Question about space elevators:

Originally posted by Metal Brain
How stupid are you? Skyscrapers don't reach the ionosphere. Humy is equally ignorant. An astonishing electric charge from the ionosphere is not chance like thunderstorms, it is certainty. You are all idiots.

Where did you get the idea the ionosphere starts at 20 to 25 miles up? Show us your source of information. Here is MY source:

http://www.qsl.net/zl1bpu/IONO/iono101.htm

This work shows the lowest it ever gets is 250,000 feet altitude and that only in daylight hours. At night the lowest level is more like 60 miles up, well over 300,000 feet altitude.

If you have something different, please show us the links.

I have been using the ionoshere for over 50 years in my ham calls.

Originally posted by googlefudge
The ionosphere starts above 85km, we are talking about a 20~25 mile high tower,
it will never reach the ionosphere, so even if you were correct [you are not] you
would still be wrong and an idiot [which you are].


EDIT: and as for the cable...

http://www.mill-creek-systems.com/HighLift/chapter10.html

Discharging the Ionosphere

The ...[text shortened]... ly a small volume of centimeters radius would show any affect from the cable's presence.

"we are talking about a 20~25 mile high tower"

You think it is possible to build a tower that high? What do you propose making it from? If you tell me steel it will be the ultimate lightning rod. It will never stay upright either. You are the idiot.

Originally posted by sonhouse
Where did you get the idea the ionosphere starts at 20 to 25 miles up? Show us your source of information. Here is MY source:

http://www.qsl.net/zl1bpu/IONO/iono101.htm

This work shows the lowest it ever gets is 250,000 feet altitude and that only in daylight hours. At night the lowest level is more like 60 miles up, well over 300,000 feet altitude. ...[text shortened]... please show us the links.

I have been using the ionoshere for over 50 years in my ham calls.

"At night the lowest level is more like 60 miles up"

Don't you mean km?

Even at 37 miles a space elevator 25 miles high would be vulnerable. It would be very risky. Lightning has been known to travel 25 miles. People have been struck by lightning on a day with a clear blue sky. Lightning also travels from clouds to the ionosphere from the negatively charged part of the upper cloud called sprites. I learned about them on PBS, probably Nova or Nature.

A space elevator would be plagued with all sorts of problems and would not be cost effective even if it was possible. Building a 25 mile high tower is a failure waiting to happen. Even if a tether could be made from a non-conducting material it would be crazy to think it could be put in place without all sort of things going wrong as well. It would never work. It is a stupid idea.

Carbon nanotubes conduct electricity.

Originally posted by Metal Brain
"At night the lowest level is more like 60 miles up"

Don't you mean km?

Even at 37 miles a space elevator 25 miles high would be vulnerable. It would be very risky. Lightning has been known to travel 25 miles. People have been struck by lightning on a day with a clear blue sky. Lightning also travels from clouds to the ionosphere from the negativel ...[text shortened]... rong as well. It would never work. It is a stupid idea.

Carbon nanotubes conduct electricity.

It is not a stupid idea. The technology is already in place to do it except for the cable itself. We have carbon nanotube cables but they are spliced together right now and we are waiting for some genius to be able to make continuous lengths in one piece. THEN we have the stuff in place. All the problems you think you know about have been dealt with in theory.

Also, it is slightly ridiculous to think you need a tower 25 km high in the first place. All you need to do is have a base on top of an equatorial mountaintop, that will work fine, something way less than 1 km, maybe something just like the Eiffel tower.

I was playing devil's advocate about the lightning thing. There IS no ionosphere at 25 Km up at any time except maybe during a Coronal Mass ejection which can push Earth's magnetic field pretty much flat against the surface. Other than that, it is pretty tame with known parameters. If you DID build a 25 km tower there would be no lightning and if there were, lighting rods would take care of the issue anyway. Besides, the most energetic layers are the ones highest up, a couple hundred Km. You can see the effect of it from the ISS where they can see aurora below them but they are in fact cutting through the highest layers and they have no effects to worry about.

They get more effects from cosmic rays hitting their eyes which causes a visible flash even in total darkness. That is more worrisome than any kind of lightning problem from the ionosphere.

Originally posted by sonhouse
It is not a stupid idea. The technology is already in place to do it except for the cable itself. We have carbon nanotube cables but they are spliced together right now and we are waiting for some genius to be able to make continuous lengths in one piece. THEN we have the stuff in place. All the problems you think you know about have been dealt with in theo ...[text shortened]... n total darkness. That is more worrisome than any kind of lightning problem from the ionosphere.

They get more effects from cosmic rays hitting their eyes which causes a visible flash even in total darkness.

Actually, that sounds kind of cool to me.

Some (rare) ultra-high energy cosmic rays have energies exceeding those of a medium paced cricket delivery. Is this a scientific explanation for the blinding flash on the road to Damascus?

Have they experimented, or looked at, magnetising long term stations. It's cut out some of these things.

Originally posted by sonhouse
It is not a stupid idea. The technology is already in place to do it except for the cable itself. We have carbon nanotube cables but they are spliced together right now and we are waiting for some genius to be able to make continuous lengths in one piece. THEN we have the stuff in place. All the problems you think you know about have been dealt with in theo ...[text shortened]... n total darkness. That is more worrisome than any kind of lightning problem from the ionosphere.

" If you DID build a 25 km tower there would be no lightning and if there were, lighting rods would take care of the issue anyway."

https://en.wikipedia.org/wiki/Upper-atmospheric_lightning

"You can see the effect of it from the ISS where they can see aurora below them but they are in fact cutting through the highest layers and they have no effects to worry about."

The ISS is not grounded as a tower would be. Are you suggesting that lightning rods will protect workers while they are building the tower? The higher you go the greater the chance of sprites. How is the lightning rod going to be raised that high without putting workers at high risk?

"All you need to do is have a base on top of an equatorial mountaintop, that will work fine, something way less than 1 km, maybe something just like the Eiffel tower."

I always wondered why space rockets were not launched from mountain tops. Still 1 km even on an equatorial mountain top is hard for me to believe. What is your source of information?

In any case it cannot be done with today's technology. Are you suggesting that carbon nanotube cables be used for the lightning rod?

edit: Even if it could work in theory after the right technology is developed that does not mean it would be cost effective. I'm sure it would be insanely expensive and then you have to worry about something going wrong like the tower blowing down.

Originally posted by Metal Brain
" If you DID build a 25 km tower there would be no lightning and if there were, lighting rods would take care of the issue anyway."

https://en.wikipedia.org/wiki/Upper-atmospheric_lightning

"You can see the effect of it from the ISS where they can see aurora below them but they are in fact cutting through the highest layers and they have no effects ...[text shortened]... y expensive and then you have to worry about something going wrong like the tower blowing down.

I think you are blowing the lightning problem all out of proportion. They already know there will be currents in any kind of conductive ribbon because if you move a conductor through a magnetic field you get electric current generated so they can actually use that current to power some of the equipment. The problem with that scheme is you don't get that energy free. It comes with the cost of the cable slowing down so you have to have some method of keeping the geo sync point in orbit since it would be losing velocity to the magnetic energy generated by the cable.

But like I said, the cable might attract lightning but that energy can be handled, its not like there would be terawatts generated.

Where was your source of information this could be a problem?

Has there been energy measurements made of the energy in those sprites?

I don't think every lightning strike is accompanied or preceding by a sprite.

Originally posted by sonhouse
I think you are blowing the lightning problem all out of proportion. They already know there will be currents in any kind of conductive ribbon because if you move a conductor through a magnetic field you get electric current generated so they can actually use that current to power some of the equipment. The problem with that scheme is you don't get that ene ...[text shortened]... those sprites?

I don't think every lightning strike is accompanied or preceding by a sprite.

It seems I was hasty in using the term sprite. Blue jet would be a closer term and gigantic jet might be the one I am looking for. Don't ask me why they called them jets. I would have gave them a different name.

http://www.scientificamerican.com/article/gigantic-jets-connect-thu/

Originally posted by Metal Brain
It seems I was hasty in using the term sprite. Blue jet would be a closer term and gigantic jet might be the one I am looking for. Don't ask me why they called them jets. I would have gave them a different name.

http://www.scientificamerican.com/article/gigantic-jets-connect-thu/

I know, I saw that in the print issue.

Originally posted by sonhouse
I know, I saw that in the print issue.

Given that lightning can go from the top of thunderstorms to the ionosphere, I think it is a valid concern that anything much higher than that would attract strikes more often. The only way to avoid that danger is to use non-conducting materials.
Trying to erect a lightning rod will attract a strike before it gets 20-25 miles high. The surface of the earth is slightly negatively charged. Electrons will want to follow the path of least resistance. Since the distance from the upper troposphere to the ionosphere is so great cutting the distance in half with a conductor seems crazy. Whoever is convinced that is safe better be sure of themselves before trying to endorse this idea.

Originally posted by Metal Brain
Given that lightning can go from the top of thunderstorms to the ionosphere, I think it is a valid concern that anything much higher than that would attract strikes more often. The only way to avoid that danger is to use non-conducting materials.
Trying to erect a lightning rod will attract a strike before it gets 20-25 miles high. The surface of the e ...[text shortened]... oever is convinced that is safe better be sure of themselves before trying to endorse this idea.

I'm sure they will find out one way or the other. But the best bet for the elevator cable ATT is carbon nanorods or some variation, which will be excellent conductors.

If it was a problem, maybe they would need to have cables angled off going to ground like guy wires but 30 or more km long.

I don't think it will be a problem but if solutions are already thought of, things go a lot better getting from the labs to the world.

Originally posted by Metal Brain
.... better be sure of themselves before trying to endorse this idea.

Don't you think that scientists would naturally think about these obvious things? You massively underestimate their intelligence while arrogantly massively overestimate your own. Obviously, they won't be putting any such cables up until they have done all the calculations of such things and made sure they resolved all these safety issues. You must arrogantly be under the delusion that scientists are incredibly stupid -we are not.

Originally posted by humy
Don't you think that scientists would naturally think about these obvious things? You massively underestimate their intelligence while arrogantly massively overestimate your own. Obviously, they won't be putting any such cables up until they have done all the calculations of such things and made sure they resolved all these safety issues. You must arrogantly be under the delusion that scientists are incredibly stupid -we are not.

The concept of a space elevator has been around a very long time before the discovery of ionosphere to troposphere discharges (gigantic jets). Gigantic jets are a recent discovery, so much was written about the idea of a space elevator before gigantic jets were known.
You would think scientists would think about these things NOW, but they may not be so obvious to scientists who could possibly be running with an old idea without being up to date about ionosphere discharges. Scientists do stuff like that even though they are smart people. Also, people often engage in "group think" and intelligence has nothing to do with it. Even a genius cannot escape human nature.

If you surround yourself with people who all support an idea you will only hear the good things about the idea. What you hear the most shapes your whole belief. That is why the BBC has you convinced climate change is going to kill billions of people. It doesn't matter how absurd the idea is as long as you hear it enough.

http://www.livescience.com/1956-study-gossip-trumps-truth.html

Originally posted by humy
Don't you think that scientists would naturally think about these obvious things? You massively underestimate their intelligence while arrogantly massively overestimate your own. Obviously, they won't be putting any such cables up until they have done all the calculations of such things and made sure they resolved all these safety issues. You must arrogantly be under the delusion that scientists are incredibly stupid -we are not.

"Don't you think that scientists would naturally think about these obvious things?"

Did you think of it before I brought it up?

Originally posted by Metal Brain
"Don't you think that scientists would naturally think about these obvious things?"

Did you think of it before I brought it up?

YES. Who hasn't heard of lighting?