So you got thrown in a bottomless pit......

[MechAg94]

http://www.foxnews.com/science/2015/03/30/how-long-to-fall-through-earth-quicker-than-thought/

Apparently, you won't fall forever.....at least in that one direction.  

How long would it take to fall through a tunnel from one side of the Earth to the other? The new answer: 38 minutes and 11 seconds, reports Science.

I imagine you might be a bit crispy by the time you make it through to the other side.  I guess you could bounce all the walls a bit also.

[HankB]

Hmmm . . . assuming you did have a  hole all the way through the earth, wouldn't it have to be along the axis for you to fall straight through?

And . . . what would the atmospheric pressure be at the bottom (or is it the middle?) of said hole?

[BryanP]

Well, there's also the problem that once you reached the center there's no gravitational pull to take you on out the other side, now is there? 

[K Frame]

Well, there's also the problem that once you reached the center there's no gravitational pull to take you on out the other side, now is there? 

Wouldn't momentum take you through the center, or would that decay as you got farther down?

[BryanP]

Wouldn't momentum take you through the center, or would that decay as you got farther down?

I guess so, but then the closer you got to the other side the more gravity you'd be fighting to pull you back to the center, right?

[K Frame]

I guess so, but then the closer you got to the other side the more gravity you'd be fighting to pull you back to the center, right?

Beats the hell out of me. I was a history major.

[erictank]

Wouldn't momentum take you through the center, or would that decay as you got farther down?

In the classic physics-problem fashion, we must of course neglect to consider air friction or impacts. Assume a perfectly-straight fall path free from obstruction, with no atmospheric friction or other resistance. In theory, you should pop out from the hole on the other side of the Earth as you hit zero-speed, put your feet out to catch yourself, and walk away.

In practice, assuming a hole you COULD fall through and resistance to the mantle's and core's heat and pressure, you'd experience friction all the way, not make it to the other side, and oscillate up and down the hole, reversing at a lower and lower point each time until you ended up stopped in the center for all time.

Sounds like fun, no?

[BryanP]

[lupinus]

So you are going down. Momentum carries you past center. Gravity, however, pulls you back down.

So do you just king of bounce up and down before settling in the center? And gravitationally just where would it be? The very center or offset based on mass? If it didn't stop you what stops you on the other end?

[K Frame]

"you'd experience friction all the way, not make it to the other side, and oscillate up and down the hole, reversing at a lower and lower point each time until you ended up stopped in the center for all time."

Sounds like just another day at the office...

[lupinus]

"you'd experience friction all the way, not make it to the other side, and oscillate up and down the hole, reversing at a lower and lower point each time until you ended up stopped in the center for all time."

Sounds like just another day at the office...

yeah I hate extra friction in the hole office days

[freakazoid]

Would gravity become greater, lesser, or stay the same the closer to the center you got?

[MechAg94]

Would gravity become greater, lesser, or stay the same the closer to the center you got?

I would assume the acceleration of gravity would fall off as there is less material below you. 

I also think that we would likley not fall straight down and end up hitting the sides a bunch.  Once you gain some speed falling, any movement is going to move you around in the hole.

[Headless Thompson Gunner]

Gravity is inversely proportional to the square of distance.  So shouldn't the forces increase as you get closer to the center?  Gravity is also proportional to mass, and isn't the core supposed to be more dense than the crust?

I dunno.  That's as much impractical physics as I remember from high school.

[Zardozimo Oprah Bannedalas]

Would gravity become greater, lesser, or stay the same the closer to the center you got?

Gravity's a function of mass and distance. Less gravitational pull when you're on a mountaintop than when you're in the Mariana Trench, due to your distance from the bulk of the earth's mass.

Falling through a hole in the earth, your rate of acceleration would increase until you get somewhere around the core/mantle boundary. Then the rate of acceleration would be reduced, due to the mass of the mantle behind you cancelling out much of the gravitational pull of the core in front of you.

In a frictionless system, you'd cease your now-upwards journey and begin descent at the exact same height that you left at.

Real world problems: friction, intense heat, pressure, the earth being non-homogenous. Last one is an issue as it means you'll likely have sufficiently unbalanced gravitational forces from the sides that your magic capsule of frictionlessness will be slammed into one side of the hole or another as you go down. Bar service might be a bit iffy.

[griz]

Once you say "bore a hole all the way through the earth", real world problems can safely be ignored.

[vaskidmark]

All this scientific stuff is interesting and all that, but what I want to know is would the heat evaporate the water from the hose, or would I still have to put the lotion on?

stay safe.

[lupinus]

Once you say "bore a hole all the way through the earth", real world problems can safely be ignored.

Spoilsport

[KD5NRH]

Once you say "bore a hole all the way through the earth", real world problems can safely be ignored.

All you have to do is go halfway twice.

[lupinus]

All you have to do is go halfway twice.

If you start in the ocean at one end and dry land on the other does that mean the ocean will drain out onto the other side of the planet?

[MechAg94]

Gravity is inversely proportional to the square of distance.  So shouldn't the forces increase as you get closer to the center?  Gravity is also proportional to mass, and isn't the core supposed to be more dense than the crust?

I dunno.  That's as much impractical physics as I remember from high school.

I was thinking the equations we used in college assumed a point source for the gravity.  It definitely isn't a point source in reality.  I am thinking the acceleration wouldn't change a great deal, but would fall off as you moved toward the center and had more mass above you (as Oprah mentioned above). 

It is ironic that we are talking about applying real physics when in reality would just have a really big volcano. 

[Perd Hapley]

Wouldn't you at some point have gobs more air pushing down on top of you than you're used to?

[230RN]

But a hole is just nothing.  Why are we talking so much about nothing?

[Marnoot]

Lots of physicsy stuff about this very question:

http://www.askamathematician.com/2012/08/q-if-you-could-drill-a-tunnel-through-the-whole-planet-and-then-jumped-down-this-tunnel-how-would-you-fall/

Wouldn't you at some point have gobs more air pushing down on top of you than you're used to?

25 kilogobs per square smidgen.

[Hawkmoon]

But a hole is just nothing.  Why are we talking so much about nothing?

Because that's what we do best.