Comment on How much earth would compress and expand if all of it was 50°C
GreyEyedGhost@piefed.ca 1 day agoGiven the quaint physics of circles, the expansion of a ring of silicate around the earth would be quite noticeable. C = 2×pi×r, which can be converted to r = C/(2×pi). Plugging in those two values gives us
40000/(2×pi) = 6366.1977 km
40008/(2×pi) = 6367.4710 km
So, taking this ring from 0° to 50° would cause it to rise 1.2 km into the air, assuming it kept its integrity.
A simpler way to write this is
(40008 - 40000)/(2×pi) or 4×pi.
A tiny difference, relatively speaking, but a quite notable difference given the context.
XeroxCool@lemmy.world 18 hours ago
Yes, that would be one way to make it noticeable. If all land/sea floor lifted, gradually, 1.2km into the air, we wouldn’t see it. I also Flubbed the per-km increase of the ruler and edited it to correct the increase down to 20cm per km. So as far as our ability to tell things are 0.02% further, no mere mortal would recognize it. But with a lap band around the Earth, we’d definitely notice the new halo floating above us instead of being a tripping hazard.
That reminds me of a fun fact about how the increase in circumference does not care what your starting values are. If you wanted to wrap a rope around a soccer ball, then make the rope lift 1m above the surface of the ball all around, you’d do probably do the pid math like (pid2)-(pi*d1) :
3.140.022m=0.069m of rope around the ball
3.14(0.022+1+1)=6.349m of rope to float 1m above the ball
6.349-0.069=6.28m of extra rope
Then do it for the planet.
3.1440,000,000m=125,600,000. 00m of rope around the planet
3.14(40,000,000+1+1)=125,600,006.28m of rope to float 1m above the ground 125,600,006.28-125, 600,000= 6.28m of extra rope.
1m above, or 2m greater diameter, can just be fed directly into pid as derived from pi(d2-d1) since we know it’s a basic request to lift it 1m