In cosmological 'braneworld' models, our Universe exists on a brane embedded in higher-dimensional space. It's hard to test this theory, but there may be a laboratory analogue in helium-3 to probe brane-antibrane collisions — collisions that could have led to the Big Bang.Here's the University's press release, which boldly begins:
Low-temperature physicists at Lancaster University may have found a laboratory test of the "untestable" string theory.Peter Woit was skeptical, and notes how the UK press typically hyped the story -- here's the Telegraph, which makes the finding sound definite:
A "universe in a test tube" that could be used to assess theories of everything has been created by physicists.And then it goes on and on about extra-dimensions and p-branes and all that.
So I thought I'd ask Edward Witten, one of the predominant string theorists in the world, and sure enough here's what he told me:
There is definitely no test of string theory here.He goes on to say,
However, if one sets the bar a little lower, there is something that is interesting. Nature has a remarkable way of generating similar structures at different length scales, so the occurrence of various kinds of string and other topological defects in superconductors, liquid helium, etc. is a possible hint that nature likes such things at a much smaller length scale.