wtf wrote:Maybe I just don't understand your blog.
Maybe I'm not explaining it very well, but it's meant to be in the form of a logical argument; each post presenting the evidence for a particular premise, or clarifying a point. The structure is more or less as follows:
Where did the universe come from?
The red shift of galaxies is best explained by the Doppler effect, which implies that the universe is expanding.
By reversing the process, you have a contracting universe, but there is no apparent cut-off point where the universe had a particular size and calling that the beginning. Bertrand Russell made the point that there is no logical contradiction in claiming that the universe began 5 minutes ago, complete with the holes in his socks. That might seem ridiculous, but claiming that the universe was created with
any size or structure is problematic for the same reason.
The conclusion is that the smaller and simpler the starting point, the less trouble you have explaining it. That doesn't explain
why there was a big bang, frankly, I have no idea. As has been pointed out, Lawrence Krauss has attempted to show that you can get something from nothing, and there is no end to the religious nuts who will trot out some version of the ontological argument. In my view, the former is mathematical sophistry, and the latter is just piss poor sophistry.
What we do know is that there is a bunch of phenomena that looks like a universe.
What is the universe made of?
Assuming the simplest origin of the big bang, an infinitesimal point with one component, it is further assumed that this point is actually made of something identifiably 'physical'. To mathematical physics, the relevant properties of quantum fields are the demonstrable effects they have on matter. The maths is very difficult, but breathtakingly accurate. There is no question that the fields of influence described by physicists are real. The philosophical question is what is the mechanism that causes the influence? According to quantum field theory, matter/energy are just excitations in various quantum fields. Following on from the assumption that the universe is actually made of something, fermions are one type of excitation...
What are photons?
...and bosons are another.
How do prisms work?
This is establishing the principle that particles travel through different media at different velocities and that the acceleration manifests as a change of direction, where the incidence is other than 90 degrees.
A medium such as air can be condensed and rarefied, thereby changing its refractive index...
How does gravity work?
...big bang stuff is a medium more like air than glass, so its refractive index is dependent on its density. The density diminishes according to an inverse square law, so does the refractive index, so does the acceleration, so does the change of direction, so does gravity.
There are a number of assumptions and extrapolations involved, any or all of which could be wrong. We simply don't know whether the universe is actually made of some material with physical properties, but we know a lot about how it behaves. All I'm doing is taking that behaviour and slapping it on to some actual stuff.