Why Don’t Airplanes Hover In The Sky And Let The Earth Pass Beneath Them?

The answer is – NO, you cannot have an airplane go straight up and let the Earth pass underneath to reach your destination, unless you are willing to burn an incredibly large amount of fuel and make the journey downright uneconomical.

This is something that I used to wonder about quite often when I was a kid. However, if you pause for a moment and consider the idea, that line of thinking is not completely illogical, right? We all know that Earth spins on its axis and completes one rotation every 24 hours. Following simple reasoning, why can’t airplanes simply take off, go straight up into the sky and then hover at a higher altitude for a while, letting the Earth spin underneath? When the intended destination comes into view below, the pilot can make a quick landing.

Advertisement

‘Using this technique, wouldn’t we be able to save a lot of fuel, thereby reducing the costs of flying to a great extent?’

It may seem intuitive, but just try proposing this to a member of the aviation industry. Their response will be something like this….

How fast does the Earth rotate?

There are certain things in the world that we know are true without the need for any explanation. Just as we know that 2+2 equals 4, rather than 5, we also know that Earth rotates on its axis all the time. However, since we don’t live in a tiny world where we can see mountains, forests, buildings and other structures spinning endlessly, the rotation of Earth becomes quite difficult to visualize. That’s why we tend to ignore its effects, which leads to questions like the one proposed in the title of this article.

Even so, just because we don’t see things spinning around us doesn’t mean that the Earth isn’t spinning too. In fact, it’s spinning extremely fast. At the equator, the rotational speed of the planet is at its maximum – 1037 mph (1670 kmph) (Source), and this speed decreases as you move away from the equatorial regions towards the poles. This rotational speed is faster than many things on the planet, including the fastest trains and cars, and even a bullet! So, one thing should be very clear…

The atmosphere is NOT still; it’s also moving VERY fast

Another thing that people mistakenly assume is that the atmosphere just ‘sits there’ enveloping the entire Earth. However, it doesn’t work that way. The atmosphere is not a single entity; rather, it is a collection of gases and other constituents that moves along with the Earth. It would have escaped millions of years ago, in fact, or not even existed in the first place, if not for the strong gravitational pull of our planet, that keeps it adhered and prevents the gas from escaping into space.

Advertisement

The main takeaway from this is that, due to the rotation of Earth, the atmosphere gets ‘dragged’ along the surface of the planet, as opposed to being stationary.

Why can’t airplanes go straight up and let the Earth pass beneath?

Now that we’ve looked at the two important factors involved in this proposed idea, it should be much easier to understand the reason behind our brusque answer of “No”. Consider this: when you drop a stone from the top of a building, it falls next to the base, not meters away due to the spin of the Earth.

stone thrown from top of a building

When a stone is dropped from the top of a building (A), it doesn’t fall far off from its base (B); rather it falls right next to its base (C)

Following the reasoning of ‘going straight up and hovering in the sky’, shouldn’t the stone fall at least a few meters away from the base of the building? Between the time you released the stone and the time it hit the ground, didn’t the Earth spin, thus moving the base of the building away?

Similarly, when you throw a ball in the air while walking, it lands in your hands, not somewhere behind you. Going by the above logic of hovering in the air, the ball should land behind you because you moved away beneath the ball as the world turned.

A boy catching a ball

When a running boy throws a ball up in the air (A), it doesn’t fall behind him (B); rather it falls right back into his hands (C)

However, that doesn’t happen. Similarly, a plane cannot hover in the sky and land at a different destination.

This is because, when the plane is parked on the runway, it’s already moving at a very high speed (almost 1000 mph) due to the rotation of the Earth. Then, when it takes off, its final speed is the sum of two different speeds – the speed that it gained by firing its engines, and the speed that it already has due to the rotation of Earth.

The planet rotates from West to East, so when the plane takes off, it’s already moving westwards. When flying to locations that lie to the west of an airport, a plane has to accelerate faster than it would do while going eastwards.  This means that the plane doesn’t have to accelerate as much while going eastwards by letting the Earth slip underneath itself.

Advertisement

If you insist, however, on going straight up in the sky and hovering, then the first thing you’ll need is an airplane that can hover for a long time (‘hovering’ is not what airplanes are built for, FYI). Then, you would need to burn a huge amount of fuel in order to stay stationary and resist the strong winds slapping against the plane at that altitude. All in all, traveling via this technique would be a terrible idea, both financially and practically.

If this question pops up in your head again, simply ask yourself this: can I travel from the front to the rear of a non-accelerating bus by jumping up and down (inside the bus), letting the bus travel beneath me?

References

  1. Cornell – Ask an Astronomer
  2. Wikipedia – Earth Rotation
  3. NASA
The short URL of the present article is: http://sciabc.us/DaQGe
Related Articles



Add comment

E-mail is already registered on the site. Please use the Login form or enter another.

You entered an incorrect username or password

Sorry, you must be logged in to post a comment.

3 comments

by Newest
by Best by Newest by Oldest
1

Once you take off in an airplane you are no longer sitting on the Earth or tethered to it. If the Earth was rotating and you traveled against the spin and flew at 500 mph (east to west), in one hour you should cover 1500 miles. If flying at 500 mph in the same direction of the spin, since the Earth (at the equator) is supposedly spinning at roughly 1000 mph you would lose 500 miles of distance every hour (for the Earth is moving 500 mph faster than you are), and you would never make it to your destination.

2

"The planet rotates from West to East, so when the plane takes off, it’s already moving westwards. When flying to locations that lie to the west of an airport, a plane has to accelerate faster than it would do while going eastwards. This means that the plane doesn’t have to accelerate as much while going eastwards by letting the Earth slip underneath itself." What a load of crap!

Planes do not "accelerate" faster when going in the "other" direction.

The Earth is probably flat and motionless as the re-emerging paradigm may suggest. It would seem the time has come that the current and persistent theories about the shape, size and motion of the planet need to be revisited. Maybe, just maybe, mistakes were made with calculations or observations, but it's "too late to change the text books now" just as with the true nature of the atom and the fantastic theory of how electrons orbit the nucleus in fixed and certain paths; quantum science has since proved this a falsity... How many people, dead or alive, have been to the center of the Earth (or even to the moon) to validate the inner core/outer core crap that is taught in schools? Why all the BS about Antarctica? For instance, no 24 hour sun and no unescorted explorations allowed... Why all the BS about NASA? For instance, CGI images of Earth, has the Van Allen belt been crossed or not? The original moon landing tapes have been lost?! Did we really go to the moon or is Stanley Kubrick rolling around in his grave laughing? Project Fish Bowl; did they find the dome or not? Female astronauts wearing hair gel to keep the illusion of micro gravity, bubbles in space, snorkels for astronauts?! Really?! Why is no difference felt between the angular rotational speed at the equator, which is supposedly greater than 1000 mph, and that as one approaches the poles, which by deduction approaches zero?

Saying the Earth is flat is motionless does sound absolutely absurd and probably boarders insanity, but there seem to be legitimate questions that are not being answered in addition to observations that go against the current "best guesses".

3

JohD - you are so right