Posted: Nov 19, 2019 9:07 pm
by Thommo
I thought this was a pretty fair summary of the big bang theory:
The Big Bang theory is a cosmological model for the observable universe[1][2][3] from the earliest known periods through its subsequent large-scale evolution.[4][5][6] The model describes how the universe expanded from a very high-density and high-temperature state

One of the things to draw attention to is that yes, the singularity that comes at the limit of the extrapolation can be legitimately criticised because it is not conventionally understood as being central to the theory. That seems to cover at least one misunderstanding in this thread.

A second misunderstanding might be in using the Copenhagen interpretation, which isn't science, of Quantum Mechanics, which is science, to criticise science via analogy with the science of Chemistry. If the Copenhagen interpretation is fuel for criticism of anything, it's fuel for criticism of philosophy, which is what it is more accurately an example of (although I would hesitate to say it's going to be a strong or effective criticism even then).

I thought this was a pretty good summary of the four basic lines of evidence for TBBT as well, it's basic, but that seems to be about appropriate for this thread: ... ng/bb_evid
1. Redshift of Galaxies
2. Microwave Background

Very early in its history, the whole Universe was very hot. As it expanded, this heat left behind a "glow" that fills the entire Universe. The Big Bang theory not only predicts that this glow should exist, but that it should be visible as microwaves - part of the Electromagnetic Spectrum.

This is the Cosmic Microwave Background which has been accurately measured by orbiting detectors, and is very good evidence that the Big Bang theory is correct.

3. Mixture of Elements
4. Looking back in time

It outlines briefly the four main independent lines of evidence which point to an initial hot dense state from observations, and indicates what alternate hypotheses have failed to explain.

This page offers a suprisingly clear and succinct summary of the Steady State Hypothesis and how evidence emerged that contradicts it:
Problems with the steady state model began to emerge in the 1950s and 60s, when observations began to support the idea that the universe was in fact changing: bright radio sources (quasars and radio galaxies) were found only at large distances (therefore could have existed only in the distant past), not in closer galaxies. Whereas the Big Bang theory predicted as much, the steady state model predicted that such objects would be found throughout the universe, including close to our own galaxy.
For most cosmologists, the definitive refutation of the steady state model came with the discovery of the cosmic microwave background radiation in 1964, which was predicted by the Big Bang theory. The steady state model explained microwave background radiation as the result of light from ancient stars that has been scattered by galactic dust. However, the cosmic microwave background level is very even in all directions, making it difficult to explain how it could be generated by numerous point sources and the microwave background radiation shows no evidence of characteristics such as polarization that are normally associated with scattering. Furthermore, its spectrum is so close to that of an ideal black body that it could hardly be formed by the superposition of contributions from a multitude of dust clumps at different temperatures as well as at different redshifts.

There also seems to have been a rather idiosyncratic use of the term "faith". Faith as conventionally defined, in its senses relevant to science, is:
b(1) : firm belief in something for which there is no proof
(2) : complete trust
(3) : something that is believed especially with strong conviction

This is distinct from a gamble, in which one may or may not have a high degree of confidence, and in which what matters is that something is at stake based on an uncertain outcome.

Whilst we could semantically quibble about exactly how "complete" trust must be before it becomes a complete trust and thus faith in that sense - for example, am I "completely" sure the sun will rise tomorrow? - the point about science is that confidence should be held only as is commensurate to the evidence. It is reasonable to think the observable universe arose from a hot dense state precisely because we have abundant evidence that supports that hypothesis and does not support competing hypotheses.

There also seems to be a bit of a muddle surrounding formal logic. Formal logic is essentially mathematical logic, and whilst it's a set of powerful tools it is seldom used directly by most people in most walks of life, including science and philosophy.

Objections to science (e.g. in this case to inferences of singularity from TBBT or support for a steady state model) are invariably made informally, but are expected to roughly conform to the principles of logic such that they could hypothetically be formalised were it required. It tends not to be a useful exercise to conduct though as it's incredibly difficult to interpret even for trained logicians and impossible for the layman. Akin to asking for this thread to be explained in binary instead of plain English, perhaps.