If this actually happened would anyone recognize it as a message from the past? It would not be traveling into the past, but forward into the future and we all travel into the future. What if we in the present send a message into the future, will we ever have our message acknowledged?
2007-07-13 00:40:39 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Sure, that is exactly what the research program SETI (Search for extraterrestrial intelligence) is based on. You make these huge antennas and you hope to pick the signal.
Ken D, radio signal are also electromagnetic waves, so they travel at the speed of light. The signal is then capture by an antenna which "transforms" the electromagnetic wave into an electric current, the electric current is then "transform" to a vibration allowing us to hear it.
The problem is that unlike the light from the stars, you can only produce radio signals of so much power (in principle you can produce them with the same power, but since we need equipment to do that we put limitations), and then as the signal travels it spreads out (spherical wave) and it becomes really hard to detect it because the intensity has been decreased a lot.
Anyways, every time you turn your radio on, you are listening to the past, though it is a very immediate past. Same thing for anything in outer space though the distance is larger therefore the message comes from further back in time.
Hope that answers your question.
2007-07-13 02:15:00 · answer #1 · answered by Ralph L 2 · 0⤊ 0⤋
Yes! However, it would have to be sent many years away from Earth. If a star and it's events take one year for us to see a particular event at the speed of light it will take many more years for a radio signal to reach us at the speed of sound. Therefore, a satelite could travel a few light years and then send the radio message. We would know that the message is from the past and are hearing it many years in the future as that would be part of the message. Basically, you let a satelite travel for five light years and then wait a further 30 or 40 years for the message to arrive.
2007-07-13 00:49:33 · answer #2 · answered by kendavi 5 · 0⤊ 1⤋
Yes. This happens every time to turn on a radio. The voices you here were actually produced in the past. If the station is in town, that would be around 1/1000'th of a second ago. The further away the station is, the further in the past the signal was sent due to the finite speed of light (and radio). If the station was on the nearest star other than the sun, it would have been sent 4.5 years ago.
2007-07-13 02:59:00 · answer #3 · answered by Dr. R 7 · 0⤊ 0⤋
particular! although, it is going to ought to be sent an prolonged time removed from Earth. If a celebrity and it is activities take one 3 hundred and sixty 5 days for us to work out a special social gathering on the cost of sunshine it is going to take many extra years for a radio sign to attain us on the cost of sound. for that reason, a satelite could adventure a pair of gentle years and then deliver the radio message. we'd comprehend that the message is from the quicker and are listening to it an prolonged time sometime as which would be somewhat of the message. basically, you enable a satelite commute for 5 mild years and then wait yet another 30 or 40 years for the message to reach.
2016-10-01 12:36:34 · answer #4 · answered by ? 4 · 0⤊ 0⤋
i thnk so
2007-07-13 00:49:39 · answer #5 · answered by Prince Yahoo! 3 · 0⤊ 0⤋
maybe.
2007-07-13 01:13:25 · answer #6 · answered by moonrider 6 · 0⤊ 0⤋