It might be worthwhile to list statements about present-day society that would have seemed incredible to me at various times in the past. For example:

1. That nobody has been to the moon since 1972.

2. That the Soviet Union no longer exists and there has been no nuclear war. (One or the other would have been plausible but not both.)

3. That we're still using fossil fuels on a large scale.

4. President Ronald Reagan.

5. That there is a major communications network that is not run by any single organization.

6. That there would be a high-quality computer operating system based on free software.

I've recently been trying to think of how to explain non-Euclidean geometry (or, what's worse, Cantorian set theory) to ancient Greek mathematicians. Is today's mathematics the same as their mathematics? After all, ancient Greek mathematics made falsifiable claims about actual measurements.

Meanwhile, over at the next table, there was the following conversation:

"I believe science teaches us that human-caused global warming is an urgent crisis."

"You mean if it's either not a problem or can be fixed easily, it proves science is false?"

One problem with a professor telling students "I may be wrong." is that many of the students will hear that as "You must be right."

Why would cryonics etc. be incompatible with a traditional view of an afterlife? Physical immortality is supposed to be limited to Aleph_0 years and there are much larger cardinalities.

On the one hand, Judaism (and other traditional religions) accumulate experience that is post-dated to the origin of the religion. On the other hand, when parts of a traditional religion admit that experience can accumulate, the fact that change is actually possible frequently turns into a belief that change is possible at will and you eventually wind up with a "trendier-than-thou" religion.

You can compare this phenomenon to fiat currencies. Gold (or whatever the standard happens to be) might be an arbitrary sign of value, but it's a mistake to think that currency can be changed at will.

Some of Archimedes most potentially-important research involved things he regarded as trivial toys. So if we advise him to get interested in Rubik's cube...

It might make sense to ignore evidence that you are likely to fail if it is a competitive situation and the evidence comes from a rival who is likely to gain if you give up.

As far as Casey Serin was concerned, that didn't apply. The evidence came from a bank that stood to gain if he succeeded.

But when it comes to the actual meat of the religion, prophets and priests follow the ancient human practice of making everything up as they go along. And they make up one rule for women under twelve, another rule for men over thirteen; one rule for the Sabbath and another rule for weekdays; one rule for science and another rule for sorcery...

???

I thought those rules were the outcome of competition between different factions. The factions with the better rules were more likely to win. For example, a century or two ago, part of the Jewish community decided to try ignoring the requirement to not eat shrimp etc. It looks like that isn't working very well. As far as Jews are concerned, God really does hate shrimp.

I suspect some Greens will take a spectral analysis of cerulean, point out that it differs from standard blue paint and that there's some green in it, and argue that the sky really is green after all. A new debate might start on the proper definitions of "blue" and "green."

BTW, what happens if the sky is overcast and gray?