Japan Plans Sail-Paced Space Elevator For 2050

At least it will be sail paced instead of snail paced... So what method of production might they be using to create the thousands of miles of carbon nanotubes? Is the cart before the horse again?

"Where were you when they built that ladder to heaven..."

I thought it was a Stairway to Heaven.

Nowadays the religions which promise an elevator to Heaven are the fastest growing.

A week in this elevator? With my luck, that's the week the elevator music system would have a glitch and we'd all be stuck listening to Rebecca Black's 'Friday' for 176 hours straight.

Carbon nanotubes are conductors, aren't they? Wouldn't passing a conductor through the ionosphere either rapidly (as in one huge lightning stroke) or slowly (as charges drift from other regions to the conductor) discharge the ionosphere? In either case, it would disrupt communications and expose us to more radiation etc.

I can't imagine being able to insulate the cable from ionospheric voltages...

Even insulated, the compressing of the magnetic field by rotating in the sun field, it will build charges in the elevator that will have to be dealt with.

Passing a conductor through magnetic fields at above escape velocities, even when the angle approaches 0, takes some planning. When the space shuttle tried to unreel a conductive space tether, the tether burned up as I had predicted. And it was miles not hundreds of miles long.

A big difference is the space elevator would be grounded to the earth. The electrical potential would be huge at times to say the least.

So travel to the base of the space elevator could kill you. Your car tires insulate you until you stepped out of the car. Unless the potential was so great it jumped to the car while traveling. Then the dynamics get fuzzy with ifs.

Brad

Correction not ...hundreds of miles long. But 60,000 miles long.

A magneto of epic proportions is an understatement.

Hmmmm... At first glance, your postulate appears credible. However, Obayashi seems to be quite the formidible challenger for this undertaking. The (thickness of) the ionosphere represents only a miniscule fraction of the total length involved. And, I'm willing to bet, one of their geniuses has already considered whatever 'dielectric' sections and 'drains'/'sinks' would need to be incorporated .... [()].

{Also, isn't our sun's radiation constantly "building/recharging" the ionosphere, to preclude 'loss-of-protection'...?}

The earthquake in Japan certainly didn't hurt Obayashi's stock one iota. Can't help but wonder exactly what is going thru their minds, concerning the long-term payback for THIS monumental undertaking...(?) Lots of speculation, I'm sure. But..."Hey!" Elevator to bring back gold, titanium, helium3 etc from our moon and/or asteroids ... not-to-mention the possibilities of the station (orbit-end) becoming a base for future asteroid-avoidance technologies. This just might actually be a part of the grand plan......!

Ionosphere is not the issue or at least only a small part.

http://www.youtube.com/watch?v=ulSeES6AS0Q&feature=related

Now swing a 60,000 mile wire around through this field every 24 hrs.

I don't believe they will need an external power source.

"Neat simulation" ... ("PS"~_{my previous reply was actually a collective response to 6,7&8 altogether}).

Perhaps my awareness as to the relative weakness of the earth's magnetic field contributed to my sloughing-off the possibility of an insurmountable problem from it.*

I was made aware (via NACE) some years ago, of NOAA's Nat'l Geophysical Data Center ... maintaining a web-based database of solar activity that could be used by personnel who perform Cathodic Potential Surveys on pipelines.

One example of telluric activity on a cross-country pipeline revealed potential fluctuations on the order of "a couple of volts" (significant, when -850 millivolts with respect to the reference cell is what is mandated by federal law).

I admit that I have no idea what the charts (from the end of the simulation, below) represent ... (can you expound on them, perhaps?)

* Trying to grasp the gist of what you are stating, here ... I assume that you were referring *not* simply to induction in the nanotube-wire from cutting-thru the lines of earth's field ("magneto"), but, from something in the solar wind...? Or, where am I misunderstanding the point you were making (which fellow CR4'ers GOT)...

"Neat simulation" ...

If I understand correctly, this is NOT a simulation, rather a depiction of real data.

I'm not sure about the four values shown in the graphs, but they are apparently magnetic field strengths in nT (nanoTeslas), and of course the horizontal axis is time for one day.

My concern about the ionosphere had nothing to do with magnetism. I picture a huge capacitor, with the earth as one electrode and the ionosphere as the other. If lightning is any indication, the potential on this capacitor could be billions of Volts. Short circuit that capacitor, and there have got to be some significant fireworks! Am I totally off base?

My 'icon' above [()] was indication that I, myself, am uncertain of numerous points pertaining to this discussion. {and, perhaps *I* am wrong in having used the word "simulation" ... but ... I took it from the fast-rolling credits at the end of the video : "Pressure Simulation Copyright@Nict"}.

Nonetheless , the point of my first post (9) was simply that I'd bet dollars-to-doughnuts that Obayashi had already taken the "major concerns" into consideration ... and, most likely have determined how to take advantage of lightning discharges, etc (perhaps melting salts, or heating oil/glycol, or 'what-have-you').

I highly doubt that they would make such an exclamation lightly. Potential investors would certainly ask such questions themselves, would they not? I'd like to be the proverbial fly-on-the-wall, able to hear their responses......(wouldn't you...?)

Blessings to all ~

The lightning show from the capacitance discharge of the ionosphere will be awesome.

After doing the math at 60,000 miles the end will be traveling only 16,000 mph. The cut through the magnetic field of the earth is not as bad as I thought. Now the 67,000 mph around the sun plus or minus 16,000 mph can get interesting.

My motor / magneto theory is rusty to say the least. I get some time I may have to crunch some hard numbers, but my intuition tells my they are going to have more problems with conducting more than they can handle with no need for any external power supply.

Just ran into this from before my time here.

Here was the shuttle tether that burned up.

At 3500 volts at let say 10 miles (there was quite a bit on the spool yet) is 35,000 volts at 100 miles and 350,000 volts at 1000 miles and not every 1000 miles will be the same but it could easily be 3.5 million volts over the span.

So power a town and use 2 ribbons with isolating rungs between them. drain the voltages at different rates and use the difference to power the elevator.

Of course what do i know?

Thanks for that link ~ very interesting story, which I don't recall ever having heard about.

It causes me to consider, though : in the same context as the difference between telluric effect on pipelines traveling E-W as opposed to those running N-S ... would there not be much LESS effect on a "tether" strung-out vertically, in a "fixed" position within earth's magnetic field, compared to one laid-out perpendicularly to the lines of (earth's) field, and traveling at three times the speed of a bullet THROUGH those lines...?

Just wunderin'......

Angle of incidence is important mostly for the fact of how many lines of force, at what strength, the conductor crosses in a given time. As I remember it.

The space elevator will cut through the lines of force at 1,000 mph at the base and 16,000 at the top. Not all of the 24 hours will be equal. Sun side during solar maximum and solar flares will have the most energy density.

It just dawned on me that this is also going to put motion into the tether. Depending on the direction the north south field is crossed. Solenoids work on that effect.

This may help: Left hand and right hand rules. Also known as this.

I still think it is possible but they are not talking about the hard issues.

Hmmm... Even after re-reading a couple different sites, I am still not "with ya" on why the elevator would be cutting-thru so many lines of field at such speed:

<<< LINK

While it is true that the earth is rotating, such that a 'pin' sticking out of it would be traveling at such speeds as you give (different speeds exhibited/experienced at the top versus the bottom of the 'pin', or elevator) ... are not the lines of magnetic field also rotating with the earth? Certainly NOT at the exact same rate.....it is understood that the molton iron core is causing a spaghetti-fying of the lines, as depicted above.

However: the magnetic field of the earth is not "stationary" while the earth spins around within it ... n'est ce pas...?

I see what you are taking about and you are correct.

The lines are not static though. The points of origin move very slowly, but the lines themselves are quite active. They are compressed by the suns magnetic field. A top down view would be even better. The tether is 8.5 times the diameter of the earth.

I tried taking a wire compass and strong magnet to experiment and had no effect.

But I could only find a model under solar flare conditions. The conditions are fairly normal until 05:00, then the whole field compresses and lines are bent even more side to side. If the scale is correct then it will also be subject to the solar wind and flares as well.

And you were right I was not taking the fields rotation, with the earth, into account only the shifting of the lines by the suns field.

Thanks, Brad.

And this is what it needed to be able to handle as far as solar Flares.

"At the time of the Carrington Event, telegraph stations caught on fire, their networks experienced major outages and magnetic observatories recorded disturbances in the Earth's field that were literally off the scale."

Re: Solar Flares and the Carrington event.....

Hopefully the NEXT "Big_Events" will all take place on the side of the sun that is AWAY from us..

However, if that doesn't turn-out to be the case, I would hope that the elevator has already been built, WITH its "Modification-Addition#1"...

... a "parasol-net" , which , like a force-field, will divert the most dangerous portion of the radiation around our magnetosphere, instead of directly into it. Only deployed (like an auto's air-bag) from the orbital-station when needed, of course!