1. Aug 8, 2010

### Lukas1121

i was trying to look for which forum to put this in so sorry if its in the wrong one. :D

Im working on a project and i need a material that is able to reflect radio waves, like a mirror reflects light.

any ideas for which material will reflect?

2. Aug 8, 2010

### kuruman

Any metal surface will do. It can even have holes in it as long as the size of the holes is considerable less than the wavelength of the signal. The door of a microwave oven is built to reflect microwaves but not visible light waves. You can see what is going on inside (visible wavelength is much smaller than the hole size), but you don't get zapped by microwaves (microwave wavelengths are much longer than the hole diameter).

3. Aug 8, 2010

### Lukas1121

okay thank you :D

and if i were to use an alternating current to make radio waves using an electro magnet. Would it give the same results, and how long would a radio wave like that last in fx a ball of radio reflectant material?

4. Aug 8, 2010

### kuruman

All electromagnetic waves behave the same in this respect regardless of how they are generated.
I don't understand what you are asking here.

5. Aug 8, 2010

### Lukas1121

i mean all radio waves eventually deteriorate, if i were to capture one in a ball of that stuff that reflects radiowaves, how long would the wave last?

6. Aug 8, 2010

### Dr Lots-o'watts

Reflection is never 100%. There is also absorption. Assuming two straight walls instead of a ball and 1% absorption at each reflection, after the wave has bounced back and forth 500 times, there's less than 1% left of the original intensity. Now t=500x(distance between the 2 walls)/c = a few nanoseconds.

7. Aug 8, 2010

craps....