Quote from: RocketmanUS on 02/02/2012 04:05 amHas anyone tried this in the lab to see if how much if any amount of Sun radiation ( type that would heat Venus atmosphere and surface mass ) would be blocked by this idea?Any idea how much power just the lasers would need?No power at all because the physics is wrong. See Sohl's original post.
Has anyone tried this in the lab to see if how much if any amount of Sun radiation ( type that would heat Venus atmosphere and surface mass ) would be blocked by this idea?Any idea how much power just the lasers would need?
So you're saying fog alone should do this? The lasers are just for fun?
My prediction is that you you won't get less of the spotlight beam getting through. You seem to think it will. If you are in the visual arts, you should be able to set up a stage with this experiment. Try it and tell us what happens.In fact, I am very certain it will be slightly _higher_ than the previous step if anything, because you are pumping _more_ light into the box and some of that additional light will be scattered toward the target.
Quote from: Sohl on 02/03/2012 06:36 pmMy prediction is that you you won't get less of the spotlight beam getting through. You seem to think it will. If you are in the visual arts, you should be able to set up a stage with this experiment. Try it and tell us what happens.In fact, I am very certain it will be slightly _higher_ than the previous step if anything, because you are pumping _more_ light into the box and some of that additional light will be scattered toward the target. Well using the combination of laser as I mentioned earlier I think it may come out a very very translucent brown, (If the laser curtains can act similar to a gel filter that is). How ever I do not have access or resources to set up such experiment. It does give me food for thought.I would like to thank every one for the replies, Its probably clear I'm thinking way out side the box.
Well using the combination of laser as I mentioned earlier I think it may come out a very very translucent brown, (If the laser curtains can act similar to a gel filter that is).
Quote from: Da5id on 02/03/2012 10:49 pmWell using the combination of laser as I mentioned earlier I think it may come out a very very translucent brown, (If the laser curtains can act similar to a gel filter that is).They don't act like gels. Adding lasers together makes more white light not less brown light. Think of it this way: the gels are colored before the light comes along; the fog wouldn't be colored until the laser light shows up. That means you're adding instead of subtracting.
The physics is wrong because Sohls interpretation of the original idea is wrong.Light through a translucent medium will fade out light eventually, depending on it's density.
Quote from: Da5id on 02/03/2012 11:29 am You can't block light with light.
Quote from: douglas100 on 02/04/2012 09:38 amQuote from: Da5id on 02/03/2012 11:29 am You can't block light with light.I beg to differ.http://www.livescience.com/8012-twisted-physics-scientists-create-light-knots.htmlBut It can be manipulated.
Quote from: Da5id on 02/05/2012 08:48 amQuote from: douglas100 on 02/04/2012 09:38 amQuote from: Da5id on 02/03/2012 11:29 am You can't block light with light.I beg to differ.http://www.livescience.com/8012-twisted-physics-scientists-create-light-knots.htmlBut It can be manipulated.You are correct that light can be manipulated. But my point still stands. The article you cite is about holograms. A hologram is a physical object which intercepts the light. A giant hologram put in front of Venus would certainly reduce the amount of light reaching the planet. But that is not what was being proposed.I wasn't going to post on this thread again, having criticised the need to ever attempt to terraform Venus and the enormity of the effort required to do it. It is a task for a civilisation well up the Kardashev scale. But treating it as a purely theoretical exercise, the most straightforward way to shade Venus using foreseeable technology would be to use a very large number of solar sails. I think that a single giant shade would be very difficult to make and would be subject to tidal forces that would make it hard to control. A cloud of billions of small solar sails, each kilometers in size and independently maneuverable would be a better solution.As for spinning up Venus, well it's OT and the effort and energy to do it is magnitudes greater than building a planetary sun shade.
Venus Mass = 4,868,500,000,000,000,000,000,000 kgAs soon as we master space-time to induce a spin on Venus...Lacking the mastery of space-time we could build a ring that both shades and reflects, to mimic a 24 hour cycle. Early on though it would be 100% shade to reduce temps to something Earth normal. Large quantities of gasses will need to be imported to provide an adequate hydro and nitrogen cycle.
More like 36 million solar sails 1 km x 1 km would effectively cover Venus on the Sun side in low orbit. At a given distance between the Sun and Venus 1,000 solar sails would do the job of shading Venus from the Sun light.