One: You cant use newton’s laws to handle relativistic phenomena. And two, if your leg has a mass of 2kg, 1.1×10^10 J of kinetic energy would require your leg to be moving at about 150 km/second not faster than the speed of light.
launch him anyway
Submitted 8 months ago by fossilesque@mander.xyz to science_memes@mander.xyz
https://mander.xyz/pictrs/image/d7961040-0f35-4e6b-b7f0-acf24d58e2e5.jpeg
Comments
xkforce@lemmy.world 8 months ago
wahming@monyet.cc 8 months ago
Pretty sure you’re generating twice as much energy as needed, the required speed is only about 106km/s
dQw4w9WgXcQ@lemm.ee 8 months ago
Besides, if you really needed those kinds of speed, you’d obviously have to calculate with relativistic formulas. Energy is asymptotical at the speed of light.
xkforce@lemmy.world 8 months ago
150 km/sec is not relativistic and even if it were, at no point would that object need to or could exceed the speed of light. Its a fundamental limit that cant be broken.
asuka@sh.itjust.works 8 months ago
Yeah, their answer just intuitively seems very wrong. The ratio between the kid’s weight and your foot’s weight should be equal to the ratio between their final speed and your foot’s required speed. Ridiculous.
BigBenis@lemmy.world 8 months ago
Not to mention the fusion reaction triggered by a FTL foot connecting with said child’s backside would annihilate both parent and child immediately.
zalgotext@sh.itjust.works 8 months ago
There would be a crater where the parent and child were, and buildings would be leveled by the resulting shockwave.
sharkfucker420@lemmy.ml 8 months ago
Thats inefficient, you dont need to cancel the angular momentum as there was no time limit on how long it takes rhe child to enter the sun and there also was not a specified required trajectory. The child can just spiral into the sun
Faust@feddit.de 8 months ago
There are no spiral orbits. Canceling the forward motion is exactly what you need to do, to bring down the next periapsis to 0. Now, you can go with a periapsis of about half a million km, because the sun is pretty big, but that is not a significant difference. Getting anywhere near the sun, is the hard part.
sushibowl@feddit.nl 8 months ago
It’s much more efficient in this case to do a bi-elliptic transfer: raise apoapsis very far out, then lower your periapsis once you are at apoapsis. Wikipedia says you could do it with about 8.8 km/s delta v. Versus 24 or so for a basic Hohman transfer (still a bit better than 30)
Sadly the bi-elliptic transfer requires two burns so you can’t do it with a kick.
milicent_bystandr@lemm.ee 8 months ago
Right, I wanted to ask: is that actually the minimum energy to make the child reach the sun? What’s the minimum energy to launch something so it reaches the sun?
KISSmyOS@feddit.de 8 months ago
The minimum would be something like punting your kid to the orbit of Venus for a gravity assist that takes it to one of the outer planets where another gravity assist can push it to the edge of the solar system.
Out there, the angular momentum of the orbiting child will be very low and can be canceled out by a small thrust.
The child will then fall back into the sun. But this requires remote controlled thrusters strapped to the child. And a life support system if you want your child to actually die by burning in the sun. And then, the child will be well into their teens by the time they reach it.
Cutecity@hexbear.net 8 months ago
I don’t think you can achieve a spiral orbit in an area with so little friction, mostly devoid of dust and gas, else the earth would be on one of those too…
Turun@feddit.de 8 months ago
Right, and what force is acting on the child to make it deviate from a circular orbit into a spiral one?
EddoWagt@feddit.nl 8 months ago
You could use a gravity assist from another planet
PotatoesFall@discuss.tchncs.de 8 months ago
Okay the math is obviously wrong, and it’s not even answering the question.
The question was, how much force. If punting the kid involves a kick, let’s say the foot makes contact with the kid for about 25 cm. Then the force required over this distance is on average 45 GN.
This is equivalent to the child experiencing roughly 180,000,000 G
Sentient@sh.itjust.works 8 months ago
Faster than the speed of light.
Lol that is some shit maths for a checks note astrophysicist i am shit at maths and even i know its wrong.
JustAnotherRando@lemmy.world 8 months ago
Are you arguing that 1.12 billion m/s is NOT faster than the speed of light, or are you arguing that the speed required by the kick is not 1.12 billion m/s? Because if it’s the former, the speed of light in a vacuum is 300 million m/s (to 3 significant figures), or less than one third of that kick speed. If you’re arguing the latter, I don’t feel like checking all of the calculations this early in the morning.
gandalf_der_12te@feddit.de 8 months ago
Velocity addition and conservation of momentum don’t work like that if the speeds are close to the speed of light.
For further details, please check out special relativity theory.
Kaput@lemmy.world 8 months ago
The reliable way to get an answer from the internet is to provide the wrong answer, then someone will come and correct you, providing the answer you seek. (Xkcd, probably maybe?)
meyotch@slrpnk.net 8 months ago
This is a proven fact. Expose yourself early and often, that’s my motto.
lugal@sopuli.xyz 8 months ago
Or just get another child. I know they don’t grow on trees but I’m sure they grow somewhere
psycho_driver@lemmy.world 8 months ago
The fiery pits of hell
Sabre363@sh.itjust.works 8 months ago
That not a nice name for the uterus
ignirtoq@fedia.io 8 months ago
Cut the extra inch off the long side to get a 4" square, then cut the remaining 1" x 4" piece into 4 1" squares. The boy never said the squares had to be the same size.
If the triangles have already been cut, it's a peanut butter sandwich: use peanut butter on the edges to glue it back together and cut the squares. The child gave you a challenge, think outside the box!
FuglyDuck@lemmy.world 8 months ago
starman2112@sh.itjust.works 8 months ago
If the triangles have already been cut, the kid gets a brand new sandwich fully intact, crust and all, and a knife. Let’s see you cut this sandwich better than I can brayxtyn
KISSmyOS@feddit.de 8 months ago
If that’s the child’s name, you have no one to blame but yourself, and are probably underqualified for handling a butter knife.
ulterno@lemmy.kde.social 8 months ago
Parent’s already thinking outside the biosphere.
FiniteBanjo@lemmy.today 8 months ago
Why cancel the angular momentum when we can utilize it?
Strawberry@lemmy.blahaj.zone 8 months ago
i may be mistaken but I don’t think it can be utilized to descend toward the sun
FiniteBanjo@lemmy.today 8 months ago
It’s the foundational principle of “Launch Windows.” Because the earth rotates the sun and also spins on an axis, we can launch at a time of day that gives us time to accelerate and then leave earth orbit in the direction of earth’s orbit around the sun with minimum amount of energy required. The majority of energy used is simply to escape Earth orbit. Once orbiting the sun, comparatively very little energy would be required to approach it utilizing it’s own gravity.
During Perihelion the sun is 147100632 KM away, as the distance from the sun is not constant for earth’s orbit.
BluesF@lemmy.world 8 months ago
Still this approach seems wasteful. Just making it sufficiently far from the surface travelling in the right direction should be enough… As long as you aren’t in a rush.
Kolanaki@yiffit.net 8 months ago
Why does it have to be a kick? Could I generate that force with a car?
HiddenLayer5@lemmy.ml 8 months ago
“Then you’ll be fired.”
“Fine!”
“Out of a canon into the sun.”
nifty@lemmy.world 8 months ago
Do. It.
siderealyear@lemmy.world 8 months ago
I think I scared my wife and kid I laughed so hard.
Bishma@discuss.tchncs.de 8 months ago
Surely they’re not so mad that they need to kick their child into the sun. I’m sure a low solar orbit would suffice.
AtmaJnana@lemmy.world 8 months ago
Always funny to see the memes show up here a week after I get sent them from friends who still use Facebook and Fark.
fossilesque@mander.xyz 8 months ago
The circle of memes
Anticorp@lemmy.world 8 months ago
Then how does Superman throw people into the sun? I think this mathematician needs to read a few comic books.
Omega_Haxors@lemmy.ml 8 months ago
It’s your own damn fault for not asking first what they wanted.
Evilsandwichman@hexbear.net 8 months ago
Can’t they use a ladder?
strawberry@kbin.run 8 months ago
or
heavier foot
tape + brick
Jerkface@lemmy.world 8 months ago
I wanted a least squares solution, but all I got were these right triangles!
Iron_Lynx@lemmy.world 8 months ago
What if you could kick him into space, making an orbital transfer to Jupiter, from which the kid gets a gravity assist that bounces the kid into a more elliptical orbit that then sends him into the sun?
JusticeForPorygon@lemmy.world 8 months ago
I was really hoping he was going to convert the amount of energy needed into calories, then from calories into peanuts butter sandwiches
psycho_driver@lemmy.world 8 months ago
1 calorie is interchangeable for approximately 4.1868 joules. Therefore, assuming his math was correct (many say it was not), I’m coming up with 2,687,016,337 calories needed. According to google, sourcing from the USDA, your average peanut butter sandwich has 384 calories. Therefore you’d be expending approximately 6,997,438 peanut butter sandwiches worth of energy to punt the ungrateful little shit into the sun.
wanderer@lemmy.world 8 months ago
In the US, the calorie used in nutrition data is actually a kilo calorie.
cyberic@discuss.tchncs.de 8 months ago
384 cal or 384 kcal per sandwich?
Pandoras_Can_Opener@mander.xyz 8 months ago
Same.