3
$\begingroup$

Is there anything at all that can be created from nothing? Maybe on the quantum level?

I’m aware of pair production but even that requires a photon with energy equal to the 2 particles.

$\endgroup$
1
  • $\begingroup$ If you talking about something that gets created in practice, then what would prevent it to fill the entire universe? And if it's about something that merely may exist but was never observed, it's essentially a Russel's teapot. $\endgroup$ Sep 21 at 11:12
6
$\begingroup$

On some level this is a philosophical question.

From the physical side, to the best of our knowledge, i.e. based on all experimental data to date, nature is constrained by certain conservation laws that prohibit e.g. charge disappearing once it exists. This is related to the the totalitarian principle, one form of which says 'anything that is not forbidden is compulsory'. This is relevant to your example of pair production, which still requires some initial particle state with non-zero energy.

The situation is more complicated when it comes to e.g. the origin of the Universe. On the one hand, if we assume that there was a time when there was nothing, i.e. no matter, energy, time, or space, then clearly yes, things can be created from nothing, because these things now exist. On the other hand, we run both into conceptual issues when thinking about a 'time' when nothing existed, and observational limitations about the early Universe. The steady-state model of the universe, now largely discredited, posited that the universe had always existed, and that new matter was constantly coming into existence, hence side stepping these problems. But this is not compatible with the conservation laws.

Even if there was some physical law that permitted 'something' to come from 'nothing', that would beg the question as to where the phyical law came from, and then we are back to philosophy.

$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.