The anthropic principle asserts that the fundamental parameters of the Universe, such as the strength of fundamental forces, have been finely tuned to support life. Whether or not this is true, or even whether it merits scientific investigation, has been hotly debated. A new paper offers some ways to test this and could perhaps subject the topic to scientific scrutiny for the first time.
The idea of the anthropic principle was first suggested by physicist Brandon Carter in 1973. Carter’s proposal was presented at a conference marking the 500th anniversary of the birth of Nicolaus Copernicus. The principle attempts to rationalize the apparent “fine-tuning” of various universal parameters that support a cosmos where observers like humans can exist. If the parameters are slightly different, life may not have evolved.
There are two versions; the weak anthropic principle which posits that we observe the universe as being compatible with our very existence because, the argument goes, we would not be here to observe it otherwise! Then there is the strong anthropic principle which goes much further by simply stating that the universe must have parameters that make life possible.
Science of philosophy? Regardless, for a theory to be useful, it must be testable. Until now, it was thought that the anthropic principle was impossible to test. The paper, published in the Journal of Cosmology and Astroparticle Physics, was authored by Nemanja Kaloper of the University of California and Alexander Westphal of Deutsches Elektronen-Synchrotron. They propose for the first time a way to test the principle experimentally.
The AP proposes that if the universe is to develop as a place where our carbon-based life can evolve, it must have started with a very specific set of parameters. The gravitational constant, Planck’s constant and the electronic charge are parameters such that, if they had been different at the beginning of time, the universe would have been very different, very different even.
Kaloper and Westphal identify the first parameters implied by the anthropic principle and manage to model the way in which the universe would have evolved. It would then be possible to compare the result to the cosmos observed today. Any discrepancy between the model and the observed universe would provide a measure of the validity of the principle.
According to the team, a number of predictions can be used as a measure, including cosmic inflation and the nature of dark matter. It may be frustrating to be on the verge of proving, one way or another, the validity of the principle, but it will still be a few years before we can acquire all the necessary evidence. Until then, the anthropic principle remains a very interesting curiosity and which, since the publication of this last article, deserves at least our attention.
Source : Falsification of the anthropic