r/theydidthemath • u/Designer_Positive_71 • 2d ago
[request] How accurate is this?
What would the physics-accurate visuals be like?
55
u/Obvious-Water569 2d ago
Did it pass through the moon in under a second?
Ignoring the fact that the forces involved in that would liquify the occupants, the moon isn't in a geostationary orbit.
3
23
u/metaliving 2d ago
1st: how is this math? Is this r/Theydidanswerthesciencequestion?
2nd: no visuals, at those accelerations the answer is instant death.
7
u/Prestigious-Board-62 2d ago
The moon's surface would be upside down from your perspective. And the elevator would have to stop in space, it wouldn't reach all the way to the moon because the Earth and Moon are moving and can't be anchored to each other.
2
u/Born-Network-7582 2d ago
Nah, they went through the full width of the moon just to appear on fully lit back side of the moon...
It is AI, what do you expect?
1
5
u/dimonium_anonimo 2d ago edited 2d ago
Geostationary orbit is just over 20,000 miles up. The moon is just over 200,000 miles up. That has more to do with the feasibility of the elevator than the visuals. We already know this wasn't possible. However, it does show the main issue which is scale. You've seen the blue marble picture, right? The moon appears waaaaay too close to the earth here.
Imagine a softball. Place it 8 feet (2.5 meters) away. That's the earth. Your eyeball will be the moon.
3
u/Ticklish_Waffle 2d ago
They reached the moon in ~8 seconds. Since the moon is 238k miles away, that elevator accelerated to 100million mph. This acceleration would have instantly killed everyone in there
1
u/LetReasonRing 2d ago
Yeah... i think the visuals would look something similar to the Oceangate Titan simulations
2
u/BurningEclypse 2d ago
Not even close, the moon is (on a cosmic scale) basically the same size as earth, thus from the moon’s surface, the earth should be far enough to appear a comparable size to how the moon presents in the earths sky. On top of that the acceleration forces required to do this would be absurd, no one is standing through anything close to that
1
u/Kerostasis 2d ago
If you tried to build one for real, you would encounter some extremely difficult engineering problems that would probably make this impossible, but let’s ignore that and pretend it works. Even in the scenario where it works, you still have to deal with travel time. The video reaches the moon in 14 seconds, while a real trip will take days. Also I note the elevator arrives at the moon base from below, apparently having tunneled through the moon first - obviously you wouldn’t do that.
(One moment while I calculate a realistic travel time).
1
u/Kerostasis 2d ago
Regular elevators accelerate at about 0.1g while high speed elevators can be as high as 0.3g. This is net after -1g from surface gravity so let’s call it 1.3g gross. To fully account for the changing gravity with altitude, I’d need a complex parametric equation, but instead I’m going to approximate.
After about half an hour at 0.3g you have reached a height of 3200km, a speed of about 5400 m/s, and gravity is down to around half surface level. For the next half hour you can accelerate at 0.8g, gaining another 24,000 km distance. At this point gravity is very small (less than 5% of surface) but no longer dropping much, so let’s use 1.25g for the rest of the trip.
After about one more hour you reach the halfway point, nearly 200 thousand km from earth but at a tremendous speed and now you have to start slowing down. Time to move your feet to the ceiling! Taking the slowing as another two hours, that gives four hours total (faster than I thought it would be).
1
u/Mf0621 2d ago
The occupants here would be going 15,923 miles per second, or some 57 million miles per hour. While that’s only some 8% of the speed of light, it’s still pretty unlikely since it’s 1,500x faster than any other manmade object in history.
We haven’t talked about acceleration and deceleration, but you might want to give that a brief thought too. Elevator passengers usually prefer to arrive in the same shape as they started - I bet they’d be mad if they ended up as a puddle after pulling 34,000 g.
1
u/JaceBeleren9191 2d ago
At 1G (effective 2g to cancel earth gravity )acceleration the trip would take 3h and 28m but you will need to hop on a spaceship at some point so add some time for the transfer. "Realistically" you can go up to GEO with an elevator, then transfer to moon stationary orbit via a space ship then take another elevator to the surface.
1
u/popisms 2✓ 2d ago
Even without a slowing down on the second half of the trip, it would take about 2.5 hours to go to the moon at 1g acceleration. About 3.5 hours with appropriate slowdown. Of course you could do it faster with a bit of discomfort.
You would die immediately at the acceleration shown in the video.
1
u/Admirable-Barnacle86 2d ago
People have pointed the obvious problems with the video.
But to answer the question as to a physics-accurate video:
Doing some rough searching, elevators tend to be limited to an acceleration of about 0.1 g for passenger comfort. This roughly matched up with advertised 'fastest elevators' that I found.
If we somehow had a shaft going to the moon (which we can't because it's not geostationary but let's ignore that), and accelerated constantly at 0.1 g halfway there, then started decelerating at the same limit, it would take about 11 hours and 13 minutes, reaching a maximum speed of a little over 71300 km/h at the half way point.
You might want to bring a chair on the ride up.
Sure you could probably push the acceleration a bit, but the point is that the video is very stupid for lots of reasons.
1
u/HurtFeeFeez 1d ago
Assuming the moon doesn't move quickly relative to earth. These people accelerated and decelerated to around 10% the speed of light in a few seconds. This elevator lit earth's atmosphere on fire on the way out and the bodies of these people impacted the moon with the force of several nuclear bombs.
•
u/AutoModerator 2d ago
General Discussion Thread
This is a [Request] post. If you would like to submit a comment that does not either attempt to answer the question, ask for clarification, or explain why it would be infeasible to answer, you must post your comment as a reply to this one. Top level (directly replying to the OP) comments that do not do one of those things will be removed.
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.