Pleiades Wrote:Suppose you want to light a 60 Watt light bulb with broadcast power. The lampshade is built to be the reveiver antenna, and is 10 cm (about 4") in diameter. A 10 cm (0.1m) circle has an area of pi*0.1^2 = 0.01 sq. m. (m^2)(actually 0.0079, but I'm going to round off). That means you need 60W/0.01 m^2 = 6000 W/m^2 power density to light the bulb.
If you are 1 km (about 1/2 mile) from the transmitter, the tramsmitter needs to generate P = 6000 W/m^2 / (4*pi*(1000m)^2) = 7.54 x 10^10 Watts = 75,400 MW (meagwatts). This assumes the power is broadcast spherically throughout the atmosphere, and there are no losses. The Shoreham nuclear plant was supposed to generate only 400 MW. If you are 10 km away (about 6 miles) then either the power transmitted has to increase by a factor of 100, or your antenna has to be 100x larger.
:eek:
Is there going to be a test on this? Because I have a really good excuse for not studying, honest!
Lisa
Lisa Wrote::eek:There was going to be a test, but after I saw that I misspelled receiver and megawatts I was so bummed out that I decided to skip it.
Is there going to be a test on this? Because I have a really good excuse for not studying, honest!
Lisa
Gee, that was fun. Haven't said "bummed out" in decades!
You really only need three things: WD-40, Duct Tape, and a pointy stick. If it's supposed to move and doesn't, use the WD-40. If it moves and isn't supposed to, use the Duct Tape. If you want it to move and it doesn't want to, use the pointy stick. The rest of life is easy.
This thread reminds me an sf book I read many, many years ago. The Good Guy and the Bad Guy are having a heavy discussion.
GOOD GUY: So how many times has practical fusion been discovered and surpressed?
BAD GUY: Three. (BROAD GRIN) Isn't it funny how the most advanced scientists can meet with the most foolish accidents?
And for the life of me, I can't recall the book. James Blish, A TORRENT OF FACES, maybe?
GOOD GUY: So how many times has practical fusion been discovered and surpressed?
BAD GUY: Three. (BROAD GRIN) Isn't it funny how the most advanced scientists can meet with the most foolish accidents?
And for the life of me, I can't recall the book. James Blish, A TORRENT OF FACES, maybe?
Don't you just hate it when someone resurrects an old thread?
There was a colloquium on Broadcast Power at Brookhaven Lab a couple of days ago. It works over short distances as long as the power demands aren't great and the transmitter and receiver are tuned to exactly the same resonance frequency. It could be useful for charging cell phones or laptops in a room. Why wasn't it thought of before? The researcher says if he had tried this 15 years ago, he would have ignored it a a useless technological trick. Now, we are so dependent on rechargeable batteries that it might have some applications.
I saw the speaker the day before the talk having a friend take his picture in front of Tesla's lab in Shoreham.
There was a colloquium on Broadcast Power at Brookhaven Lab a couple of days ago. It works over short distances as long as the power demands aren't great and the transmitter and receiver are tuned to exactly the same resonance frequency. It could be useful for charging cell phones or laptops in a room. Why wasn't it thought of before? The researcher says if he had tried this 15 years ago, he would have ignored it a a useless technological trick. Now, we are so dependent on rechargeable batteries that it might have some applications.
I saw the speaker the day before the talk having a friend take his picture in front of Tesla's lab in Shoreham.
You really only need three things: WD-40, Duct Tape, and a pointy stick. If it's supposed to move and doesn't, use the WD-40. If it moves and isn't supposed to, use the Duct Tape. If you want it to move and it doesn't want to, use the pointy stick. The rest of life is easy.