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Around the world but still stay in one spot?
February 18, 2008 2:59 PM   Subscribe

If the right helicopter were to exist, could I rise X number of feet (not to far mind you) above the earth point myself in the right direction hover there and then watch the world go by underneath me? How fast would I have to go and should I bring a change of clothes?
posted by pianomover to Travel & Transportation (22 answers total) 9 users marked this as a favorite
 
Yes, but you wouldn't be hovering, you'd be flying at a high rate of speed, with the necessary speed varying depending on your latitude. At the equator, you would have to be flying at somewhere a little more than 1000 miles per hour. Altitude is irrelevant, all other things being equal. The Earth doesn't start spinning more slowly as you get farther from its surface.

You will run out of fuel rather quickly, and the only reason that you should bring a change of clothes is in case you soil yourself when you realize that you have just run out of fuel at 1000 miles per hour only a few feet above the surface of the Earth.
posted by The World Famous at 3:04 PM on February 18, 2008 [2 favorites]


No. The atmosphere rotates with the earth, so if you hover you'll be travelling with the atmosphere and thus with the earth. Helicopters don't work outside the atmosphere.
posted by ssg at 3:07 PM on February 18, 2008


It would be no different if you were in a helicopter or a car. The atmosphere rotates with the surface of the earth. If you were hovering, it would be the same as if you were standing on the surface -- you wouldn't go anywhere. If you want to see the earth move beneath you, you could drive your car at 60 miles per hour or you could fly your helicopter at 60 miles per hour. It would be no different.

World Famous above is talking about something different -- how fast would you have to fly in order to keep up with the sun.
posted by JackFlash at 3:09 PM on February 18, 2008


It would be possible if the helicopter was completely sealed, able to withstand being in a vaccuum, and was rocket powered. You would be literally orbiting the earth.
posted by blue_beetle at 3:13 PM on February 18, 2008


The Earth doesn't start spinning more slowly as you get farther from its surface.

Although, it may appear to do so. But that's an optical illusion.
posted by Cool Papa Bell at 3:24 PM on February 18, 2008


The way my psychics teacher explained it to me if I remember correctly was that the earth is rotating at about 1000 MPH and everything on the earth is rotating at the same speed. So that helicopter is rotating at 1000 MPH and taking off from the earth you would still be going the same speed as the earth. Its like taking a ball and throwing the ball straight up in the air the ball won't suddenly shoot off in on direction it will fall in place. So in other words no unless you left the earths atmosphere.
posted by lilkeith07 at 3:33 PM on February 18, 2008


There was a Marvel superhero named Guardian who possessed a suit with "the ability to lock himself relative to the Earth's electromagnetic field. Essentially, he cancels out the effects of the Earth's rotation upon himself. This allowed him to apparently "vanish", while actually being whisked westward at the speed of the planet's rotation."

The science sounds wonky, but you'd definitely need more than a helicopter.
posted by Brandon Blatcher at 3:49 PM on February 18, 2008 [2 favorites]


The circumference of the Earth at the equator is 24,900 miles. To stand still (relative to the sun) at the equator you'd have to travel at 1038 miles per hour. The "official" speed of sound is 770 mph, so you'd have to travel at Mach 1.35.

No helicopter can travel that fast. That's at least 5 times what a helicopter is capable of.
posted by Class Goat at 4:20 PM on February 18, 2008


You might be interested in reading about the physics behind Geosynchronous satellites which basically give you what you would want (though at 20,000 miles away)
posted by bottlebrushtree at 4:23 PM on February 18, 2008


You need a supersonic jet. And it's literally just going to look like it's whizzing by underneath you... which is what it's doing.
posted by Netzapper at 4:42 PM on February 18, 2008


you'd have to travel at 1038 miles per hour. No helicopter can travel that fast.

You need a supersonic jet.

No and no.

The earth, the atmosphere, the jet and the helicopter are all part of the same rotating system. If you want to see the earth move beneath you all you need are your own two feet. Just walk -- in any direction. It has absolutely nothing to do with the speed or direction of rotation of the earth. A jet or helicopter is no advantage unless you just want to see it all faster. And in that case it doesn't matter if you fly north, south, east or west.

You might be interested in reading about the physics behind Geosynchronous satellites which basically give you what you would want (though at 20,000 miles away)

No, a geosynchronous satellite would always have the same fixed spot under it. You wouldn't see the earth surface move at all. It would be no different than standing on the earth or hovering in a helicopter.
posted by JackFlash at 5:14 PM on February 18, 2008


You make a good point, JackFlash. I assumed that the question was asking how fast one would have to travel in order for the Earth to rotate underfoot at its actual rotational speed. Now that I look again at the question, I see that it is only actually asking how fast to go to "watch the world go by underneath me." The answer, as you have put it, is any speed at all, in any direction, at any altitude, by any means. No change of clothing necessary.
posted by The World Famous at 5:40 PM on February 18, 2008


Hmmm...I wouldn't be so fast to concede The World Famous. While I think that JackFlash got the question right if you interpret it literally, the gist of it seems to be more what you were answering originally. And to the point of whether or not the Earth moves at different speeds at different altitudes, I think that the answer is yes, the outer edges of the atmosphere being like the outermost ring of a record. RPM would be the same, but velocity would be different, no? I think that the difference would be minimal (altitude relative to the diameter of the earth), but it's still not quite right to say there's no difference.
posted by hue at 7:20 PM on February 18, 2008


The question has incompatable premises. In the first sentence, the questioner refers to hovering, and in the second, he or she asks about how fast they would have to go. Hovering involves no forward motion and no speed.

The answer is as follows:

(1) Hovering over a spot would keep you in that same spot because the atmosphere is moving along with the rest of the earth generally.

(2) One could go forward at a speed that would be the same as the rotational speed of the earth, but this would be forward travel, not allowing for the earth to rotate below them.

(3) The plane takes off. The conveyor belt does not affect the wheels which spin freely as the plane's engines push against the air.
posted by Ironmouth at 7:40 PM on February 18, 2008


So basically if you had a jet capable of 1038 mph you could fly in the opposite direction the earth was rotating and if you did so for 24 hours and then landed, you would finish where you started and would have been able to see the whole world pass beneath your feet.

So in essence you would have remained in the same "space" or the same "location" in space. In this situation your use of the word "hover" is not incorrect.
posted by crewshell at 7:48 PM on February 18, 2008


So basically if you had a jet capable of 1038 mph you could fly in the opposite direction the earth was rotating and if you did so for 24 hours and then landed, you would finish where you started and would have been able to see the whole world pass beneath your feet.

Not exactly. It wouldn't matter what direction the jet traveled -- north, south, east, or west. You would travel completely around the earth and land in the same place in 24 hours.
posted by JackFlash at 8:48 PM on February 18, 2008


I think the idea of the question was more about having the earth travel while you remained a constant. Of course that would be a constant in "space" not a constant in relation to the earth.

If you flew 1038 miles north or south you would trace a diagonal line around the earth as your movement took you vertically, while the earths rotation was taking your lift off spot perpendicularly. Of course you would end up at the same spot when the cycle was complete.

Actually with more thought to this I guess you wouldn’t be standing still in "space" either as the whole orbit of the planet around the sun would end up causing you to bust out of the atmosphere if you were in deed suspended at one point in space....
posted by crewshell at 9:03 PM on February 18, 2008


If you flew 1038 miles north or south you would trace a diagonal line around the earth as your movement took you vertically, while the earths rotation was taking your lift off spot perpendicularly.

You wouldn't follow a diagonal line. If you took off from Greenwich and flew north you would follow the prime meridian great circle all the way around the earth, crossing both poles.

You are correct about the earth moving through space around the sun. It travels about 1.6 million miles per day.
posted by JackFlash at 9:25 PM on February 18, 2008


The entire solar system and galaxy are also moving. You'd want to figure out a way to remain stationary compared to the entire universe, too. That's really the tough one.
posted by The World Famous at 9:36 PM on February 18, 2008


However if one wanted instead to follow a fixed latitude instead of a great circle one can keep up the pace at a sedate walk near the poles.
posted by Mitheral at 10:58 PM on February 18, 2008


This is essentially a frame of reference problem.

For most objects the frame of reference is being on the spinning earth with a tremendous amount of built-in velocity. To watch the earth spin you would have to cancel that velocity somehow. You can't do this without some sort of extraordinary propulsion or violation of the laws of conservation of energy or something, but if you're willing to work within the limitations of the Newtonian system, you can in fact navigate around the Earth quite easily. You just can't really "hold still" (within your frame of reference) anywhere except geosynchronous orbit -- or on the surface.

A space elevator is a hypothetical device that would travel between those two spots using a perfectly balanced tube along which pressurized containers could travel. It's somewhat related to this concept of yours. The tube would in theory "hang" from space down near the surface -- pretty loopy.

But what you're talking about is little different from an orbit or an airplane flight in the right direction and at the right speed to give you the possibility of seeing outside your frame of reference so you could experience this spinning-Earth illusion.

I'd just try breaking your frame of reference in some simple ways, like going to an amusement park, or taking a huge banking approach to O'Hare in a 757 directly over downtown Chicago. Get those buildings tilted and look out the window, the whole time held comfortable via Newtonian mechanics in your banking airplane, and imagine it's the Earth gimbaling around you instead of the other way 'round. Not that hard once you get the hang.
posted by dhartung at 12:09 AM on February 19, 2008


Thank you all for responding - I've been thinking about this since middle school, when I first asked this question, and was told I was being foolish and wasting class time, shout out to Mr. Calkins.
posted by pianomover at 12:12 PM on February 19, 2008


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