2006-11-28 02:25:08 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Physics
That frequency is interesting for radio astronomy and astronomers don't want artificial signals interfering with their observations. However I had not heard of an international agreement not to use that frequency.
2006-11-28 02:26:57 · answer #1 · answered by campbelp2002 7 · 1⤊ 0⤋
That's the frequency of the 21 cm line of atomic hydrogen, the fundamental spectral line for studying the Milky Way. There is indeed an international agreement not to transmit there, but it is slowly being eroded as commercial interests lobby for increased bandwidth.
2006-11-28 10:39:26 · answer #2 · answered by cosmo 7 · 1⤊ 0⤋
1420 Mhz is close to the resonant frequency of water.
That's how a microwave works and why the mobile phone bands are 900 and 1800Mhz.
If you transmitted a radio signal at around 1420Mhz and strong enough you would cook every living thing in range.
Also fibre optic cables are also banned from using 1420Mhz for the same reason.
2006-11-29 15:18:45 · answer #3 · answered by Andy S 2 · 0⤊ 0⤋
Since this is the frequency of the hydrogen line astronomers don't want anyone else using it!
2006-11-28 10:35:38 · answer #4 · answered by David B 2 · 0⤊ 0⤋
that's the frequency they run the space mind control lazers at
2006-11-29 14:30:44 · answer #5 · answered by gbiaki 2 · 0⤊ 0⤋