Hot Texas, etc.. cool off with Orbiting Sunshade

[oscar111]

The idea is a lot cheaper than letting global roasting create superhurricanes that do a Katrina to NYC, Miami, Baltimore, Huston, etc

Not to mention texas style blackouts halting the economy, and heat in mexico increasing the tide of illegals. Or a billion in the third world dying of heat and thirst.

read what a Livermore research scientist says on it....



http://www.cbsnews.com/stories/2001/01/15/archive/main264362.shtml

[Redstone]

1. And they'll finance it by selling advertising space.

No, thank you.

Redstone

[depakid]

5. LOL- but ya couldn't see the ads from L1

I remember reading about this for the first time in David Goodstein's little physics primer "Out of Gas." As I recall he was pretty dismissive about it.

"The sooner, the better," says Dr. Edward Teller, a promoter of the plan. Teller, who helped harness the destructive power of the atom 60 years ago, now believes man can dim the power of the sun."

One would think that this guy was smart enough to understand why this is a foolish idea in light of the complex dynamics involved. All too typical of the "technological fix" crowd....

[babylonsister]

2. This won't fix the problem we all have. nt

[Canuckistanian]

3. Edward Teller? My God, will this man live forever?

The inventor and principle proponent of the Hydrogen bomb?

He should be forever reviled as the "bringer of death" as portrayed in the Bhagavad Gita.

[Raster]

4. teller the bringer of death, no, that dishonor belongs to someone else.

[Canuckistanian]

6. To whom, then?

I'm speaking of the horrible technology that some men pursued with the fervor of a religious quest - the ultimate killing machine.

Of course, the politicians who exploit their work are evil. Hiroshima and Nagasaki were bad enough, but no-one has advocated the use of these more powerful weapons - until recently.

[Raster]

10. Mr. antichrist himself, the true bringer of death

bush*

[Dogmudgeon]

9. Teller also "invented" Chemtrails

He wrote an influential paper in the 1990s proposing what became known as "Chemtrails". I strongly suspect that the real purpose of the paper wasn't to float the idea of using clandestine weather manipulation, but to cause a panic among the conspiracy-minded at a time when weather patterns were visibly changing anyway.

Indeed, it doesn't even take a conspiracy theory to imagine Teller doing that -- he has long been infamous as a cynical, manipulative Machiavellian.

I don't have a link off hand, but it's not difficult to find on-line.

--p!

[Canuckistanian]

11. Thank you

I've always believed that Teller was a bad influence.. he sold out early to the MIC....

[amitten]

7. Wow. I think that might actually be a great idea.

It may give us more time to get our emissions down. But they need to think through any possible bad effects.

[Dead_Parrot]

8. Bullshit.

Google "solar sail". This thing wouldn't stay in place for 5 minutes, even at a lagrange point.

edit: Just for fun, I worked out the thrust: To keep this thing in place, it would need an engine about the same size as a shuttle SRB behind it. except it would have to burn forever, not just 2 minutes.

He should stick to blowing things up.

[amitten]

12. It doesn't need to stay "in place"...it could travel, following the

Earth's course, I suppose.

[Dead_Parrot]

13. It would need to stay at,

or near, the sun-earth L1 point - where the soho satellite is now. Here, the gravity of the earth and the sun cancel out, and you are constantly between both. But solar pressure would be constantly pushing it outwards towards the earth: the thing would come crashing back on top of us within a couple of days.

[amitten]

14. Well, how is the other satellite doing it, then? n/t

[Dead_Parrot]

15. It's fine...

Solar pressure on Soho in tiny, and the engines onboard are quite capable of dealing with it. But then, it's not ~1,200 miles across...

[amitten]

16. So how about several tiny satellites?

Hell, there are practically enough up there already. What about a large satellite made from lighter materials?

[Dead_Parrot]

17. Lighter is actually worse...

in terms of the effect the sun has. I based my sums on existing light films, that weigh about 10g/m2: To cover 2% of the sun at L1, you need 3,043,675 km2 of material, (which incidentally would weigh 30 million tons - tricky to get there): pressure from the sun is 0.00000453 newtons/m2, which is 13 million newtons over the whole area - about the same as a shuttle booster. To stop it de-orbiting, we'd have to have an engine on the "dark side" putting out the same power, which again is technology we don't have.

It would also need to be spun very quickly to stop it folding up, beyond the current strength of the films.

In short, the whole thing is centuries ahead of our current abilities. If we're still here in 2200AD, it might be an option, but for now we'll have to try something else.

Lots of small sattelittes is interesting, but I wouln'd fancy having to work out the millions of orbits to stop them bouncing off each other... :(

[amitten]

18. So why are they even considering this? I mean if it's that easy to

debunk, why would someone put their reputation on the line suggesting it?

There must be a way...

[Dead_Parrot]

19. Well, in term of cooling the climate

it's a really nice idea. Knocking the sun down by 2% feels like it would do the job: If he says he's done the sums, I'll accept it on principle.

Unfortunately, he's not an astrophysicist (which I am, at least by training). The mechanics of the scheme are too big for us to handle at the moment: we just don't have the materials or means of propulsion needed.

:(

[Ready4Change]

20. Why can't solar pressure be an advantage, not disadvantage?

Use the same principles proposed to move solar sails around? Rather than park this thing in an L point, instead drive it around using solar pressure as your thrust. Turn the problem into a solution.

Seems to me that a solar sail craft, once in orbit, could need no fuel at all. Solar pressure is the motive thrust, and solar panels can power the motors to pull the control lines or gyroscopes to guide it about.

No need to "constantly thrust against solar wind." USE the wind instead.

[Dead_Parrot]

25. Ah, but...

I'd agree that solar sails have a huge potential as a means of propulsion - a constant thrust, which should be available all the way to the heliopause, would give any craft a huge free boost: From a standing start, a 10-ton probe with a 1km sail would hit interstellar space in ~10 years - and would be doing around 200,000 mph at the time.

Unfortunately, this thing's a sunshade: we want it sitting between us and the sun constantly, not developing a red-shift out in the Oort cloud. The only way to pin it in between us and the sun is to put the same force in the other direction, which implies a big, everlasting motor. I guess an ion drive might do it, if we can build one 200,000,000 times bigger than we've done so far...

Edit for the usual typos. :)

[depakid]

26. Sounded like R4C was talking about tacking

like a sailboat.

An interesting thought....

[Dead_Parrot]

29. Tricky without a keel, though.

It works for a boat because it's shape, and the medium it's in, makes it 'want' to move forwards (or backwards, badly), not sideways. In space, the direction you're pushed in is the direction you go.

[depakid]

30. and a "duh" moment

:dunce:

[Dead_Parrot]

31. ;-) nt

[Ready4Change]

32. That assumes you reflect the light directly back to its source.

But, if your sail is something like silverized mylar, which is the most frequenty suggested solar sail material, you can turn your sail to an angle, and reflect the light to the side. As you change those particles direction from outward to sideways, Newtons law says there will be an equal and opposite force.

There is still an outward vector. But, you have now introduced a sidways vector. In other words: you CAN tack. You can increase or decrease your orbital velocity. You can drive yourself above or below the Earths orbital plane.

Even more: If you want to get closer to the sun, you can fold up your sail and the suns gravity will pull you inward. If folding the sail is too problematic, just turn the whole thing edge on to the sunlight. Down (or rather, In) you go. Once you are in far enough, unfold the sail (or turn ti to face the sun once more) and you are outward bound again. (You can accomplish the same by decreasing your orbital velocity. That's really the better approach than brute force.)

This even allows you to operate outside of the L points, which is nice for all the other space craft that would like to sit there. Actually, you WANT to be outside the L points. With your larger surface area you want to have the Suns gravity have more influence than Earths, and use the solar wind to counter that.

[Dead_Parrot]

34. I'm a total moron!

:dunce:
Apologies to yourself, oscar111, depakid, amitten, and Teller if he happens to be reading. I'm going to blame CBS for saying at L1 and getting my brain stuck, but basically I'm being retarded: You're absolutely right, there would be a sweet spot sunwards of L1 where you could park it in a powered orbit. Where that is would depend on the total weight and the size of the sail (which would depend on where it is, so I'm not going to attempt to work that one out), but it would be a long way sunwards of L1: somewhere around Venus' orbit, for a guess.

I still don't think it's practical - but for the more mundane reasons of launching or constructing what is now over 3 billion tons of satellite (guesstimate), not to mention trying to maneuver the beast into place, and having it stay in one piece (it would still need to spin to stay in shape, and the stresses would be enormous).

I'm off to the shredder with my BSc, then I'm going to make a big sign that says "engage brain before approaching keyboard"

:blush:

[depakid]

36. Actually, CBS was just being... well, CBS

This is what they said:

"That could mean putting the device where the SOHO satellite is now observing the sun's solar storms. The huge solar shield would act as an orbiting sunshade to cool the earth."

The fools writing their copy wouldn't know Lagrange points from Lamarkian inheritance.

I just assumed that since SOHO was at L1, that's where they'd plant the "parasol."

Goes to show what happens when you multi-task and don't think....

[Dead_Parrot]

40. Yeah, but I'm still kicking myself

for not spotting that... :dunce::)

[Ready4Change]

37. Made my brain work too.

I love this kind of stuff. It's fun to think what if, and if, how?

I agree with the lack of practicality. The infrastructure needed to build such a thing is daunting. Plus, I'd guess there are some technical challenges we don't yet have answers to. (I wonder what sort of electrical charges can build up on such a structure in that environment, and how you could keep those from becoming a problem?)

And while I like the novelty of the idea, I'm concerned with how it supports the idea that we can keep on screwing up our environment, because eventually we can just blot out the sun. Doesn't seem like a wise mindset.

[Dead_Parrot]

41. On the plus side...

Anybody (ie, NASA) given the job of actually building the thing would quickly turn around and say "piss off", so I can't see it being a major distraction from solving the problem.

But you're right, it is fun (in a geeky sort of way). I've decided to work out where & how big the thing would be, if only to satify my curiousity: I'll see if I can pin it down in the next few days. As to the charges building up, I suspect the protons and electrons from the sun would cancel each other out, but if not you could install a wide angle ion drive on the base unit, to squirt the sail/shield with the difference (net thrust would then be zero). Hook it up to a bussard collector and solar panels and it could run indefinately (yeah, in 500 years. What the hell.)... :)
:freak:

[amitten]

23. You should try to contact him and try to discuss this.

I think extensive collaboration by all different disciplines is long overdue.

[Dead_Parrot]

27. I'll see if I can find an email address...

...although I imagine NASA have already flagged some objections if it's got that far :).

[Dead_Parrot]

35. Correction: I'm actually a total gimp. nt

[One_Life_To_Give]

44. Needs to be sailed

Actually by locating it slightly closer to the Sun. It should be possible to use the "Solar Sail" to both block some of the radiant energy from reaching earth and to actively maintain its position relative to the Earth-Sun.

But this would be difficult to control if made up of multiple satellites. Hence we would really need to build a single unit in orbit. Which could be deployed upon completion of construction.

[Odin2005]

21. I'm all for climate control.

It's obvious that things are so far gone that stopping GW is impossible, but hopefully we can reverse it someday and terraform Earth back to interglacial normality.

[Odin2005]

22. BTW Whats will all the Teller bashing?

I don't see may people criticizing Oppenheimer for the A-bomb.

[Dogmudgeon]

24. Teller liked the A-Bomb; Oppenheimer feared it

Teller was a hawk and an advocate of "psy-ops" for most of his life; Oppenheimer opposed the Cold War, to the point that he was investigated several times for supposedly being a Communist.

I also bashed Teller for getting the Chemtrail thing going. If it's for real, it's an amazingly evil program; I personally think it isn't real, but that Teller wrote it up as part of some kind of psy-op, which is nearly as evil, and more cynical.

I could be wrong about any of the details, but I stand by my assertion that Teller was a cold warrior. And plenty has been written about it, too.

--p!

[Odin2005]

28. Ah, gotcha!

[Dogmudgeon]

33. This isn't really about Edward Teller, is it?

--p!

[oscar111]

38. RECOMMEND AND KICK

ZZZ

[oscar111]

39. WEIGHT solution

use the cloud idea mentioned for nearearth orbit, only out at/beyond the L1 point.

Magnetic field to hold it together, as in tokomak fusion bottles... the field generated by nurse satellites, PV cells on them... ion engines if needed to hold nurses in place.

Since the cloud would not be solarsail problemized, the cloud might be at Mr. Lamark's spot. Or not, .. whatever would be best.

A ring of nurses, bottling a cloud, would likely be the general design

bush might like it, as much as he dislikes Kyoto.. because his pals would reap nice profits off the booster rockets. Thus, it is more practical than Kyoto.
=================
MAGNETICS ALONE can bend light rays. anyone know if the field needed to deflect some solar flow, is of small enough value to be done? Consider too, the closer to the sun, the less mag field strength needed to result in deflection totally off of the earth.
====================
CONGEALED SOLAR PARTICLES AS SUDDEN CLOUDS

any ideas for using the "matter found at hand", so to speak? Could the heavier solar wind particles.. alpha particles, say.. be made to clump into light absorbing particles?
Any magnetics from "clumping" satelites able to carry that out?

[amitten]

42. Now there's some creative thought.

Though I have no idea what to say to this. I'm an artist, for God's sake. An artist worried about global warming. :cry:

An artist who wishes all you brainiacs could figure out SOME kind of solution to this disaster! I'll do my part to conserve, but beyond that, it's up to the genius folk. Get ta work!!!

[Dead_Parrot]

43. Just for shits and giggles, I've finally worked it out...

I've spare you the math (mainly 'coz I can't type up the equations very well on DU) But the trick is to finding a balance between the gravitational pull of the sun, vs the pull of the earth, plus the force of the sunlight, plus the centripetal force. Which is fiddly, because the size of the sunscreen (and therefore the mass, and also extra variable in the sunlight pressure) varies as you move it around (if it's going to cover 2%, it needs to be bigger as it gets further sunwards)

Anyway, it balances out if put it about 3 times closer to the sun than lagrange 1: 4,191,775.47 km from Earth, to be exact.

The beast would be just under 24 trillion sq meters (about 2½ times the size of the US) and have a mass of ~238 million tons.

So now you know...

Sorry, but it's been bugging me. :silly:

[phantom power]

45. Sweet. Now all we need...

is a plan to lift 238 million tons out of earth's gravity well.

[Nihil]

46. Yeah ...

... then we get D_P to calculate how much CO2 that puts into
the atmosphere and how much that increases the average temperature.

After that, he can work out how much the new thermal differential
(global temp increase vs small local shade temp decrease) will
affect the wind patterns so that the involuntarily shaded
inhabitants know whether to prepare for cool breezes or just the
occasional tornado.

Oh I do like nonsense threads like this on a Friday afternoon!

:hi:

[Dead_Parrot]

47. Sorry, I've run out of envelopes.

:P

[Nihil]

48. How about the brown bags ...

... that you wrap around the vodka bottles?
:toast:

[Dead_Parrot]

49. I ate them

Having blown all my money on vodka to get over that bloody elephant, I had nothing left for lunch. It's a sad life. :(

:toast:

edit: And my pencil, before you come with any other ideas... :D

[Dead_Parrot]

50. Actually...

You could theoretically make it carbon-neutral (at least for fuel) by burning corn-based ethanol and LOX from electrolosys in an Saturn-V type rocket. Albeit, a fucking big one. I'm not touching that sum with a bargepole.

And at this distance, the shade would be everywhere, so it shouldn't disturb weather patterns other than to slow them down...

:silly: