Yes radio does lose power when it travels long distances.

I think radio might be the most appropriate for this kind of communication because it should be the first method of communication that technological civilizations discover. That means everybody should be able to send and receive radio.

Radio is the only kind we can send at our technology level. Any electromagnetic signal (this includes radio) we send decreases in power with the square of the distance.

I have no idea. But thanks for talking down to me and feeling foolish for asking a legitimate question I had and trying to advance my own knowledge.

Have a good day.

[removed]

Neutrinos or gravity waves are some of the more exotic/advanced theoretical communication methods proposed.

The Earth is invisible in this photo. Blue dot is illustrating 200 ly. Diameter.

Edit: to further blow your mind and put it in perspective it would take you 200 years to go from one edge of that blue dot to the other traveling at a constant speed of almost 300 million meters per second (186,000 miles/second).

There is a caption, with an arrow pointing at the blue dot that reads “200 light years in diameter.”

The Earth is only about 8,000 miles in diameter.

The arrow isn’t pointing at the box.

Therefore the blue dot is a volume of space 200 light-years in diameter.

Let’s just keep this discussion to the Milky Way, okay? No need to bring in stuff many billions of light-years away, when the interesting aliens are the one most likely to communicate with us (if they exist), within a few 1000 light years.

Is radiowave signal the most appropriate for this kind of communication? Suppose that we want to send a signal out there to be picked up, would it be radio?

Does radio lose power when it travels long distances?

…Do you think the Galaxy is only like 1000ly wide?…

What if it takes them 5000 Earth years to rotate around their own star just once and the last time they called was the earth year 1001. They'll not call again for a while.

Well yes and no… i guess…

If they had the technology and lived only maybe 5000 lightyears away, they could get our messages in about 5000 years… i believe that by then we would have met already because technology is advancing at a tremendous rate and we are already researching different new types of drives for space transportation. It’s certainly still a very long time until mankind will reach 0.1 times speed of light, but 5000 years? Who knows what we have until then…

If you think you know, what we will have in 5000 years: think again… our ancestors from 5000 years ago would simply be unable to understand what kinds of tech we have. It would be magic to them… a simple lighter would mean you have to be a god!

Now if we today send out a signal into space, those who would eventually receive it would probably already know before any earth signal ever reached them.

And yes, i believe that we will find a way to effectively travel faster than light in that kind of timeframe.

Wait wait wait you mean we have smaller galaxies closer?

There's also signal-attenuation to consider.

Radio signals disperse in open space and eventually become indistinguishable from the background radiation.
For all but our most powerful directed transmissions, this is in the realm of a couple hundred lightyears at most.

A world 2000 lightyears away wouldn't be able to understand or recognise the signal even when the radio waves start passing it by. At best it'd be a slight increase in radio complexity drowned out by the cosmic background noise.

Is the blue dot just earth or the 200 light years or is the box 200 light years?

An earth-like planet with a similar technological civilization would have to be no more than 122 light years away to detect our signals because we've only been using radio for that long. Most likely they'd have to be much closer or the signals would just be too weak to pick out from the background noise.

122 light years sounds like a long distance, but keep in mind that our Milky Way galaxy is over 100,000 light years across. Any other galaxy would be hopelessly too far away to ever receive a radio signal. The closest major galaxy is Andromeda at over 2.5 million light years away.

It's entirely possible there are several radio signals from other planets traveling from planets in our galaxy but they either haven't reached us yet or are too weak to pick up by the time they've crossed that vast distance.

What if they’ve been sending us messages for thousands of years? Maybe one every year to wish us a happy new year?

Just Imagine if that was true.

Due the faster light speed expansion of the universe, there are always going to be parts of the universe that we'll never get signals from no matter how long we wait (given no ability to move faster than light ourselves). More and more as time goes on.

It's possible to detect signals, but even if a planet 2,000 ly away has the same tech and sends us a message, we won't receive it until 4023. By then we could well be long gone.

This image illustrates it nicely.

[removed]

I heard the lead singer was in a band in the 60s. They supposedly had a hit here and there. Nothing much happened to them.

Easy. There was no Big Bang.

(Because the theory is not compatible with actual observations.)

Now comes the hard part, if there was no Big Bang, then the observations that lead to the creation of the Big Bang hypothesis are interpreted wrongly. And that opens up for a lot of things to be changed.

Ohh, that sounds exciting. What's the most likely alternative in your opinion?