# Radio communication from the galaxy's far side?

• modus
In summary: We can see that the dust is there, but we can't see through it. So we look in other wavelengths to see what's behind it. And that's how we know there's a black hole there.In summary, it is possible for radio communication to travel from the obscured part of our galaxy to Earth, although it may take 25,000-50,000 years to reach us. The amount of dust in the galactic plane may affect the clarity of the communication, but longer wavelengths like radio can propagate through the dust without being significantly absorbed or scattered. In
modus
Is it at all possible for radio communication to travel from the obscured part of our galaxy to Earth? If so, about how long would it take to reach us?

I have an idea for fiction where we're able to receive communications from the far side of the Milky Way, but we can't figure out how to communicate back, and the pursuit of trying to communicate back divides people and so forth. However if it's completely impossible in the realm of physics to receive communications from the far side of the galaxy, I'll have to rethink the idea.

Note: I have little to no scientific background. Sorry, I'm working on it, though I have math-related disabilities.

If so, about how long would it take to reach us?
We are ~25000 light years away from the galactic center, if the sender has the same distance (but in the opposite direction) it takes ~50000 years per direction.

Is it at all possible for radio communication to travel from the obscured part of our galaxy to Earth?
I don't know about the absorption, but if you want 1-way communication, you can use a different technology level: Assume that the sender emits a real powerful signal, and we cannot reach a comparable intensity yet.

The hydrogen line is regarded as being a good candidate for interstellar communication but as has been pointed out any message is going to take tens of thousands of years to get there and an equal time to get back.

modus said:
Is it at all possible for radio communication to travel from the obscured part of our galaxy to Earth? If so, about how long would it take to reach us?

I have an idea for fiction where we're able to receive communications from the far side of the Milky Way, but we can't figure out how to communicate back, and the pursuit of trying to communicate back divides people and so forth. However if it's completely impossible in the realm of physics to receive communications from the far side of the galaxy, I'll have to rethink the idea.

Note: I have little to no scientific background. Sorry, I'm working on it, though I have math-related disabilities.

The dust in the galactic plane scatters radiation, but the amount of scattering is proportional to the fourth power of the frequency. This means short wavelengths like light are heavily absorbed, but longer wavelengths like radio propagate through the dust without being significantly absorbed or scattered. So yes, radio waves can travel to Earth from the far side of the galaxy. As others have said, it will take 25,000-50,000 years, depending on where it is coming from.

mfb said:
We are ~25000 light years away from the galactic center, if the sender has the same distance (but in the opposite direction) it takes ~50000 years per direction.

Thanks for the answers so far, very heartening to know this is in the realm of possibility. 50,000 years in the grand scheme of things isn't too terribly long.

Ryan_m_b said:
The hydrogen line is regarded as being a good candidate for interstellar communication but as has been pointed out any message is going to take tens of thousands of years to get there and an equal time to get back.

This is a little above me but thanks, I understand the underlying concept. I was also lead to an article about the Pioneer Plaque which sort of blew my mind a second time. I never asked how we could communicate to outside intelligent life about where we're located, but that exact question occurred to me earlier today. Question answered.

phyzguy said:
The dust in the galactic plane scatters radiation, but the amount of scattering is proportional to the fourth power of the frequency. This means short wavelengths like light are heavily absorbed, but longer wavelengths like radio propagate through the dust without being significantly absorbed or scattered. So yes, radio waves can travel to Earth from the far side of the galaxy. As others have said, it will take 25,000-50,000 years, depending on where it is coming from.

That's great. I thought that was impossible. But to my understanding viewing the obscured part of our galaxy is impossible, right?

modus said:
50,000 years in the grand scheme of things isn't too terribly long.
In terms of evolution of the universe and life, it is short. In terms of human technology, it is extremely long.
50000 years ago, our ancestors used stone tools and invented gods for thunder and lightning, as they had no idea how to explain it otherwise.
We can receive radio signals for less than 100 years now, and laser signals for less than 50 years (if we look at the right frequency and in the right direction).
Every 10 to 20 years, new telescopes are so much more powerful that the older ones are not competitive any more. At the same time, computing power increases by a factor of ~30-1000.

modus said:
That's great. I thought that was impossible. But to my understanding viewing the obscured part of our galaxy is impossible, right?

If by viewing, you mean looking with your eyes, then yes. If by viewing, you mean using instruments in other frequencies, then not necessarily.

phinds said:
If by viewing, you mean looking with your eyes, then yes. If by viewing, you mean using instruments in other frequencies, then not necessarily.

Right. For example, infrared telescopes are capable of seeing through the dust and imaging the starts at the galactic center. This could count as "viewing".

mfb said:
In terms of evolution of the universe and life, it is short. In terms of human technology, it is extremely long.
50000 years ago, our ancestors used stone tools and invented gods for thunder and lightning, as they had no idea how to explain it otherwise.
Just to add to this our species is only 200ky old.

phyzguy said:
Right. For example, infrared telescopes are capable of seeing through the dust and imaging the starts at the galactic center. This could count as "viewing".

I think astronomers would take issue with "could".

phinds said:
I think astronomers would take issue with "could".

I'd say so. I know I count it as "viewing".

## 1. What is radio communication from the galaxy's far side?

Radio communication from the galaxy's far side refers to the transmission and reception of radio waves from distant regions of the galaxy that are beyond our line of sight. This allows us to communicate with and gather information about objects and phenomena that are located on the far side of the galaxy.

## 2. How does radio communication from the galaxy's far side work?

Radio communication from the galaxy's far side works by using radio telescopes to detect and amplify radio waves emitted by objects and phenomena in the distant regions of the galaxy. These waves are then converted into signals that can be transmitted and received by communication devices on Earth.

## 3. What can we learn from radio communication from the galaxy's far side?

Radio communication from the galaxy's far side allows us to gather information about the composition, structure, and movement of objects and phenomena in the distant regions of the galaxy. It also helps us to study the evolution and history of the universe and to search for signs of extraterrestrial life.

## 4. How far can radio communication from the galaxy's far side reach?

The distance that radio communication from the galaxy's far side can reach depends on various factors such as the power of the radio waves, the sensitivity of the equipment used, and the presence of any obstacles that may block or distort the signals. However, with modern technology, we are able to receive radio signals from objects that are billions of light years away.

## 5. What are the challenges of radio communication from the galaxy's far side?

One of the main challenges of radio communication from the galaxy's far side is the interference from other sources of radio waves, such as those emitted by human-made devices. Another challenge is the distortion of signals caused by the Earth's atmosphere and other cosmic objects. Additionally, the vast distances involved also pose technical and logistical challenges in terms of transmitting and receiving signals accurately and efficiently.

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