It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Thank you.
Some features of ATS will be disabled while you continue to use an ad-blocker.
In 1974 a number of modifications had been carried out to the transmitter, enabling it to broadcast signals at a power of up to 20 terawatts (1 terawatt = 1 trillion watts) and as an inaugural test of these improvements it was decided by SETI to transmit an encoded message to the heavens. This signal was aimed towards the globular star cluster M13, some 25,000 light years away and consisting of some 300,000 stars in the constellation of Hercules.
en.wikipedia.org...
In free space, all electromagnetic waves (radio, light, X-rays, etc.) obey the inverse-square law which states that the power density of an electromagnetic wave is proportional to the inverse of the square of the distance from a point source [5] or: \rho_P \propto \frac[1][r^2]. Doubling the distance from a transmitter means that the power density of the radiated wave at that new location is reduced to one-quarter of its previous value. The power density per surface unit is proportional to the product of the electric and magnetic field strengths. Thus, doubling the propagation path distance from the transmitter reduces each of their received field strengths over a free-space path by one-half.
Originally posted by Unvarnished
reply to post by ShAuNmAn-X
Wouldn't the distance be limited to atleast 30 light years or less? That would be crazy! But cool point.
Originally posted by ShAuNmAn-X
reply to post by The Old American
I have always been fascinated by the Arecibo reply. Especially when you look at the similarities between the reply and the Betty and Barney Hill story.