STRING THEORY - 4
Although it is not possible to observe the strings, since equipment of the size of Planck's length would be needed (the minimum length that makes sense on a scientific level), some clues seem to support the theory.
First, the observation of cosmological phenomena and the initial conditions of the Universe could provide us with some evidence. This brings back an outdated concept, the cosmic strings, that were then discarded due to the lack of confirmation. According to this idea, the expanding Universe may have stretched a fundamental string up to macroscope dimensions. A string of this type could therefore be defined through old calculations, those performed before the advent of the Superstring Theory, that however assumes the existence of strongly elongated one-dimensional D1-branes. They would emit detectable gravitational waves, as well as causing slight irregularities in the Cosmic Background Radiation. As always, however, scientific confirmations are lacking and given that the non-existence of these branes would not undermine the entire theory, the principle of falsifiability (according to which to consider a theory scientific, it must be possible, starting from its premises, to produce an experiment that can prove it is completely false) is not respected.
Representation of cosmic strings
Another evidence may derive from the discovery of the existence of particles with fractional charges, such as quarks and antiquarks, but with different ratios. Even in this case, however, the falsifiability principle is not respected, since the non-existence of these particles would not compromise the entire theory.
PIC CREDITS
Unknown – Chris Ringeval