Don’t. Not only are radio transmissions probably washed out by distance, they really haven’t gone all that far in the scheme of things. Our signal range is 100 light years in any direction at this point… in a galaxy around 100,000 light years across. The little blue dot in the image puts distance in perspective.

https://www.sciencealert.com/h...ace-as-you-think/amp

Mind-Boggling Image Shows How Far Into Space Humanity's Voice Has Actually Reached

It's the big mystery: Intelligent life should be out there in the Universe, so why haven't we found any evidence for it? This question is called the Fermi paradox, and there are a few potential answers.

But this one image (below) just really brings it home. Space is super, duper big, and humanity's reach into it? It's super, duper small.
The galaxy in the image is a reconstruction of the Milky Way, if it were about 110,000 light-years in diameter (more recent research suggests it's even bigger than that).
The itsy bitsy blue dot is how far our radio signals have travelled from Earth - a diameter of about 200 light-years.



The invention of radio was the work of many great minds over the course of several decades during the 19th century, but the first transmission was made in 1895. Radio broadcasting came along a few years later.
The first intentional radio transmission to space, called the Arecibo message, wasn't until 1974, but we've been leaking radio signals into space for over 100 years.
Many of those are probably garbled by the ionosphere. Even those that aren't (like Earth-space communications), by the time they're 100 light-years away, are so attenuated and weak that they're basically undetectable anyway.
So, if there are any intelligent aliens beyond that radius, and if they have radio technology, they probably couldn't pick up what we're putting out there.

The same could be true in the other direction. Maybe, somewhere over 100 light-years away, there's an alien civilisation that just happens to have developed radio technology at exactly the same time as we did - and their signals are so weak that we can't detect them.
It seems unlikely that, as vast as the Universe is, intelligent life could only have emerged the once… but, as vast as the Universe is, it's also unlikely that we're going to find it anytime soon.
But we can still dream, right?

quote:

by the time they're 100 light-years away, are so attenuated and weak that they're basically undetectable anyway.

The inverse square law in action.

[richardburtonvoice] “No-one would have believed, in the last years of the nineteenth century, that human affairs were being watched from the timeless worlds of space. No-one could have dreamed that we were being scrutinized, as someone with a microscope studies creatures that swarm and multiply in a drop of water. Few men even considered the possibility of life on other planets. And yet, across the gulf of space, minds immeasurably superior to ours regarded this earth with envious eyes, and slowly and surely, they drew their plans against us…” [/richardburtonvoice]

At least we have the MIB.

quote:

Originally posted by gearhounds:
Our signal range is 100 light years in any direction at this point…

How do we know this? Is there a receiver 100 light years away that we're in communication with and waited 200 years to confirm transmission?


I swear NASA pulls these numbers out of their ass.

quote:

Originally posted by Hildur:

quote:

Originally posted by gearhounds:
Our signal range is 100 light years in any direction at this point…

How do we know this? Is there a receiver 100 light years away that we're in communication with and waited 200 years to confirm transmission?


I swear NASA pulls these numbers out of their ass.

We've been using radio waves for a little over 100 years.
Radio waves travel at the speed of light, so our earliest emissions have traveled about a hundred light years.
No receiver needed to confirm it.

Once again, the L.A.P.D. is asking Los Angelenos not to fire their guns at the visitor spacecraft. You may inadvertently trigger an interstellar war.

quote:

Originally posted by Hildur:

quote:

Originally posted by gearhounds:
Our signal range is 100 light years in any direction at this point…

How do we know this? Is there a receiver 100 light years away that we're in communication with and waited 200 years to confirm transmission?


I swear NASA pulls these numbers out of their ass.

c

quote:

Originally posted by WaterburyBob:

quote:

Originally posted by Hildur:

quote:

Originally posted by gearhounds:
Our signal range is 100 light years in any direction at this point…

How do we know this? Is there a receiver 100 light years away that we're in communication with and waited 200 years to confirm transmission?


I swear NASA pulls these numbers out of their ass.

We've been using radio waves for a little over 100 years.
Radio waves travel at the speed of light, so our earliest emissions have traveled about a hundred light years.
No receiver needed to confirm it.

So signals via microwaves and light don't degrade over distance? I can shine my flashlight at the stars and some alien 100 light years away 100 years from now is going to wonder where that came from?

quote:

Originally posted by Hildur:

quote:

Originally posted by WaterburyBob:

quote:

Originally posted by Hildur:

quote:

Originally posted by gearhounds:
Our signal range is 100 light years in any direction at this point…

How do we know this? Is there a receiver 100 light years away that we're in communication with and waited 200 years to confirm transmission?


I swear NASA pulls these numbers out of their ass.

We've been using radio waves for a little over 100 years.
Radio waves travel at the speed of light, so our earliest emissions have traveled about a hundred light years.
No receiver needed to confirm it.

So signals via microwaves and light don't degrade over distance? I can shine my flashlight at the stars and some alien 100 light years away 100 years from now is going to wonder where that came from?

Yes, they degrade.
Only the stronger signals would make it that far without completely dispersing.

A quick read on EMF would help you greatly.

People of already stated some well-known laws of nature including the inverse square rule and the speed of light which is known as a constant by the letter c.

Power and direction matters, focus matters.

We know the stuff because of science. Not nasa.

Fair enough. We see stars hundreds of light years away but that's also emitted by a source much more powerful than anything on Earth.

Yes and many are billions of light years away.

Your eyeball collects a few photons. You’re looking back in time to see what it was billions of years ago.

quote:

Originally posted by Hildur:
So signals via microwaves and light don't degrade over distance? I can shine my flashlight at the stars and some alien 100 light years away 100 years from now is going to wonder where that came from?

Radio waves, microwaves, light, and even gamma rays are all forms of electromagnetic waves, and subject to degradation by the inverse square law. Cosmic rays and high-energy particle jets can travel much greater distances with little degradation.

The stars and galaxies we see that are hundreds, and even billions of light-years away are visible only because they were very intense to begin with.

flashguy

Soooo.. If we knew messages couldn't be received at any meaningful distance, why did we spend good money trying to listen to worlds far beyond??

I'm too simple minded to comprehend the magnitude of the numbers we're talking about. When I was younger I could throw millions and billions around like nothing. Now that I'm older it hits different.

^^^^
Why listen? I believe the hunger of just wanting to discover if there is any intelligent life out there. Conceivably we could detect evidence of such and from much further away depending on the strength of the signal. The question is, what would we do if we discovered any?

Until we find a way to travel faster than light (debatably questionable) this image puts traveling anywhere on anything but a one way trip in perspective. And truly gives an idea of the true size of not only the Milky Way, but the universe as a whole. It may be comforting knowing that a belligerent race might take forever to get to us but depressing at the same time that contact with any life at all is just as unlikely.

All of the space stuff is beyond my ability to comprehend. At least if we get hit by the comet I won’t see it coming

quote:

Originally posted by preten2b:
Soooo.. If we knew messages couldn't be received at any meaningful distance, why did we spend good money trying to listen to worlds far beyond??

Just because we haven't figured out how to make something happen doesn't mean something else out there hasn't.

Our understanding of the world is not comprehensive nor even confirmed to be accurate for the bits and pieces we have claimed to figure out.

There is stuff so far outside our understanding of the world that we don't even have words to articulate it. Imagine a cave man trying to describe molecular bonds to another cave man. That's us.

Faster than light travel might exist out there. It might not be discovered by a far away civilization for another billion years. Or it might have already died out with a civilization a billion years ago.

Given the astronomical distances and time frames, it's really little surprise that we haven't encountered anything else out there.

IF our transmissions have such limited range...
AND IF radio waves are like light waves...
THEN images of a galaxy shown are complete and utter conjecture.

If 200 light-years is as shown here, then the distance across the spiral galaxy depicted here would be about 100,000 light years.
https://imagine.gsfc.nasa.gov/...c/milkyway_info.html

We cannot see all the stars depicted in the image of the galaxy, nor can we measure the distance from a star to the earth with any reliability. If the light is visible, yet 100,000 years are required for it to arrive, the star's existence can be debated.

No one knows. It is amazing that we pay people to be astronomers and galactic physicists (cosmologists?) when nothing is truly knowable in this field of study. Because they can't explain observations, they invented dark matter. It can't be seen, it can't be measured, it can't be identified, but it must exist.