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/sci/ - Science & Math

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2710347 No.2710347 [Reply] [Original]

Hey /sci/,
say you would dig a hole through earth (see picture). What would happen if you jump through that hole?

Would you fall out in space or would you get stuck in the hole or get swooshed up to the surface of the other side?

>> No.2710355

If you dug a hole like that, I'd imagine you'd just impact the wall of the tunnel after a seconds of falling.

>> No.2710357

Gravity pulls you towards the center of the planet, not the outside of it.

>> No.2710361

Ever walked through a flat corridor?
It'd be a long fucking corridor, assuming that you could actually keep the walls and floors solid.

>> No.2710354

You would get stuck in the hole. It does not go straight down, so there would be a lot of friction with the edge.

>> No.2710383

You smash into the side shortly after jumping. Are you truly this stupid?

>> No.2710392

>>2710357
So you wouldn't even fall through it?

Also, what if the hole was in the middle and you couldn't die from the heat?

>> No.2710402

>>2710392
get crushed into tiny pieces

>> No.2710408

>>2710392
>"Could you die from the heat?"
>death by plummeting into the core of the Earth

Yeah...Don't think you can.

>> No.2710412
File: 7 KB, 800x600, shiit.png [View same] [iqdb] [saucenao] [google]
2710412

>>2710392
Oh you'd fall through it.
This is a diagram that explains what it would feel like.
It'd feel like a giant valley.
Seriously, it's so big that the direction of gravity changes- the corridor is flat but the pull of gravity changes, just like a smaller valley.
A bit hard to understand if you're not as smart as I am.

>> No.2710417

Assuming you did fall straight through, I guess it'd take something like 15 days to 'come out the other end'.

Bitch you'll be thirsty.

>> No.2710422

It would work if you were in some sort of frictionless capsule, in theory you would make it

>> No.2710428

>>2710392
Assuming you would be resistant to the heat, if you jump in, you would accelerate until you hit the core and due to the speed you maintain, you would fall away from the core, but gravity would constantly slow you down, so you would fall to the other end of the hole and come out at still stand on the surface

>> No.2710440

>>2710347
That isn't really a hole, more of a tunnel that goes at a steep angle through the earth. You could SLIDE partway I suppose but because it doesn't go through the center of gravity it wouldn't go straight down.

>> No.2710462

>>2710392
You would oscillate in simple harmonic motion with R distance from the center where R is a function of time:

<div class="math">R=R_0cos(t \sqrt{ \frac{4}{3} \pi G \rho})</div>

Where <span class="math">R_0[/spoiler] is the height from which it is dropped (assuming this is at or below the surface of the earth), <span class="math">t[/spoiler] is time, <span class="math">G[/spoiler] is the gravitational constant, and <span class="math">\rho[/spoiler] is the average density of the planet.

From this, you get a period of oscillation of:

<div class="math">T=\sqrt{ \frac{3 \pi}{G \rho}}</div>

The time it takes to get to the other side is half the period.

>> No.2710469

>>2710428
but how would you come out of the hole? would you get thrown off, going into a jumping motion? Or would you just magically stand over the hole like a modern jesus?

>> No.2710474

>>2710347
do some trig, a bit of SUVAT, ignore some friction and yeah the force at which you fall once you get to the centre will start to cancel out by gravity acting in the opposite direction, your velocity will decrease and be 0 at the point at the other end of the hole

>> No.2710476

>>2710469
I'd recommend grabbing the ledge of the hole or someone giving you a hand or else you will fall back into the hole, all the way back to the other side.

>> No.2710486

Interestingly enough, if you had a frictionless tunnel and were relying entirely on gravity, then it would take precisely 42 minutes to travel through the hole to the other side.

Always 42 minutes, no matter where the entrance and exit holes are, as long as the tunnel is a straight line between the two points.

>> No.2710491

>>2710476
So say you're alone, you'd just keep pending between the endings in all eternity?

>> No.2710493

>>2710469
if you jumped in at 2 metres above the hole you will pop out 2 metres 'below' the second hole and then fall back in repeating the motion ad infinitum, assuming there's no friction

>> No.2710497

>>2710491
>>2710493
that

>> No.2710500

>>2710462

What the fuck?

That's a slope not a vertically downwards tunnel and there can't be possibly SHM with that much friction.

>> No.2710502
File: 19 KB, 500x263, gravity.jpg [View same] [iqdb] [saucenao] [google]
2710502

This is what would happen: Its called gravity

>> No.2710512

>>2710502
hole != slice

>> No.2710513

>>2710347
First it would act like a slide, the angle of the slide would change as you went down. The angle would be greatest at either end of the hole and the angle would be 0 at the center. So at the center it would essentially feel like youre standing on level ground, or more precisely, the bottom of a valley.

>> No.2710515

>>2710500
You should probably read the post I was responding to.

>> No.2710534

>>2710515

My apologies. For a minute I thought this was some kind of group troll thing.

>> No.2710536
File: 27 KB, 648x588, 1300216726665.png [View same] [iqdb] [saucenao] [google]
2710536

This

>> No.2710542

>>2710536
but what is there was no friction?

>> No.2710547

Humans have a terminal velocity of about 70 ms^-1-- this is how fast we would be traveling once we reach the core. Using basic equations of motion, we find that subject to a deceleration of 9.8 ms^-2, we would travel a distance of 250 m. Considering the surface is about 6000 km from the core, we wouldn't reach anywhere near the other side.

>> No.2710545

http://www.damninteresting.com/the-gravity-express

>> No.2710553

>>2710542
Friction isn't the problem when you go splat, it's the normal force itself upon impact.

>> No.2710560

>>2710553

But what if the hole is only 5 feet wide?

>> No.2710566

>>2710547
terminal velocity is due to air resistance, not some limit that gravity places upon us,

>> No.2710567

>>2710560
then you'd be fine

>> No.2710573

>>2710566

So now we're turning the hole into a vacuum?

>> No.2710580

>>2710547
Well you're right but... At the center of the earth gravity would be 0. so it would go from 0 to 9.8. But then again as you approach the center terminal velocity would decrease.... So there are a lot of variables.


But this example doesn't go through the center of the earth.

>> No.2710595

>>2710580
>at the center of the earth gravity would be 0
um not unless you are literally a zero dimensional being

>> No.2710601

>>2710595
Lol, I assure you I'm right.

what creates gravity? Mass? Where is all the mass when you are at the center of earth? All around you? No gravity.

>> No.2710603

What, you guys think gravity would be 0 at the center of the earth? Wouldn't the gravity of all the matter around you pull you in all directions at once?

Captcha: Love entns

>> No.2710609

>>2710603
Yeah, so the net force would be 0 XD

>> No.2710638
File: 29 KB, 600x600, Earth-G-force.png [View same] [iqdb] [saucenao] [google]
2710638

>> No.2710670

HEY GUYS
If one were to take an Earth size mass and hollow out, say, a couple hundred kilometer wide sphere in the center and reinforced the edges so no matter could fall further into it, does that mean that at the "center" you would be pulled towards one of the edges instead of the middle?

>> No.2710667

If you guys are so smart why do you reply to this thread... You really do show somethign bad about yourselves when you try and prove how smart you are on the interwebs.
Yes I made a spelling mistake on purpose. I bet you were about to call me out on that.

anyway I lol'd at thread

>> No.2710686

>>2710670

nope, you would be entirely weightless

>> No.2710694

>>2710417
No, if you do the math, it takes 42 minutes to come out the other end, assuming no friction. It doesn't matter which two points on the surface you connect this way, it'll always be 42 minutes. If you know Lagrangian mechanics, it's pretty easy to work out.

>> No.2710697

>>2710686
You're right

>> No.2710709

>>2710670
At all points interior to a hollow sphere, the net gravitational force is zero.

>> No.2710717

>gravity train.


waoh, the universe really is our playground.... now if only we were tall enough for the rides :(

>> No.2710722

>>2710709
And yet "Hollow Earth" faggots continue to believe that not only is the Earth hollow, but that there is a civilization on the inside surface, and a central sun.

The net force would be towards the center again, because of the central sun. Yeah, civilization is tricky when walking to the grocery store ends with you falling into a star.

Not to mention that rock doesn't have the strength to support such a large hollow shell.

>> No.2710729

>>2710609
If the earth was a perfect sphere, I would agree with you.

>> No.2710732

>>2710722
that would be sooo coool. i think dr who already did it though :|

>> No.2710742

>>2710729
You are retarded

>> No.2710744

Most of /sci/ cannot into Gaussian surfaces.

>> No.2710813

>>2710744
Can you explain?

/sci/ should be renamed /edu/

>> No.2710855

>>2710813
http://en.wikipedia.org/wiki/Gaussian_surface

>> No.2711325

>>2710855
yeah i read that but i dun understand it. hoped you could put it simply in relation to this thread.