can electromagnetic waves be sent back in time?
2006-10-14 02:20:38 · 6 answers · asked by rajesh bhowmick 2 in Science & Mathematics ➔ Physics
I am also quite interested in the research work being done in this field and have kept your question in the watchlist. Thanx for asking such interesting questin.
2006-10-14 02:34:49 · answer #1 · answered by Mani G.India 4 · 0⤊ 0⤋
We report the first experimental demonstration of time-reversal focusing with electromagnetic waves. An antenna transmits a 1–µs electromagnetic pulse at a central frequency of 2.45 GHz in a high-Q cavity. Another antenna records the strongly reverberated signal. The time-reversed wave is built and transmitted back by the same antenna acting now as a time-reversal mirror. The wave is found to converge to its initial source and is compressed in time. The quality of focusing is determined by the frequency bandwidth and the spectral correlations of the field within the cavity.
:)
2006-10-14 09:28:01 · answer #2 · answered by ☺♥? 6 · 1⤊ 0⤋
Have you heard of the "Philadelphia Experiment" that Albert Einstein worked on? Sometime the 1940's The U.S. Military's top scientists sent a battleship 30 years into the future. (The ship "mysteriously" appeared at the same site in the 1970's) A set of twins were on the ship. One twin got off the ship in the "future" (1970's) and one remained on the ship, which was returned ("recalled"?) back to the present (1940's).
When the ship returned many crew members were "mangled" into the ships walls, etc. (molecular scrambling?), but some arrived intact. The twin was one who returned intact. He actually met his twin brother in the 1970's. The twin who got off the ship in the 70's was ("still") in his 20's, and the twin that returned to the 1940's and aged normally was in his 50's. Yet they were twins.
So, I would say the answer be "yes", forward and back in time.
Of course the above would be denied by the military, but there is also much documentation about it. Please do check. Please note I may have forgotten some important points about the story.
2006-10-14 10:04:47 · answer #3 · answered by BarbaraRamDass 1 · 0⤊ 0⤋
At our current level of technology I am yet unaware of any particles that might be able to be sent back in time.
2006-10-14 09:30:17 · answer #4 · answered by T F 3 · 0⤊ 0⤋
Yes, this is the property that is made use of in radio communication.
2006-10-14 09:52:11 · answer #5 · answered by Trad 2 · 0⤊ 0⤋
theoritically yes. read '' the history of time" by stephen hawkings. you will understand lot beyond your doubt. and you can understand it with minimum knowledge of physics.
2006-10-14 09:47:17 · answer #6 · answered by Anonymous · 0⤊ 0⤋