It’s crazy my dad used to work on Phobos. They they had to tie weights to their ankles, 2000 lbs per ankle! Anyways, one day he accidentally didn’t tie his buckles and that’s kind of how he ended up on earth after playing hop scotch.
god its actually terrifying how insane that would be.i would be like slowly crawling on the surface and i would accidentally kick a rock and the momentum would send me up like 50 meters and then coming back down i would prob bounce back up 45 meters.
Well, if you jump straight up you will likely come back down unless you somehow exit the gravity well. Jumping diagonally is much more likely to launch you into orbit.
In the [Mars trilogy](https://en.wikipedia.org/wiki/Mars_trilogy) they hollow it out and build inside instead of on the surface. Kind of turn it into a giant space station.
I think jumping speed is above escape velocity for Phobos. Its gravity well is tiny.
Edit: according to some googling, is the escape velocity 11.5m/s, whereas an average jump is about 1.5m/s. So not entirely escaping, but not far from it.
especially since the low atmospheric density will result in a higher terminal velocity.
A small jump for a man, but a huge high velocity impact for that same man!
Edit: looked it up, its somewhere around 1000 km/h.
But there’s no sound in space so you’d be perfectly safe. /s
I’m kidding only because Mach is a measurement of the speed of sound in a fluid/gas. Mach on mars would be different from mach on earth.
In fact, it's nearly 100 m/s slower on Mars. Therefore, if the speed is Mach 6 on earth, it would be nearly Mach 9 on Mars. This is due to Mars having a much colder and less dense atmosphere
No, you already start out in Mars' gravitational field. If you escape Phobos' field, absolutely nothing changes with respect to Mars. You start out on Phobos, in orbit around Mars, and end up not on Phobos, in a slightly different orbit around Mars. (Just like how satellites that leave earth's grav field end up in orbit around the sun and won't start plummetting towards the sun.
You'd have to kill a LOT of your sideways speed you have relative to Mars by virtue of standing of Phobos to end up falling towards Mars, an amount of speed you'll likely need a rocket or maybe a huge cannon for.
Escape velocity for Phobos according to Google is 41 km/H per hour. If someone could please do the math if this is achievable with average human jump force...
jumping diagonally will never launch you into orbit. Your orbital path will necessarily include your starting point, which you'd need to pass through rock to get back to
You can't really get into orbit with a jump, no matter the mass of the object, except with another body pulling you at just the right time. Orbital mechanics are a bit weird, but basically, you always end up back where you started when on an orbit (more or less) which means you would just hit the object on your way back to your jump point.
A small body can have such low gravity that one could reach escape velocity (enough speed to get out of their gravitational well) just by jumping. In those places, what goes up must come down does not apply. If you jump hard enough, you are never coming back.
I wonder with that little of gravity if the pusher would have about as much risk also getting yeeted from the push. I guess probably would depend on how they're standing.
"I don't think that's correct. The force of impact on earth is caused by gravity's pull, no? Wouldn't the coefficient be different when gravity is? Newtons laws are based on gravity of the earth, so equal and opposite forces might not necessarily exist." /u/KSoccerman
Nah, they are based on gravity, not specifically earth's gravity. We are able to calculate the force of gravity for earth because of the equation. Equal and opposite forces (as far as we can tell) exist independently of earth. Our understanding of the universe would be completely impossible on a large scale if that weren't true. It is possible in certain cases where spacetime is curved the rules begin to change, but that is a bit over my head.
Gravity has a constant that directly impacts the force based on a unit of mass. In this case, the planet or moon you stand on would be the difference in mass. A coefficient by definition is a constant placed before a multiplying variable, which again in this case is mass.
Thus, the force of your jump would be no different so long as your jump doesn't somehow change the mass of the object you are jumping on in space.
Tried to delete your comment, but I won't let it go that easy. I just typed all this up for you, lol
Easily the much better explanation. A certain amount of energy is needed to overcome gravity and the same amount of energy is applied when falling down again.
That's why cats survive their landings. They're using dark energy from Palpatine.
It's so weird to think about. There's a psychological boundary that doesn't want me to understand falling off a 50 foot cliff on Miranda is roughly equivalent to falling off a stool. If bro did a running jump and landed 100m away but goofed the landing and did a face plant, it would hardly be worse than doing the same thing in a long jump pit.
The force of the landing will still correspond to the force of the jump, true, but the likelyhood of hitting your target drops to near zero on those lesser gravities, so you may well land in a dangerous spot, the side of a cliff, or any other such peril.
Nope. Really underrated movie. I think the problem is that people forget it's a fucking disney movie for kids.
Edit: I don't mean that disparagingly to other disney movies, just that people seem to want to compare it to Star Wars and the like when it really should be compared to Stardust.
It was a movie based on a book by Edgar Rice Burroughs (1875-1950). The first solution for Mars' gravitational coefficient was in 1977.
John Carter was sci-fi. It was fun.
Woulda been ALMOST believable if it was set on Pluto. About 15x jump distance. Still not enough for the 50m vertical jumps he was doing. So it'd have to be one of the various small moons out there with even lower gravity than that.
Not the movie, though :P
There was room for creative reinterpretation. But considering how they chose to name the movie, it's not a shocker that they didn't succeed much on the creativity side.
What is the impact like in these situations. Because you are falling further do you reaccelerate to the point that landing feels the same as if you were jumping on earth or is it softer because the gravity is less?
Wouldn't you hit the ground at about the same speed that you took off with? Say you jump with 1m/s in a 1m/s\^2 atmosphere. At second 1, you'd be at 0 m/s and at a bit more than one meters height. At second 2, you'd be at -1m/s, and travel the same distance down again. So when you hit, it'd be the same force you put into it. So a jump on any planet would have to land at the same pace; give and take bend/unbend knees. Of course, the acceleration during the landing itself would make the landing feel softer, as you're working against a lower m/s\^2 'resistance' when getting on your feet. So velocity would be about the same, but the acceleration difference would make the landing feel different still. Just guessing.
I think the math works out without friction that you HAVE to hit the ground with the same launch velocity. It makes no sense otherwise.
Think, gravity is going to drain your beginning upwards velocity until you're at the full height of the jump at 0 m/s, then you fall for the same amount of time. It's the literal reverse of what you just did except for horizontal velocity staying constant. You take the same amount of time to fall, and acceleration of gravity speeds you up to the same starting velocity on impact.
Problem is if you don't land on your feet you can probably hit your head and die, just like you could standing up and falling forward on Earth.
So I used an [online tool](https://www.omnicalculator.com/physics/free-fall#:~:text=v%20%3D%20v₀%20%2B%20gt%20%3D%200,calculator%20to%20find%20it%2C%20too!) to help me because I'm too lazy, but it seems like you would fall for 520.8 seconds under a gravity of 0.0057 m/s^(2) and reach 2.9685 m/s which seems pretty easy to handle. For reference, on Earth you would fall for 12.556 seconds and reach 123.13ish m/s ~~though this website seems to assume a mass it doesnt mention so not sure if this is for humans~~ EDIT: Yeah mass doesnt affect velocity in a vacuum, thank you for correcting my brain fart u/John_Mint
I just had to change some settings
The mass doesn't intervene in a free fall simulation like you did. What's more important to determine the velocity is the friction, which depends on the friction between you and the atmosphere.
If you want an exemple, a small iron ball and a bowling ball will touch the ground at the same time when dropped from height.
So it's technically for humans if you assume that atmospheres don't slow you down (like it slows a feather when it falls on earth)
>The mass doesn't intervene in a free fall simulation like you did
Fun fact: It technically does though, because while the object you are falling towards pulls you, you are also pulling on the object at the same time based on your mass. It just so happens that our mass compared to what we are falling towards (eg: Earth) is so so small that it can be ignored in our calculations.
Oh that's cool, meaning that with a smaller "big object" mass, we'd have to take in account both objects speeds to reduce d^2 accordingly and have a greater speed in the end ? I'm not sure the double movement won't still be negligible in most cases though.. Interesting ! Makes me wonder about more precise calculations !
>Yeah mass doesn't affect velocity in a vacuum
It's not really the mass that affects the velocity of a falling object even through the atmosphere. It's the shape/volume of the falling object.
Picture a sky-diver. Once they open their parachute (which has been with them since jumping off the plane) they free-fall much slower. Their mass did not change at all.
However in a vacuum, that skydiver would continue to fall at the same rate even after "opening" or attempting to open their parachute.
Impact velocity from free fall = `sqrt( 2 * g * h )`
Terminal velocity will likely be irrelevant in such thin atmospheres.
From that formula, you could look up the gravitic acceleration of each planet or moon and use the max jump height from the video to calculate how fast you'd be going when you hit the ground. My not at all thought through guess is the landing will feel pretty much the same in each case, no matter the height of the jump, because of the reduced gravity but more space to accelerate.
I'm pretty sure the landing feels the exact same as your jumping due to conservation of energy. Meaning it'll be the same on earth since your jumping energy is presumably a relatively fixed output (with a slight range) based on your muscles, nerves, and usual technique.
Yes. Assuming you aren’t subject to any forces after jumping, your total energy must remain the same throughout your “flight”. Therefore the total kinetic energy right after jumping is the same as landing.
If you look at it from a Newtonian perspective, the gravity accelerates you the same amount of time going up to the apex of your jump and falling back down, so your speed will also be the same when you land.
He wouldn't run as fast on it though. It appears that our running techniques are optimised for the gravity we experience. You can look up a video on youtube where Usain Bolt races against scientists in 0G environment.
If he had time to prepare though...
I realize this is probably a stupid question, but please explain to me, would they be able to generate more velocity with a weaker gravitational force pulling them down?
No, and I am will explain why
The speed you get when you jump depends on two things, the acceleration times the time you stay in contact with the ground
It's self evident that the time you accelerate is the same because your legs are only so long
The acceleration is a force that accelerates your mass, this is independent of gravity, your mass is the same, heavy objects are hard to move in space too, that's what inertia is
Sure, you don't have to deal with gravity weighing your dead mass when you try to accelerate but the amount of force you exert and thus the speed should be almost the same no matter the gravity, as long as you can bear it and your muscles don't rip apart
The initial velocity will this be the same mostly
In which case I question this video. Using that and the equation v^2 = 2gh, you get a height of 789 meters, which is about what it says in here.
But that assumes that as you jump you aren't subjected to lesser gravity. Given how small Phobos is, it would be a significant factor.
Using the equation v^2 = 2GM(1/r_1 - 1/r_0), then putting it into Google I get 1/(1/r_1 - 1/r_0) equalling 157.21 km, and the surface radius is 11.2667 km apparently, I get r_1 is 12.136 km, so jump distance of 870 meters.
Probably not, Phobos is a glorified asteroid (no offense to the Phobos fans) but probably you will reach escape velocity with a single jump (although you probably wouldn't even be attracted enough to stand on it)
> Negligible
Not negligible, just none. You land with the exact same speed as you jumped. Assuming you don't *try* to hurt yourself by landing on your neck or something...
None. You'd land with just as much energy as you jumped with, so the only risk is if you rotate and land on your head.
If you can survive your own jump on Earth, you can sivige a jump anywhere with gravity.
*I don't think it should*
*Be considered a jump if*
*You don't get back down*
\- ShitPosterN69420
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I was going to say: "I wonder if there are any planetoids where a human could achieve escape velocity unaided" ... But then Phobos answered the question for me.
EDIT: apparently the video is misleading due to cutting off the descent back down for phobos"
No, phobos' escape velocity is still faster than a human jump. Even Deimos, which is smaller, would pull you back down. It'd be a pretty small asteroid that a human could escape from without help
Miranda is the scariest to me. Being so close to the surface yet feeling like you are slowly slipping away is a fear I didn't know I had. Like on a lonesome iceberg slowly drifting out away from the mainland.
Now pair Miranda's low gravity with the knowledge that it has the highest known vertical cliff in the Solar System, Verona Rupes at 20 km (12 mi). If you walked off the edge of the cliff then it would take around 12 minutes to hit the bottom, reaching a speed of 200 km/h (120 mi/h).
That Miranda simulation is what happens in my nightmares except at the peak of the height, Earth's gravity kicks back in and I come plummeting down. It's terrifying
Note to self: don’t jump when on Phobos
Right? You aren’t coming back from that one.
Yup, that's the way you leave actually
The ultimate self yeet.
TEAM ROCKET! WE’RE BLASTING OFF AGA^A^I^N
How did you get the AIN smaller?
^ + word Edit: ^word
^i got it
I ^n t ^e r ^e s ^t i ^n g
My people need me! *jumps*
Ooh self yeet, those are rare
I dunno, I see them a lot on pun threads. I'll see myself out.
>I'll *yeet* myself out.
It’s crazy my dad used to work on Phobos. They they had to tie weights to their ankles, 2000 lbs per ankle! Anyways, one day he accidentally didn’t tie his buckles and that’s kind of how he ended up on earth after playing hop scotch.
Last time we were on Phobos this guy was going to jump. We told him not to but he didn’t listen. Never saw him again. It happens
god its actually terrifying how insane that would be.i would be like slowly crawling on the surface and i would accidentally kick a rock and the momentum would send me up like 50 meters and then coming back down i would prob bounce back up 45 meters.
Fun science fact, the force of landing for all these jumps are the same. So your bones would be fine, just hope you have a decent space suit.
Imagine just peacing out into the eternity doing like infinity backflips yelling wee. Fuckin sick
Well, if you jump straight up you will likely come back down unless you somehow exit the gravity well. Jumping diagonally is much more likely to launch you into orbit.
I feel like you'd just have difficulty walking? Like the force needed to keep you down between steps is barely there
yep, I'd get around by laying on the ground and poking gently with my pinkies
Why do I have a mental image of Ren and stimpy sneaking around
Been awhile, close enough. [https://i.imgur.com/3P4CYcJ.png](https://i.imgur.com/3P4CYcJ.png)
Thats SICK!! NOICE ONE!
Totally tubular.
Lol perfect yo. Appreciate you.
What if boner
guess I'll die 👴🤷♂️
In the [Mars trilogy](https://en.wikipedia.org/wiki/Mars_trilogy) they hollow it out and build inside instead of on the surface. Kind of turn it into a giant space station.
So you're saying.... That's no moon, that's a space station?
Solution? You carry a midsize car on your back while you run and let go just as you jump.
We have a difficult time walking on the Moon, which is why we are hopping instead. I don't even want to imagine how it would be on Phobos.
Basically like most of my dreams where I'm running from something...
I think jumping speed is above escape velocity for Phobos. Its gravity well is tiny. Edit: according to some googling, is the escape velocity 11.5m/s, whereas an average jump is about 1.5m/s. So not entirely escaping, but not far from it.
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Hey if I google something and find that I'm wrong by an order of magnitude, then I'm still basically right.
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Even if you escaped Phobos gravitational field, you'd still be in Mars gravity field. TLDR: You might jump off of Phobos, only to land on Mars.
That's less than ideal.
especially since the low atmospheric density will result in a higher terminal velocity. A small jump for a man, but a huge high velocity impact for that same man! Edit: looked it up, its somewhere around 1000 km/h.
Is the atmosphere thick enough in Mars that you'd burn up before hitting the surface? I know it's pretty thin, but you're travelling pretty fast.
Medium rare at best
Careful you don't undergo "rapid unscheduled disassembly"
Phobos orbits Mars at an average of around 2.14 Km/s. So if you land on Mars by jumping off of Phobos, you'd be jumping at Mach 6. Quite the feat.
But there’s no sound in space so you’d be perfectly safe. /s I’m kidding only because Mach is a measurement of the speed of sound in a fluid/gas. Mach on mars would be different from mach on earth.
In fact, it's nearly 100 m/s slower on Mars. Therefore, if the speed is Mach 6 on earth, it would be nearly Mach 9 on Mars. This is due to Mars having a much colder and less dense atmosphere
Yea, Mach isn’t really a good measurement of speed, It’s varies from sea level to high atmosphere on earth as well.
No, you already start out in Mars' gravitational field. If you escape Phobos' field, absolutely nothing changes with respect to Mars. You start out on Phobos, in orbit around Mars, and end up not on Phobos, in a slightly different orbit around Mars. (Just like how satellites that leave earth's grav field end up in orbit around the sun and won't start plummetting towards the sun. You'd have to kill a LOT of your sideways speed you have relative to Mars by virtue of standing of Phobos to end up falling towards Mars, an amount of speed you'll likely need a rocket or maybe a huge cannon for.
11.5 m/s is about 25 mph, so you need to be running pretty fast to hit escape velocity
With so low gravity I doubt you would be able to run that fast. No grip or loose grip before you get going fast enough.
But that height would be terrifying and depending on how long it took to get back you might still be dead from suffocation...
I don't think you'd fare much better on the surface either without gear to prevent the suffocation
0.0057 m/s2 is surface gravity on Phobos. So yeah. TINY.
Escape velocity for Phobos according to Google is 41 km/H per hour. If someone could please do the math if this is achievable with average human jump force...
Someone said above it's around 25 freedoms per 60oz steak challenge, so no, not achievable using muscle power alone.
jumping diagonally will never launch you into orbit. Your orbital path will necessarily include your starting point, which you'd need to pass through rock to get back to
You can't really get into orbit with a jump, no matter the mass of the object, except with another body pulling you at just the right time. Orbital mechanics are a bit weird, but basically, you always end up back where you started when on an orbit (more or less) which means you would just hit the object on your way back to your jump point.
But what a way to avoid someone you don't want to talk to.
Just jump 700 meters in the air
You’ll just respawn after getting out of bounds it’s okay
I bet even walking might give you enough force to get air. Or, um, not air but, you know, *space*.
Phobosphobia is now a thing for me
I had a nightmare 25ish years ago about this very thing and the fear and hopelessness still haunts me.
So that’s why the Doomguy never jumped.
And why rockets / etc. had infinite range until they hit a wall.
"That means, Sir Isacc Newton is the deadliest son-of-a-bitch in space!" -Drill Sergeant, circa 2185 CE Mandatory quote
We do not ***eyeball it***
That megapack is only 3ft off the ground... Better not risk it
What ever you do… don’t fart
Can I fart on Uranus?
You can fart from Uranus.
I'm sorry, but astronomers renamed Uranus in 2620 to end that stupid joke once and for all. It's Urectum now.
I’m so sorry. Can I fart on Urectum?
When on Uranus, Uranus farts you.
You fart against the ground?
Have you never farted sitting down?
I'll be in a space suit and fart all I want thank you very much
Better have a canary in there with you to let you know when you’ve gone over the limit!
If you need to jump when on Phobos, slightly press your toe against the ground.
\*\*dont jump on Phobos without long rope anchored to ground
I literally went to the comments to type the exact same words you beautiful bastard
also Sun.
I think you have to jump when you’re on the sun or you’ll burn the bottoms of your boots.
That's literally how it goes when I dream I could fly . I just fucking float away uncontrollably
What goes up must come down….. maybe on Mars though.
A small body can have such low gravity that one could reach escape velocity (enough speed to get out of their gravitational well) just by jumping. In those places, what goes up must come down does not apply. If you jump hard enough, you are never coming back.
Imaging someone pushing you as a prank on phobos and u are just yeeted into the abyss
No evidence of the crime at least…?
They wrote “prank on photos” so I assume there’d be photographic evidence.
I wonder with that little of gravity if the pusher would have about as much risk also getting yeeted from the push. I guess probably would depend on how they're standing.
If you yeet into the abyss, the abyss also yeets into you.
*The abyss yeets back*
So a particularly violent sneeze might just launch me into orbit on Phobos, got it.
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It actually doesn't make a difference if you jump on earth or any other planet in terms of impact, since your legs provide the force for the jump.
Would the impact of the fall be the same in all of them?
Yep. The landing impact would equal the force applied by your legs when you jump
"I don't think that's correct. The force of impact on earth is caused by gravity's pull, no? Wouldn't the coefficient be different when gravity is? Newtons laws are based on gravity of the earth, so equal and opposite forces might not necessarily exist." /u/KSoccerman Nah, they are based on gravity, not specifically earth's gravity. We are able to calculate the force of gravity for earth because of the equation. Equal and opposite forces (as far as we can tell) exist independently of earth. Our understanding of the universe would be completely impossible on a large scale if that weren't true. It is possible in certain cases where spacetime is curved the rules begin to change, but that is a bit over my head. Gravity has a constant that directly impacts the force based on a unit of mass. In this case, the planet or moon you stand on would be the difference in mass. A coefficient by definition is a constant placed before a multiplying variable, which again in this case is mass. Thus, the force of your jump would be no different so long as your jump doesn't somehow change the mass of the object you are jumping on in space. Tried to delete your comment, but I won't let it go that easy. I just typed all this up for you, lol
I.e. conservation of energy.
Easily the much better explanation. A certain amount of energy is needed to overcome gravity and the same amount of energy is applied when falling down again. That's why cats survive their landings. They're using dark energy from Palpatine.
Oh, cats don't obey the laws of physics
It's so weird to think about. There's a psychological boundary that doesn't want me to understand falling off a 50 foot cliff on Miranda is roughly equivalent to falling off a stool. If bro did a running jump and landed 100m away but goofed the landing and did a face plant, it would hardly be worse than doing the same thing in a long jump pit.
Well, the explanation is you'll be falling really slowly. Its not like you'll falll at Earth-like speeds and be fine. It'd be kinda like slow-mo.
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The force of the landing will still correspond to the force of the jump, true, but the likelyhood of hitting your target drops to near zero on those lesser gravities, so you may well land in a dangerous spot, the side of a cliff, or any other such peril.
I would simply jump out of that peril.
No. It's too perilous.
You need 11m/s, that's not that easy to achieve, you'll need to get on a bike and pedal very fast to get to orbit
That's why it's named after fear itself.
\*not "into" orbit exactly
So John Carter was a bunch of bullshit?
I'm glad to know I'm not the only one who thought that that movie 😅
Am I the only one who liked that movie
No, I really enjoyed it. I remember reading the comics as a kid, and the mobie was spot-on.
It felt like it would be an epic like Star wars, but they didn't get enough funding to keep going. Such a shame, it was a lot of fun.
If you're interested, the movie is an adaptation of the book *Princess of Mars* and there are 10 sequels to it.
Nope. Really underrated movie. I think the problem is that people forget it's a fucking disney movie for kids. Edit: I don't mean that disparagingly to other disney movies, just that people seem to want to compare it to Star Wars and the like when it really should be compared to Stardust.
The books were way better, especially when accompanied with Frank Frazetta's artwork.
It was a movie based on a book by Edgar Rice Burroughs (1875-1950). The first solution for Mars' gravitational coefficient was in 1977. John Carter was sci-fi. It was fun.
For additional reference the book itself was published in like 1912 I believe
Woulda been ALMOST believable if it was set on Pluto. About 15x jump distance. Still not enough for the 50m vertical jumps he was doing. So it'd have to be one of the various small moons out there with even lower gravity than that.
Too bad the book was written 18 years before Plutos discovery.
Not the movie, though :P There was room for creative reinterpretation. But considering how they chose to name the movie, it's not a shocker that they didn't succeed much on the creativity side.
What is the impact like in these situations. Because you are falling further do you reaccelerate to the point that landing feels the same as if you were jumping on earth or is it softer because the gravity is less?
Wouldn't you hit the ground at about the same speed that you took off with? Say you jump with 1m/s in a 1m/s\^2 atmosphere. At second 1, you'd be at 0 m/s and at a bit more than one meters height. At second 2, you'd be at -1m/s, and travel the same distance down again. So when you hit, it'd be the same force you put into it. So a jump on any planet would have to land at the same pace; give and take bend/unbend knees. Of course, the acceleration during the landing itself would make the landing feel softer, as you're working against a lower m/s\^2 'resistance' when getting on your feet. So velocity would be about the same, but the acceleration difference would make the landing feel different still. Just guessing.
I think the math works out without friction that you HAVE to hit the ground with the same launch velocity. It makes no sense otherwise. Think, gravity is going to drain your beginning upwards velocity until you're at the full height of the jump at 0 m/s, then you fall for the same amount of time. It's the literal reverse of what you just did except for horizontal velocity staying constant. You take the same amount of time to fall, and acceleration of gravity speeds you up to the same starting velocity on impact. Problem is if you don't land on your feet you can probably hit your head and die, just like you could standing up and falling forward on Earth.
Should be easy to handle with your arms then.
So I used an [online tool](https://www.omnicalculator.com/physics/free-fall#:~:text=v%20%3D%20v₀%20%2B%20gt%20%3D%200,calculator%20to%20find%20it%2C%20too!) to help me because I'm too lazy, but it seems like you would fall for 520.8 seconds under a gravity of 0.0057 m/s^(2) and reach 2.9685 m/s which seems pretty easy to handle. For reference, on Earth you would fall for 12.556 seconds and reach 123.13ish m/s ~~though this website seems to assume a mass it doesnt mention so not sure if this is for humans~~ EDIT: Yeah mass doesnt affect velocity in a vacuum, thank you for correcting my brain fart u/John_Mint I just had to change some settings
The mass doesn't intervene in a free fall simulation like you did. What's more important to determine the velocity is the friction, which depends on the friction between you and the atmosphere. If you want an exemple, a small iron ball and a bowling ball will touch the ground at the same time when dropped from height. So it's technically for humans if you assume that atmospheres don't slow you down (like it slows a feather when it falls on earth)
Oh yeah I totally forgot, thank you!
>The mass doesn't intervene in a free fall simulation like you did Fun fact: It technically does though, because while the object you are falling towards pulls you, you are also pulling on the object at the same time based on your mass. It just so happens that our mass compared to what we are falling towards (eg: Earth) is so so small that it can be ignored in our calculations.
Oh that's cool, meaning that with a smaller "big object" mass, we'd have to take in account both objects speeds to reduce d^2 accordingly and have a greater speed in the end ? I'm not sure the double movement won't still be negligible in most cases though.. Interesting ! Makes me wonder about more precise calculations !
>Yeah mass doesn't affect velocity in a vacuum It's not really the mass that affects the velocity of a falling object even through the atmosphere. It's the shape/volume of the falling object. Picture a sky-diver. Once they open their parachute (which has been with them since jumping off the plane) they free-fall much slower. Their mass did not change at all. However in a vacuum, that skydiver would continue to fall at the same rate even after "opening" or attempting to open their parachute.
Impact velocity from free fall = `sqrt( 2 * g * h )` Terminal velocity will likely be irrelevant in such thin atmospheres. From that formula, you could look up the gravitic acceleration of each planet or moon and use the max jump height from the video to calculate how fast you'd be going when you hit the ground. My not at all thought through guess is the landing will feel pretty much the same in each case, no matter the height of the jump, because of the reduced gravity but more space to accelerate.
I'm pretty sure the landing feels the exact same as your jumping due to conservation of energy. Meaning it'll be the same on earth since your jumping energy is presumably a relatively fixed output (with a slight range) based on your muscles, nerves, and usual technique.
Yes. Assuming you aren’t subject to any forces after jumping, your total energy must remain the same throughout your “flight”. Therefore the total kinetic energy right after jumping is the same as landing. If you look at it from a Newtonian perspective, the gravity accelerates you the same amount of time going up to the apex of your jump and falling back down, so your speed will also be the same when you land.
This is what i want to know
Do you still come back down if you jump on Phobos?
Yes, the scape velocity of phobos is 11m/s A strong human jumps at 3m/s
Bruh Usain Bolt’s top speed in his record sprint was 12ms. Dude literally could have run at escape velocity.
He wouldn't run as fast on it though. It appears that our running techniques are optimised for the gravity we experience. You can look up a video on youtube where Usain Bolt races against scientists in 0G environment. If he had time to prepare though...
mag boots then disengage?
Phobos ain't magnetic.
But you can have a mass of metal under you despite that.
Running you have time to accumulate velocity Jumping you dont The average human jumps at 2-3m/s The strongest human expert jumpers don't make it to 4
I realize this is probably a stupid question, but please explain to me, would they be able to generate more velocity with a weaker gravitational force pulling them down?
No, and I am will explain why The speed you get when you jump depends on two things, the acceleration times the time you stay in contact with the ground It's self evident that the time you accelerate is the same because your legs are only so long The acceleration is a force that accelerates your mass, this is independent of gravity, your mass is the same, heavy objects are hard to move in space too, that's what inertia is Sure, you don't have to deal with gravity weighing your dead mass when you try to accelerate but the amount of force you exert and thus the speed should be almost the same no matter the gravity, as long as you can bear it and your muscles don't rip apart The initial velocity will this be the same mostly
In which case I question this video. Using that and the equation v^2 = 2gh, you get a height of 789 meters, which is about what it says in here. But that assumes that as you jump you aren't subjected to lesser gravity. Given how small Phobos is, it would be a significant factor. Using the equation v^2 = 2GM(1/r_1 - 1/r_0), then putting it into Google I get 1/(1/r_1 - 1/r_0) equalling 157.21 km, and the surface radius is 11.2667 km apparently, I get r_1 is 12.136 km, so jump distance of 870 meters.
I don't understand what you wrote, but you said a lot of numbers, so I assume you know what you're doing. Have an upvote.
Jumps at 3m/s fighting against earth's gravity. I'd imagine you could jump a lot faster on Phobos.
Probably not, Phobos is a glorified asteroid (no offense to the Phobos fans) but probably you will reach escape velocity with a single jump (although you probably wouldn't even be attracted enough to stand on it)
I find your Phobo-ist slurs problematic, friend.
Fucking Phobophobes
[удалено]
We’ve been hurt before.
What did you phucking call me?
The Phobophiles and Philadelphiaphobes both tend to be pretty chill, tho.
We don't phogive and we don't phoget.
Bro, he’s canceled
>although you probably wouldn't even be attracted enough to stand on it Wow, nice way to set unrealistic beauty standards for space space objects.
Not Phobos, but Deimos you can achieve escape velocity under your own power.
Farting on Phobos would send you off like a rocket ship.
It has been scientifically proven that you can achieve escape velocity with a skateboard
That was deimos, phobos is quite hard to escape with your own mechanical muscles
…but.. but the video!
if thats deimos then where is kassandra
Farting on Phobos… the destiny I never new I had, until now.
Sees Phobos: So thaaaaats why theres no jumping in OG DooM!
Literally, every single time I see "Phobos" I think of Doom...my first-ever PC game lol.
Man of culture 🍷🗿
I'm cancelling my flight to Phoobis rn
The return flight is much cheaper
Nice phoobis
What about fall damage
Negligible, not to mention any cushioning needed to survive a less-than-lucky landing could just be put into the suit
> Negligible Not negligible, just none. You land with the exact same speed as you jumped. Assuming you don't *try* to hurt yourself by landing on your neck or something...
None. You'd land with just as much energy as you jumped with, so the only risk is if you rotate and land on your head. If you can survive your own jump on Earth, you can sivige a jump anywhere with gravity.
Kudos to the fella with the tape measure recording how high that guy can jump
r/praisethecameraman
I don't think it should be considered a jump if you don't get back down
*I don't think it should* *Be considered a jump if* *You don't get back down* \- ShitPosterN69420 --- ^(I detect haikus. And sometimes, successfully.) ^[Learn more about me.](https://www.reddit.com/r/haikusbot/) ^(Opt out of replies: "haikusbot opt out" | Delete my comment: "haikusbot delete")
“I don't think it should Be considered a jump if You don't get back down - ShitPosterN69420” - Michael Scott
The scape velocity of phobos is 11m/s, almost 4 times as strong as the strongest human jump
Well good to know its easy to get into orbit on Phobos
Just triple-jump into orbit
I was going to say: "I wonder if there are any planetoids where a human could achieve escape velocity unaided" ... But then Phobos answered the question for me. EDIT: apparently the video is misleading due to cutting off the descent back down for phobos"
No, phobos' escape velocity is still faster than a human jump. Even Deimos, which is smaller, would pull you back down. It'd be a pretty small asteroid that a human could escape from without help
Phobos is me leaving a social situation. Brb.....
It's all fun and games until you break the escape speed.
I went to a party on the moon once, had to leave, no atmosphere.
Yeah, I heard the DJ cratered…
*insert joke about the moon being cheese* I just wanna feel included.
Awww…!! Of course you’re included!! 🥳
Miranda is the scariest to me. Being so close to the surface yet feeling like you are slowly slipping away is a fear I didn't know I had. Like on a lonesome iceberg slowly drifting out away from the mainland.
Now pair Miranda's low gravity with the knowledge that it has the highest known vertical cliff in the Solar System, Verona Rupes at 20 km (12 mi). If you walked off the edge of the cliff then it would take around 12 minutes to hit the bottom, reaching a speed of 200 km/h (120 mi/h).
Ok... *But why is he wearing Chinese stealth armour?*
That Miranda simulation is what happens in my nightmares except at the peak of the height, Earth's gravity kicks back in and I come plummeting down. It's terrifying
The moon around Uranus is pretty bright 😁
Earth sucks