# a hole in the earth **URL:** \ **Category:** Factual Questions\ **Created:** [September 25, 2001, 1:42pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679 "2001-09-25T13:42:43Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![vanilla](https://avatars.discourse-cdn.com/v4/letter/v/f19dbf/32.png) [@vanilla](https://boards.straightdope.com/u/vanilla)\ **Post date:** [September 25, 2001, 1:42pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/1 "2001-09-25T13:42:43Z")
What would happen if we drilled way down to the core? Would gravity be affected? Would the heat escape and propel the earth? ---
**Author:** ![Niobium\_Knight](https://avatars.discourse-cdn.com/v4/letter/n/bc8723/32.png) [@Niobium\_Knight](https://boards.straightdope.com/u/Niobium_Knight)\ **Post date:** [September 25, 2001, 1:50pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/2 "2001-09-25T13:50:19Z")
dont know but it aint possible anyway. ---
**Author:** ![Niobium\_Knight](https://avatars.discourse-cdn.com/v4/letter/n/bc8723/32.png) [@Niobium\_Knight](https://boards.straightdope.com/u/Niobium_Knight)\ **Post date:** [September 25, 2001, 1:51pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/3 "2001-09-25T13:51:20Z")
actually, you’d hit lava eventually which would come rushing up the hole and totally bugger the drilling equipment. ---
**Author:** ![Earthworm\_Jim](https://avatars.discourse-cdn.com/v4/letter/e/f07891/32.png) [@Earthworm\_Jim](https://boards.straightdope.com/u/Earthworm_Jim)\ **Post date:** [September 25, 2001, 1:58pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/4 "2001-09-25T13:58:21Z")
Cecil has something to say on the subject [here](http://www.straightdope.com/classics/a1_165.html) ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [September 25, 2001, 2:02pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/5 "2001-09-25T14:02:07Z")
Well, sorta. It was called the Moho Project (after the Mohorovicic (sp?) Discontinuity area). I don’t know how far they actually intended to drill, maybe all the way to the Moho itself, but it didn’t work, at least from a scientific standpoint. However, rumor has it that the drillers were buddies of LBJ (who was prez at the time), and they made off with a bundle of pork (which might have been the real intent all along). Don’t know if any of that last part is true, though. Could just be UL. ---
**Author:** ![Phobos](https://avatars.discourse-cdn.com/v4/letter/p/3d9bf3/32.png) [@Phobos](https://boards.straightdope.com/u/Phobos)\ **Post date:** [September 25, 2001, 2:10pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/6 "2001-09-25T14:10:37Z")
> [@](#): > > \*Originally posted by vanilla \* > \*\*What would happen if we drilled way down to the core? > Would gravity be affected? > Would the heat escape and propel the earth? \*\* The link Beelzebubba provided answers most of this. As far as propelling the Earth by venting all that heat…nah, you would just make a new volcano (that’s what volcanos are…cracks through the Earth’s crust that allow magma to escape). ---
**Author:** ![Naski](https://avatars.discourse-cdn.com/v4/letter/n/d07c76/32.png) [@Naski](https://boards.straightdope.com/u/Naski)\ **Post date:** [September 25, 2001, 2:20pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/7 "2001-09-25T14:20:04Z")
But reading Cecils explanation, he suggests a central empty cave (with an opening each end so that you could fly through it in a pendulum sort of way). I was just thinking imagine that the central hollowed core is sealed and the radius is that of an average living room. The gravity would be on the outside so you’d be able to walk around the walls (gravity being strongest on the wall your walking on as your nearer that pul of the outside earth). Also you’d be able to jump in the centre where you’d float, but only if you stopped dead in the centre, otherwise you’d fall back to where you jumped from (if not enough power) or go flying through into what seemed like the roof [which would become the floor once you were through the central point] (if you jumped too vigourously) Is this a correct assumption (i was always taught to think of gravity as a point force so i’m guessing what happens when it isn’t) Nask ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [September 25, 2001, 2:31pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/8 "2001-09-25T14:31:33Z")
Nope. You’d be weightless. Even though gravity is a point source, it exists for every single point that makes up the earth. You’d be pulled equally in all directions, therefore weightless (as weightless as the Earth is, since you’d be freely falling around the sun in exactly the same orbit). ---
**Author:** ![MHand](https://avatars.discourse-cdn.com/v4/letter/m/e5b9ba/32.png) [@MHand](https://boards.straightdope.com/u/MHand)\ **Post date:** [September 25, 2001, 8:52pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/9 "2001-09-25T20:52:53Z")
Cecil’s answer doesn’t seem to account for the Coriolis Effect. It would certainly be significant in the infinite pendulum case and I’m guessing even in the single jump through case. Since the earth is rotating, I’d guess that if the hole were drilled stright from the North Pole to the center of the earth (still ignoring the molten core as Cecil did), you’d scrape against the wall as you fell. More accurately, the wall would move into you. Perhaps you could drill some sort of curved hole that accounts the Coriolis Effect and allows you to fall freely? Thoughts? ---
**Author:** ![g8rguy](https://avatars.discourse-cdn.com/v4/letter/g/7cd45c/32.png) [@g8rguy](https://boards.straightdope.com/u/g8rguy)\ **Post date:** [September 25, 2001, 9:59pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/10 "2001-09-25T21:59:26Z")
The problem, **MHand** , is that the Coriolis effect is proportional to the cross product of the angular velocity of the reference frame (in this case, the Earth) and whatever’s moving (the person falling through the hole). Since the Earth rotates about a line connecting the poles, the angular velocity and regular velocity would be parallel; hence there’d be no Coriolis force on the person. Were we talking about a hole dug through any OTHER diameter, then I’d agree that it would make things problematic. ---
**Author:** ![vanilla](https://avatars.discourse-cdn.com/v4/letter/v/f19dbf/32.png) [@vanilla](https://boards.straightdope.com/u/vanilla)\ **Post date:** [September 26, 2001, 1:39pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/11 "2001-09-26T13:39:15Z")
I know this couldn’t happen, but theoretically, what if we drilled in the ocean? Would the water all shoot out? ---
**Author:** ![MHand](https://avatars.discourse-cdn.com/v4/letter/m/e5b9ba/32.png) [@MHand](https://boards.straightdope.com/u/MHand)\ **Post date:** [October 1, 2001, 9:11pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/12 "2001-10-01T21:11:50Z")
Good point g8rguy. I guess I didn’t notice that in Cecil’s example the hole was interpolar. I was putting the hole in my backyard for convience. So – In Cecil’s infinute pendulum, we’d probably see n Focault Pendulm. From the frame of reference of the earth, the person would appear to rotate as he fell, his head facing a different direction each time it bobbed up at the pole he had jumped from. ---
**Author:** ![Glenoled](https://avatars.discourse-cdn.com/v4/letter/g/c0e974/32.png) [@Glenoled](https://boards.straightdope.com/u/Glenoled)\ **Post date:** [October 1, 2001, 9:58pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/13 "2001-10-01T21:58:50Z")
> [@](#): > > \*Originally posted by Mjollnir \* > \*\*Well, sorta. > > It was called the Moho Project (after the Mohorovicic (sp?) Discontinuity area). > > I don’t know how far they actually intended to drill, maybe all the way to the Moho itself, but it didn’t work, at least from a scientific standpoint.\*\* How deep did they manage to drill, in that project? ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [October 1, 2001, 10:28pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/14 "2001-10-01T22:28:38Z")
OK, I got it wrong. It was the _Mohole_ project. Plug that into Google, and you’ll get a bunch of stuff on it. Suffice it to say, they barely scratched the surface. ---
**Author:** ![Ringo](https://avatars.discourse-cdn.com/v4/letter/r/779978/32.png) [@Ringo](https://boards.straightdope.com/u/Ringo)\ **Post date:** [October 1, 2001, 10:34pm UTC](https://boards.straightdope.com/t/a-hole-in-the-earth/83679/15 "2001-10-01T22:34:03Z")
The Russians’ Kola (also called SG-3) is, I believe, the deepest borehole ever drilled. I remember hearing that they were near 40,000 feet many years ago. Looking it up on the 'net I found a total depth of 12.26 km (~7.356 miles) listed at [Kola Superdeep Borehole](http://asuwlink.uwyo.edu/~seismic/kola/). Looking up Project Mohole found several sites that refer to its contributions to deepwater drilling and its political implosion, but I didn’t find a lot of borehole depth data.