Cyan comments on Evolutionary psychology as "the truth-killer" - Less Wrong

10 Post author: Benedict 23 July 2012 08:44PM

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Comment author: Cyan 25 July 2012 02:00:39PM 0 points [-]

That's a nice essay, but it's worth noting that Asimov misunderstands the question of Newtonian versus relativistic physics. In particular, nothing in Newtonian physics requires light to propagate instantaneously.

Comment author: Kindly 25 July 2012 02:31:38PM 4 points [-]

I think he means it in the sense that if you take relativistic equations, and substitute infinity in for c (or, more rigorously, take the limit as c goes to infinity), you will get Newtonian equations. Thus the behavior of objects at small speeds is roughly Newtonian, because c is already well on its way to infinity compared to those speeds; conversely, when an object is traveling at a rate of 0.1c, it matters greatly that c is finite.

Comment author: Cyan 25 July 2012 07:42:58PM 4 points [-]

Upon re-reading, I see that you are probably correct. Thanks!

Comment author: [deleted] 25 July 2012 02:57:35PM *  3 points [-]

<nitpick>

conversely, when an object is traveling at a rate of 0.1c, it matters greatly that c is finite.

Not that greatly: the size of most relativistic effects is v²/2c² + O(v^4) which for v = 0.1c is 0.005. I would have used a bigger number for the example, say 0.9c.

</nitpick>