2006-10-02 17:58:10 · 4 answers · asked by juliecn01 1 in Science & Mathematics ➔ Physics
radio waves travel at the speed of light (3.0 x 10^8 m/s). It depends, of course, which galaxy you are talking about.
"For a long time, the Large Magellanic Cloud, an irregular type satellite galaxy of our own, was held to be the closest galaxy to the Milky Way. It is 179,000 light-years away.
But in 1994 the Sagittarius Dwarf Elliptical Galaxy was discovered at 80,000 light-years." http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/020206a.html
So it would take 80,000 years for radio waves from the Sagittarius Dwarf Elliptical Galaxy to reach Earth.
2006-10-02 18:10:56 · answer #1 · answered by borscht 6 · 0⤊ 0⤋
Electromagnetic radiation such as a radio wave travels at about 186,272 miles per second or roughly 300,000,000 metres per second in a vacuum.
Divide the distance to the galaxy by the rate and you will have the time.
Sometimes distances are given in light-years, which can be calculated by multiplying the rate times the number of seconds in a year.
2006-10-03 01:14:32 · answer #2 · answered by hls 6 · 0⤊ 0⤋
depends on how far the galaxy is.
2006-10-03 01:05:15 · answer #3 · answered by Connor 3 · 0⤊ 0⤋
about a day
2006-10-03 01:06:59 · answer #4 · answered by IKnowAll 3 · 0⤊ 0⤋