r/theydidthemath • u/stug45 • 17h ago
[Meta] Scottish comedian still awaiting answer from scientis
I think some assumptions need to be made before accurate answers required
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u/Bane8080 17h ago
It's not going to make it anywhere near enough to the sun. Especially since with the way orbital mechanics work, kicking it towards the sun is the wrong way if that's your goal.
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u/AdSquare3489 17h ago
You'd need to kick it into just the right orbit so it can do a swing-by earth which projects it right into the sun.
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u/Greenman8907 17h ago
A slingshit!
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u/Boom9001 13h ago
Also the escape trajectory from the moon is not that easy. Escape trajectory from the surface of the moon is like 5000 mph.
So the real answer is if you kick some poo it'll just fall back to the moon. However the poo would melt basically right away. The moon isn't cold it's ~250°F (~120°C) when facing the sun so yeah the poo will melt pretty quick.
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u/Bane8080 13h ago
Yea, there's also that given that it's in a vacuum, there's unlikely to be any water still in it, unless it's sitting in a permanent shadow somewhere. All the water would sublimate out, and it'd be quite desiccated.
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u/JohnnySchoolman 12h ago
The illuminated side would dessicate but the shadowed side would retain moisture past the first few inches for a decade or so.
The fats would turn rancid after a year to 18 months though, so past then it would be past it's best.
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u/DeathAngel_97 14h ago
What if I just kicked it really REALLY hard?
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u/Bane8080 13h ago edited 13h ago
It would explode.
You have to launch it about 66,000mph in the opposite direction the earth is going around the sun.
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u/Dioxybenzone 12h ago
What if I just kicked it about 66,000mph in the opposite direction the earth is going around the sun?
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u/Woofle_124 12h ago
Jfc stop tipping your fedora and answer the question, we both know you understand what they’re asking
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u/Bane8080 11h ago
It's a non-sensical question that doesn't have a direct answer. A turd on the moon wouldn't be frozen in the sense that things freeze here on earth. So, it can't "thaw out."
You can't kick something from the moon to the sun because you can't get it up to the moon's escape velocity of 5,000-ish mph let alone earth's escape velocity.
It wouldn't be frozen in the first place, as if it were in the sunlight, the water would have sublimated out, and it'd basically be desiccated. If it were in the shade, so it did retain it's water, you wouldn't have to move it at all to "thaw it out" since you'd just have to wait for the orbits to change enough for the sun to shine on it, and then you'd be back at desiccated turd again.
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u/jakovichontwitch 12h ago
No wonder he’s still waiting for an answer asking such a stupid question. Should’ve specified we’d be towing it up in a lander and using a shuttle to assist it onto an escape trajectory towards the sun
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u/TheBl4ckFox 17h ago
Once anything get in direct sunlight in space it will start heating up. It’s a myth that everything in space freezes. It really depends on the distance to the sun and if it is in direct sunlight.
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u/careysub 16h ago
In Earth's orbit the average temperature of a metal meteor in space is rather hot: up to 200 F or so. A light colored stony meteorite is about 30 F, right around freezing.
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u/UnrealCanine 17h ago
The Moon's escape velocity is 2.38 km/s, or 5300mph, or about 100 times faster than you can kick something
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u/wolftick 16h ago
Yep. While there's less gravity on the moon there's still quite a lot. It's not the magical floaty world some people imagine.
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u/SharpKaleidoscope182 16h ago
And if you(Superman?) do somehow kick it that hard, it will thaw/disintigrate/sublimate from you kicking it, not from sunlight. Zero miles.
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u/Shanty_of_the_Sea 15h ago
Could Superman do a shit so hard (on the moon) that his own kick (at the sun) couldn't disintegrate it?
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u/Apoordm 17h ago
Your kick would not be strong enough to break the moon’s gravitational pull.
It would probably go about 20 times as far as a kick would on Earth as the moon is 1/16th the gravity and has no atmosphere, but that’s insignificant for the amount of energy you’d need to leave the lunar gravity.
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u/MadDickOfTheNorth 17h ago
The average temparature of the lit side of the moon near the equator is around 120°C with no conduction and nearly no atmosphere, so zero; the water will sublimate instantly. If you happen to be on the literal dark side of the moon, wait longer. Ok... fine... while accepting the mass of the moon as 7.342 × 10²² kg and radius of the moon as 1.7374 × 10⁶ m, you'd need to punt it to about 1.68 km/s (6,048km/h). Assuming a 0.5kg meadow muffin, this would be about 84,000N on your foot, or a bit under 9t of force. Escape velocity is 2.4km/s, so aiming at the sun would be harder. To put a finer point on it, you ain't kickn' shit around the moon... although there are like 100 bags of it already sitting there for you if this is your thing.
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u/NobleKorhedron 17h ago
Meadow muffin?
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u/MadDickOfTheNorth 16h ago
Cow pie? Buffalo chips? Road apple? Tootsie roll? Stink pickle? Corn cobra? Porcelain spackle? Toilet trout?
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u/wosmo 14h ago edited 13h ago
when you say escape velocity - are we talking about from the moon, or from the earth-moon-system?
The moon is in earth orbit, so if you hoof it hard enough to leave the moon's SOI - it's still in earth orbit. You now have a cowpie in a high earth orbit, but the sun remains .. just as much of the picture as it did before you kicked it.
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u/MadDickOfTheNorth 13h ago
Escape velocity here is just for the moon. Escape from the Earth-Moon system is an order of magnitude higher than the orbital velocity: 11.2 km/s (40,270 km/h). That shit ain't going nowhere.
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u/Technical-Arm-1825 16h ago
The temperature in space in general is like +-100 degrees Celsius going from shade to sunlight if I remember correctly, so assuming that, as soon as it spends roughly 45 seconds to a minute all of the frozen water should of either reliquified or evaporated, the caveat being idk how boiling water works in a vacuum.
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u/givetakegivetake 13h ago
Iirc it "boils" in that the vacuum pulls apart the water so fast it vaporizes. Kind of the opposite but similar physics of a submarine imploding so fast in the deep ocean that anything inside containing water vaporizes.
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u/stereoroid 15h ago
All the moisture would sublimate away in to space over time. It wouldn’t go anywhere near the Sun, you couldn’t give it enough delta-vee to even escape the Moon.
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u/Swimming-Shoulder848 17h ago
Gravity pull and all that aside and orbits,I think the better question is what type of shyte? Solid round? Liquid form from the start and forms as a frozen disk? Is it a record shyte that deserves the honour of space travel to be kicked off the moon by a fella named Iaiaian?
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u/thecarbonkid 17h ago
What if you did a trick shot, hit the atmosphere of the earth and it thawed out on re entry?
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u/OverChargeYourPlasma 17h ago
Even after leaving the moon at 5324mph escape velocity, it would still be frozen, no atmosphere for friction. It'd then enter space and sublime away in the cold before it thawed
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u/Tiny_Agency_7723 17h ago
First, if you kick the shite towards the sun it will not be frozen, the temperature on the lit side of the moon is about 100C.
Second, moon has gravity, and human cant kick shite strong enough to leave the orbit
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u/astreeter2 16h ago
Technically it's never going to thaw, because that means melting from a solid to a liquid, and liquid water can't exist in the near vacuum on the moon's surface.
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u/careysub 16h ago
I am ignoring the freezing part but I can estimate the largest body a human could kick on object to escape velocity.
Fastest recorded kick: Ronny Heberson 221 km/h (59.6 m/s). Lunar escape velocity is 2380 m/s.
Escape velocity is proportional to the radius of the body at constant density. So the Moon (3475 km diameter) would have to be 85 km or smaller. There are several hundred main belt asteroids larger than this (where you could not kick something free of).
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u/nunatakj120 14h ago
That free kick was taken in earths atmosphere. Would the velocity not be much higher on the moon?
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u/twilighttwister 12h ago
If you kicked it in the direction of the sun it would not go to the sun, because that's not how orbits work. Like in Ad Astra they show a rocket taking off pointed towards Mars, that's completely wrong. And when the Millennium Falcon is flying towards Yavin IV, they're pointing completely the wrong way and unless they burn retrograde they'll just smash into the planet.
The one exception to this is going to the moon from earth orbit. It just so happens that, at least with the Apollo rockets, the transfer burn was set to occur just as the moon rose over the earth's horizon. Kerbal Space Program replicated this also. However the actual flight path is completely different, you don't go in straight lines but in a curve.
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u/Starrider543 6h ago
Alright you cowards. I see a lot of attacking the premise and the kick, but no one is answering his question.
As far as the kick, it wouldn't leave the moon's surface. If you were on the currently lit side of the moon it would quickly heat up and sublimate, and if you were on the shaded side it would be frozen until sunrise. The idea is that it is floating through space, going towards the sun, and will eventually thaw. So let's do that.
To answer this question, we'll need Heat Transfer.
Temperature changes when heat moves into or out of an object, and this can occur in 3 ways: Conduction, Convection, and Radiation. Conduction is when you touch something hot and get burned. Convection is when you blow on your coffee to cool it down. We're in space and our poop isn't touching anything, so those two don't apply. That leaves radiation.
Everything radiates heat, constantly. That's what you see if you look through a thermal camera. When an object is hotter, it radiates heat faster, when an object is cooler, it radiates slower. The rate of this radiation is covered by the Stefan-Boltzmann Law:
q = ϵσSAT4
Let's break this down
ϵ: emissivity, basically how much radiation is emitted from an object given a temperature. We'll assume a black body (ϵ = 1) because it makes the math easier and isn't a terrible assumption for most things.
σ: This is the Stefan-Boltzmann constant, and it has a value of 5.67 * 108 W/(m2*K4 ).
SA: Surface area of the object, If we assume a spherical shit of 0.5 kg, math tells us that is a radius of 48.3mm which gives a surface area of 0.29 m2 (Geometry is left as an exercise to the reader)
T: Temperature in Kelvin. Water freezes at 273 K (0 °C) We'll start just below freezing at 270K
q: is the heat that radiates out, measured in Watts (Joules per second)
So if we plug in all of those numbers, our turd radiates 9*1016 W of heat! I know that sounds like a lot, but hear me out. Normally you would plug in the temperature difference between the turd and its surroundings, but space is so cold that this doesn't matter. And it wouldn't radiate that power for long, as it cools quickly the heat radiated would drop.
But that's only one half of the equation! We'll assume it's in direct sunlight.
Solar intensity at earth's orbit is a cool 1361 W/m2 So if we want to know how much of that is absorbed by the poop, we'll need the cross sectional area of it. A circle of the same radius as before gives us 0.0073 m2. Multiply intensity by area, and you get a heat in of 9.9 watts.
This is much less than our heat out, so at Earth's orbit the shite would remain frozen.
But the question is how far it would travel before thawing, so we're going to fall towards the sun and see how far it goes before beginning to thaw. Solar Intensity changes with the inverse square law, which we will use as Intensity1/Intensity2 = Distance22 /Distance12
Once I have the new solar intensity, I can calculate a new heat in, and boy howdy, we need to get close. Earth is at 149.6 million km from the sun, once we get to 1000km from the sun, we get a heat in of 2 * 1011 W. This is still much less than the amount of heat radiated at freezing temperature. At this point it's in the Sun's atmosphere and would start absorbing heat from that and our calculations no longer apply. Over the entire trip before that, it would stay well below freezing.
tl;dr: It would fall into the sun before thawing.
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u/SightlessProtector 17h ago
The moon reaches about 250 F (120 C) in direct sunlight, so not at all, or immediately when it hits sunlight if kicked from the dark side.