Air baloon and came back down about 12 hours later

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In summary, the conversation discusses the feasibility of traveling halfway around the globe in an air balloon, assuming no wind and disregarding practical difficulties. It is determined that the atmosphere thins out and the Earth's rotation would affect the balloon's movement, making it difficult to achieve such a trip. It is also mentioned that the Earth's rotation speed varies based on latitude, and that rising in a balloon would result in traveling on a Great Circle. Ultimately, it is concluded that this method is not an efficient way of traveling long distances.
  • #1
gm5170
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If I went up in an air baloon and came back down about 12 hours later (assuming there was no wind), would I be half way around the globe ? this has been rattling my brain for a while. there are obviously practical difficulties, but theoretically, is this feasible ? if not, why ?
 
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  • #2
The thing is here is that the air mass rotates with the Earth as well. Otherwise the wind would be blowing at about 1000 miles per hour at the equator. If the balloon left the atmosphere I guess it would work.
 
  • #3
interesting. how high up does the 'atmosphere' stretch ?
 
  • #4
The atmosphere does not have a 'limit,' but its pressure decreases rapidly with increasing altitude.

From wikipedia http://en.wikipedia.org/wiki/Earth's_atmosphere#Pressure

Therefore, most of the atmosphere is below 100 km (99.9999%) although in the rarified region above this there are auroras, and other atmospheric effects.

Think about it this way. When your balloon is in contact with the Earth's surface, it's moving the same speed as the Earth's surface. The Earth's surface is, in fact, rotating at about 1000 mph (at the equator) with respect to the Sun.

Objects in motion tend to stay in motion -- this is Newton's first law of motion. Your balloon would continue moving at the same speed, 1000 mph, hovering over the same point on the Earth's surface, unless some force acted upon it. You could fire a rocket motor, for example, in the direction counter to the Earth's rotation.

You could eventually sit still with respect to the Sun, and watch the Earth's surface rush past below you at 1000 mph. As has been said, though, you'd have to deal with the air also rushing past you at 1000 mph, and it might not be a very pleasant ride.

- Warren
 
  • #5
Quite a bit further than a balloon will take you, like 100 km or so. It thins as you go up, so a balloon will become less bouyant a lot sooner.
 
  • #6
It also depends on your latitude. If Earth had no atmosphere, and your baloon could rise anyway (baloons need air) then the Earth would rotate under you. But imagine trying this at the North Pole. You wouldn't be halfway around the world when you landed 12 hours later. You'd still be at the North Pole. The speed which the Earth rotates is ~1000 km/hr * cos(latitude). cos(0)=1 so at the equator the Earth rotates ~1000 km/hr. cos(38)=0.788, so in San Francisco, the Earth rotates 788 km/hr. cos(90)=0 so at the North Pole (& South Pole) the Earth rotates 0 km/hr.

But when you rise you will have the velocity of the ground you were on. So actually, you'd ultimately change hemispheres as you would be traveling on a Great Circle and the ground you were on holds steady to its latitude.
 
  • #7
dang! so my hopes of an efficient way of traveling long distances isn't possible this way :(

thanks all 4 ur responses.
 

What is an air balloon?

An air balloon is a type of aircraft that is lifted and propelled by hot air or gas, usually helium or hydrogen. It consists of a large balloon or envelope filled with the lifting gas, attached to a basket or gondola for passengers and a heat source to control the temperature of the air inside the balloon.

How does an air balloon stay in the air?

An air balloon stays in the air because of the principle of buoyancy. The hot air or gas inside the balloon is less dense than the surrounding air, causing it to rise. As the balloon rises, it displaces more air, creating an upward force that keeps the balloon airborne.

How high can an air balloon fly?

The maximum altitude an air balloon can reach depends on various factors such as the size and weight of the balloon, the lifting gas used, and weather conditions. Generally, air balloons can reach altitudes of up to 20,000 feet, but some special balloons have reached heights of over 60,000 feet.

How long can an air balloon stay in the air?

The duration of an air balloon flight depends on the amount of fuel or heat source available, wind conditions, and the weight of the balloon and its passengers. On average, an air balloon can stay in the air for 1-2 hours, but some long-distance balloons have stayed airborne for several days.

What happens when an air balloon comes back down?

When an air balloon comes back down, the pilot controls the descent by releasing some of the hot air or gas inside the balloon. As the balloon descends, the air inside cools down, making it less buoyant and causing it to sink. The landing is usually smooth, and the balloon is then packed up for its next flight.

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