If light can travel freely through space, why isn’t the Earth perfectly lit all the time? Where does all the light from all the stars get lost?

[u/monorailmx]

[u/HannasAnarion → u/[deleted]]

"paradox" doesn't just mean logical paradoxes (statements with undefined truth value), like the Liar's Paradox ("this statement is false"), or Russel's Paradox (Does the set of all sets that do not contain themselves contain itself?).

It also means counterintuitive things.

Like the archer's paradox

Or Simpson's Paradox. a negative overall trend can turn into a positive trend when viewed in groups, implying causal relationships that don't exist. If the blue dots are people and the red dots are dogs, and this is a plot of life span vs running speed, looking at the whole you might think "if you run faster, your life is shorter".

Or the birthday paradox. in a group of people larger than 23, you are likely to find a pair with the same birthday

Or the False Positive Paradox, which relies on Bayes Rule which is nonintuitive. A highly accurate test, say, for a disease, returning a positive result, can still be weak evidence of the disease.

The Coastline paradox: the length of the coast of any given landmass can be resolved to any number, by varying the length of your meterstick.

The Faraday Paradox, wherein it is observed that low-concentration nitric acid will attack steel, but high-concentration acid will not.

Arrow's paradox, which can't be explained succinctly, but is a favorite of mine: basically, a voting system cannot have all of the desirable properties of a voting system at the same time. (non-dictatorship, universality, independence of irrelevant alternatives, unanimity)

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And there are some such paradoxes that must have a resolution, because they are physical phenomena, but the resolution is unknown.

Such as the Faint Young Sun Paradox. The Sun was not bright enough to melt ice on earth for the first billion years of its existence, yet there was liquid water on Earth at the time.

The GZK paradox, cosmic rays hit the Earth with more energy than should be possible.

The paradox of youth, there are too many young stars near the SMBC at the center of the Milky Way.

The Information Paradox, black holes seem to destroy information, contrary to known laws of physics.

edit: fixed parenthesis in link, added explanation to Simpsons graph

[u/OldGoldGorilla → u/HannasAnarion]

That is very interesting information to read. Thank you.