On Tuesday, June 12, 2018 at 1:50:58 PM UTC-7,
numbernu...@gmail.com wrote:
> The point is that immediately after leaving the transmission antenna, no matter what the shape the the anatenna the intensity of a radio signal is dependent on the inverse of the second order of the distance I = A cos^2(kr)/r^2 . After propagating the distance of 238,000 miles (3.83 x 10^8 m) the intensity of a 1 kW radio signal would be reduced to 10^-13 W that is not detectable. In another words, there is in fact a limit to the range of a radio wave that cannot reach the moon which prove NASA is a hoax.
A radiowave cannot reach the Moon? I suppose then we can't control spacecraft beyond the Moon? Or receive signals from them?
How do we get radiowaves from SigA* in the center of our galaxy? Or from other galaxies, pray tell? Radioastronomy is a hoax, you think?
Okay, here's your clue: Although your equation is correct, you don't know what "A" is. It's the initial power or amplitude of the radio beam, but that's not the power to the radio transmitter. The whole point of a high gain antenna, is that it takes the power of the radio transmitter and amplifies it in one direction (which removing it from others, due to conservation of energy).
Just a 2 m dish antenna, the kind satellite crazies have in their back yards, can give you a gain of 44 dB, which is 10^4.4 = 25,000 at the wavelength used. If you feed such an antenna with 100 watts of power, along the beam direction it's putting out 25,000 times the isotropic power, which is something like 2.5 million watts (if it were going in all directions, which it is not. It works like a magnifying glass with sunlight.
So 25 million watts is your "A". And it drops by 1/r^2, but it starts out very large.
http://www.astrosurf.com/luxorion/qsl-antenna5.htm
SBH