"Mankind has been broadcasting radio waves into deep space for about a hundred years now — since the days of Marconi.
"That, of course, means there is an ever-expanding bubble announcing Humanity’s presence to anyone listening in the Milky Way. This bubble is astronomically large (literally), and currently spans approximately 200 light years across.
"But how big is this, really, compared to the size of the Galaxy in which we live (which is, itself, just one of countless billions of galaxies in the observable universe)?" -- | jackadamblog
For hi-res:
Maybe we should talk faster.
Posted by: Gagdad Bob at May 18, 2012 12:48 PMSeeing that picture leads me to the only response possible - I AM SIGNIFICANT!
(Thanks Bill Watterson)
Posted by: NCMike at May 18, 2012 6:54 PMWhat will the Political Poobahs do if something responds to our radio/TV signals and shows up, demanding we stop polluting the Universe, OR ELSE.
Posted by: Peccable at May 19, 2012 5:12 AMWe've been broadcasting RF for 100 years.
The radio transmissions have reached 200 light years out.
RF travels at twice the speed of light.
I just don't get this new math. How's it work?
Posted by: Frisco Scooter Trash at May 19, 2012 8:08 AMRadius of sphere = 100 light years.
Diameter of sphere = 200 light years.
Posted by: vanderleun at May 19, 2012 8:28 AMFrisco, since we broadcast in all directions, we create a circle, the radius of which would be 100 light years, and the diameter of which would be 200 light years. We have only broadcast 100 light years out in any given direction, but the circle around us would be 200 light years across. Hope that helps, I would never be a good math teacher...
Posted by: drdave at May 19, 2012 8:35 AMWhile it is true that our radio signals have propagated in a sphere 200 light years across, due to the fact that the signal strength decreases on the square of the distance, our transmissions have likely attenuated at that range as to be virtually indistinguishable from the cosmic background radio noise.
Larry in Rochester
Posted by: Larry Anderson at May 19, 2012 2:07 PMIt's true. At 200 lightyears, everything starts to sound like NPR.
Posted by: Gagdad Bob at May 19, 2012 6:04 PM"It is impossible to speak in such a way that you cannot be misunderstood." -- Karl Popper N.B.: Comments are moderated to combat spam and may not appear immediately. Comments that exceed the obscenity or stupidity limits will be either edited or expunged.
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