[avandonk]

Mike is correct we can only go on the available evidence. To us Physicists a theory only becomes valid when all the evidence points to only one possible theory. In physics a theory is not a belief but is backed up by a vast amount of solid internally consistent evidence.

Now we come to the tricky bit. Any current theory is not the last word on any phenomena. Newtons theory of Gravity was replaced by Einstein's theory of General Relativity. This did not make Newtons theory invalid but improved it.

In the late 1890's science did not accept the existence of atoms as there was no evidence for them! Yet now atomic theory is taught in primary school.

The proof for the Higgs Boson by data from the LHC filled the last empty hole in the Standard Theory for all the matter that we are made of including all the visible Universe. This is only about 4% of the total as Dark Matter and Dark Energy make up the other 96%.

The evidence for the existence of Dark Matter and Dark Energy is irrefutable and yet we do not know what they are.

In the past the mathematics has given us clues about where to go next. Dirac postulated that there would be anti matter because of the mathematics. We routinely use positrons in synchrotrons rather than electrons as they stay focussed in the beam as they are repelled by the residual gas positive ions in the vacuum of the tube they fly in. A positron can be thought of as an electron travelling back in time.

String Theory currently has no way of being tested experimentally. The LHC at higher energies may give some evidence.

If you are worried about living in an infinite Universe where there are an infinite number of Earths and an infinite number of each of us it is even stranger than this.

The Mathematics of String Theory leads to an infinite, well not quite 10^500 universes, all with different laws of Physics. Our so called Big Bang was just one Universe of the very many that are being created continuously without beginning or end.

The fact that we exist and our mere existence depends on Our Universe having just the correct exquisitely tuned laws. As an example if any of the fundamental four forces were a tiny bit different we would not exist.

Bacteria blindly and randomly had about four billion years to do all the chemical experiments.

Our biology is built on the results of these blind random experiments. In fact quantum effects are at the basis of biology. The enzymes and molecules you use to burn sugar at 37 degrees C rely on quantum tunnelling for their efficiency. Photosynthesis relies on the energy from the captured photon being transported through all possible paths in the molecular complex and the deciding when 'it' gets there what path it took. This turns out to be the most efficient path.

There is a small bird a Robin that actually 'sees' the Earths magnetic field by using the sensitivity of quantum mechanically entangled particles in its optic nerves. This is extraordinary as we can only maintain and detect quantum mechanical entanglement in very simple systems at temperatures close to absolute zero.

Nature has had about four billion years of experimentation. We have at best a few thousand.

Our Universe has had about 13.7 billion years of blind experimentation. Other universes have potentially been at it for eternity.

I do not know for sure if we are alone as there is no direct evidence. The mathematics tell me life is everywhere in our universe. Fortunately they are far enough away to not be a problem to us, or us to them.

I have believed for a long time that the human brain must have quantum mechanical abilities somewhere/everywhere in the 100 billion neurons and 300 trillion synapses. I based this on our ability to get a solution to an intractable problem as if it came from nowhere. It could also explain this very strange ability we have called consciousness.


This is the best answer I could come up with for Alex's original questions.

Sorry if it is a bit long.

Bert