h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

The Americans have announced their plan of surrounding the planet with a 100,000 kms ring of billions of tiny mirrors (according to my radio at least) with the idea of reducing sunlight by 2%. Have they finally taken leave of their senses or what?

What will keep the mirrors pointing in the right direction? If they just face at random, then the reduction in sunlight between the earth and sun will be compensated for by the increase in sunlight from parts of the sky where we wouldn't normally see the sun.

So the answer appears to be yes, they have taken leave of their senses, or an April 1st report was leaked.

not really. There's been various mooted ideas like this, either to reflect sunlight away or to move it to where it is wanted (there's a town somewhere that doesn;t get a lot of sunlight due to mountains or something that are thinking of installing a huge mirror to give them some sunlight). Technically, it is perfectly feasible if, I would imagine, very expensive and not really worth the return on investment.

Practically speaking it's probably not that hot an idea. I mean, why reflect it? Why not just use a dust cloud or somesuch to block the light?

Rather than billions of small mirrors that would be hard to control, I would suggest a large piece of foil similar to a solar sail.
I´ve also heard the one about using large mirrors in orbit to give sun to disaster struck places or places that just don´t get much sun.

The Guardian has a copy of the Official US Govt Doc "Mitigation of Climate Change" on its website. "Reflective smoke" it seems we're actually talking about here!

I still say we just paint everything white.

Traveller in Tiem with a more drastic colour
"Let us paint everything Goo Blue ! "

Please don't say the "Americans" have taken leave of their senses just b/c you hear some crackpot scheme by the government - especially the *current* administration.

Would you like it if I said "look at those crazy British" everytime Tony Blair said something?

Arnie,
I apolgise to all those Americans who haven't taken leave of their senses. I know there are quite a few. It was the ones responsible for the smoke-mirrors I meant to castigate.

As for the crazy British domiciled in the land of Mr. Bean, Peter Sellers, and John Cleese, Well, I don't suppose we've changed very much since Shakespeare said we're all crazy, send Hamlet! You can mostly say what you like about the Brits. It's usually water off a duck's back.

Sorry Lucky, I didn't mean to react so stridently. There's just a lot of crackpot "American" schemes out there, most of which (luckily) don't get enacted.


What I should have said (which would have been much more constructive) is that I work as a scientist for the US govt, and I keep up on what is going on in the scientific community, and I have yet to hear anything about this. Could you provide a link or news story, etc.?

I dunno, if an American were to go on about how humourless Brits are I'm sure they'd get some pointed responses.

The problem with American crackpot schemes is they have the money to enact them!


The whole idea of tiny mirrors sound ludicrous! Whats next giant water pumps to keep the golf stream moveing. Oh no, that will never happen, because that wont affect our cousins across the pond it is only us Brits that have to worry about that.

Also I thought the current US adminstration did not 'believe in' climate change thats why they wont sign up to polution control treaties it not that it would actually cost them money or anything. They would rather ameliorate the situation after the fact.


it's all smoke and mirrors anyway.

sorry to quote the enemy but ...... http://en.wikipedia.org/wiki/Kyoto_Protocol#Position_of_the_United_States

Arnie, Have to dash. The Guardian newspaper homepage will take you there if you click through their stories for last few days. There's even an official US Govt Document you can print off - although it's very technical and I don't understand a word of it.

OK, well this may sound lazy, but I don't have time to browse through the last couple days worth of the Granuiard to find the article...

you're just pandering to the stereotypes now arnie

HAHA I didn't even think of that . Well, to fight stereotypes, maybe I'll look through some science journals, etc. for any news of the plan.

If you think thermodynamically, the heat energy reaching your mirrors or dust-cloud has to go somewhere. Ultimately, these things will warm up and re-radiate the heat on its merry way. That's why, for example, the dust-cloud answer to Olber's Paradox doesn't work.

Olber Paradox?

"If you think thermodynamically, the heat energy reaching your mirrors or dust-cloud has to go somewhere. "

If the mirrors are mostly reflective, then it does go somewhere - elsewhere - and in fact it doesn't heat up the mirrors. That's what is meant by the word "reflective".