Slashdot Mirror
Space Ring Could Combat Global Warming
telstar writes "Though the debate continues around global warming, a new proposal suggests building an artificial space ring around the Earth to block the light of the sun and bring a balance to solar radiation, cloud cover, and heat-trapping greenhouse gases. The ring could be comprised of particles which would scatter the sunlight, or be built by an interconnected ring of spaceships aligned to block the light. The former proposal is estimated to cost anywhere from $6 trillion to $200 trillion dollars, while the spaceship solution would run approximately $500 billion. Halo fans rejoice."
Why not put a disk direct between us and the sun at a stable gravity point?
We know how well solar eclipses work... why not just a permanent 'dimming'?
Telcos have alot of dark fibre in the States. Most people assume that's optical fibre...but it's actually moral fibre.
Additionally, the ring could have solar panels on the outside and thus power the whole Earth cleanly...unless there is too little silicon on Earth to build that many solar panels...yes I know there is a lot, but that's a lot of solar panel...
They can't be serious. Who could fund this? Isn't World GDP only around $40-50T?
Tristan Yates
Or we could just cut down on pollution for FREE!
Honestly, how much would it cost to require an SUV to get 30+ MPG instead of 15?
That might even take the pressure off the environment, as you could probably shut down most of the world's coal-fired power stations.
Why would anyone engrave "Elbereth"?
But that heat would be taken out of the chunk we produce when we consume energy from other sources, so it is still a net gain on the inward flux. Reducing emissions by closing coal plants would increase the outward flux. This also reduces the energy expended on getting at our current sources of energy, so less heat is produced by us. We win on all fronts.
Personally, I'd like to have the huge space-bound solar collector with microwave transmitter, but in a place where it doesn't reduce the sunlight on earth. If we clean up our act with emissions we should have plenty of breathing room and not have to block out the sun just yet. And sunlight is useful for so many things.
The enemies of Democracy are
The Earth has been through many, many periods in its history where it was warmer than it is today. This was before cars or factories. It managed to cool itself down.
Most people aren't really worried about the Earth. They're worried about the inhabitants. Mass extinctions usually accompany planetary wide climate change.
:wq
I find the resistance to taking even the slightest measure a little ridiculous. Much like evolution, no one has definitively proved anything. Also like evolution, the basic mechanics are of global warming are understood and the theory has been sitting around 100+ years waiting for someone to poke holes in it (GW was first posulated in 1890). No one has.
In simpliest terms: There is no doubt adding large amounts of carbon dioxide to the atmosphere will tend to raise temperatures. There is no doubt that we are adding large amounts of carbon dioxide to the atmosphere. There is no doubt that temperatures are rising. Q.E.D.
WWJD? JWRTFM.
Eskimoes are supposed to be referred to as Inuit. I don't think Eskimo is too insulting (last time I looked it up, that's the conclusion I reached), but they're referred to as Inuit here in Canada by most people. As times change, so does language and terminology. Nobody uses the term Negroe anymore.
Inuit has a nice ring too, it's not cumbersome like the 'African-American' conjunction is.
For some reason, I'm getting an image of a charred barren hillside a few miles from the collector.
That was examined in considerable detail a few decades ago, with an eye to preventing exactly that scenario (along with things like microwave-cooked birds falling out of the sky ready to eat). A fine solution was found:
First: Pick a frequency that, unlike the band used in microwave ovens, is NOT readily absorbed by the water composing most obstructions or potentially damagable natural structures (clouds, birds, cows, plants) or by other materials found in lifeforms. (There are some fine bands for this in the milimeter wavelengths.)
Second: Put up a "rectenna" site (antennas with microwave semiconductors - "Crystal sets of Inconcevable Power" to quote a pardoy of Doc Smith). This covers tens or hundreds of acres, and catches essentially all of the energy while letting most of the sunlight through. (You can graze cattle under it if it's not at Fort Stinkin' Desert - and even there it won't bother the lifeforms beneath it once the constructin is done.) Even if the beam were pure heat it would only be a large-single-digit multiple of the amount of sunlight shining on the area on a clear day, and it's nearly all caught by the rectenna.
Third: Transmit a "pilot carrier" from an antenna in the middle of the array to synchronize the transmitters spread out across the broad structure of your solar collectors (or across a number of them).
The result is a "synthetic aperture" antenna of large size, tightly focussing the return power on the receiving rectenna site. If the pilot signal is lost the beam immediately defocusses - within milliseconds - as the syncronization is lost, with most of the energy missing the entire planet and the rest being orders of magnitude weaker than a distant radar site. (Ditto for the energy from an individual transmitter that loses sync - it stops being combined with the rest of the beam and turns into a much smaller microwave beacon.)
From synchronous orbit the earth is a small fraction of the visible sky, and any target on it is not visible to the naked eye. If the energy from the beam were all visible light and defocussed you'd have a hard time spotting it in daylight.
You could do the same pilot beam hack with laser light. But why bother? Lasers are less efficient, more more would be absorbed by the atmosphere, and less converted to useful power at the output. Even with the tech available in the '70s you could get 85% or better from DC in at the satellites to power to the grid on Earth.
Construction costs would be comparable to those of an earthbound plant. Then fuel is free for the life of the plant and there's no waste to dump (except the plant itself if you ever decommission it, or any burned-out parts).
Semiconductors on the ground. Vacuum transmitting tubes in orbit. (Vacuum tubes are EASY in orbit, and very efficient. B-) )
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way