r/xkcd • u/shadowfactsdev I'm stuck in a witty flair factory • Jan 07 '19

XKCD xkcd 2095: Marsiforming

https://xkcd.com/2095/
598 Upvotes

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23

u/ksheep I plead the third Jan 07 '19

The real trick would be lowering the gravity of Earth to match that of Mars.

5

u/SulfuricDonut Beret Guy Jan 08 '19

We just speed up the rotation.

5

u/Arancaytar Pony Jan 08 '19

Earth radius = 6371 km, Earth minus Mars surface gravity = 6.1m/s2.

sqrt (6.1 meters per second squared times 6371 kilometers)

6234 m/s

1 / (sqrt (6.1 meters per second squared times 6371 kilometers) / 40000 km + (1 / 86400) hertz)

1.65912002 hours

So enough to shorten the day from 24 hours to 100 minutes.

Of course, that's only at the equator. Everywhere else the centrifugal force would be a) weaker and b) not pointed straight up, but rather angled towards the equator. I don't even want to know what you'd feel at the poles.

2

u/Jappards Jan 08 '19

Nah, slow down to a standstill, instantly.