/sci/ - Science & Math

FTL communication

>>8300245
Come on, that doesn't count... still chuckled, though

>>8300250
Its the best one

>>8300381
>The opposite end of the rod responds to movement immediately

Well memed, friend

>>8300381
Whoa, hey, can we talk about this for a second? I know that it wouldn't work even if I was remotely possible/practical, just want to go over why.

It would compress as the signal travelled along it, right? What would be the signal speed? Same as in an electric current?

>>8300411
the rod would bend and i think the signal would travel at the speed of sound max

>>8300413
Would it be some kind of function of the speed at which it was jiggled, or would it be independent of that? Would it decay?

>>8300415
i think we need an actual physicist in here

>>8300418
Sorry to derail, just got excited. Never thought about this before.

>>8300415
>Would it decay?
That's an interesting thought. Intuitively, I think it would make sense, given that it's pretty much a sound wave moving through a dense medium.

I'm probably a retard, though. I can't into physics.

>>8300415
>>8300418
>>8300422
the jiggle travels down the rod as a longitudinal wave at the speed of sound, max, regardless of how hard you jiggle the rod
if you try to jiggle the rod faster than the speed of sound in the rod, the rod will break

the rod is only 'rigid' when talking with distances short enough that a sound wave traveling through the material can cross said distance in a negligible amount of time. In this sense, air is basically rigid when dealing with incredibly small distances, because the speed of sound in air is 343m/s.

Even if you built the most rigid rod in the universe, the speed of sound in the rod could not exceed the speed of light in a vacuum, because the sound wave traveling through the rod does so through layers of particles colliding with each other and those particles cannot move faster than the speed of light.

Source: We used to have this thread all the time three years ago and I have a good fucking memory.

>>8300413
>the rod would bend
What? It's a traverse wave, motherfucker.

>>8300438
longitudinal*

sheeeeeeeiiittttt

>>8300437
>We used to have this thread all the time three years ago
all me haha

>>8300415
>Would it be some kind of function of the speed at which it was jiggled
No, that would be the phase speed (or phase velocity), which isn't relevant to how fast the information travel.

The wavefront will propagate at the group speed, which is the speed of sound. I may be constant or a function of your perturbation frequency spectrum depending on the dispersion relation of the material the rod is made of.

You don't need an "actual physicist" to tell you that, it's all part of undergrad wave mechanics.

>>8300442
>undergrad wave mechanics
I learned that in physics class when i was 12
what fucking education are you paying for?

>>8300447
ah yes the famous middle school wave mechanics classes

Hey thanks, /sci/, learning is the shit!

>>8300452
>physics teacher has a spring
>creates compression and rarefaction in it
>"this is a longitudinal wave. this is how sound works. it's also how seismic waves work. these are not to be confused with transverse waves"
>proceeds to use a rope to make transverse waves
>made me memorize some algebra about nodes or whatever
>get a C on the test because i stayed up all night playing vidya
8th grade, nigga
i'm guessing you grew up in the middle of nowhere

>>8300466
What does any of it has to do with deriving the speed of a wave packet according to the dispersion relation of your material?

>>8300471
in 9th grade we calculated the speed of light in the universe
and then next week we calculated the speed of sound in a spring based on it's hooke constant, and there was something about 'if you compress or stretch the spring too much you fuck it up forever so there's a limit to how fast you can actually actuate the end of the spring to send a sound wave'
I didn't turn in the lab because i was still playing video games all night
it doesn't take a genius to tell you that the critical point where the spring gets fucked up is related to the hooke constant and the dispersion relation of the material
and also it doesn't take a genius to tell you that light traveling through a vacuum is always going to beat a longitudinal wave in a spring in a fucking race

>>8300490
>young enough to remember 9th grade

Mods...

>>8300505
>implying you wouldn't need to generate a space hadouken to decelerate from lightspeed to 0

>>8300490
But how did you handle the triple integrals?

>>8300373
I wonder if theirs actually a strong enough magnet to pull a 120 poundish human and a small plastic cart?

>>8300525
Wait... what's wrong with this?

>>8300548
Corners still exist

>>8300548
it's not an axiom, thats the problem

>>8300548
limit of the length isn't the length of the limit

>>8300568
kek r is between centers of mass and thus will never be zero for different objects

Checkmate, energy conservation fags.

Let's see how retarded /sci/ really is.

>>8300512
>wanting to decelerate
no brakes on this train motherfucker

>>8300575
what if you get a ball and a parabola? because the parabolas center of mass exists outside the body, the center of mass of the ball can be laid precisely over that of the parabola

>>8300575
>>8300639
brainlet BTFO
freshmen on suicide watch

>>8300639
if you are inside the object so to say it has to be dealt with differently since the effect isnt comparable to a point masss

>>8300652
for balls it is. are you sure you know about this?

>>8300568
that would be undefined not infinity

>>8300654
what of balls

>>8300629
Right side is pulled down, so less buoyant, negating higher buoyancy of left

>>8300656
the effect of a quantity that decreases quadratically with distance (like gravity) from a point outside a sphere (like any point in the parabola) upon the sphere is equal to what it would be if the sphere was actually a point

>>8300660
>Right side is pulled down
why?

>>8300661
you cant accurately model the parabola as a point the sphere is open season this is for the same reason the equation would misrepresent the nature of the gravitational force exerted by a dyson sphere on an object inside itself if it were reduced to a point but be accurate for an object outside of it

>>8300548
a+b > sqrt(a^2+b^2)

>>8300663
Not him, but I assume he means due to gravity pulling down on the lids.

>>8300685
same thing on the left side

>>8300685
Wait, disregard, had a brain fart, both sides have lids

>>8300411
The movement from the rod would turb into a wave that woukd travel along the rod.

It woukd loose force eventually because of the same resistance within the material.

If it was a perfect material or whatever the wave would travel across the whoke rod and it coukd be used to send a signal, but the speed of the wave is given by the cgaracteristics of the rod, hardness and specific frequency. I'm not that into specific frwquencies and all that but i doubt that a material could be hard enough to transport vibration at the speed of light or higher

>>8300663
>>8300686
>>8300688

I mean the right is pulled down towards the stick, making it denser and so less buoyant

>>8301221
>the worry when I can't figure this one out

>>8300531
The strength of the magnet is not the problem. That whole concept is bullshit by default

>>8301245
But the left is pulled down away from the stick, making it more buoyant.

>>8300490
Ignorance is Bliss

>>8301252
Please...

>>8300575
>>8300639
>>8300652
F=(Gmm)/r^2 only works when r>>R

This is baby stuff...

>>8301252
step 5 is intentionally misleading
the 3*$9 subtracts the $3 returned to the kids, not the $2 kept by the friend; so adding $2 is an erroneous step

you can't solve the problem within the framework it gives you b/c it's flawed.

>>8301252
Kids pay you $30, you have $30. You give $5 to your friend, you have $25. The $5 is distributed. Still $30.

Kids pay you $9*3=$27, you have $27. You give $2 to your friend, you have $25.

Relax bro.

>>8300629
>no answer
I consider energy conservation disproven
where is my Nobel prize bitches?

>>8301488
Write up the paper, faggot.

>inb4 "hurrr where's muh funding?!"

>>8301539
I think I can send it to PRL in its current form

>>8300548
when applying infinitesimal approximations, the error should be a higher-order infinitesimal than the approximation, i.e. the ratio of error to approximating infinitesimal should tend to zero. In this case the limit of said ratio at a point on the circle where the tangent to the circle has an angle phi with the horizontal is sin phi +cos phi - 1, which is generally nonzero, so the error is an infinitesimal of the same order as the approximation.

>>8301657
there are way more efficient solar thermal generators/techniques than that

>>8300552
>>8300525
Considering that circles don't exist in nature, it is more correct than 3.14.

>>8301657
>free energy

>requires energy from the sun

KYS

>>8300238
Isn't this actually true, you just need an enormous amount of light? Like the kind coming from an evaporating, proton sized black hole?

>>8301731
It's no different than an ion thruster, yet it's mocked while ion thrusters are taken seriously.

>>8301252
its 3*9 - 2 for your bro

it's +2 for him

troll math

>>8301221
You're supposed to subtract the $2 to get $25 right?

>>8301687
5 billion years of sun energy
literally indistinguishable from free energy

>>8300238
You know how, if you leave a cold bottle of water out in the heat, condensation makes water appear around the bottle?

You can use this to create infinite beer. Just leave cold beer bottles out in the heat, more beer will condensate around the bottle ;^)

>>8301221
in the blackboard it should say

(30 - 5) + 3 + 2

or

27 from the kids
>you have 2 of those 27
>while your friend has 25
>the other 3 are owned by the kids

>>8300568
Wait, what's wrong with this?

ITT: people unironically """""correct""""" troll physics

>>8301687
are you retarded?

>>8302185
too bad that you'd need an absurdly big piece of paper for this to work

>>8300373
>mfw I took some time to get why it wouldn't work

>>8302201
lolno

you can only fold a paper 8 times

>>8302201
Also paper apparently explodes if you fold it too much.

>>8302208
nice https://www.youtube.com/watch?v=KuG_CeEZV6w

>>8302214
Can anyone explain why this happens?

>>8300525
>Problem Archimedes?

I died

>>8302217
because when you fold it, something exponentially

>>8300593
Fuck, I can't stop laughing at this one.

>>8302217
Because a ton of energy and pressure is being internalized within the folding paper, and the paper can't hold all of the energy within, so it just lets it all out (explosion). This is just a brainlet's guess.

>>8302207
>>8302208
you're telling me that a 1000x1000km(for example) sheet of paper with 0.1 mm thickness wont fold more than 7 times? that doesn't sound right

>>8302258
world record is 13

>>8300373

Isn't this just the Hyperloop?

>>8302263
but what size of paper did they use?

>>8302271
30km

>>8302258
I'm pretty sure it will, but that is an edge case. Regardless however, I do imagine that it would still eventually reach the point where you can no longer fold it without catastrophic failure.

>>8302272
>>8302275

i'm really shit at math, is there a function to calculate how much paper one would need to be able to fold it n times?

>>8302279
I would assume as much. I am ill-equipped to do such a thing though.

>>8302279
>>8302303
[math]f(x)=4.99998x-34.9997[/math]
Where [math]x[/math] is the number of folds and [math]f(x)[/math] is the size of one side of the paper in kilometers.

:^)

>>8300238
I remember an extremely elaborate one with bouyancy, water and some ping pong balls creating infinite energy by having a sort of belt of ping pong balls connected by a string. One side of the belt was engulfed by a sort of tube filled with water and a seal at the bottom that would never let out water. The ping pong balls would enter this, float to the top because buoyancy and somehow this would power the belt and create infinite energy.

>>8301657
I remember having huge 200+ reply threads on /sci/ trying to prove and prod this one true or false

same shit with the plane on the gigantic treadmill

>>8302275
>>8302303
>>8302348
https://en.wikipedia.org/wiki/Britney_Gallivan#Paper_folding_theorem

>>8300548
consider the fact that you could impose a different shape than a square of perimeter four onto the outside of the circle. then repeat the process and the value of pi is different, no?

>>8300629
can someone please explain to me why this wouldn't work

>>8300381
In the future we communicate with space cable

> service Dow due to atmospheric conditions
> cable drifted into a sun

>>8300437
How fast does electricity travel?

>>8300245
lel

yeah reddit got ahold of coolface somewhere along thte line and fucked it up for everybody. . Shame.

>>8301687
>free energy
>energy you don't pay the electric company for

Shit, ikr, I'm almost out of sunbucks.

>>8303372
You have no fucking clue.

>>8300438
Minor imperfections in the rod will cause that longitudinal motion to be translated into sideways motion.

Once the sideways motion is there, the longitudinal motion will cause it to increase.

>>8303359
Water pressure is isotropic, meaning it's exerted in all directions. There isn't "more pressure" pushing down than pushing up.

>>8303376
What the fucking shit is this?

>>8301986
No matter how small, the ball is still not 0 units from your hand.

>>8300505
From the perspective of the troll, the light wouldn't build up though.

>>8303428
isn't that Ben "Empty my nine down the welfare line" Garrison's book?

>>8303376

>>8303376

Sweet mother of mercy what is this fresh hell? Sometimes I hate normies so god damn much.

>>8303376
https://www.youtube.com/watch?v=OSCiMbMVDLI

>>8301731
I don't see how. Photons have no mass and no acceleration. They can't push the car in any way, regardless of the amount of light.

>>8300593
That's easily the best one in the thread.

>>8301252
Each kid paid 9, the total is 27, and that includes the 2 they don't know he stole.

>>8301877
>>8302044
>>8303374
Dumbass it's not trolling physics if it's just a way to produce energy, any dolt can buy a solar panel and get "free energy".
The trolling comes from perpetual energy, which this isn't, because of the sun.

>>8301290
Step five pretends to give the "total" but it doesn't consider the $3 returned to the kids.

>>8303376
WHAT THE FUCK IS THIS BOOK?!?!?

>>8302258
Mythbusters folded a paper 11 times in 2007.

https://www.youtube.com/watch?v=kRAEBbotuIE

>>8303057
And then?

>>8303376
This looks legit educational.

>>8303370
not that other guy, but I'll do my best
anons feel free to point out if I fuck something up
assume a conductor which conducts a charge current (not necessarily electrons, let's just assume particles with charge q)
>let's say there's a potential difference U over the conductor, which has a resistance R
>current I
>surface of crossection is S
>length L
>volume V=S*L
>if there are n charge bearers per unit of volume, the total charge ΔQ that passes through a surface S in a timeframe Δt is: ΔQ = nV*q = nSL*q = nSvΔt*q
>this v is the drift velocity
>current I = ΔQ/Δt = nSq*v
>drift velocity v = I/(nSq)

3 assumptions were made here
>current density j is equal over the entire surface, a more general notation is v = j/(nq)
>there is only 1 type of charge bearer, differen bearers will all contribute to the total current but have different drift velocities
>velocity of the particles is constant

now, if we keep these assumptions a little longer and add three more:
>the electric field E in the conductor is homogenous
>the conductor follows Ohm's law
>same for Pouillet's law
then
>U = E*L
>I = j*S
>Ohm's law: R = U/L
>Pouillet's law: R = r*L/S
>r is the resistivity, which depends on the material and the temperature (and probably pressure as well)
>so U = E*L = (jS)*(rL/S) = jrL
>j =E/r =nq*v
>v = E/(rnq)

now I've saved this part for last because I don't know how to do vector notation on this site

it may or may not be clear from the math that current, current density and electric field all have the same orientation; current being positive charges by convention and positive charges experiencing force parallel to the electric field that applies it
the orientation of drift velocity's base vector is the same as that of current density and electric field, so the orientation of drift velocity depends on the only factor that can be either positive or negative: the charge q
so e.g. the vector v of an electron in a conductor is antiparallel to the vector E or j or I

>>8303559
neeerrrrddd

>>8303582
I'll give you this nice XRF spectrum (pic related) if you don't steal my lunch money again D:

>>8303586
Nice try geekazoid, gimme ur milk money or I pound you >:D

>>8303600
joke's on you, I'm lactose intolerant

>>8303604
We don't take kindly to intolerance here, Einstein.
*kicks you*
Phss nothing personnel

>>8303616
Look, I understand you hate nerds and geeks, which is your sovereign right. But did you have to make me think of Coldsteel the Edgehog again?

>>8300575
Very clearly not true.

https://www.youtube.com/watch?v=d4E5T9PSbo0

>>8303632
Sorry man,
<spoiler> nothing personnel </spoiler>
This joke would work better on a board with spoilers enabled, but just pretend, ok?

>>8303049

I remember being 4 and trying to fly by pulling up on my ankles. I know I was four because I just got fireman boots for my fourth birthday. I used to scream into a jar and cap it thinking it would trap my voice.

>>8302258
You can fold a roll of toilet paper in half a whole shitload of times

Problem is people keep trying to use paper that's both long and wide and folding it across two different alternating planes instead

>>8303447
No, I have his book he has a few pages about shit like this but those are not his pages. This is some academic bullshit.

>>8303656
Heh, toilet paper, shitload.

>>8300525
It technically wouldn't be a circle. Maybe a circle in the pixel sense, but not actually a perfect circle

>>8303553
3 orders of white rice

>>8303376
WTF, 4chan has become a subject of study

>>8300238
Ahh one of my favorite but fucked up comics by Reddit, just like with the original rage comics.

>>8300505
is this feasable? non-physicist here

>>8300411
The compression wave would move through the rod at the speed of sound through that material

>>8303049
>Hold each other

Gay.

>>8303676
I once had a compass with only half a needle.

>>8303496
light can actually exert force. look up solar sails.

>>8302207
Thats a meme pls kys

>>8303676
>those poles
God damn it, I lost

>>8303779
no

>>8303412
wrong, nigger
Do you even understand Archimedes theorem?

>>8303359
I'm still hoping someone on /sci/ can find the answer by himself. If nobody does I'll know this board truly is retarded.

>>8304925
People who waste their time explaining why perpetual motion machines don't work to below-average teenage boys on the internet are the real retards.

>>8304937
>below-average teenage boys

What did he mean by this?

>>8304937
cry harder, maybe you'll manage to forget you can't solve such a simple problem

>>8304925
>secretly hoping someone will solve it because he doesn't know

>>8304925
I'm not smart and this thread is nearly dead. Could you explain?

>>8305036
I solved it long ago in undergrad. I thought it was an interesting problem, so here is why I share it.
Of course, all I saw was meme answers on the levels of "durrr magnets lose power"

>>8305063
The reason it won't work is because you can't have a sliding wall that is also watertight. There will always be some leakage, and if there isn't leakage then the amount of friction between the walls is enough to cancel out all that free energy.

>>8305237
I hope you're trolling.

>>8305237
Alright then, wise guy. Now apply pic related to >>8300629 and explain why the resulting machine wouldn't work.

>>8305360
an accordion bag can't be waterproof because accordion bags have holes. Also what the fuck is an accordion bag? Do you mean accordion?

>>8305366
A bag with accordion folds on the sides

>>8305380
A bag full of gas will take the shape of a sphere, it doesn't matter how you attempt to fold the sides.

>>8300373
Before you read this I am not a smart man

This doesn't work because the magnet on the left pulls the magnet on the right so they equal out right? What if the magnet on the right was stronger?

>>8305384
Have you ever seen an accordion before? It retains its folds because it has metal frames supporting the folds. The metal frames will keep what you described from happening.

>>8305393
The accordion also has holes. Thats why it's compressible. If it's watertight and underwater and has a metal frame (kinda pushing the definition of "bag" there btw) then it will retain that shape.

>>8305392
Even if you are the strongest man in the world, the car wont move if you are sitting on it and push against the steering wheel

>>8305400
That's why I specified that it's a watertight accordion bag, meaning that it's like an accordion bag except watertight. This isn't a hard concept, anon.

>>8303779
Basically, yes (in a purely physical sense, never mind engineering feasibility).

If you're going that fast, the light would be blue-shifted and therefore much more energetic (same number of photons, but much higher energy for each). The pulse would also be length-contracted (photons would hit spread out over much less time, so the beam would be more intense as well).

You can also throw a marshmallow out of a relativistic space ship and it'll hit like a nuclear bomb.

>>8305403
Ahh okay thanks anon

>>8305408
you're right, it isn't hard. The watertight accordion bag will act no different from the frame standing alone without the air inside.

>>8305417
Correct. I'm glad you've finally got that figured out.

>>8300525
I followed up until the part where π = 24

>>8305360
kys

>>8304925
>>8303359
hint: gravity isn't the only force acting on the lid

>>8303651
When did your parents realize they were raising a prodigy?

>>8305443
Yes, that is part of the answer. There is another important element though.

You guys see the one where you use memes to break momentum conservation? Apparently a lot of normies actually bought into it.

>>8305415
I feel as if a marshmallow thrown into an atmosphere at relativistic speeds would just cause an enormous explosion in the atmosphere rather than hit the ground, but effects would still be felt on the ground (given a marshmallow's mass, it would release about 1 or 2 orders of magnitude less energy than the Tunguska event).
If you mean thrown at an atmosphere-less body, then without a doubt it would release a few megatons of energy.

Also, the comic isn't feasible because .99c isn't c, so even from a stationary reference frame (compared to the person in the ship), light would be travelling quicker than the ship. Never mind that from the ship's perspective, light is just moving like normal, at c.

>>8305392
Μagnets attract each other with equal force, just like you attract the earth with the same force as it attracts you.

Some of these seriously make me kek

>>8302379
Unless the wings are getting lift, the plane is going nowhere.

>>8303676
This might actually come true with magnetic monopolies

>>8305415
>>8303779
Light doesn't follow vector addition, faggots. The light will move away from you at speed c, no matter how fast you're going.
Do niggas on this board really not understand special relativity?

>>8305399
Assuming the ring structure is perfectly inline at all points with the center of gravity, has perfectly distributed weight, and assuming that it wouldn't break due to structural stress, wouldn't that work ?

>>8306253
that configuration is not stable

>>8306215
depends on the observer

does this count?

>>8300593
I don't get it

>>8306273
No it does not.
The person on earth sees a very fast-moving but time and length-dilated spaceship fire a laser that moves toward earth at c, AND moves away from the spaceship at c.
The person in the spaceship sees earth approaching time and length-dilated, at sees the laser fire toward earth at speed c and move away from the spaceship at speed c.
I cannot emphasis enough how basic this knowledge is.

>>8303553
Fap.

>>8306312
I wonder what fapping in 0g feels like.

>>8306405
You'd be spraying semen vapour out of your dick.

>>8303779
Yes.

>>8303376
SHUT IT DOWN THE GOYIM KNOW

>>8306474
Sounds hot

>>8300525
Please someone explain this

>>8306773
The corners still exist, and you actually do end up subtracting from the circumference (on certain subtractions), going from 4 to pie

>>8300525
shouldn't it be π=2?

>>8306104
this reminds me of a thread we had on /k/ a day or two ago when we were contemplating how to invade the international space station. since we're mostly American, this lead to how to destroy it. one person proposed releasing some ball bearings in the orbit of the ISS, going in the opposite direction.

now, sure, that would definitely annihilate the station, but it's not /k/ until magic happens.

So I proposed going in the opposite direction and gently placing a banana peel in the exact orbital path of the ISS, goung the opposite direction.

The math I got came out to something like the force of a 30 or so pound projectile going about 3000fps.

Assuming the nanner peel weighs 60 grams, and the ISS is moving about 17'000mph and going off of that, what kind of energy would we be dealing with in the nanner peel? Yes, I know it's kinda like the whole two cars smacking together head-on thing, so there's probably some weird shit about the energy of both the ISS and the nanner peel mixing on impact. Or maybe it could be treated as the nanner peel's speed relative to the station..

halp. I am but a simple lover of things that kill shit.

>>8306932
dude no circumference = 2πr = 2π(1/2) = π

>>8306280

the weight is 6 when going up and 9 when going down

>>8305399
so saturn?

>>8300245
I don't get this one

>>8300466
>proceeds to use a rope to make transverse waves
Playing with a parachute in kindergarten isn't wave mechanics.

>>8306773
You need some advanced level pathological equations terminology to truly disprove it, but the simple answer lies in the derivative of any part of this pseudocircle and finding that it = is either 0 or Undefined, whereas a normal circle can be derived normally.

>>8301288
lel dude, have you ever heard of cavendish? what about r>>R in the experiment?

>>8300381
im too stupid to understand why this is impossible so im just going to assume ur a fuckn genius who just discovered ftl communication

>>8308158
the signal travels through the rod at the speed of sound in the material

>>8308160
signal? isn't the bar just being pushed back and forth?

>>8308176
Say you have a steel bar a lightyear long.
If you push on one end of that bar, the whole bar doesn't move instantaneously
a piece of the bar pushes a piece of itself a little way down, and that piece pushes another piece, etc.
Instead of discrete pushes however, its a more continuous push, which can be thought of as a mechanical signal travelling down the rod.

>>8308179
yeah that makes sense, i kept thinking of the bar as a single entity

>>8308186
Think of it like electric current through a copper wire. Electrons are moving through the wire, but an individual electron doesn't actually zip from one end to the other at the speed of lightning- they go much more slowly than that (something like a meter a minute, but don't quote me on that). However, there's a domino effect of electrons dislodging other electrons, which dislodge still other electrons, and we can refer to that domino effect as the "signal"- that *does* move at something near light speed.

The "wave" at a sports event is a similar example of signal transference, except in that case there's actually zero movement at the individual level.

>>8306943
So physics isn't my area of study, more a mild curiosity, but my best guess with a banana peel hitting the ISS is that it would do practically nothing. Micrometeoroids rarely do any significant damage to the ISS, and they're much less compressible than a banana peel. Given how a peel is made of very weak, fleshy fibres, I'm assuming that this can be treated essentially as a perfectly inelastic collision.

So:
[math]v_{banana peel} = -7660 m/s[/math]
[math]v_{ISS} = 7660 m/s[/math]
[math]m_{banana peel} = 0.060 kg[/math]
[math]m_{ISS} = 419455 kg[/math]

Thus, [math]v_{banana peel & ISS} = \frac{m_{banana peel}v_{banana peel} + m_{ISS}v_{ISS}}{m_{banana peel} + m_{ISS}} = \frac{(0.060 kg \times -7660 m/s) + (419455 kg \times 7660 m/s)}{0.060 kg + 419455 kg} = 7659.99781 m/s[/math]

A banana peel wouldn't do shit.

>>8308933
Fuck, I don't know Latex at all. Just know that the ISS would be travelling at approximately the same velocity after colliding with a 60 gram banana peel.

>>8303376
Isn't the one on the top and bottom left Ben Garrison's book?

>>8305400
>if it didn't have holes it wouldn't be compressible
You know gases are compressible, right?

>>8309071
Alright, then the volume decrease causes a temperature increase in the gas and water surrounding it, therefore there will not be equal buoyancy everywhere because there is a non-constant temperature distribution in the water.

>>8303372
>coolface

>>8307887
coolface was right

>>8306148
This is so wrong I can't even. You would have slightly less than a kg of gold and a whole bunch of hydrogen you can vaporize japs with

>>8300593
Wait, why wouldn't this work?

>>8305399
Funny thing is this would actually work, for about .0001 seconds. Still, it is accurate.

>>8306253
Assuming all those things yes it would work. But none of those things are true. The ring would break from structural stress and more importantly, Gravity isn't equal from place to place on the earth. The ring would get pulled stronger in one direction than the other and would crash into the earth

>>8302348
You didn't account for paper coulor.

>>8303064
RAA is the worst kind of proof, especially in situations like this. It doesn't illuminate what's wrong with the procedure at all.

>>8303496
>What is conservation of momentum.

>>8306943
>liking muh boom boom pow

This board isn't for underage

>>8306212
>monopolies
kek
also nobody told china that they coulden't make monopole magnets, so they made them without realizing it was impossible

>>8300593
This one's fucking great.

>>8305401
This isn't actually a troll. This is just a very simplified version of an em projectile shield.

>>8305471
>We're going to go to the moon in 3 hours!

I remember making one that I posted all the time to bait newfags.
It was a problem that went like:

>A guy is on a boat in the ocean carrying steel bars
>he throws the steel bars into the ocean
>does the water level go up, down or stays the same?

I love the ones that destroy the logic of maths and leave everyone scratching their heads.

>>8310593
Right coolface inserts 20 dollars, gives 30 dollars to left coolface and gains 40 dollars. -20 - 30 + 40 = -10
Left coolface inserts 20 dollars, gets 30 dollars from right coolface. -20 + 30 = 10

>>8310712
Is there something wrong with this one? It seems to make sense.

>>8310722
There's probably laws against it or something.

>>8310712
Sadly, this works. Also, I wish I'd seen this before the Brexit.

>>8310722
It should work. However, you'd have to take out a huge loan which would be really really difficult if you're not already rich.

>>8300238

I found the ones the most funny that sound stupid but actually work
Anything with magnets was unfunny as shit though

>>8300531
>>8302205
>>8305392

>brainlets on /sci/

>>8306253
>>8305399

I recently saw a video that actually suggested doing just that. Humanity should build a sphere around earth and live just there and let nature and wildlife on earth regenerate.
Forgot what video that was, but I think it was in conjunction with terraforming. If anyone knows what video I'm talking about I'd be glad if you posted it

>>8310781
>build sphere around earth
>block out sun
>everything but those who live off of tectonic activity die
great plan

>>8310786

It wasn't really a sphere but more hexagonic shapes linked together like a beehive

>>8310722

How do you think jews got so rich

>>8309626

Yes.
That' the problem. Not that your doing fucking nuclear fission

>>8300434
Yeah it would decay, same way as sound and (maybe) electricity, thinking of the first transoceanic telegram lines.

>>8303376
I do.

>>8310721
hmm...
Isnt there any regulations stoping this?

>>8300593
wait, what's wrong with it?

[math]1=\lim_{x\to0}1=\lim_{x\to0} (x \frac{1}{x})=(\lim_{x\to0}x)(\lim_{x\to0}\frac{1}{x})=0
\\
1=0[/math]

Wouldn't it be difficult to make the water not escape from where the balls go up into the water?

>>8311092
The force needed to open the seal would be greater than the buoyancy of the balls in the water

>>8309907
Actually you can place small magnet inside the box

>>8310903
You can`t write limit of a product of the functions as a product of the limits if one of the functions is not continuous.

Am i right? I sort of forgot about the rules of the products, so please elaborate.

>>8300381
What about a graphite or diamond rod?

>>8311264
I think you can't do it if they don't converge to a real number.

>>8311264
The problem is that using the limit rules (product in this case) requires the limits to exist, and the [math]\lim_{x\to0}\frac{1}{x}[/math] doesn't exist.

>>8311092
If you calculate the work required to pull a ball in the tank, you find that it is at least the amount you gain from those balls already inside the tank.

>>8307887
Literally how we got to the Moon.

>>8306943
Once the parts are on their way towards the station, there is no "opposite" direction.

Think about it.

>>8306148
You can actually do that (if not as described), and it's been done.

At Physical-Technical State Institute of Berlin, the bombarding particles were given a high speed by means of a field of 30,000 volts, and a small, but observable quantity of gold was produced from quicksilver.

Unfortunately, in addition to the fact that such laboratory transmutation can't really be reproduced on a commercial scale, the amount of mercury you go through is worth more than the gold you create.

>>8300593
Best one I have ever seen.

>>8310721
>trusting Brasil
kek

>>8310712
George Soros?

>>8306711
No, it would actually be very cold but you wouln't really feel it since you could only dissipate heat through radiation.

>>8303496
I'm guessing you also think light isn't affected by gravity because it has no mass. Light has energy, and energy can move mass. So you're wrong

>>8306284
Einstein taught us that the laws of physics depend on the observer dumbass. Stop trying to sound smart by saying things like "length-dilated", those aren't even real terms

>>8307887
it is an anti-joke. it's not really troll physics

>>8301221
>>8301252
The blackboard in step 5 should say (10*3) - 5 + 2=27. The "missing 3" are in the kid's pockets.

>kids give you 30
>you give 5 to bro
>bro gives 3, keeps 2
>you went from 30 to 27, missing 3 are in kids.

>>8301657
I think it would work, but it's stupidly inefficient.

>>8310824
>what is real interest rate

>>8310824
Yeah.
Banks won't give you a loan if you outright told them you were doing something this fucking silly.

>>8303372
Calling it coolface just shows you dont know where it came from

>>8310781
That seems really interesting. If you could find it(I tried looking) I would really appreciate it.

>>8311239
Most likely someone in China shilling.
Look at their English. Missing "a" in a literally one sentence post.

>>8306284

the beam of light would be blue shifted
what you are saying implies that the beam of light is moving away from the spaceship at c plus the speed of the ship

>>8300245
HAHAHA GOLDEN

>>8305399
Dyson Sphere The Beginning

>>8305392
The magnets exert force on the arm and frame of the car not the ground

>>8300525
I didn't get fooled by this in elementary school, come on.
Also anyone have that perpetuum mobile with 9 and 6?

>>8310824
the reason interest is high is because the risk is also high
brazil vs japan come ona non

>>8311239
What if you'd place it halfway in the box so that one pole is in the box (and thus blocked by the box) and the other is outside.

>>8303376
wtf i hate science now

>>8300505
https://en.wikipedia.org/wiki/Alcubierre_drive#Damaging_effect_on_destination

>>8300238
Ha ha you guys think you're so clever.
How many of you can actually explain why this does not work?

>>8300373
>>8310774

Suppose instead of a pole attached to the back of the car holding a magnet in front, there was another car infront of the first car with that magnet on the back, and so on and so forth until the top of a hill, at which another car with a powerful magnet on the back started to roll down the hill with a chain of say, 10 or 15 of these lightweight "cars"?

>>8306126
How can I attract the Earth?

I am not a magnet.

>>8315925
photon has no mass, thrust needs mass from newton third law

acceleration goes to 0 as mass increases as it nears relativistic speeds, not enough energy

>>8315952
>photons
>newton's laws
dude

Didnt totally spies do something similar to this once?

>>8300593
toppest of keks. This one is actually good.

>>8303376
Lol American Bear is controlled by the "Jews"

why the quotes?

>>8303376
This must be the Correct The Record training manual for normies.

>>8305401
>consoleshooter.jpg

>>8310731
You will reach a point where you don't have enough gas to make the pistons do a full rotation.

>>8304588
underrated post

Okay, hear me out.
>get solar pannels
>attach lightbulbs near solars
>solars get energy from sun
>get power for lightbulbs
>lightbulbs sustain themselves
>free lighting and extra when sun comes out
Checkmate darkness.

>>8305452
don't tell you didn't breathe into a plastic bag and put in the freezer to make dry ice when you were a kid

>>8312106
that's how lasers work

>>8310712
this is just pump and dump, it's well known and is probably happening constantly with bitcoin

>>8303553
write a paper

>>8310805
i see no problem as you can sell H2

>>8312106
>turn off flashlight

kek

>>8316757
>lightbulbs sustain themselves
ya sure?

>>8300381
This is not moving faster than the speed of light

its just a large object moving a little

i dont get it

>>8318214
remember objects are made of atoms. When you move an object your just making them knock into each other but not hard enough so they maintain their shape.

>>8318162
Remember what thread you're in