How many Americans have heard that if you dig a hole straight down, you’ll end up in China?
Well, it ain’t so. According to this way cool GoogleMap tool, anywhere in the continental US of A you dig, you end up in the Indian Ocean (if you start at Hawaii you’ll end up in Botswana). That’s pretty nifty.
I can think of some fun uses of this tool (though the host site uses it to help you create the biggest sandwich in the world). One of these days I’ll finish my essay on what would happen if you dug a hole through the Earth. You can find limited info on it on the web, but nobody I’ve ever seen really pushes this idea as far as it can go… but alas, I’ve already written 3000 words and I’m only half done. Maybe someday I’ll submit it to a magazine. It’s an interesting idea.
June 27th, 2006 at 2:51 pm
You will have to live in Chile, Argentina or the southern fringe of Bolivia, to be able to dig a hole straight through the earth to end up in China.
I’d call these people Americans, although they are not part of the US of… eh… A.
June 27th, 2006 at 3:01 pm
There’s a path between the very upper edge of Alaska and the rim of Antartica, if you’re desperate to pull off the Earth sandwich idea with just one plane trip…
June 27th, 2006 at 3:33 pm
In Britain we’re (erroneously it seems) taught that Australia is on the other side. In fact, Australia seems like a slightly better match than China for much of the US. Just one of those things I always assumed were true but never checked.
June 27th, 2006 at 4:41 pm
We need one of these for Mars. That way, we can input the face at Cydonia and determine if there’s a another anatomical feature at the antipode.
June 27th, 2006 at 4:56 pm
Did you notice that there is very little overlap between the main continental landmasses and their ‘opposite’ region? It’s almost always ocean. Southern South America covers a bit of Asia, Greenland/Canadian Arctic cover parts of Antarctica and New Zealand covers part of Spain & Portugal, but that’s pretty much it.
I guess it’s not too surprising considering that the earth is mostly covered in water, but it’s still interesting. There’s probably some mathematical formula based on the percentage of the Earth’s surface covered in water that makes it obvious why there’s so little overlap. That would make me feel dumb, but it wouldn’t be the first time!
June 27th, 2006 at 5:04 pm
Reminds me of a recent story on Damn Interesting:
The Deepest Hole
It’s about a Soviet project that tried to penetrate the Earth’s upper crust and sample material between the mantle and crust.
June 27th, 2006 at 5:06 pm
Well, I’m in central New Jersey and it looks like I’m roughly 1000 km south west of western Australia. Most of Australia is opposite to the middle of the Atlantic.
June 27th, 2006 at 5:14 pm
Whilst sitting here, bored to death on a conference call, my mind got to wandering so I Googled the volume of the Indian ocean… 292,131,000KM^3 if you were wondering… and then calculated how large the hole would have to be to drain the entire Indian ocean into said hole.
I said I was bored.
The answer (for those too lazy to do the minimal math themselves) is about 85.4KM Thats a big hole.
June 27th, 2006 at 6:09 pm
Cool, if I dig straight down then I would come out just slightly north of the Panama Canal
Let’s run Internet cables that way rather than around the top, it’d cut latency way down. What? Pressure? Molten core? But it was such a *good* plan…
June 27th, 2006 at 6:10 pm
“One of these days I’ll finish my essay on what would happen if you dug a hole through the Earth.” I bet that if you did, the biggest complaint you’d get would be that it wasn’t close enough to the science that they showed in the movie ‘The Core’. That, and to check your research more until they matched. (No, I’m not kidding either.)
June 27th, 2006 at 6:17 pm
This is all nonsense.
Everyone knows the Earth is flat…
June 27th, 2006 at 6:28 pm
Thousands of miles under my feet there’s an ocean.
June 27th, 2006 at 6:34 pm
The coolest assignment question from a mechanics course I took a few years ago was that if you did dig a hole through the earth and dropped something into it, the object would oscillate (gravity is directed radially towards the center of the earth).
What is cooler is that the period is the same as a satellite orbiting the earth at the one earth radius (about 85 minutes I think, but that is off the top of my head, it has been two years since I did the problem).
What is even cooler is that the period of the oscillation is independant of the angle you drill the hole on. If you drilled the hole at a 80 degree angle from vertical, the hole would be much shorter, but the time it would take to come back to you would remain the same (the radial component of acceleration would be smaller).
Of course you have to assume that the holes are completely frictionless, and that the earth is a perfect sphere made of a material of homogenius density.
The problem really isn’t that hard to solve, but I still think it is one of the coolest mechanics problems I have seen.
Another prof of mine told me about a different problem called the terrestrial brachistochrone. It is similar, but instead of drilling straight holes you drill holes which curve. The object is to find an expression for the constraining curve such that when falling under gravity, the time for the particle to get to any other point on the earth is minimised. This is closely related to the original brachistochrone problem, except that it occurs on a sphere instead of a plane.
I tried for a little while to solve this one but gave up. In hindsight I realise that I probably needed to know some variational calculus to figure it out, which a the time was quite advanced.
In any case, the moral of the story is that if you drilled a hole to china and jumped in, you could beat the fastest aeroplanes without using any energy at all!
June 27th, 2006 at 6:38 pm
Anybody seen the latest at Yahoo news? Another Asteroid!!! Complete with the following links:
Gallery: Asteroids
Top 10 Ways to Destroy Earth
Video: Killer Comets and Ominous Asteroids!
New Cosmic Defense Idea: Fight Asteroids with Asteroids
Astronomers Gear Up for Historic Asteroid Pass in 2029
Neptune Linked to Potential Swarm of Asteroids
All About Asteroids
Visit SPACE.com for more offering rich and compelling
Good Lord can they get any more hysterical?
June 27th, 2006 at 11:49 pm
There is an old russian book (T. Perelman, Physics Can Be Fun )that deals with this problem , and if i recall correctly the solution given is , if you were to drill a through hole and jump into it .gravity + momemtum would make you swing back and forth in the hole from end to end …… !!!
The gravitational force would act differently when you are in the middle of the gravitating mass then when you are on its periphery….
June 28th, 2006 at 3:57 am
I wish that map showed cities so I would know what the longest possible nonstop airline flights would be.
Qantas is considering nonstop flights connecting Sydney and London, which would be the longest ones ever (I think). Trade winds would make the flight TO London a bit longer.
June 28th, 2006 at 5:26 am
I’d really love to read that article, and I’m sure I’m not the only one that would!
I don’t know why we always say we’d end up in China…
June 28th, 2006 at 5:30 am
Google Earth’s ruler tool is cool too. Not only does it find distances, it draws great circle routes between points. This is handy if you want to get quick and not too dirty estimates of the ground tracks of ballistic missiles or the initial ground track of a satellite launch. Throwing in a bit of eastward windage to take earth rotation into account improves the estimate some.
June 28th, 2006 at 8:03 am
Mike B, Roger Zelazny wrote a story that involves studying the MohoroviÄić discontinuity, or “Moho.” It’s in “I am Legion”, a collection of SF mystery stories by Zelazny. The plot of one story centers on scientists drilling the ocean floor, and people who don’t wish that to happen. That was my first encounter with the topic.
June 28th, 2006 at 9:17 am
Tim G. said “Trade winds would make the flight TO London a bit longer.”
As an international pilot and planner, I have to make a slight correction to your statement. Trade winds are insignificant for jet planning except when dealing with cross winds for landing. Trade winds are generally mild (~25-35 kts), blow from east to west and are a low altitude (sfc-10k ft) phenomenon.
On the contrary, jetstream winds are significant. They generally occur at higher altitudes (~18-40k ft), are higher speed (~100-175 kts or more), and run from west to east at mid latitudes. These winds severely affect jet traffic especially on long westbound flights at flight levels in the mid 30K ft (FL 350).
Unfortunately, great circle routes for aircraft are problematic due to the cost of clearances for overflight of some countries. Sometimes the longer way around is cheaper even at higher costs for fuel.
June 28th, 2006 at 11:30 am
Heck, I can describe a tunnel through the Earth in 3 words: “AAAAAAA! It BUUUUUUUURNS!”
June 28th, 2006 at 12:04 pm
… but alas, I’ve already written 3000 words and I’m only half done.
Take heart. From here, you have nowhere to go but up!
June 28th, 2006 at 12:38 pm
What struck me about it is that the asteroid impact crater off the Yucatan is very close to opposite the approximate position of India when the flood basalts that made the Deccan traps were laid down.
I wonder if there might be a harmonic or something.
June 28th, 2006 at 1:38 pm
Be careful… I hear the Earth’s Core is as hot as the Sun’s surface!
June 28th, 2006 at 4:00 pm
I suppose a movie called “The Botswana Syndrome” might not have had the same box office.
Let’s see… seven-tenths of the surface is water, so if I pick a random point it’s probability 0.3 to be on land, if the distribution of land is random (obviously it isn’t, it comes in clumps) then the opposite point also has an independent probability of 0.3 of being land, so the probability of both ends of any line through the centre of the earth being dry is 0.3 x 0.3, i.e. 9%. One in eleven. The line is wet at both ends 49% of the time. Rough work, good enough for this Web site
(Would any article here be complete without an little regretful appendix about the maths…)
If you drop a mass down a hole right through the earth, don’t other things come into play; air resistance obviously, the planet’s rotation? But if it’s a vacuum and we aren’t rotating… I’m not sure how we achieve that… and maybe we have to get rid of the moon and tides as well (oh yeah, the sun has to go too)… then you can drop your test mass down the frictionless hole and wait for it to come straight back up, I guess. But wait, what about adjustment for general relativity…
July 30th, 2007 at 1:19 am
“Even if the U.S. atom bombs were so powerful that, when dropped on China, they would make a hole right through the earth, or even blow it up, that would hardly mean anything to the universe as a whole, though it might be a major event for the solar system.”