by Alexei V. Filippenko and Jay M. Pasachoff
Insights from modern physics suggest that our wondrous universe may be the ultimate free lunch.
In the inflationary theory, matter, antimatter, and photons were produced by the energy of the false vacuum, which was released following the phase transition. All of these particles consist of positive energy. This energy, however, is exactly balanced by the negative gravitational energy of everything pulling on everything else. In other words, the total energy of the universe is zero! It is remarkable that the universe consists of essentially nothing, but (fortunately for us) in positive and negative parts.
You can easily see that gravity is associated with negative energy:
If you drop a ball from rest (defined to be a state of zero energy), it
gains energy of motion (kinetic energy) as it falls. But this gain is
exactly balanced by a larger negative gravitational energy as it comes
closer to Earth’s center, so the sum of the two energies remains zero.
The idea of a zero-energy universe, together with inflation, suggests
that all one needs is just a tiny bit of energy to get the whole thing
started (that is, a tiny volume of energy in which inflation can begin).
The universe then experiences inflationary expansion, but without
creating net energy.
What produced the energy before inflation? This is perhaps the
ultimate question. As crazy as it might seem, the energy may have come
out of nothing! The meaning of “nothing” is somewhat ambiguous here. It
might be the vacuum in some pre-existing space and time, or it could be
nothing at all – that is, all concepts of space and time were created
with the universe itself.
Quantum theory, and specifically Heisenberg’s uncertainty principle,
provide a natural explanation for how that energy may have come out of
nothing. Throughout the universe, particles and antiparticles
spontaneously form and quickly annihilate each other without violating
the law of energy conservation. These spontaneous births and deaths of
so-called “virtual particle” pairs are known as “quantum fluctuations.”
Indeed, laboratory experiments have proven that quantum fluctuations
occur everywhere, all the time. Virtual particle pairs (such as
electrons and positrons) directly affect the energy levels of atoms, and
the predicted energy levels disagree with the experimentally measured
levels unless quantum fluctuations are taken into account...
Full article: https://www.astrosociety.org/publications/a-universe-from-nothing/
