extreme edges of the universe. Can these analogues help solve the big bang’s mysteries?

By James Owen Weatherall Posted 05.07.2008 at 3:30 pm 9 Comments

This is not an isolated problem. Cosmological phenomena—black holes, for instance, or the big bang—do not lend themselves to experimentation. Cost aside, you don’t want a supernova going off in your laboratory. So how are scientists to test large-scale theories of the universe? Physicists working in the growing field of “quantum analogues” have an answer that may seem strange: Look at the very small.

The Business End: The small tube poking out of the bottom contains the entire helium mini-universe. Jonathan Worth

Two Branes in the Night

The particular type of inflation that the Lancaster group reproduced is called brane inflation, and it is most often associated with string theory, which posits that everything is made of infinitesimal strings. A brane—short for membrane—is an object embedded in some higher-dimensional space, called the bulk. Many things can count as a brane. An infinitely thin string is a 1-brane, because it has only one dimension (its length); a flat sheet is a 2-brane. According to some cosmologists, the universe may be a 3-brane, living in a four-dimensional bulk.

If so, then our universe may not be the only one. There could be many 3-branes, some like the one we live on, floating around in the bulk. According to the theory, two approaching branes would build up just enough energy to trigger inflation—that sudden, rapid expansion of space. Then, once the branes collide, that energy suddenly vanishes, ending the inflation just as quickly as it started.

To test this version of inflation, the Lancaster group watched two pools of ultra-cold liquid helium collide. Helium serves as a good substitute for the early universe because of its symmetry—essentially, the regular patterns underlying its structure. Scientists believe that the hot, young universe was homogeneous and symmetric. As it cooled, some of those symmetries disappeared. The same thing happens with cold helium.

At just 0.0003°F above absolute zero, the superfluid helium in this experiment lines up in one of two orientations, the “A phase” and “B phase.” The group set up the system so that an A-phase part separated two B-phase parts, and the two A-B interfaces represented two branes [see the explanatory gallery]. The team then smashed the two B phases together in the same way that the universe could have smashed into another brane. In both cases, the way the symmetries disappear are identical.

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9 Comments

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fromagesfondus

05/08/08 at 10:10 am

This quandtum stuff is very interesting but remains very confusing to me. Good article though,

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jmnowell

05/09/08 at 1:02 am

I think you mean 0.0003 K above absolute zero. At about 4 K, liquid helium has a boiling point well below 0.0003 F, which is around 255 K, where it would only exist in its gaseous state.

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Toomanytoys

05/09/08 at 12:15 pm

In the article, the author writes: "The trouble is in the details—no one knows why it happened, nor quite how. It takes an awful lot of energy to make a universe accelerate, and pretty powerful brakes to get it to slow down again."

The answer is simple. God did it. He knows why and how it happened.

Just kidding! I would be a fool to try to explain science with religion or try to support religion with science.

Religion is "Faith".

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pernicious

05/09/08 at 1:39 pm

could someone please explain to me how it is they "watched" this process as stated in the article? also, as i understand it, wouldn't their observation of the experiment actually change the results and also render it different from the true Big Bang which one can only assume was absent of the "observer"?

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paulkruger

05/09/08 at 2:15 pm

Imagine the original big bang as a tiny singularity and look at it today. Then imagine an experiment like this gone wrong.

A new "little bang" as a singularity. Of course that would fit in the space of this little gadget. But how big and how fast would it grow if the results were similar to the real thing?

Obvious lack of mass aside...this could make for a chilling SciFi story, right?

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philbert

05/09/08 at 4:54 pm

jmnowell said:
> I think you mean 0.0003 K above absolute zero. At about 4 K, liquid helium has a boiling point well below 0.0003 F, which is around 255 K, where it would only exist in its gaseous state.

0 °F is about 255 K, as you say. Absolute zero is 0 K, or about -460 °F. So 0.0003 °F above absolute zero is still very nearly -460 °F.

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librtyship

05/09/08 at 6:43 pm

Yes things do get more and more complex the deeper we go. For instance Darwin theory seemed pretty reasonable as individual live cells in the body were assumed to be litle gelatinous globs. Now it has been discovered that they contain millions of intricate tiny components which means that each one is a complete tiny factory, then all these cells make up a human body which is an organizm of mind boggling complexity which renders the theory of evolution totally invalid and has to lead to the conclusion that life is created by an extremely high intelligence that we really can't grasp with our limited mental capabilities, then we also have all the other wonders of the universe to ponder, yes Toomanytoys had the right answer, all of these marvels were indeed the handiwork of God and he understands us and understands all else in the universe as he is the creator.

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pastkev

05/09/08 at 10:17 pm

It would be really nice to hear about evidence without the spin of religious atheists. Atheism is just as much a religion as anyone who believes in God. Atheism is based on faith and cannot be proved.

It is fine to have a worldview, but please keep your worldview out of the science, it has no place in real science and is offensive to those interested in the facts to have to hear your worldview about them.

Evidence is evidence, let it speak for itself and leave your religious worldview to discuss with your friends who will probably think you are smart; the rest of us do not care.

As he said in Dragnet, just the facts please.

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Alex R.

05/16/08 at 6:27 pm

"Evidence" is a very twistable term to use, as it can go more than one way.

Atheism is like a religion! It implies faith in supposed "evidence", does'nt it?