- What Are Extraterrestrials Watching? - 7 Updates
| amdx <nojunk@knology.net>: Aug 19 04:26PM -0500 >> somebody travels pretty damn close to us and is listening carefully for >> them. > Is that according to only 1970s or 80s research. OH, so they are still in anticipation of the Kardashians. Mikek |
| Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Aug 20 01:15AM +0200 On 19-8-2017 12:38, Cursitor Doom wrote: > I'd always suspected so. But is there any respectable research to back up > this figure of 1.5 light years? We know the signal strength (inverse square law), and we know a lot about noise received from space. When the noise is drowning the signal, you cannot receive the signal. So, yes, we know the reception quality for a given transmitter power and distance. To reach twice as far you need 4 times as much power, and as distance increases, you quickly lose that game. |
| bitrex <bitrex@de.lete.earthlink.net>: Aug 20 08:01AM -0400 On 08/19/2017 06:38 AM, Cursitor Doom wrote: >> Greg > I'd always suspected so. But is there any respectable research to back up > this figure of 1.5 light years? The problem with communicating with Voyager is on the uplink side, not the downlink side. Even at Voyager 1s distance and current power output of a few 10s of watts, in the appropriate spectrum Voyager 1 is a blazing beacon far outshining most other objects of interest studied by radio astronomers. I think it's possible to do much better than 1.5 light years, if you can make some assumptions about what area of the spectrum you're looking in, and what kind of patterns you're looking for. It's not like there aren't ways to recover periodic signals/signals with structure that have been corrupted by noise. |
| N_Cook <diverse@tcp.co.uk>: Aug 20 02:43PM +0100 On 20/08/2017 00:15, Sjouke Burry wrote: > and distance. > To reach twice as far you need 4 times as much power, and as distance > increases, you quickly lose that game. But these very clever aliens have worked out how to use galactic scale gravitational lensing to survey the comms of lesser inteligencies. |
| Cursitor Doom <curd@notformail.com>: Aug 20 01:46PM On Sun, 20 Aug 2017 08:01:18 -0400, bitrex wrote: > and what kind of patterns you're looking for. It's not like there aren't > ways to recover periodic signals/signals with structure that have been > corrupted by noise. So even if we could do 3 light years, there's still nothing much within that radius that we could expect to communicate with. Why did all that effort go into SETI, then? Surely all the nerds that ventured into that, or granted the SETI nerds spare time on their idling computers to analyse the data obtained from the world's radio telescopes must have known they were wasting their time! -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition. |
| Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Aug 20 04:15PM +0200 On 20-8-2017 15:43, N_Cook wrote: >> increases, you quickly lose that game. > But these very clever aliens have worked out how to use galactic scale > gravitational lensing to survey the comms of lesser inteligencies. Bollocks. Lensing more noise/weak signal does not change the ratio, and does not make for better reception. And your lensing works only over millions of light years. Which leaves you micro-micro-micro watts of received power. |
| Mike Coon <gravity@mjcoon.plus.com>: Aug 20 04:54PM +0100 In article <59999ab7$0$1718$e4fe514c@textnews.kpn.nl>, burrynulnulfour@ppllaanneett.nnll says... > and does not make for better reception. > And your lensing works only over millions of light years. > Which leaves you micro-micro-micro watts of received power. I take your point about the scale over which lensing works. But why is the effect not similar to using a high-gain aerial, which is common enough? Mike. |
| You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com. |
No Response to "Digest for sci.electronics.repair@googlegroups.com - 7 updates in 1 topic"
Post a Comment