B Hypothetical Gravity Question #2

[jayromano]

TL;DR Summary

A revolutionary mode of point-to-point transportation

Hello all,

My second hypothetical question for the day (and last).

Suppose you drilled a hole from the surface of the earth, through the Earth's core, and out the other side. The sides of the hole are reinforced preventing any of the hot stuff from escaping the Earth's core, in fact this hole is particularly impressive as it’s drilled perfectly straight through the center of the earth. You're feeling brave and decide to jump into the hole wearing your advanced suit which provides oxygen and protects you from heat and other nasty environmental variables which might kill you. It's a particularly good jump too, as you don't touch the sides at any point during your journey.

Scenario A (wind resistance): Do you accelerate to terminal velocity, pass the most central point of the Earth's core, and then gradually decelerate, failing to reach the surface on the other side because wind resistance has prevented you from reaching a velocity that will allow you to overcome the gravitational forces pulling you back toward the Earth's core once you pass the center? Would you then gradually accelerate back and forth with decreasing velocity until you came to rest at the central point of the Earth's core?

Scenario B (vacuum): Do you continue to accelerate until you pass the central point of the Earth's core, and then gradually decelerate until you reach the surface on the other side of the earth, at which point you stop falling very close to the surface on the other side as the gravitational forces are relatively balanced?

Thanks,
An insomniac who is kept awake by these thoughts.

 

[anuttarasammyak]

As for scenario A, the pilot goes to and fro with diminution and stops at the center.
As for scenario B, the pilot stops at the other end of the tunnel and falls down back again.

 

[jayromano]

Thanks for the reply anuttarasammyak,

To take this problem a little further, let’s add in the imbalance of the earth’s spherical mass (i.e. mountain ranges, below sea areas) and the gravitational forces of other planetary bodies. Now we have small forces influencing our human free-falling in the tunnel. My thoughts are that in Scenario B these forces would result in our human being pulled into the walls of the tunnel at certain points, which would result in deceleration and a failure to reach the surface on the other side?

Suppose we created a capsule which fit the dimensions of the tunnel minus a few millimetres on either side to eliminate friction (think of a pneumatic tube messaging system). This capsule travels through a vacuum (i.e. Scenario B). We let it free fall under its own weight. Would the minor forces pulling the capsule toward the walls have a braking effect, preventing the capsule from reaching the other side due velocity losses? For this system to hypothetically work, it would need some method of assistive light propulsion to overcome these minor forces?

 

[jbriggs444]

My thoughts are that in Scenario B these forces would result in our human being pulled into the walls of the tunnel at certain points, which would result in deceleration and a failure to reach the surface on the other side?

Unbalanced gravity from mountain ranges and such are minor annoyances. The bigger problem is Coriolis. You would be subject to enough normal force from the walls to cancel your 600 to 700 mile per hour motion on the surface of the rotating Earth to zero miles per hour by the time you hit the center (about 45 minutes later if I recall correctly).

 

[Janus]

Summary:: A revolutionary mode of point-to-point transportation
Scenario B (vacuum): Do you continue to accelerate until you pass the central point of the Earth's core, and then gradually decelerate until you reach the surface on the other side of the earth, at which point you stop falling very close to the surface on the other side as the gravitational forces are relatively balanced?

Thanks,
An insomniac who is kept awake by these thoughts.

You might what to check this out:
https://en.wikipedia.org/wiki/Gravity_train

 

[jayromano]

You might what to check this out:
https://en.wikipedia.org/wiki/Gravity_train

Yes, that's it, I'm only 300 years too late :|