Interesting. I googled “eternity in six hours” and found http://www.fhi.ox.ac.uk/wp-content/uploads/intergalactic-spreading.pdf , which looks to be a preprint of the same paper (dated March 12, 2013); the preprint version does say “The lightest design would be to have very large lightweight mirrors concentrating solar radiation down on focal points” and contains the phrase “disassembly of Mercury” 3 times; while the published article Daniel Kokotajlo linked to lacks all of that. Indeed, in the published article, the entire 8-page “The launch phase” section has been cut down to one paragraph.
Maybe you should read the preprint too. I’ll excuse him for reading the wrong obsolete preprint even though that search would also show him that it was published at #3 and so he should be checking his preprint criticisms against the published version (I don’t always bother to jailbreak a published version either), but you are still failing to read the next sentence after the one you quoted, which you left out. In full (and emphasis added):
The lightest design would be to have very large lightweight mirrors concentrating solar radiation down on focal points, where it would be transformed into useful work (and possibly beamed across space for use elsewhere). The focal point would most likely some sort of heat engine, possibly combined with solar cells (to extract work from the low entropy solar radiation).
If he read that version, personally, I think that reading error is even more embarrassing, so I’m happy to agree with you that that’s the version weverka misread in his attempt to dunk on the paper… Even worse than the time weverka accused me of not reading a paper published 2 years later, IMO.
(And it should be no surprise that you screwed up the reading in a different way when the preprint was different, because either way, you are claiming Sandberg, a physicist who works with thermodynamic stuff all the time, made a trivial error of physics; however, it is more likely you made a trivial error of reading than he made a trivial error of physics, so the only question is what specific reading error you made… cf. Muphry’s law.)
So, to reiterate: his geometric point is irrelevant and relies on him (and you) being bad at reading and attacking a strawman, because he ignored the fact that the solar mirrors are merely harvesting energy before concentrating it with ordinary losses, and aren’t some giant magnifying glass to magically losslessly melt Mercury. There are doubtless problems with the mega-engineering proposal, which may even bump the time required materially from 6 hours to, say, 600 hours instead—but you’re going to need to do more work than that.
For the record, I find that scientists make such errors routinely. In public conferences when optical scientists propose systems that violate the constant radiance theorem, I have no trouble standing up and saying so. It happens often enough that when I see a scientist propose such a system, It does not diminish my opinion of that scientist. I have fallen into this trap myself at times. Making this error should not be a source of embarrassment.
either way, you are claiming Sandberg, a physicist who works with thermodynamic stuff all the time, made a trivial error of physics;
I did not expect this to revert to credentialism. If you were to find out that my credentials exceed this other guy’s, would you change your position? If not, why appeal to credentials in your argument?
Interesting. I googled “eternity in six hours” and found http://www.fhi.ox.ac.uk/wp-content/uploads/intergalactic-spreading.pdf , which looks to be a preprint of the same paper (dated March 12, 2013); the preprint version does say “The lightest design would be to have very large lightweight mirrors concentrating solar radiation down on focal points” and contains the phrase “disassembly of Mercury” 3 times; while the published article Daniel Kokotajlo linked to lacks all of that. Indeed, in the published article, the entire 8-page “The launch phase” section has been cut down to one paragraph.
Perhaps weverka read the preprint.
thanks for showing that Gwern’s statement that I am “bad at reading” is misplaced.
Maybe you should read the preprint too. I’ll excuse him for reading the wrong obsolete preprint even though that search would also show him that it was published at #3 and so he should be checking his preprint criticisms against the published version (I don’t always bother to jailbreak a published version either), but you are still failing to read the next sentence after the one you quoted, which you left out. In full (and emphasis added):
If he read that version, personally, I think that reading error is even more embarrassing, so I’m happy to agree with you that that’s the version weverka misread in his attempt to dunk on the paper… Even worse than the time weverka accused me of not reading a paper published 2 years later, IMO.
(And it should be no surprise that you screwed up the reading in a different way when the preprint was different, because either way, you are claiming Sandberg, a physicist who works with thermodynamic stuff all the time, made a trivial error of physics; however, it is more likely you made a trivial error of reading than he made a trivial error of physics, so the only question is what specific reading error you made… cf. Muphry’s law.)
So, to reiterate: his geometric point is irrelevant and relies on him (and you) being bad at reading and attacking a strawman, because he ignored the fact that the solar mirrors are merely harvesting energy before concentrating it with ordinary losses, and aren’t some giant magnifying glass to magically losslessly melt Mercury. There are doubtless problems with the mega-engineering proposal, which may even bump the time required materially from 6 hours to, say, 600 hours instead—but you’re going to need to do more work than that.
For the record, I find that scientists make such errors routinely. In public conferences when optical scientists propose systems that violate the constant radiance theorem, I have no trouble standing up and saying so. It happens often enough that when I see a scientist propose such a system, It does not diminish my opinion of that scientist. I have fallen into this trap myself at times. Making this error should not be a source of embarrassment.
I did not expect this to revert to credentialism. If you were to find out that my credentials exceed this other guy’s, would you change your position? If not, why appeal to credentials in your argument?