lukeprog comments on Great Explanations - Less Wrong
You are viewing a comment permalink. View the original post to see all comments and the full post content.
You are viewing a comment permalink. View the original post to see all comments and the full post content.
Comments (113)
I will never get a ping time to American servers from my home here in Melbourne of less than the distance times two divided by c.
If I drop a really heavy rock and a somewhat lighter rock from a moderate height there will be only a slight difference in how long they take to fall to the ground.
If I find some stuff that is really, really heavy and leave it in my pocket I will probably die of cancer.
Cars traveling towards me will sound slightly higher in pitch than after they go past me.
If I buy bullets that are designed to travel slower than sound they will probably make less noise than the bullets that go faster than the speed of sound.
If you give me some charts that show how much light of various wavelengths there is coming from two different stars and it so happens that they look really, really similar except that one is kind of 'stretched out' over the 'wavelength' axis I can tell you that the stretched out one is farther away from us.
And, the critical one:
You might believe that my lack of status as a mathematical physicist doesn't give me the right to make claims about Quantum Mechanics implications but the universe doesn't care. I can apply basic principles of rational thinking to filter large swathes of evidence from those who popularize physics and, particularly, the verbal, non-mathematical claims of physicists in order to work out whether or not a specific claim is likely to be correct.
Funny you should mention that. I spent years working in IT, and this knowledge was actually useful once. I tried to ping a DNS router in Europe (I forget where) from California, and it came back in 1ms and I thought "Ummmmmm... no. You lie." It turned out one of the smart switches on the local network was fucked up and was somehow returning all pings itself.
Behold! Even a pop-sci understanding of physics controlled my anticipations in a way that was useful for accomplishing goals in the world.
That is pretty awesome, but I also don't think it's necessary to think about light speed to solve that problem. Anyone who spends a lot of time debugging networking problems knows that 1ms is unreasonably fast for any communication with a machine more than a couple router hops away, even if it's physically nearby.
I see that this is getting upvoted, but your example sounds like someone who realizes that a device doesn't work because it's not plugged in, and then makes a self-satisfied comment that his knowledge of electromagnetic theory usefully controlled his anticipations in this situation.
In other words, it's about simple conventional nuts-and-bolts technical knowledge, not an improvement on such knowledge brought by more advanced understanding of anything. There's no way someone who works in network administration wouldn't know that a "<1ms" ping coming from around the world is anomalous.
Actually, yes: I think this is correct.
But, I think I would have noticed something was wrong even if I hadn't worked in IT before. But I'm not certain of that.
This great story is related.