SETI and Signal Leakage: Where Do Our Transmissions Go?
centauri-dreams.org
centauri-dreams.org
Or manufacture a few billion tons of some exotic element that doesn't exist in nature and dump it into the sun on a regular basis. But it looks like somebody else might have already had that idea.
"What was that flash??"
"Dunno"
The end of our legacy haha. We really should get a backup planet sorted out at some point once we've fixed gestures at everything
Because their signals would be under the noise level (except for a few stars)?
Indeed those stars that close enough to our interstellar probes will be also informed of our existence.
"The transmissions to Voyager 2, Pioneer 10, and Pioneer 11 have already encountered at least one star, while those to Voyager 1 and New Horizons will encounter their first stars in the near future."
In the book “Project Hail Mary” by Andy Weir, Eridians who are at a similar stage as humans were oblivious to Ionizing Radiation and Relativity.
Also our sample size is 1. This is all speculation, none of it has any practical meaning since we know nothing about even where life on earth came from. Let alone if it exists elsewhere. I love science fiction but we should not get it confused with reality.
Humans are barely intelligent enough to be at any level of development.
We don't have great apes beat by as much as people think.
It's conceivable to me that we are the absolute minimum level of intellect to be a species that can develop tools allowing us to escape our ancestral environment.
At the same time the notion of "absolute minimum level of intellect" is somewhat poorly defined. It's somewhat hard to imagine, but there could be a set of physics theories that don't include relativity or gravity or any of our familiar concepts, but still enable interstellar travel.
Maybe another civilization skipped our fragmentary and incorrect understanding and hit directly on a unified field theory. Or maybe we both have fragmentary and incorrect understandings, both are essentially wrong in every way, and yet they are close enough for practical purposes. Is the civilization which developed the more practical model of physics "smarter" or just lucky?
Does "smarter" mean that you develop a model of physics which is closer to ground truth, or one that enables you to build better spacecraft, or one that enables you to build better computers?
Meanwhile we're impressed when an ape uses a tool in a clever way.
We obviously don't know enough to travel in person to distant stars, and we don't even know whether or not that might one day be possible, but we can consider the possibility, which is something other great apes can't.
If anything, it's a reaffirmation of the original point.
I don't know anything about this stuff, it's just a fun armchair thought.
This article doesn't explicitly point out the distinction between broadcast (which taper off rapidly in power) and narrow beam signals (which lose far less power over distance), but it's pretty clear that it is largely about that distinction. It lists signals aimed at specific spacecraft that hit only a limited number of stars. That tighter beam hopefully means a significant signal will be detectable there.
It's cool that they calculate when the return signal might arrive here. It would have been even cooler if they'd calculated how strong the signal would be when it arrives at that star. But it's possible that's far too uncertain to determine; stars near the edge of the beam probably receive far less power than those in the center.
SETI fans don't seem to want to answer that.
He's just a science enthusiast, but it touches all the points it needs to.
Strongest radar we have ever made could do perhaps a few hundred light years? The Milky Way is 100,000 light years across and there are only about 59,000 stars visible with a telescope within 100 light years of earth. I think it would take a very charitable reading of the Drake equation to believe our signals even met intelligent life capable of receiving them.
As you can tell, I just watched "Contact" last night as it came onto HBO for the first time in forever.
But what about our focused beams from airport and weather radars?
Perhaps a small tube creating a Radiolaser?
The idea that aliens can pickup a radio station or TV station doesn’t seem likely to me. The rotation of the Earth would sweep that signal across them.
They might be able to detect “noise” at unusual frequencies but it wouldn’t appear coherent.
What if we as humans want to send a signal? Would we just detonate a bomb in space?
Couldn't it be possible that someone out there figured out how to travel tremendously fast but is just not able to find anyone?
I find this doubtful because they could travel outward in a sphere, touching every celestial object in the universe as they go.
Like only one flight per month.
Or they know how to do a very fast straight line but nothing local. Therefore needing to recharge and shot themselfs one waypoint after the next.
A kilowatt won’t get far - the signal strength decreases over distance. I seem to recall CB radios with an amplifier could easily attain that.
No doubt someone here could calculate the theoretical wattage needed to appear above the background noise on, say, Proxima Centauri.
Then a laser is a better choice?
<https://public.nrao.edu/ask/how-strong-is-the-signal-from-th...>
Signal attentuation follows the inverse-square law. A 1 kW signal is 43 times stronger than the Voyager's transmitter. It should reach about 6.6 times further.
So your 1 kW transmitter, if coming from a quiet noise floor (which the terrestrial environment is not) could reach at least 0.01 light years. Possibly further.