Space elevator and ionoshphere

In summary: So even if you could build a space elevator capable of reaching 250kV, you would not be able to use it to power anything.
  • #1
mee
213
1
space elevator and ionosphere

would a space elevator short circuit the 250,000 volt difference between the Earth and the ionoshere making it dangerous?
 
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  • #2
I don't know about short circuit. A space elevator would have a pretty high resistance.

Do you have a source on the 250kV number? If that's the voltage, then the elevator would probably get quite hot!
 
  • #3
enigma said:
I don't know about short circuit. A space elevator would have a pretty high resistance.

Do you have a source on the 250kV number? If that's the voltage, then the elevator would probably get quite hot!

I'm sorry, I don't remember the name of the show but it was on television about an hour ago. Probably on the science channel. It also was not mentioned in passing but specifically pointed out with diagrams.
 
  • #4
Never heard of this. But hey, if it's true, it could be a great way to make
power ! :cool:
 
  • #5
mee said:
I'm sorry, I don't remember the name of the show but it was on television about an hour ago. Probably on the science channel. It also was not mentioned in passing but specifically pointed out with diagrams.

Always remember that something appearing in print has no relevance on its being true or not.
 
  • #6
LunchBox said:
Always remember that something appearing in print has no relevance on its being true or not.

It was not actually in print. Also, being on a television documentary doesn't necessarily make it suspect either.
:rolleyes:
 
  • #7
linky thingy
mee said:
It was not actually in print. Also, being on a television documentary doesn't necessarily make it suspect either.
:rolleyes:

Actually it was well covered in the press one or two months ago. Maybe it was overlooked by some due to the conventions. Here’s one site linky thingy or do your own Google for "space elevator". The proponent wants to use carbon-nanotube-composite ribbon for the needed strength.



http://www.space.com/businesstechnology/technology/space_elevator_020327-1.html
 
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  • #8
enigma said:
I don't know about short circuit. A space elevator would have a pretty high resistance.

Do you have a source on the 250kV number? If that's the voltage, then the elevator would probably get quite hot!

In his Lecture series, Feynman indicates a typical value of 400,000 volts potential between sea level [in a clear atmosphere] and the region at about 50,000 meters. At lower altitudes we find a gradient of about 100 volts per meter on a clear day.

I don't think the carbon materials considered for a cable are conductive.
 
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  • #9
Ivan Seeking said:
At lower altitudes we find a gradient of about 100 volts per meter on a clear day.

Whaaa?

That's not right...
 
  • #10
enigma said:
Whaaa?

That's not right...


It sure is. See Feynman. [Edit: Book II, page 9-1; sixth printing, 1977.]

There is a nice experiment to demo this fact. Fill a metal bucket with water and hang it from a tree using a good insulator. Poke a small hole in the bucket and allow the water to drip. The bucket will acquire a charge of about 100 volts per meter above ground level [in ideal conditions] as a result of the excess charge carried away by the water droplets. Note that this can result in dangerous shock depeding in part on the size of the bucket.
 
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  • #11
I should add that this lower altitude potential is not going to induce significant current flow. The ionic rain that falls in accordance with this only carries a current density of one micro-micro amp per meter squared. So the potential would only matter when you reach the ionosphere, AFAIK.

Note that the people who launch model rockets loaded with trailing wires which induce directed lightning strikes, only launch when an ambient electric field strength of about 30KV/meter is measured.
 
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1. What is a space elevator?

A space elevator is a proposed method of transportation that involves a cable stretching from Earth's surface into space. It would allow for large objects, such as spacecraft or payloads, to be transported from the ground to orbit without the need for rockets or other expensive launch vehicles.

2. How does a space elevator work?

A space elevator would use a combination of centrifugal force and gravity to keep the cable taut and in place. A counterweight would be located at the end of the cable in space, and the rotation of the Earth would help keep the cable upright. Elevators or climbers would then travel up and down the cable using mechanical or electrical power.

3. What is the ionosphere and why is it important for a space elevator?

The ionosphere is a region of Earth's upper atmosphere that is ionized by solar and cosmic radiation. It plays an important role in radio communications and navigation, and it also helps protect Earth from harmful radiation. For a space elevator, the ionosphere would be a critical factor in determining the location and design of the cable, as it can affect the strength and stability of the cable.

4. What challenges are associated with building a space elevator?

One of the biggest challenges of building a space elevator is developing a strong and lightweight material that can withstand the extreme forces and conditions of space. Other challenges include finding a suitable location for the base of the elevator, dealing with potential collisions with debris and spacecraft, and addressing safety concerns for humans traveling on the elevator.

5. Are there any current plans to build a space elevator?

While there have been many proposals and studies on the concept of a space elevator, there are no current plans to build one. The technology and materials needed are still in development, and there are many technical and financial challenges that would need to be overcome. However, research and testing continue to take place, and it is possible that a space elevator could become a reality in the future.

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