I’ve had many interesting reactions to my recent post about inflation, this idea that the early universe expanded exponentially and thereby flattened and smoothed itself. The maybe most interesting response to my pointing out that inflation doesn’t solve the problems it was invented to solve is a flabbergasted: “But everyone else says it does.”
I’m not sure why that is so. Those who I personally speak with pretty quickly agree that what I say is correct. The math isn’t all that difficult and the situation pretty clar. The puzzle is, why then do so many of them tell a story that is nonsense? And why do they keep teaching it to students, print it in textbooks, and repeat it in popular science books?
One reason these stories survive – despite my best efforts to the contrary – is certainly that they are simple and sound superficially plausible. But it doesn’t take much to tear them down. And that it’s so simple to pull away the carpet under what motivates research of thousands of people makes me very distrustful of my colleagues.
The argument itself is best enjoyed by those familiar with the field but here’s the gist:
This fineprint, that there are still initial values incompatible with data, often gets lost. A typical example is what Jim Baggot writes in his book “Origins” about inflation:
“when inflation was done, flat spacetime was the only result.”ell, that’s wrong. I checked with Jim and he totally knows the math. It’s not like he doesn’t understand it. He just oversimplifies it maybe a little too much. More.
Let’s remember this when someone tells us that cosmic inflation proves something or other about the nature of things (for example, that a multiverse, which explains everything, exists).
We ought to ask, in that case, if cosmic inflation theory collapses, are the propositions it supports less believable? If not, why not?
See also: Physicist at Forbes: The inflationary universe is not science any more
Cosmic inflation theory loses hangups about the scientific method
Zombie Killer: The “Icons of Evolution” Have Joined the Ranks of the Undead