The point of the quantum mechanics sequence was the contrast between Rationality and Empiricism. Eliezer argues that the rational response to uncertainty when empirical evidence is absent or equipoise is to assign higher probability to the simpler explanation.
Schoolkids often learn about this with Ptolemy vs Copernicus, I believe. It’s a much less confusing example.
I think the subtext: was: even professional physicists don’t get it.
Edit: Based on the responses, it appears I have confused Copernicus and Kepler pretty badly.
To the extent that “Copernicus is better than Ptolemy” does not pay rent in anticipated experience, I stand by my position that rationalists have no reason to assess the probability that the sentence is true.
Can you expand further? Because my impression was that “Copernicus is better than Ptolemy” pays rent pretty much immediately. Ptolemy can only keep up when there are no new observations. But the moment new observations occur, Copernicus says “Oval shaped orbits,” while Ptolemy needs to explain why it never noticed the need for another epicycle.
In short, the need to avoid privileging the hypothesis is distinct from the possible desirability of simpler theories. Or as Karl Popper might say, “Falsifiability, baby.”
But the moment new observations occur, Copernicus says “Oval shaped orbits,” while Ptolemy needs to explain why it never noticed the need for another epicycle.
Can you expand further? Because my impression was that “Copernicus is better than Ptolemy” pays rent pretty much immediately. Ptolemy can only keep up when there are no new observations. But the moment new observations occur, Copernicus says “Oval shaped orbits,” while Ptolemy needs to explain why it never noticed the need for another epicycle.
There’s a lot wrong with this. Timtyler below pointed one serious issue out. but also ellipses were not used by Copernicus but only later by Kepler. Copernicus has epicycles just like Ptolemy. Moreover it doesn’t pay rent immediately at all (either Kepler or Copernicus). Kepler’s work only paid rent because he had access to Tycho’s extremely precise observations over the course of many years. There are ways that Kepler’s system pays rent also that Ptolemy can’t at all, such as the transit of Venus across the sun but that only happens twice every hundred years. To a naive observer, or even to a naked eye astronomer, all three give pretty decent predictions over the course of a few decades.
Kepler’s work only paid rent because he had access to Tycho’s extremely precise observations over the course of many years. There are ways that Kepler’s system pays rent also that Ptolemy can’t at all, such as the transit of Venus across the sun but that only happens twice every hundred years. To a naive observer, or even to a naked eye astronomer, all three give pretty decent predictions over the course of a few decades.
Tycho was a naked eye astronomer. No telescopes, just money and awesomeness.
To a naive observer, or even to a naked eye astronomer, all three give pretty decent predictions over the course of a few decades.
Ignoring for the moment my huge confusion between Copernicus and Kepler, I don’t see why I care that naive observers can’t tell the difference between Kepler and Ptolemy—just like I don’t care that a naive observer can’t tell the difference between Newton and Einstein.
I don’t see why I care that naive observers can’t tell the difference between Kepler and Ptolemy—just like I don’t care that a naive observer can’t tell the difference between Newton and Einstein.
It is possible that I interpreted “Because my impression was that “Copernicus is better than Ptolemy” pays rent pretty much immediately” badly but I guess I didn’t see months of observation using telescopes would be what I would normally call “pretty much immediately” then. But this may be just an issue of timespan and equipment that is called to mind for “immediate”.
Schoolkids often learn about this with Ptolemy vs Copernicus, I believe. It’s a much less confusing example.
I think the subtext: was: even professional physicists don’t get it.
Edit: Based on the responses, it appears I have confused Copernicus and Kepler pretty badly.
To the extent that “Copernicus is better than Ptolemy” does not pay rent in anticipated experience, I stand by my position that rationalists have no reason to assess the probability that the sentence is true.
Can you expand further? Because my impression was that “Copernicus is better than Ptolemy” pays rent pretty much immediately. Ptolemy can only keep up when there are no new observations. But the moment new observations occur, Copernicus says “Oval shaped orbits,” while Ptolemy needs to explain why it never noticed the need for another epicycle.
In short, the need to avoid privileging the hypothesis is distinct from the possible desirability of simpler theories. Or as Karl Popper might say, “Falsifiability, baby.”
Never. Orbits were circles for him. He “only” put the Sun in the center.
That sounds like the “epicycles on epicycles” fallacy.
It’s circles all the way down!
There’s a lot wrong with this. Timtyler below pointed one serious issue out. but also ellipses were not used by Copernicus but only later by Kepler. Copernicus has epicycles just like Ptolemy. Moreover it doesn’t pay rent immediately at all (either Kepler or Copernicus). Kepler’s work only paid rent because he had access to Tycho’s extremely precise observations over the course of many years. There are ways that Kepler’s system pays rent also that Ptolemy can’t at all, such as the transit of Venus across the sun but that only happens twice every hundred years. To a naive observer, or even to a naked eye astronomer, all three give pretty decent predictions over the course of a few decades.
Tycho was a naked eye astronomer. No telescopes, just money and awesomeness.
Yes he did naked eye astronomy but with a level of accuracy, precision and regularity not rivaled by any prior individuals.
Ignoring for the moment my huge confusion between Copernicus and Kepler, I don’t see why I care that naive observers can’t tell the difference between Kepler and Ptolemy—just like I don’t care that a naive observer can’t tell the difference between Newton and Einstein.
It is possible that I interpreted “Because my impression was that “Copernicus is better than Ptolemy” pays rent pretty much immediately” badly but I guess I didn’t see months of observation using telescopes would be what I would normally call “pretty much immediately” then. But this may be just an issue of timespan and equipment that is called to mind for “immediate”.