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Test for String Theory Developed

Posted by ryuzaki0 on from the new-dimensions dept.

inexion writes "PhyOrg is reporting that SLAC (Stanford Linear Accelerator Center) scientists have found a way to test the revolutionary theory, which posits that there are 10 or 11 dimensions in our universe. This past December, Joanne Hewett, Thomas Rizzo, and student Ben Lillie published an article in Physical Review Letters which shows theoretically how to measure the number of dimensions that comprise the universe. By determining how many dimensions exist, Hewett and Rizzo hope to either confirm or repudiate string theory under specific conditions which would consist of creating and examining 'micro-black holes', which could be formed by smashing two high energy protons together. Using the predicted decay properties of the emitted neutrinos, Hewett and Rizzo solved equations to find that our universe may have more than 10 or 11 dimensions -- too many dimensions to be explained by string theory."

3 of 155 comments (clear)

  1. A Lot of 'Theoreticals' by eldavojohn · · Score: 5, Interesting

    How many micro-black holes have we measured in a lab?

    None.

    How many micro-black holes have we even seen?

    None, as it turns out.

    This is a story of hope and speculation--much like the story of super string theory.

    Hell, do we even have the capabilities to smash two high energy protons together?

    To be fair, Bosonic Super string theory has room for 25 dimensions but it's flawed with tachyon, the so called imaginary mass.

    I'd be interested to know how they intend to measure the micro-black holes.

    --
    My work here is dung.
    1. Re:A Lot of 'Theoreticals' by kebes · · Score: 5, Informative

      Hell, do we even have the capabilities to smash two high energy protons together?

      Well particle accelerators have been smashing high-energy protons together for a long time... but can we smash them hard enough to create micro-black-holes? No. ... not yet, anyways. But that's why the Large Hadron Collider is being built! This is the frontier of particle physics.

      I'd be interested to know how they intend to measure the micro-black holes.

      The LHC has been in the works for a long time, and should come online sometime in 2007. This instrument will be able to probe these questions, and set limits on the possibility of micro-black hole production, as well as extra dimensions.

  2. The universe is safe. by kebes · · Score: 5, Informative

    All black holes emit Hawking radiation, which is essentially black-body radiation (the object is trying to come into thermal equilibrium with the rest of the universe, so is emitting/absorbing radiation to do so). The origin of Hawking radiation is vacuum pair production, if anyone is interested. This radiation causes the black-hole to slowly "evaporate." The temperature (hence rate of evaporation) is inversely proportional to the black-hole mass (hence size).

    Micro-black-holes are (obviously) very small. Thus, they evaporate very, very quickly. In fact, they are well below the sustainable threshold, and will evaporate much faster than they accumulate new mass. Also note that these micro-black-holes have quite low mass, hence their graviational attraction is pretty much nill. They are "black holes" because their mass density is infinite, and they are thus a singularity, but nothing about "black holes" definitely implies "consumes matter indefinitely" (this only happens for black holes of sufficient size).

    So, no, there is no danger with micro-black-holes eating up the entire Earth. Yes, our current theories may be incorrent (you never know), but if micro-black-holes were able to grow without bound, then you'd expect the universe to be littered with black holes all over the place (which is not the case). Thus there's no reason to worry: the LHC will not gobble up the Earth.