Quantum
gravity is an overall term for theories that attempt to unify gravity with the
other fundamental forces of physics (which are already unified together). It
generally creates a theoretical entity, a graviton, which is a virtual
particle that mediates the gravitational force.
Loop
quantum gravity tries to achieve this goal by looking at the smooth fabric of spacetime in general relativity and contemplating the question of whether,
like regular fabric, it might be made up of smaller fibers woven together. The
connections between these quanta of space-time may yield a
background-independent way of looking at gravity in the quantum world.
If found,
the graviton is expected to be massless
(because it acts instantaneously at long distances) and have spin 2 (because
gravity is a second-rank tensor field).
Using the
simplest words I can use, since gravity is a force that explains from the way
entire galaxies (with
solar systems)
behave and connect with each other and
quantum means microscopic, there’s a basic disconnection between trying to
explain in with physical and mathematical models why the earth rotates around
the sun and why an apple falls from a tree.
This is the
reason why researchers have come up with both the concepts that a theory of
quantum gravity must exist. Whether or not gravity is exactly what we think of
as quantum mechanics is fundamental to quantum gravity remains open. A general
suspicion is that gravity, in the geometrical trappings of Einstein’s theory is
not fundamental. In this sense “quantum gravity” may be a misnomer, but the key
point is that it pertains to a unified description of physics, whatever that
turns out to be.
As you’ll
see my new hero – Michio Kaku – gives a truly precise description of the way every
physicist feels like when trying to mathematically explain these new quantum
entity…….infinite plus infinite multiplied by infinite divided by infinite,
results in ………(too
bad that my injured brain knows the answer…. daaaahhhh….).
- https://www.wired.com/2016/01/quantum-links-in-time-and-space-may-form-the-universes-foundation/
- https://www.quantamagazine.org/20161201-quantum-gravitys-time-problem/
- https://phys.org/news/2016-11-theory-gravity-dark.html
- https://en.wikipedia.org/wiki/Quantum_gravity
No comments:
Post a Comment