[neilep (OP)]

Greets Peeps,

I would welcome your speculated deliberations on the feasibility of building a shield/filter to stick somewhere in space between the Earth and Sun to filter out all the bad nasty naughty rays that harm us, but allowing the good kind lovely rays through.

I realise the closer to the sun it would be, the smaller it would need to be because of angle stuff !! (can you tell that I don't know the technical term ?)..ahh !!..is it a line of sight type of thing ?...anyway...whajafink ?...possible ?..plausible ?...improbable ? impossible ?....ludicrous idea ?

Some ideas of size in relation to distance would be nice !

Please let me know as I've already made a start collecting two pairs of old sunglasse lenses...but I think I may need more !

[ukmicky]

quote:Originally posted by neilep

Greets Peeps,

I realise the closer to the sun it would be, the smaller it would need to be because of angle stuff !! (can you tell that I don't know the technical term ?)..ahh !!..is it a line of sight type of

Hello mate. Cool idea but probably just a tiny bit beyond us. Also I would have though the closer to the sun that it was positioned the larger it would need to be.

Would they be able to keep it positioned between the earth and the sun maybe it would act like a giant solar sail, slowly sailing away into the furthest reaches off our solar system taking all your old sunglasses with it,to infinity and beyond as someone quite famous once said.[]

 

Michael

[neilep (OP)]

Thanks Chum,

It would have to be in some synchronous orbit with on-board sensors to self calibrate it's orbit and toalso detect solar nasty ray output so that it could adjust it's filtration systems accordingly .

Are you sure that the closer to the sun, the larger it would need to be ?..because I assumed the opposite !

[daveshorts]

One way to do it would be to produce an extreemly fine mist of particles that were smaller than the wavelength of UV light - they would scatter out the UV preferentially (in the same way that dust and molecules in the atmoshere scatter out blue preferentially to red)  and would be considerably lighter than 40 000 trillion sunglass lenses (ok I am sad and worked that out).

You could put it at the Lagrange point between us and the sun (basically where the  time to orbit the earth is exactly 1 year so an object will stay there ), you would have to replenish it regularly as the Lagrange point is a point so everything else will drift off, but possibly still vaguely practical.

[neilep (OP)]

quote:Originally posted by daveshorts

One way to do it would be to produce an extreemly fine mist of particles that were smaller than the wavelength of UV light - they would scatter out the UV preferentially (in the same way that dust and molecules in the atmoshere scatter out blue preferentially to red)  and would be considerably lighter than 40 000 trillion sunglass lenses (ok I am sad and worked that out).
You could put it at the Lagrange point between us and the sun (where the earth's gravity means that something can be in orbit between us and the sun.

I was hoping you would !!..in fact my request for calculations was directed at you !!

I love your idea, but do you think there would be more control and ability of a piece of apparatus, over the spray from a giant aerosal ? []

[Ophiolite]

daveshorts has proposed putting your filter at L1. This is unfortunately unstable (only two of the five La Grang epoints are stable.) This instability manifests itself over a period of less than one month - so you would need rigorous stationkeeping.
The L1 point is roughly one million miles sunward from the Earth: so, about four times the distance to the moon. Roughly then, the diameter of the filter would have to be four times the moon's diameter, or say 8,500 miles: approximately the same diameter as the Earth.

[daveshorts]

I was more thinking of sending up a rocket full of fine particles every month or so, and blow it up gently..  any other place that you could put it would require you creating a ring rather than just a single shade as it would have to orbit. the earth, maybe this would be cheaper in the long run.

[Soul Surfer]

LOL

Learn, create, test and tell
evolution rules in all things
God says so!

[Ophiolite]

Certainly a cloud of regularily replenished dust would not encounter the problems of having to deal with persistent abrasion by micro-meteorites, and regular impact by larger bodies. Together these would probably render the whole L1 structure impractical - even with substantially advanced technology.

[DrPhil]

Maybe it would be easier to just fortify the ozone layer with something that would block more UV.

But it might be a bad idea to block it all. A little UV is good for us. UV radiation plays a role in the production of vitamins D and K. UV radiation also plays a role in the pollination of certain plants since many insects find reflected UV light by some plants attractive.

And lets not forget the evolutionary aspects of the effects of UV. UV radiation can cause mutations. Some of those mutations could very well be responsible for us being who we are today.

[neilep (OP)]

Thank you all for your replies. Always good to see DrPhil here too.

I admit I also did wonder at the possibility of somehow being able to control the atmosphere or the magnetic poles etc.

The reason why I still think a shield may be of more use is because I assume it would be easier to control and almost instantaneous to react if needed. Though I understand and agree with Ophiolite's points about abrasion and impacts.

However, is it possible that, in the future, that beaming waves at tiny particles as Dave originally suggested , that we could also control or change their efficacy ?

I'm thinking along the lines of big solar flares which really screw up our electronics eg Canada of a few years ago.

[sharkeyandgeorge]

dont we already have a shield called the ozone layer cant we figure out a way to repair that instead?

"your not paranoid if they're really after you"

[Soul Surfer]

I have recently bought one of those pretty electrical discharge globes and when you stick your fingers on them to make the coloured worms move around they come back smelling of ozone because of the glow dischgarge.  Maybe we should put up loads of these suspended from large reflective helium balloons.  This would top up the ozone layer and reduce global warming at a stroke.  It would also look very pretty and drive all the astronomers mad :-)

Learn, create, test and tell
evolution rules in all things
God says so!

[neilep (OP)]

Ian has come up with the most sensible suggestion all day ! []

[Ophiolite]

quote:I'm thinking along the lines of big solar flares which really screw up our electronics eg Canada of a few years ago.

You have just magnified the problem. One of the main 'targets' of solar flares are satellites, whose electronics, even when well shielded, can suffer damage or destruction from the larger events.

Since many of these satellites are in geosnychronous orbit, the required filter size just went up by an order of magnitude. Even if we use NEOs for construction material (neatly eliminating impact risks at the same time) this would rapidly become a monumental folly. (Fourth Millenium Filter, anyone?)

[DoctorBeaver]

I think a giant Venetian blind would be best. Then, if we fancied a nice hot summer, we could open it up!

[DoctorBeaver]

I've just had a very silly though (nothing new there!). You could have great fun making shadow puppets the size of Belgium.

[Hadrian]

i think the answer is near to the ground.





What you do speaks so loudly that I cannot hear what you say

[another_someone]

If all of this is to protect humanity, then why not take the opposite route, and find ways of boosting our melanin production.

George

[Hadrian]

Is not the opposite not protect humanity?