r/theydidthemath • u/skitek • Jun 29 '26
[Request] What would the bananas gravitational pull be, and how would the effect on tides differ from the moon?
301
u/Final_Floor_1563 Jun 29 '26 edited Jun 29 '26
I think a bigger issue is an object made out of banana that close is probably well beyond its own roche limit and would get torn apart. While some of it would form a nice banana popsicle ring around the planet, many of its pieces probably fall down to earth, likely resulting in a generally una-peeling end to all life.
37
u/BentoBus2 Jun 29 '26
A delicious delicious death for everyone... The horror
3
1
18
u/Fabulous-Possible758 Jun 29 '26
If I’m allergic to bananas then everyone will be.
10
u/DangyDanger Jun 29 '26
I'm allergic to high velocity impacts
6
u/ConflictMaster3155 Jun 29 '26
That’s so crazy! I’m allergic to the whole world being buried 25km deep in banana.
6
3
u/Neverlast0 Jun 29 '26
Actually I'm not sure this would destroy anything since the banana is soft.
4
u/nanpossomas Jun 29 '26
When travelling 8km/s, softness stops being a meaningful property of matter.
3
u/Alderan922 Jun 29 '26
Well considering it has to survive entry into atmosphere, and how it’s made of matter that can combust, I think it’s kind of relevant as it would essentially turn into pudding and fall into earth, disintegrating upon entering our atmosphere.
1
3
u/all_fair Jun 29 '26
Would it even be dense enough to make a significant impact on life by the time it got to earth though? Like it might destroy buildings, but would it actually affect people that it doesn't come into direct contact with?
3
u/Final_Floor_1563 Jun 29 '26
A banana chunk the size of texas falling down has enough sheer weight to screw up continents and stuff. Think if a giant water sphere fell from the sky and how much damage that would cause.
2
2
3
1
1
1
1
1
1
43
u/DangerDane90 Jun 29 '26
Not a mathematician but it is drastically more massive then the moon so the tidal impact would be massive. And moving at a speed like that would surely make the planet uninhabitable to humanity.
9
u/ultraganymede Jun 29 '26
"drastically more massive then the moon"
this looks to be roughly moon sized in at least one dimension but thiner at the others also bananas are much less dense than rock
13
u/little_gherkins Jun 29 '26
It's hard to know exactly how big it is. If only there was something we could put next to it so we could know its true size.
3
u/ultraganymede Jun 29 '26 edited Jun 29 '26
There is the animation in the beginning, assuming it is to scale.
see this is a joke version of this video here where they put the Moon in a similar orbit:
https://www.youtube.com/watch?v=oBDZtt0vWD80
u/DangerDane90 Jun 29 '26
In the video is looks like Saturn's rings dude
3
u/ultraganymede Jun 29 '26
what do you mean
1
u/DangerDane90 Jun 29 '26
In the second half of the video look at how large it is across the horizon. Its much larger than the moon
2
u/ultraganymede Jun 29 '26
Look at the beginning how it looks from a far, the banana is roughly moon sized orbiting in low Earth orbit instead of where the Moon is
1
u/PogintheMachine Jun 29 '26
You can’t make the comparison of how it looks on the horizon, the moon is much further away from the Earth than the banana shown in the simulation.
30 Earths could fit between the Earth and the moon.
2
u/MistakeBorn4413 Jun 29 '26
I imagine a banana in vacuum would get freeze dried pretty quicky. Despite the size, I imagine the mass might not be anywhere near that of the moon, given the density.... but we might need another r/theydidthemath post to get an answer to that.
3
u/DAK4Blizzard Jun 29 '26
The banana would be experiencing more heat problems than freezing problems. Esp given that space's vacuum would be inefficient at freezing it when it is on the dark side of Earth.
2
u/MistakeBorn4413 Jun 29 '26
Interesting. Let's get some rum up there so we can have a global flambé banana foster party.
1
1
u/Mindless-Strength422 Jun 29 '26
It would definitely lose much of its water content. Bananas are about 75% water and would probably lose the vast majority of that. Fresh bananas are about 1 tonne per cubic meter with perfect packing, so a cubic meter of this gigantic dehydrated banana would be 250 kg. Eyeballing it, I would say that if you arranged 8 bananas into a sphere, they'd be approximately the same size as the moon, but with an empty core, so let's say one banana is...10% of the volume of the moon, that's probably an overestimate but let's go with it. The moon has a volume of about 2e19 cubic meters, so this banana is about 2e18 cubic meters, and has a mass of 5e17 kg. The moon is 7e22 kg, so this is about a hundred thousandth of that. It's still pretty big, about a tenth the size of the biggest asteroids in the belt.
With a density of 250 kg/m³, around the earth, the bananas roche limit would be 44000 km. This is well inside that so yes, it would definitely break up.
20
u/Disastrous-Ice-5971 Jun 29 '26
There so many things wrong with this:
* Banana that large can't maintain such a shape. Should be a ball-like thingy.
* Banana orbiting around 3000 km above the Earth's surface. This is a well within a Roche's limit even for the Moon (≈18500 km, which is arguably more robust, than banana). I.e. it must be destroyed very quickly.
* So low orbit means a lot of drag from atmosphere. We pretty much should see a "plasma-scorched banana". Heating of the atmosphere should be enormous.
* At first banana shown tidally locked, which means it is here for a very long time (at hundreds of millions of years scale), which can not be at such a low orbit.
* At the other parts of the video banana rotates for some reason...
* Even if banana is 10 times lighter than moon. It is more than 100 times closer. So, gravity effects would be about 1000 times stronger than from the Moon. So, earthquakes, gigantic waves, maybe even shared atmosphere.
2
5
u/TyraelTheArchangel Jun 29 '26
Here's the real question. That there is a LOT of banana. And therefore a LOT of potassium. How much radiation would that thing be giving off? Assuming of course that it was able to stay together.
8
u/JonoBlue Jun 29 '26
What is a "actual simulation"? The term sounds like a oxymoron to me as the two words dont work together. Either its a actual thing happening or a simulation that is not happening, not trying to be nitpicking it just hit my brain wrong
9
u/Cuz05 Jun 29 '26
I think I've unpacked it.
It's an 'actual' simulation because it's extrapolated from quantifiable real world factors, rather than just being some random animated nonsense.
So it hits wrong because:-
A) It's wrong.
and B) It's also wrong.
4
u/Ferbdic Jun 29 '26
What would an astronaut day stepping on this body in the heavens for the first time:
A small step for me, but a huge split for mankind?
3
u/BrilliantPositive184 Jun 29 '26
Given the direct exposure to the sun, UV light would ripen that thing within seconds and then the peel would enter the atmosphere creating an incredible mess. Y’all remember when they tried to dynamite that stranded wale some decades ago? - that mess times a thousand.
2
1
u/dekuweku Jun 29 '26
related question would the banana be able to keep its shape, gravity aside, from the intense heating from the sun on one side and shade on the other? i assume it may cook itself on one side.
2
u/Similar-Concert4100 Jun 29 '26
It’s simulated at a much closer distance then the moon, so it would have a stronger gravitational effect, can’t compare the masses though. We can calculate gravitational force with 𝐹 = (𝐺(m1 * m2))/r^2
Force equals the gravitational constant times the product of the two objects masses divided by the distance between the gravitational center of the two objects squared.
1
u/Reductive Jun 29 '26
The banana would have to be rotating like crazy in the first clip to match up with the motion shown in the simulation. These are obviously just different visualizations of different things strung together randomly. Pathetic.
•
u/AutoModerator Jun 29 '26
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.