Stringtheorie: Wissenschaftler versuchen neue Wege, um die Idee zu überprüfen, die die gesamte Physik vereinen könnte

Physicists have been attempting to construct a theory of everything for decades. Such a theory would describe the behaviour of particles and all of the fundamental forces of nature, including gravity. It has proven to be a difficult challenge. The main candidate is string theory which proposes that the fundamental particles are made up of loops of vibrating strings.

The real issue is with testing the theory through experiments. The simple approach, that of colliding particles at extremely high energies, can not be taken as the energies required become prohibitively high. How can we then test string theory experimentally? The answer may lie in looking up to the skies.

From observations, galaxies today are moving apart faster than they were. The expansion of the universe is accelerating, but where does that extra (dark) energy come from? Dark energy could potentially be explained as being the underlying quantum energy of all the forces and particles in nature, including gravity.

Experiments at observatories are pinning down the properties of dark energy. Desi is an observatory based in Arizona, US, which is mapping out galaxies and quasars. The space based telescopes Euclid and Roman will measure the universe in unprecedented detail, mapping out the history of billions of galaxies over billions of years.

Recent results from Desi suggest that dark energy is changing in time in a way that is consistent with string theory models. This doesn’t prove string theory because string theory can produce a variety of different universes, with differing patterns of dark energy. However, the Desi results suggest that interpreting dark energy as quantum energy of strings may be on the right track.

Another way to verify string theory may be via black holes. If string theory is correct, black holes should produce a different signal when they merge, lasting longer and containing echoes.

What’s more, if extra dimensions exist, as string theory proposes, black holes may oscillate in different ways which we could also detect.