How to make your own parabolic mirror illusion?

Question

this is what im talking about....It basically makes an object appear to be there where you think it is...but when you try to grab it, you trespass it. inetersting
go here
http://en.wikipedia.org/wiki/Parabolic_reflector

Answer 1

I've never seen one before. Very interesting...

Answer 2

Parabolic Mirror Illusion

Answer 3

the americans in the 50`s experimeted with this idea but used sodium (i think as the fluid in the system) questions you need to answer in order to design this device how much sun do you get and of what density of light energy flow rate of water ( the faster the flow the less energy can be imparted on to the water ) the amount of heat required to raise the temperature to 100degrees and the latent heat of vaporisation also just a hint use reverse osmosis water rather then tap as the amount of impurities are lower then in tap water so will not fur up your system as quickly. the amountof steam you produce is more important then the amount of water flow right? then the flow rate of water is just a top up to the system once the steam has been produced. the calcs to work out how many square meters of mirror required is down to the energy density of the sun and how accurate the tracking system will be. in england there are several commercial systems which heat hot water for the household they have a design that you could be interested in. what you could do is use a thermo couple at the focal point (or several) as this can they exceed the vapour point of water and then burrny the cold end in the ground down several feet or run the water over it. more effecient for low voltage stuff. you could use ammonia rather then water as it vaporises ata lower point but it is a lot more toxic. the extraction of energy fromthe system is the important part and the conversion from liquid to gas and back again is important this state change is where most sytems get some free energy as the gas takes up shed loads more space then the liquid. but the thing to worry about is the conversion back into liquid and the removal of all the excess heat so it is usable again when it comes back to the beginning of the system. closed loop is the way to go chap or it is just wasteful of resources. hope this helps