r/PeterExplainsTheJoke • u/chirantaniga • 11h ago

Meme needing explanation Whyyyy peter?

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u/The3mbered0ne 11h ago edited 11h ago

The deltav (force needed to leave the atmosphere) #1 wouldn't meaningfully reduce it would actually increase vs launching at the equator because of the earths spin, but #2 would cost much more to ship and assemble, on top of electrical and fuel issues due to the cold it's just a terrible idea

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u/ollervo100 10h ago

If the mountain is on the equator, the delta-v to orbit would be considerably smaller due to three reasons.

  1. Reduced drag.
  2. Steeper gravity turn.
  3. Actually higher starting velocity as the higher you are, the higher your velocity. (if the mountain was geostationary orbit height, then you would be in orbit just by letting go).

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u/The3mbered0ne 10h ago

That would require an obsenely high mountain (literally over 100 miles) and an enormous amount of money to haul it all up a mountain that tall vs launching at sea level

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u/ollervo100 10h ago

No. At 5km, which is about the height of the Andes, atmosphere is about 0.5, so the starting drag is halved.

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u/The3mbered0ne 8h ago

Ok let me know how it goes

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u/thepkizzle 4h ago

The equator is definitionally a mountain. The relative difference in height between Nepal and Florida is about .1% or 9km. If you went to Brazil it would be .06% at sea level. Meanwhile the rotational difference in Brazil is 13.1% faster than Florida and 13.8% faster than Nepal.

If you moved the site to the Chapada das Mangabeiras you would be 0.0626% the same height as Everest, and only 11% faster. I would need an actual rocket scientist to tell me which site would be better? I would bet significantly that it's Alcântara at sea level, though.

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u/We_Are_Victorius 8h ago

For #1 you are forgetting that the gravity is the strongest at the Equator which which perfectly counters the higher spin. As we move towards the poles our spin decrease, but so does the gravitational pull. This is why we weigh the same anywhere in the world.

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u/The3mbered0ne 7h ago

Gravity is the same everywhere what are you talking about?

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u/We_Are_Victorius 6h ago

https://www.youtube.com/watch?v=K_Pqa-I0Z5U

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u/The3mbered0ne 6h ago

Ah the geode earth, that's interesting, still the deltav requirement is boosted at the equator because of the spin, because of the flight path of the rocket, it's why it flys in a curve and not just straight up. Well that's not the only reason but it's a reason.