[ARCHIVED THREAD] - Interesting physics question. (Page 1 of 2)
Posted: 3/22/2016 4:50:14 PM EDT
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Inspired by this thread: http://www.ar15.com/forums/t_1_5/1850894_If_you_live_in_the_United_States__what_exactly_on_the_other_side_of_the_Earth_.html
Assuming you actually COULD tunnel to the very center of the Earths core, and ignoring all the myriad reasons why you can't actually do that, and then jumped into the hole what would happen when you reached the center of the Earth? Would you float in place? New airplane on a treadmill? |
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Does the tunnel have air in it or no? Is the tunnel open to the atmosphere?
If you climbed down a ladder, into an air-containing super tunnel that wouldn't collapse to the center, and let go of the ladder in the exact center of the earth... you'd share the orbit with the earth and be 'weightless'. The problem is though, the physical center of the earth is not the gravitational moment of the earth so the zero point wouldn't be there, or even necessarily anywhere near the center. (Earth isn't a perfect sphere of uniform density.) The "gravitational center" probably wanders around quite a bit as stuff moves around over it (mostly water.) Another problem is you'd be at the bottom of a 4 thousand mile high stack of air so pressure at the center would be huge. You'd have to go down slowly and come up like a diver or get the bends... or it might be high enough to do stuff like cause some gasses to precipitate out of the air or just destroy your flesh. In reality, you'd get distracted during the digging process because the back yard is not big enough for all that dirt and we found a bunch of night crawlers so let's go fishing instead of digging a hole. |
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It would be a mistake to assume terminal velocity would remain constant below sea-level. Quoted:
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At 118mph, it would take almost a day and a half to get there. It would be a mistake to assume terminal velocity would remain constant below sea-level. I just want to know if I should bring a snack. |
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Inspired by this thread: http://www.ar15.com/forums/t_1_5/1850894_If_you_live_in_the_United_States__what_exactly_on_the_other_side_of_the_Earth_.html Assuming you actually COULD tunnel to the very center of the Earths core, and ignoring all the myriad reasons why you can't actually do that, and then jumped into the hole what would happen when you reached the center of the Earth? Would you float in place? New airplane on a treadmill? You would float in place, except for being crushed by massive pressure in molten iron/nickel. |
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I just want to know if I should bring a snack. Quoted:
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At 118mph, it would take almost a day and a half to get there. It would be a mistake to assume terminal velocity would remain constant below sea-level. I just want to know if I should bring a snack. Probably a few boxes of MRE's... It's going to take a while. |
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Remember the remake of Total Recall? they had "the Fall" which literally fell thru the center of the earth to the other side working on gravity alone. Which doesn't work. The energy gained falling towards the center would be lost past the center... Add in air resistance or any other losses, and you aren't making it anywhere near the other side. |
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You would float in place, except for being crushed by massive pressure in molten iron/nickel. Quoted:
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Inspired by this thread: http://www.ar15.com/forums/t_1_5/1850894_If_you_live_in_the_United_States__what_exactly_on_the_other_side_of_the_Earth_.html Assuming you actually COULD tunnel to the very center of the Earths core, and ignoring all the myriad reasons why you can't actually do that, and then jumped into the hole what would happen when you reached the center of the Earth? Would you float in place? New airplane on a treadmill? You would float in place, except for being crushed by massive pressure in molten iron/nickel. Yup. Gravity does not come from the center of the earth. It comes from the mass of the earth. If you are in the center of the earth the rest of the earth is going to act on you in every direction equally, nullifying any gravitational force. |
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Ignoring everything else that's wrong with your statement, didn't you mean to say IMplode? Quoted:
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The force of gravity and the rotation would crush your body VERY quickly. You would likely explode. Ignoring everything else that's wrong with your statement, didn't you mean to say IMplode? Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. |
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Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. Quoted:
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The force of gravity and the rotation would crush your body VERY quickly. You would likely explode. Ignoring everything else that's wrong with your statement, didn't you mean to say IMplode? Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. speed of what? |
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Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. Quoted:
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The force of gravity and the rotation would crush your body VERY quickly. You would likely explode. Ignoring everything else that's wrong with your statement, didn't you mean to say IMplode? Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. Pretty sure that's backwards. |
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Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. Quoted:
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The force of gravity and the rotation would crush your body VERY quickly. You would likely explode. Ignoring everything else that's wrong with your statement, didn't you mean to say IMplode? Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. Sure about that? 
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Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. Quoted:
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The force of gravity and the rotation would crush your body VERY quickly. You would likely explode. Ignoring everything else that's wrong with your statement, didn't you mean to say IMplode? Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. Lmao. No. |
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There is a great Sci-Fi short story written back in the 80's using this as a premise. I have no idea what the title of the story is. Set a short time into the future, aliens arrive in our solar system and begin to mine the core of Venus for some undisclosed reason, using fantastic technology that cores a hole through the planet. Of course, the governments of Earth get all indignant and send a mission to Venus to tell them to stop; without saying a word, the aliens destroy the ship as soon as it's in range. Everybody on board is killed except the security guy - a tough-as-nails space cowboy who has a space suit equipped like Ironman's (from the Marvel movies) with onboard AI. The aliens find him alive amongst the wreckage, and as a sick cosmic joke, throw him down the hole like you describe. Realizing his predicament as the butt of a joke in a freshman year physics problem, he works out an escape plan with his AI companion on his second trip back through the planet (the first trip almost killed him due to heat and pressure). The aliens observe him escaping and surviving the trap, and are duly impressed, as they intended to kill him. As a reward, they return him to Earth, but continue to mine the remaining planets. The diplomats try to establish communication with the aliens, but they aren't interested unless it's somebody with cajones like the main character...which is how the story leaves off. |
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Pretty sure that's backwards. Quoted:
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The force of gravity and the rotation would crush your body VERY quickly. You would likely explode. Ignoring everything else that's wrong with your statement, didn't you mean to say IMplode? Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. Pretty sure that's backwards. It is. He needs to go stand against a pole and follow its shadow. That is how fast he would rotate at the center of the earth. Actual rotational speed is the same on the surface as it is at the core. SURFACE speed increases the further from the core you get. If his logic was correct, everyone that has visited the true North or South Pole would have been ripped apart. |
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First effect you'd notice would be slapping up against the side of the tunnel, unless your hole ran exactly down the spin axis of the planet. Yeah, that's going to be a rather problematic part of the whole thing... That might actually fuck you up pretty bad, for several reasons. |
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There is a great Sci-Fi short story written back in the 80's using this as a premise. I have no idea what the title of the story is. Set a short time into the future, aliens arrive in our solar system and begin to mine the core of Venus for some undisclosed reason, using fantastic technology that cores a hole through the planet. Of course, the governments of Earth get all indignant and send a mission to Venus to tell them to stop; without saying a word, the aliens destroy the ship as soon as it's in range. Everybody on board is killed except the security guy - a tough-as-nails space cowboy who has a space suit equipped like Ironman's (from the Marvel movies) with onboard AI. The aliens find him alive amongst the wreckage, and as a sick cosmic joke, throw him down the hole like you describe. Realizing his predicament as the butt of a joke in a freshman year physics problem, he works out an escape plan with his AI companion on his second trip back through the planet (the first trip almost killed him due to heat and pressure). The aliens observe him escaping and surviving the trap, and are duly impressed, as they intended to kill him. As a reward, they return him to Earth, but continue to mine the remaining planets. The diplomats try to establish communication with the aliens, but they aren't interested unless it's somebody with cajones like the main character...which is how the story leaves off. Do you remember the title or author? |
I have some theories about what might happen to you physically as you pass through the precise center of the earth and emerge on the other side:
I'll give it a shot as soon as someone parks their personal submarine on the bottom of the Pacific in the precise location opposite my place. |
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Yeah, that's going to be a rather problematic part of the whole thing... That might actually fuck you up pretty bad, for several reasons. Quoted:
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First effect you'd notice would be slapping up against the side of the tunnel, unless your hole ran exactly down the spin axis of the planet. Yeah, that's going to be a rather problematic part of the whole thing... That might actually fuck you up pretty bad, for several reasons. Agree. At the surface, we each have a translational velocity due to the rotation of the earth. v = R x (omega). If you were to jump into the proposed hole, your translational velocity would soon have you careening off the walls of the hole. |
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Quoted: Do you remember the title or author? Quoted: Quoted: There is a great Sci-Fi short story written back in the 80's using this as a premise. I have no idea what the title of the story is. Set a short time into the future, aliens arrive in our solar system and begin to mine the core of Venus for some undisclosed reason, using fantastic technology that cores a hole through the planet. Of course, the governments of Earth get all indignant and send a mission to Venus to tell them to stop; without saying a word, the aliens destroy the ship as soon as it's in range. Everybody on board is killed except the security guy - a tough-as-nails space cowboy who has a space suit equipped like Ironman's (from the Marvel movies) with onboard AI. The aliens find him alive amongst the wreckage, and as a sick cosmic joke, throw him down the hole like you describe. Realizing his predicament as the butt of a joke in a freshman year physics problem, he works out an escape plan with his AI companion on his second trip back through the planet (the first trip almost killed him due to heat and pressure). The aliens observe him escaping and surviving the trap, and are duly impressed, as they intended to kill him. As a reward, they return him to Earth, but continue to mine the remaining planets. The diplomats try to establish communication with the aliens, but they aren't interested unless it's somebody with cajones like the main character...which is how the story leaves off. Do you remember the title or author? I wish I could, it was published in one of those re-launched pulp magazines like Amazing Stories c. 1988. I'd love to reread it. ETA: LOL - Found the cover of the issue:  |
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Lmao. No. Quoted:
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The force of gravity and the rotation would crush your body VERY quickly. You would likely explode. Ignoring everything else that's wrong with your statement, didn't you mean to say IMplode? Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. Lmao. No. I've had a little of the old brown bag special this evening, so help me out with my train of thought. 
Let's take a centrifuge (the kind the astronauts pass out in) for instance..... At the center point (axel) it would take X amount of time for the axel to traverse between two defined points. It would take the same amount of time for the pod the astronaut sits in to travel a ditance between the two points. The difference is, the distance covered by the pod is much greater than the distance covered by the axel in the same amount of time, so the pod has to be traveling much faster. |
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Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. no, that is incorrect. the outer edges are moving the fastest as they travel a greater distance per revolution. if the circumference was one mile, and a revolution took an hour, the ouster edge is doing 1 mph. as you approach the center, you are traveling less than a mile per revolution, so your speed is decreasing. |
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I've had a little of the old brown bag special this evening, so help me out with my train of thought.
Let's take a centrifuge (the kind the astronauts pass out in) for instance..... At the center point (axel) it would take X amount of time for the axel to traverse between two defined points. It would take the same amount of time for the pod the astronaut sits in to travel a ditance between the two points. The difference is, the distance covered by the pod is much greater than the distance covered by the axel in the same amount of time, so the pod has to be traveling much faster. Quoted:
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The force of gravity and the rotation would crush your body VERY quickly. You would likely explode. Ignoring everything else that's wrong with your statement, didn't you mean to say IMplode? Yes, and what else is wrong with my statement. The closer you get to the center of a rotating sphere the faster the speed. Lmao. No. I've had a little of the old brown bag special this evening, so help me out with my train of thought.
Let's take a centrifuge (the kind the astronauts pass out in) for instance..... At the center point (axel) it would take X amount of time for the axel to traverse between two defined points. It would take the same amount of time for the pod the astronaut sits in to travel a ditance between the two points. The difference is, the distance covered by the pod is much greater than the distance covered by the axel in the same amount of time, so the pod has to be traveling much faster. exactly. That is surface speed. You are still rotating at the same speed as the center hub, but as your distance from the hub increases, your surface speed increases. Surface speed on the Earths surface is rougly 1000 MPH. A geostationary satellite appears to travel at the same speed we do, because it has the same rotational speed, but its actual surface speed is rougly 6800 MPH. |