A Step Closer To The Alcubierre Drive!

[JebidiahsBigSister]

So how hard is it to build a 10c warp drive? Hard enough so that no civilization in MW galaxy has managed it until less than a million years ago, which on the scale of the age of the galaxy is equivalent to saying that nobody has built one yet.

You don't have to do FTL to colonize the galaxy. If a civilization expands outwards at only .005c average (1 light year every 500 years ) - say it can reach 10% light speed - colonizes a planet then a few hundred years to build up a .1c starship capability again - all pretty modest assumptions to say the least. Well at .005c you colonize the entire galaxy (100,000Ly wide) in an average of "only" 50 million years (actually it's half that but let's keep thinks conservative) .

50 million years maximum for a civilization to colonize the entire galaxy and you don't need FTL.

Our Galaxy is 13.2 billion years old.

That's roughly 260time slots for any civilization to conquer the entire galaxy if it choose to.

Yet we hear nothing via radio.

That's the Fermi paradox.

Edited October 22, 2013 by JebidiahsBigSister

[Scotius]

Do you habitually look outside watching for smoke signals? Or listen for the sound of signal drums? We can safely assume civilisation sufficiently advanced to colonise galaxy, will have means of communication beyond our understanding. Or ability to detect it. We might be in position of a primitive, uncontacted tribe living deep in Amazonian jungles. There is a lot of communication going around them, but are they aware of it?

[Tharios]

So how hard is it to build a 10c warp drive? Hard enough so that no civilization in MW galaxy has managed it until less than a million years ago, which on the scale of the age of the galaxy is equivalent to saying that nobody has built one yet.

You don't have to do FTL to colonize the galaxy. If a civilization expands outwards at only .005c average (1 light year every 500 years ) - say it can reach 10% light speed - colonizes a planet then a few hundred years to build up a .1c starship capability again - all pretty modest assumptions to say the least. Well at .005c you colonize the entire galaxy (100,000Ly wide) in an average of "only" 50 million years (actually it's half that but let's keep thinks conservative) .

50 million years maximum for a civilization to colonize the entire galaxy and you don't need FTL.

Our Galaxy is 13.2 billion years old.

That's roughly 260time slots for any civilization to conquer the entire galaxy if it choose to.

Yet we hear nothing via radio.

That's the Fermi paradox.

No civilization capable of that kind of expansion is going to be listening for radio, they'll be listening for whatever they use, which is going to be a lot better than radio. We're already on the cusp of leaving radio behind ourselves.

So what if the Milky Way is .5 billion years younger than the rest of the universe? It still would have to go through an entire generation of stars before any of them were capable of producing the elements needed to form proper planets with sufficient resources for life to form. So, 6 or 7 billion years for enough stars to have burned all the way to carbon or iron and gone boom? Another billion or so years for new stars to form out of the ashes of the old with planets that can properly support the formation of life, having the necessary ingredients.

Another 3 billion years for that life to reach a point where it can begin moving out from its home. So, we're up to about 4 to 3 billion years ago, roughly, when the first civilizations could reasonably have begun to explore space. Still within your time window. But I think you're being too generous.

At .1 c, it's a nearly 50 year trip from here to the nearest star...and that's just the trip. Right now, we ourselves are looking at a minimum of 50 years just to build a ship that could get to the true edge our solar system within a human lifetime. At .005 c, they won't colonize anything. The only thing anyone will ever send, are probes...and probably not even that, when it's going to be an 800 year trip.

Ok then, so scratch that. Every civilization is going to fully infest its homeworld before it even gets to the rest of its solar system. For us, that's about now, so we'll stick with the numbers we've used so far. In which case, it took us 50,000 years about, to get to that point. Considering how things have gone in the last few centuries, we could probably truly fully take over the solar system in about a thousand years, if we become hardcore expansionists and do nothing else. That's not really worth including in a billion-year timescale, so we'll mostly skip it.

Once they get to that point though, they're still staring at a trip that's going to take the better part of a century in a best-case scenario. (warp drive is off the table because, even if it works, it can't be used effectively) And they're certainly not going to be flinging colonists out there willy nilly (if they want them to succeed, anyway). So to really fully "master" a given colony world (a necessity before attempting to master another star system, itself a necessity before attempting to colonize another star), you're looking at at least another thousand years...plus another thousand to get the system under control. Now, at that point...you have two systems with which to support a third, so you could do it in about 1500 years total instead of 2000.

You're still looking at 50 year trips in between, though, and that's on the good side...assuming habitable worlds are that close together. Otherwise you're looking at having to engineer special habitats or terraform colony worlds from the very start before you can even put a reasonably large population there...tack on at least another thousand years to the colonization process.

So what're we up to now? To get 9 other star systems fully developed along with the home system (and we'll go with a drop of 1,000 years development time for every two systems colonized, to simplify), you're looking at at least 11,000 years or so (I didn't go through it all in my head)?

So after a certain point, the inner systems of this empire will no longer be viable for establishing colonies, since they're much too far away from the colonial frontier to contribute anything meaningful within a reasonable amount of time. And then we have a new problem anyway.

Once this empire hits about 20 ly across, it's going to stop expanding. Because if it expands any farther, it hits the same issue as every pre-industrial empire before it...communication. You can't build an empire when you can't talk to it, and when it takes 20 years just to make a statement and get a response, you're done. At that point, you have to turn over near complete autonomy to each star system, and not all of them are going to want to play ball with colonization anymore. And that applies even if they manage to develop some magical type of shielding that lets them safely travel at .999999999 c. The communications barrier will stop them at a diameter of around 20 to 30 ly.

If they develop FTL propulsion of some kind, that changes things, but not by much. Consider, to even double the speed of light, even with White's revisions to the warp drive, would take enormous resources. At double c, it's a 2 year trip to the nearest stars. At quadruple c, it's one year; at 8 times c, it's 6 months, etc...we all know that, right? But then, you still have to spend thousands of years fully mastering all those systems to support the energy-intensive and complex drives that you're tooling around with.

And even so, you still run into the communications problem. At even 8 times c, you only double the diameter of your empire, at best, which by then becomes 40 to 60 ly...80 if your set-up is really good. That's a 5 year trip to get from the homeworld to the outer colonies, 10 to get form one edge to the other. And it requires physical travel, not merely a "call", which is going to take even more resources, and still takes too long.

Sorry, but no, you have to have serious FTL capabilities to even consider conquering a whole galaxy. Otherwise, all you're doing is breaking your own civilization into pieces and hoping the other pieces don't decide the original piece were real jerks. And best-case scenario, it only applies to local space. No one will ever colonize vast swaths of space at sublight...period.

[m4v]

We're already on the cusp of leaving radio behind ourselves.

I read until there.

[SargeRho]

Exept for short-range transmissions, such as cellphone calls and WiFi, and perhaps a few long range things like GPS, radio isn't going to stick aroung too much longer. Lasers are going to replace much of it. Lasers will replace radio for long-range communications, specially in space.

Edited October 22, 2013 by SargeRho

[MBobrik]

50 million years maximum for a civilization to colonize the entire galaxy and you don't need FTL.

Our Galaxy is 13.2 billion years old.

That's roughly 260time slots for any civilization to conquer the entire galaxy if it choose to.

Yet we hear nothing via radio.

That's the Fermi paradox.

interstellar radio ( or lasers or whatever that works only at c ) is pretty much pointless if you've got FTL so nobody will use it and the first sign of other civilizations that newcomers will see is an alien caravel in orbit over their homeworld.

[MBobrik]

Sorry, but no, you have to have serious FTL capabilities to even consider conquering a whole galaxy. Otherwise, all you're doing is breaking your own civilization into pieces and hoping the other pieces don't decide the original piece were real jerks. And best-case scenario, it only applies to local space. No one will ever colonize vast swaths of space at sublight...period.

Following this line of reasoning, and considering the communication speed and general capability to govern large number of people back in 50 000 BC, one would reach the conclusion that we would never get far from the east African savannah where we first evolved. yet, we conquered the entire globe w/o having to maintain an unified global empire.

[m4v]

Exept for short-range transmissions, such as cellphone calls and WiFi, and perhaps a few long range things like GPS, radio isn't going to stick aroung too much longer. Lasers are going to replace much of it. Lasers will replace radio for long-range communications, specially in space.

Which is all electromagnetic communication, lasers as well. The difference between radio, WiFi and lasers is just the frequency, they all use the same physics, the same Maxwell equations. Are we at the cusp of leaving electromagnetic communication behind? don't be silly.

[SargeRho]

Nobody said electromagnetic. Radio, specifically. We are leaving that behind for almost all long-range comms. visible light and infrared lasers are superior to radio for point to point communications.

[Awaras]

Which is all electromagnetic communication, lasers as well. The difference between radio, WiFi and lasers is just the frequency, they all use the same physics, the same Maxwell equations. Are we at the cusp of leaving electromagnetic communication behind? don't be silly.

What we are leaving behind is beaming powerful omnidirectional signals leaking outside the atmosphere of the Earth. While even those would be difficult to detect from interstellar distances, directional forms of communication like lasers are much more difficult to detect because of much less 'spillage'.

[m4v]

What we are leaving behind is beaming powerful omnidirectional signals leaking outside the atmosphere of the Earth. While even those would be difficult to detect from interstellar distances, directional forms of communication like lasers are much more difficult to detect because of much less 'spillage'.

debatable, just because you don't tune an AM radio any more doesn't mean that it will disappear or that the spectrum will be left unused.

[JebidiahsBigSister]

Sorry, but no, you have to have serious FTL capabilities to even consider conquering a whole galaxy

You're making an incredible amount of assumptions, none of which you have offered any proof (and in fact most are impossible to prove in our day and age). You have an opinion. The Phds and great minds behind such concepts as The Fermi Paradox and Generation ships have other opinions. The difference between yours and theirs is that they have an enormous amount of education behind their opinion, hence it is a more informed opinion so it makes sense to me to stand behind the more informed ideas.

[JebidiahsBigSister]

Exept for short-range transmissions, such as cellphone calls and WiFi, and perhaps a few long range things like GPS, radio isn't going to stick aroung too much longer. Lasers are going to replace much of it.

YOu do realize that a laser and "radio" are essentially the same thing, electromagnetic transmissions, don't you? The only essential difference between the two is the coherency of the laser which results in a tighter beam. A laser is essentially a very tight beamed radio transmission on a much (much!) higher frequency.

[Kryten]

What we are leaving behind is beaming powerful omnidirectional signals leaking outside the atmosphere of the Earth. While even those would be difficult to detect from interstellar distances, directional forms of communication like lasers are much more difficult to detect because of much less 'spillage'.

The only real radio transmissions powerful enough to be distinguishable from background noise at all but the nearest few stars are those from OTH radar systems. They're hardly likely to be replaced by lasers any time soon.

[Scotius]

So, for the last 60 or so years Earth is spraying radio waves around. In spades Most of it degrades to white noise pretty fast, if i understand it correctly. But can this increase in white noise be detected from - lets say 40 ly? If yes, maybe we should look for stars that generate more radio waves than they should be doing?

[SargeRho]

Our radio waves are too dispersed to be detected as of roughly 2 lightyears or so.

[K^2]

Exept for short-range transmissions, such as cellphone calls and WiFi, and perhaps a few long range things like GPS, radio isn't going to stick aroung too much longer. Lasers are going to replace much of it. Lasers will replace radio for long-range communications, specially in space.

Actually, there are some developments that I can't get into detail of at the moment that might result in powerful radio broadcasts to make a re-emergence as a carrier for something that will act as point-to-point communication. Once there is a paper, I'll link it somewhere around here.

[Seret]

We don't know how sensitive an alien receiver might be, or how far away it would be, so it's difficult to say how detectable we are.

Besides active emissions there are other things we're radiating that might mark us as "interesting". The spectral lines of our atmosphere probably mark us as having an active biosphere (assuming the chemistry of Earth biology is not totally unique, which seems reasonable, given that everyone is working with the same elements and laws of physics).

[K^2]

We don't know how sensitive an alien receiver might be, or how far away it would be, so it's difficult to say how detectable we are.

Doesn't matter how sensitive the receiver is. If transmission power is weaker than cosmic background, you cannot detect it with any receiver. There are simply no means, purely mathematically, of distinguishing it from noise.

Of course, if they sent out probes, and one happens to pass close to Sol, then it's a different matter. As you said, we don't really know the distance from which transmission needs to be picked up, and something within a ly of Sol can certainly detect transmissions from Earth using sensitive enough equipment given long enough observation time.

[JebidiahsBigSister]

If transmission power is weaker than cosmic background, you cannot detect it with any receiver. There are simply no means, purely mathematically, of distinguishing it from noise.

Some sort of frequency discrimination? As I understand it (?) cosmic and/or galactic background noise peaks in certain bands of frequencies. Wouldn't a low powered transmission be discernible if not in the same frequencies and the background frequencies were filtered out? Some sort of statistical analysis ?

[SargeRho]

...Or just use Lasers. It's fairly easy for a data laser to outshine its parent star.

[magnemoe]

We don't know how sensitive an alien receiver might be, or how far away it would be, so it's difficult to say how detectable we are.

Besides active emissions there are other things we're radiating that might mark us as "interesting". The spectral lines of our atmosphere probably mark us as having an active biosphere (assuming the chemistry of Earth biology is not totally unique, which seems reasonable, given that everyone is working with the same elements and laws of physics).

This is probably far easier, also looking for life in general would be more promising than looking for an civilization who uses radio.

[m4v]

Doesn't matter how sensitive the receiver is. If transmission power is weaker than cosmic background, you cannot detect it with any receiver. There are simply no means, purely mathematically, of distinguishing it from noise.

No, it can. If you average background noise in a long enough period of time, because noise is random, you end with a signal with zero amplitude in all frequencies. But if there's a signal hidden in the noise, you will see it, how low it can be depends of the precision of your instruments and the time length of the sample. This technique is used for precise measurement of signals that aren't big enough for discriminate against noise, or where the error of the measurement is affected by noise. Edited October 23, 2013 by m4v

[PhaserArray]

My dream is to be first astronaut to try it ,but it's a dream lol

My dream is to be the equivalent of Jebediah Kerman in real life

[K^2]

No, it can. If you average background noise in a long enough period of time, because noise is random, you end with a signal with zero amplitude in all frequencies. But if there's a signal hidden in the noise, you will see it, how low it can be depends of the precision of your instruments and the time length of the sample. This technique is used for precise measurement of signals that aren't big enough for discriminate against noise, or where the error of the measurement is affected by noise.

That's if you have a constant pitch over long time. Which, by very definition, carries no information. If we were actually sending one out, it'd probably be detectable. Though, it could be mistaken for natural phenomenon. But our radio communication carries information. In that case, Shannon-Hartley applies, albeit in its corollary form, and given sufficiently strong noise, you cannot distinguish a channel with sufficiently high bit rate from the aforementioned noise.

In other words, if we were sending a steady pitch signal, it'd be pretty detectable, but our radio chatter is not.

Some sort of frequency discrimination? As I understand it (?) cosmic and/or galactic background noise peaks in certain bands of frequencies. Wouldn't a low powered transmission be discernible if not in the same frequencies and the background frequencies were filtered out? Some sort of statistical analysis ?

It has peaks, but there are not any frequencies completely devoid of noise. And you can only push statistics so far. If you could just analyze the hell out of signal, we wouldn't be having spectrum crunch issues down here.

Edited October 23, 2013 by K^2