You DO know the difference between a solar system, a galaxy, and a universe is, right?

A solar system consists of one (or two if binary) and maybe some planets or other orbiting objects. A galaxy is a collection (in the most general sense) of anywhere from millions to billions of stars. A universe (THE universe) is a collection of billions upon billions of galaxies.

Our solar system much less than a light-hour in radius. A light-hour is the distance light travels in an hour. The nearest star (Alpha Proxima, in a binary system with Alpha Centauri)is 4.2 light-years (ly) away. That means it takes light 4.2 years to get there from Earth. Our galaxy (the Milky Way galaxy) is about 100,000 ly in diameter. We are in the Virgo Arm (I think) and about 25,000 ly from the edge. That means it takes about 25,000 years for light to exit our galaxy.

I cannot agree or disagree with your assertions in the second question. I don't know about any intelligent civilizations out there and neither do you. It does NOT explain us picking up our own radio signals (and I have a request - show me where you read or heard that we do).

As to the third question... The messenger particle for the electromagnetic force is the photon (yes, everybody's favorite smallest bundle of light). Light has different wavelengths. All wavelengths of light travel at c (the speed of light). Radio waves ARE light, just as ultraviolet rays are, and visible light, and infrared, and x-rays and gamma rays and microwaves. They ALL travel at c. Here is a simple website to go to:

http://observe.ivv.nasa.gov/nasa/education/reference/emspec/emspectrum.html

Your first and last wuestions I couldn't understand. Please rephrase?

• Radio signal becomes too weak when it reaches other intelligence - alexander - January 18, 2001 - 00:40 UTC
  • Re: Radio signal becomes too weak when it reaches other intelligence - bladesinger - January 18, 2001 - 04:12 UTC