Space Discussion Thread

[Pi R Squared]

Even if our radio emissions have reached other inhabited systems, they would be well into the noise floor by that point. Unless some alien race has a probe rather close by that can still pick out the signals from background noise I don't imagine anyone/thing has detected us - at least not from just radio emissions.

Unless they've come up with some clever way to pull signals out of the noise floor that we've yet to discover - higher gain detectors don't help pull signals out of the noise, they just make the noise louder...

This is complete nonsense, just within 100 light years there are about 512 stars, not including white dwarf stars. Within 50 light years if we count just the ones visible to the naked eye from earth they number 133. I have been listening to Seth Shostak on the radio for many years now and he thinks we can detect artificial signals at more than 1000 light years even with our primitive technology. So do the Chinese with their worlds largest radio telescope they are just finishing. They even relocated 9000 people so they could build it there, paying them each the equivalent of $1500 or $1800 to relocate.

If you don't know who Seth Shostak is, he is an astronomer, currently the Senior Astronomer and Director of the Center for SETI Research.

Alan

 

[Benm]

One issue is that we still don't really know how long a planen would emit detectable signals. On earth it's been 100 years or so and is now rapidly coming to an end. Things like high power analog tv transmissions are rapidly being phased out, and fm radio stations usually are less powerful now servicing smaller areas (and being phased out for digital systems as well).

This shift from analog to digital is very important. Most digital modulation schemes spread the information over a fairly wide piece of spectrum. Also the information is encoded, sometimes encrypted, making it hard or impossible to decipher or even detect unless you know what you are looking for.

If other planets evolve similarly the window to detect one could be 150 years or so.

Also it's not unthinkable that some planets will skip/omit the whole high power transmission phase, perhaps because they live closer together and use wired or low powered systems, or skip analog and start with digital modes directly.

How often this would happen is guesswork, but it does impact chances of 'seeing' some society even if it is very close by.

 

[diachi]

This is complete nonsense, just within 100 light years there are about 512 stars, not including white dwarf stars. Within 50 light years if we count just the ones visible to the naked eye from earth they number 133. I have been listening to Seth Shostak on the radio for many years now and he thinks we can detect artificial signals at more than 1000 light years even with our primitive technology. So do the Chinese with their worlds largest radio telescope they are just finishing. They even relocated 9000 people so they could build it there, paying them each the equivalent of $1500 or $1800 to relocate.

If you don't know who Seth Shostak is, he is an astronomer, currently the Senior Astronomer and Director of the Center for SETI Research.

Alan

I didn't say we couldn't detect signals from them - for all we know they could be using incredibly powerful radio transmitters which they use to systematically transmit to different star systems with in the hopes of receiving a reply.

What I said was they wouldn't receive much, if anything from us. The majority of our transmissions A) aren't powerful enough or B) aren't directional (thus the signal "weakens" faster). Keep in mind while our radio bubble may extend ~100 light years - powerful, higher frequency, directed transmissions didn't start being common until later than that, and even then chances of someone catching one powerful enough for any length of time are very slim.

About the only transmission that has much of a chance at actually conveying much information at any reasonable distance is the Arecibo Message sent in 1974 - which was very directional (aimed at a star cluster 25,000 light years away - so it'll be a while before it gets to it's intended destination) and has "only" propagated some 40 light years. That transmission lasted for ~3 minutes - further reducing the chance of it ever being detected unless someone is specifically watching this direction continually. Even if it had propagated for 100 light years it'd miss most if not all of the 512 stars you mentioned.

So my point stands, I highly doubt anyone/anything has detected us yet.

 

[Razako]

Would it be feasible to communicate between nearby star systems(<50 light years) using powerful lasers?

 

[Rivem]

Would it be feasible to communicate between nearby star systems(<50 light years) using powerful lasers?

I'd say so. Lasers are likely the best way to communicate with specific parts of the universe over very long distances. In radio terms, there's really no beating the gain of a laser at all. Light also has less noise issues for certain wavelengths. Picking a very high power laser with very little divergence and a spectral line that the sun doesn't have would probably allow communication to any part of the universe where the sun can still be meaningfully distinguished from nearby stars.

Maybe around a million light years?

 

[diachi]

I'd say so. Lasers are likely the best way to communicate with specific parts of the universe over very long distances. In radio terms, there's really no beating the gain of a laser at all. Light also has less noise issues for certain wavelengths. Picking a very high power laser with very little divergence and a spectral line that the sun doesn't have would probably allow communication to any part of the universe where the sun can still be meaningfully distinguished from nearby stars.

Maybe around a million light years?

Was just reading about this earlier actually. You're exactly correct, pick something that isn't a spectral line and use a real narrow notch filter (to block out all other light from the star, or most of it at least) with a big space telescope (To overcome aberration introduced by the atmosphere). Perfectly feasible from what I was reading!

 

[Pi R Squared]

One issue is that we still don't really know how long a planen would emit detectable signals. On earth it's been 100 years or so and is now rapidly coming to an end. Things like high power analog tv transmissions are rapidly being phased out, and fm radio stations usually are less powerful now servicing smaller areas (and being phased out for digital systems as well).

This shift from analog to digital is very important. Most digital modulation schemes spread the information over a fairly wide piece of spectrum. Also the information is encoded, sometimes encrypted, making it hard or impossible to decipher or even detect unless you know what you are looking for.

If other planets evolve similarly the window to detect one could be 150 years or so.

Also it's not unthinkable that some planets will skip/omit the whole high power transmission phase, perhaps because they live closer together and use wired or low powered systems, or skip analog and start with digital modes directly.

How often this would happen is guesswork, but it does impact chances of 'seeing' some society even if it is very close by.

I didn't say we couldn't detect signals from them - for all we know they could be using incredibly powerful radio transmitters which they use to systematically transmit to different star systems with in the hopes of receiving a reply.

What I said was they wouldn't receive much, if anything from us. The majority of our transmissions A) aren't powerful enough or B) aren't directional (thus the signal "weakens" faster). Keep in mind while our radio bubble may extend ~100 light years - powerful, higher frequency, directed transmissions didn't start being common until later than that, and even then chances of someone catching one powerful enough for any length of time are very slim.

About the only transmission that has much of a chance at actually conveying much information at any reasonable distance is the Arecibo Message sent in 1974 - which was very directional (aimed at a star cluster 25,000 light years away - so it'll be a while before it gets to it's intended destination) and has "only" propagated some 40 light years. That transmission lasted for ~3 minutes - further reducing the chance of it ever being detected unless someone is specifically watching this direction continually. Even if it had propagated for 100 light years it'd miss most if not all of the 512 stars you mentioned.

So my point stands, I highly doubt anyone/anything has detected us yet.

You both have a valid point. There's no telling how long a civilization would use radio, there must be a better technology that we haven't discovered yet, and no telling if there's anyone close by that's at a similar stage of development to us, or anyone close by at all. Our own system is a result of a super nova explosion that happened billions of years ago. There may have been many civilizations rise and fall in that time, and there could be many that are far far more advanced than us. I would think that they wouldn't find us very interesting, those that are only a little more advanced may find us very interesting.

Alan

 

[Benm]

Perhaps they will find us interesting, we go to zoo's and like to look at the behaviour of animals somewhat less intelligent than we are.

Another unknown is how long intelligent civilisations actually last.

Humans that are similar to us have been around for 10.000 to 100.000 years depending on criteria. We have been transmitting for 100 years of that time, and may very well kill eachother off within the next 100.

The latter is obviously no guarantee, but it's not impossible either.

This leaves us with a HUGE amount of guesswork, even if we presume alien life to resemble humanity to some degree, which may not be all that realistic either.

After all, earth has had life for some 4 billion years, and has been transmitting for just about 100 years. That effectively means that earth was a radiosilent but alive planet for >99.99999% of the time it had life

 

[Pi R Squared]

Perhaps they will find us interesting, we go to zoo's and like to look at the behaviour of animals somewhat less intelligent than we are.

Another unknown is how long intelligent civilisations actually last.

Humans that are similar to us have been around for 10.000 to 100.000 years depending on criteria. We have been transmitting for 100 years of that time, and may very well kill eachother off within the next 100.

The latter is obviously no guarantee, but it's not impossible either.

This leaves us with a HUGE amount of guesswork, even if we presume alien life to resemble humanity to some degree, which may not be all that realistic either.

After all, earth has had life for some 4 billion years, and has been transmitting for just about 100 years. That effectively means that earth was a radiosilent but alive planet for >99.99999% of the time it had life

That is a very good question, one we can only guess about. I would not be surprised if there are many dead worlds out there that once had advanced civilizations. Perhaps only a few survive, we could easily destroy ourselves right now, we could even do it one day by accident. When they tested the first atomic bomb there was very real argument among the scientists about weather or not this could set off a fusion reaction in the atmosphere and roast the entire surface of the planet, remember they didn't have computers and couldn't do the proper calculations, things were so desperate at that time they did the test anyway.

Alan

 

[Razako]

Humanity is at an incredibly challenging transitional point right now. The technology that got us to this point(fossil fuels) will be our undoing unless we can transition to newer and more advanced energy sources. We also need to tackle population growth (challenging because it goes against our basic instincts to reproduce), and religious radicalism. Can people put aside their selfish and superstitious ways and work together for the good of the human race? IMO the next 100 years will make or break us as a species.

What do I imagine will happen in the future? I think we're basically at a point in the road with 3 separate paths. Our actions from here will determine which path we go down as a civilization.
1-We get our acts together and the end result would be a world something like star trek. Resources for all, relative peace and good times etc. People would eventually establish bases on other worlds/moons in our solar system and maybe even reach for the stars.
2-We fail to get our shit together and a global totalitarian government steps in to force us to. Think something like 1984, Dredd, the running man, Hunger Games, Aeon Flux, Divergent etc.
3-We completely fail at doing anything and continue down the current path blindly. What happens? Think Mad Max. WW3 over resources due to climate change and overpopulation.(religion might also be involved). Eventually nukes fly or a global pandemic comes. A large % of humanity dies from war, disease, starvation over a few decades and we're left with burned out ghost cities and scattered bands of nomadic survivors.

 

[Rivem]

Humanity is at an incredibly challenging transitional point right now. The technology that got us to this point(fossil fuels) will be our undoing unless we can transition to newer and more advanced energy sources. We also need to tackle population growth (challenging because it goes against our basic instincts to reproduce), and religious radicalism. Can people put aside their selfish and superstitious ways and work together for the good of the human race? IMO the next 100 years will make or break us as a species.

What do I imagine will happen in the future? I think we're basically at a point in the road with 3 separate paths. Our actions from here will determine which path we go down as a civilization.
1-We get our acts together and the end result would be a world something like star trek. Resources for all, relative peace and good times etc. People would eventually establish bases on other worlds/moons in our solar system and maybe even reach for the stars.
2-We fail to get our shit together and a global totalitarian government steps in to force us to. Think something like 1984, Dredd, the running man, Hunger Games, Aeon Flux, Divergent etc.
3-We completely fail at doing anything and continue down the current path blindly. What happens? Think Mad Max. WW3 over resources due to climate change and overpopulation.(religion might also be involved). Eventually nukes fly or a global pandemic comes. A large % of humanity dies from war, disease, starvation over a few decades and we're left with burned out ghost cities and scattered bands of nomadic survivors.

I have to disagree about us being at a "point" like you say. While it's certain we're headed in a bad direction towards a serious critical point, I'd say it's still going to be a long way off. Not that we can wait until then though.

We're likely not going to start seriously running low on resources until probably the end of our lives or the generation after all of us on this forum are gone. The issue is that the more we exhaust our resources and continue like we are, the harder it is to transition to something better.

There are tons of unfortunate examples:

We've built ridiculously inefficient cities and dwellings with respect to our lifestyles for the last century and a half. We're getting better, but what are we going to do about what we've already built? Not many new cities are going up, so we need some sort of way to convert current ones.

We've been using petroleum fueled vehicles for a long time and developed them a lot, but renewable and electric powered vehicles have been around just as long. Now that there's a push for EVs and biofuels, how long is it going to be until the existing fossil fuel powered vehicles stop operating?

Our power has come from coal and inefficient and environmentally hazardous dams since the beginning of the industrial revolution. We can slowly replace them with more intelligent renewables, but how long will it take until everybody stops using fossil fuel plants and replaces their old dams? Both types can last near a century or more.

Antibiotics and antibacterials have been used for over a century now on every bacterial issue big or miniscule. When everything develops a resistance to them due to overuse, what will we use? How are we going to get medicine to completely shift away from using them unless necessary in time?

People live in some places that have very few resources and still demand a lot of them. What will we do if it turns out that water would be better used elsewhere than in an inefficient desert metropolis? Make millions of people uproot themselves? Level the city and build a more efficient one?

Food has been farmed in massive amounts at factory farms far from consumers especially due to urban sprawl for the last 50 years. How would we get food closer to where it's used? Dedicate expensive indoor growing facilities in cities? Level suburban areas to reinstate farmland?

People in a lot of the developed world have mostly been using cars to get around for decades. While the American mindset might say everybody deserves to have a car, it's completely unfeasible and ridiculous for billions of cars (of any power/type) to be on the road around the world. Even communal self-driving cars are questionable. When we get to the point we need a massive and efficient public transit system to support society, where's it going to be? That kind of stuff takes years, and we've mostly destroyed our more thorough rail infrastructure in North America.

Desalination is probably going to be one of the most critical technological areas we need to advance. Not nearly enough research is going into it, and it's not at a position where it's feasible for many societies. What's going to happen when there's a widespread drought and we still need to figure out a good way to do it?

We're using increasingly rare materials in our consumer products and don't recycle well at all. What's going to happen when we've thrown most of them away and can't find a good way to re-extract the materials?

Forests are still being cleared. If we don't start to transition to faster-growing genetically-engineered tree farms that are less resource intensive, our forests' old growth will be history. What will we do about rising CO2 levels then?

The ocean is the basis of our food chain. If we don't figure out exactly what we're doing wrong with it soon, how would we cope with the issues?

The list goes on and on, but I think most of these are more "The sooner, the better" solution that could have also happened for the last two or three generations and might still be doable for the next few generations. I imagine the point of no return will feel much more dramatic than any other disaster humanity has ever experienced, and this frankly hasn't presented any signs that it's happening soon even though it is still coming in the future. Do we really want to pass our problems on instead of solutions though?

Honestly, if we don't get it together, everything's going to fall apart sometime in the future, and humanity may very well drive itself to extinction or back to the primal days. I don't think any entity will be able to pull everybody together and into a stable direction unless it happens ASAP. Comparing success at restabilization to Star Trek is also questionable. The future could go many ways depending upon how available the technology that shapes it is and how society changes with it.



Anyway, that was a bit of a rant, but I'd rather have people think about these kinds of things than not. People of all sorts all around the world have to work together over time to overcome problems like this..

 

[TheDukeAnumber1]

 

[Pi R Squared]

You are a Christian as am I, please don't tell me you think there are no ghosts. Beyond that we can take it to the other thread.

Alan

 

[InfinitusEquitas]

Razako - In Star Trek it did take WW3 and the death of a significant portion of the population, before that world, the one we saw in TNG came about.

Personally I think we as a species are headed for a population correction of some form, and it's only a question of whether it will be as a direct consequence of our actions as species or a more natural event. After that a one world government will develop, take control, and hopefully will result in eventual progress.

Fortunately, even if every nuke, biological, chemical, and conventional weapon were used, some people will survive, and the world will recover.

I find it extremely ironic and funny that you would post this, given your position in another thread.

 

[Rivem]

You are a Christian as am I, please don't tell me you think there are no ghosts. Beyond that we can take it to the other thread.

Alan

I find it extremely ironic and funny that you would post this, given your position in another thread.

This isn't a really a thread for talking about terrestrial UFO activity or really anything else in the comic, and there are plenty others that are more appropriate.

We're mostly talking about humanity's future in space and not supernatural beliefs about the Earth.

 

[NightExplorer96]

You made some great points Rivem, thanks for sharing all that. I do also believe in a little part of me that it may take some huge disasters before we realize we need to shape up, and that's a scary thought!

-Alex