Would advanced alien tech surprise you?

[PurpleBuddha]

How does the ant feel about your technology when you mow your lawn and wipe out the majority of its civilization without you even knowing it???

You're great-great grandfather would be shocked by your everyday tech, let alone someone from ancient Rome.... how would you even begin to comprehend the tech of a civilization a billion years older than our own???

I wish mowing my lawn was all it took to wipe out the majority of ant civilizations that crop up there. Unfortunately it doesn't phase the little buggers. You know their civilizations are underground, right? Despite all my tech, the little bastards remain in large numbers.

 

[John O.]

Actually, an alien probe could reach us that's not all that far ahead of us in technology. We could send a probe to a star system three light-years or so from Earth. It's more a matter of budget than technology. And if it took a few decades to get there, it could be receiving software upgrades en route and arrive more advanced than it was when launched, at least in its AI.

That's true but it would take more than a few decades at this point. Unfortunately, the best velocity we could probably hope for it .01c, and that'd still take like 300 years.

 

[FPAlpha]

The thing is that our theoretical knowledge about the laws of nature are ever expanding and have reached a point that far surpassess my intellect and i wouldn't understand a thesis paper on astrophysics even if i had all the time in the world but those few who do would get all excited about the possible implications and new areas to explore scientifically.

Go back 200 years and tell people that you could fly over the ocean from Europe to America in a few hours (faster if using the fastest planes available.. usually from the military and their secret tech) and they wouldn't believe you. They may suspect something because birds can fly and there were experimental gliders but jet propulsion and wing construction is beyond.

Now we don't know what's yet in store or possible.. just because Einstein said we can't outrun the speed of light doesn't mean there aren't other ways around that limit or ways to nullify that law. Just because someone couldn't disprove Einstein doesn't mean that no one will (given that it's disprovable) so i'm not ruling out anything.

Maybe there will also be a shift away from physical technology to something more psychic and esoteric for a race that been living in the modern age for hundreds of thousands or even millions of years.. who knows.

 

[Crazy Eddie]

So what would it take to surprise you?

Considering my current situation in life, my total lack of political or military importance, my social and cultural insignificance and the general fact that people of any importance whatsoever rue the fact that I even exist...

I would be thoroughly surprised to know anything about them at all.

 

[Crazy Eddie]

You're great-great grandfather would be shocked by your everyday tech

Hah! My mother still trembles in fear at the sight of my iPod.

By the way, it works both ways. We had a very hilarious moment yesterday where a couple of first graders discovered a VHS tape in the back office. I had to explain to them that casset tapes were what we used before they had DVDs, except they didn't have menus or extras, you couldn't skip chapters, and if you wanted to watch it again you had to wait five minutes for the tap to rewind all the way to the beginning.

They looked puzzled and slightly horrified.

 

[Bill Morris]

Hey, I still have VHS tapes, and the cases of three of my DS9 tapes were broken in the big earthquake the other day.

Anyway, it should be no surprise at all if aliens who decide to make first contact with us say they love Star Trek.

 

[FPAlpha]

Speaking of VHS.. i had TNG taped back in the 80s and 90s and it was glorious. Had a sheet made with the cassette number and which episodes were on it so i could find it without too much hassle.

Even once after graduating i watched Picard with a buddy of mine while being totally drunk.. glorious times

Now back to the topic..

 

[Bill Morris]

Actually, an alien probe could reach us that's not all that far ahead of us in technology. We could send a probe to a star system three light-years or so from Earth. It's more a matter of budget than technology. And if it took a few decades to get there, it could be receiving software upgrades en route and arrive more advanced than it was when launched, at least in its AI.

That's true but it would take more than a few decades at this point. Unfortunately, the best velocity we could probably hope for it .01c, and that'd still take like 300 years.

I was assuming something a bit more powerful than chemical rockets but not out of reach. A string of nukes has been suggested, but I was thinking more of positron-fueled ion propulsion for most of the trip and positron rockets upon arrival. The big argument that usually comes up against that is gamma radiation, but we're talking about an unmanned probe here.

 

[Asbo Zaprudder]

I think advanced alien tech would surprise me. After all, just about anything that the French come up with surprises me (usually in a good way), and aliens are probably going to be more far out than the French.

 

[Gil T.Azell]

No it wouldn't.

 

[John O.]

Actually, an alien probe could reach us that's not all that far ahead of us in technology. We could send a probe to a star system three light-years or so from Earth. It's more a matter of budget than technology. And if it took a few decades to get there, it could be receiving software upgrades en route and arrive more advanced than it was when launched, at least in its AI.

That's true but it would take more than a few decades at this point. Unfortunately, the best velocity we could probably hope for it .01c, and that'd still take like 300 years.

I was assuming something a bit more powerful than chemical rockets but not out of reach. A string of nukes has been suggested, but I was thinking more of positron-fueled ion propulsion for most of the trip and positron rockets upon arrival. The big argument that usually comes up against that is gamma radiation, but we're talking about an unmanned probe here.

Since you said "we could", I was assuming you were just talking about presently available technology. Even nuclear pulsed propulsion... we have the concept but nobody's worked it out. And ion is very very low thrust. I don't mean to be a buzzkill but sadly, if we wanted to send a probe to Alpha Centauri in the next 40 years it would have to just be one great damn big chemical rocket.

 

[Bill Morris]

Whether it's chemical or positron, R&D would be necessary, and designs for positron production, storage, and propulsion already exist but have no almost no R&D funding. But in a race to arrive at destination first and cost to build, I would bet that, although with a blank check the chemical scenario would easily win on which could launch earlier, careful comparison studies would favor positron fuel for speed of reaching destination and cost, because of the huge difference in power-to-weight ratio. Most of the material on the Web about the positron scenario is dated and doesn't take into account the recent discovery of an easier way to produce positrons. That's mostly a reflection of lack of funding but partly because the focus is normally on manned spacecraft, where the issue of gamma radiation comes to mind.

It's all theoretical, anyway. Even if we could confirm the existence of an M-class planet just a parsec away, money for a probe would still be tight. But getting back to the point I was making, an alien probe sent here wouldn't necessarily require technologies centuries ahead of ours.

 

[sojourner]

Since you said "we could", I was assuming you were just talking about presently available technology. Even nuclear pulsed propulsion... we have the concept but nobody's worked it out. And ion is very very low thrust. I don't mean to be a buzzkill but sadly, if we wanted to send a probe to Alpha Centauri in the next 40 years it would have to just be one great damn big chemical rocket.

Nope, ion is High impulse, low thrust. Chemical is High thrust, low impulse. You would never use ion to get off the planet, a function that chemical excels at. Conversely, once off the planet, the ion engine is hands down better for a stellar trip than a chemical engine. It can run for years and will eventually develop more speed on less fuel than the chemical engine.

 

[John O.]

Since you said "we could", I was assuming you were just talking about presently available technology. Even nuclear pulsed propulsion... we have the concept but nobody's worked it out. And ion is very very low thrust. I don't mean to be a buzzkill but sadly, if we wanted to send a probe to Alpha Centauri in the next 40 years it would have to just be one great damn big chemical rocket.

Nope, ion is High impulse, low thrust. Chemical is High thrust, low impulse. You would never use ion to get off the planet, a function that chemical excels at. Conversely, once off the planet, the ion engine is hands down better for a stellar trip than a chemical engine. It can run for years and will eventually develop more speed on less fuel than the chemical engine.

yes, I know, I'm a grad student in aero and I study electrical propulsion specifically... but you are still grossly understating the .... eventually part. The thrust really is very, very, very low.

 

[sojourner]

^Grossly understating? Not when dealing with stellar distances. If we were talking trips to the inner solar system, yea, a chemical rocket would probably be the best bet, but outer system and beyond an ion engine would be the better choice of the two.

 

[John O.]

You realize this argument is pointless, right? Since there is currently no such thing as a "positron fueled ion thruster", we can't even debate hard figures for thrust and Isp. You could easily say that the Isp would be 5,000 as I could say it'd be 1200; and you could easily say the thrust would be 10 kN as I could say it'd be .1 kN. It's pointless to haggle over the design points of hypothetical technology...

As for EXISTING electrical propulsion... there's a reason it's used on satellites for attitude control and why DS1 was a technology demonstrator for it to be used on deep space vessels - because the advancements and improvements to efficiency and thrust for it to be a viable deep space option are... well let's say "significant" to be conservative. This is a good example of the state of modern electrical propulsion systems:

Edit: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34201&fbodylongid=1539

Look at the thrust and you'll see what I mean - 68mN. Even at a light vessel - let's say 500 kg, since 1 N is the force it takes to accelerate 1 kg to 1 m/s in 1 second, you can do some kinematics assuming constant acceleration and constant mass (since propellant mass is comparatively light) to see how long it would take:

a = F / M = .068 N / 500 kg = .000136 m/s^2

from kinematics, d = r0 + v0t + 1/2at^2, where for our purposes 'd' is the distance to Alpha Centauri, r0 might as well be zero, and v0 might as well be zero (even if you include a reasonable starting velocity appropriate to a chemical rocket burn and a gravitational maneuver around Jupiter or Saturn to slingshot out of the solar plane, it practically won't matter unless we can achieve a velocity orders of magnitude higher than anything we've ever achieve before).

I won't belabor the post with algebra, but solving for t you get about 766 years to reach a distance of 4.2 light years.

If you do it again and take v0 to be 40,000 km/hr (I think this is somewhat similar to a fast probe like New Horizons), you get practically the same number - 763 years is what I got.

Incidentally, even if you increase the initial velocity by a factor of 10, and assume we can hit something like 500,000 km/hr, it's a negligible difference - still like 730 years.

2nd EDIT: In fact, from the Total Impulse (2E6 Ns) and propellant mass (82 kg) listed for that design, I was able to calculate an effective mass flow rate of .24 kg/s.... which means that for a trip time of 2E10 seconds, you're looking at a propellant mass much much larger than 500 kg... which means all of the above calculations are exceedingly generous...

 

[sojourner]

Um, I never said "Positron Fueled Ion Thruster". I merely brought up the advantages of ion over chemical. If we wanted to make it a fair competition I would propose basing it on engines of similar size. How would it turn out with a chemical engine of similar size to the ion thruster used on Smart-1?

 

[Bill Morris]

Setting aside ion versus propellent mass for a moment, regarding just positron versus chemical rockets, where positrons are stored in a magnetic bottle and ablate propellent, here are some links. Most, maybe all, of these were written before the recent discovery at Harvard that a shower of positrons could be produced by zapping 1-mm gold plate with a powerful laser.

And I've explained in other threads how positrons can be produced in space using large sausage-shaped balloons transparent on one side and reflective on the inner surface of the opposite side to concentrate sunlight on a central rod that carries heat out to produce electricty to power the laser, which is a just space-based implementation of what is already being done in deserts (CSP) to produce electricity but requiring far less massive hardware (balloons versus aluminum troughs, thanks to lack of wind).

A positron rocket would be launched by conventional chemical boosters then pick up a bottle of positrons in space to power the long stretch of its journey. Although this would be more for moon shuttles, etc., in this thread we're assuming a sufficient budget to send something to another star system in order to make the point that aliens could send probes here without being many centuries ahead in technology, as long as they were aware of Earth, interested enough, and not restrained financially.

The first gives some math and explains various proposed designs:
http://www.niac.usra.edu/files/library/meetings/fellows/mar06/1147Smith.pdf

A bit of a rant, but from NASA:
http://www.nasa.gov/directorates/esmd/home/antimatter_spaceship.html

A page of links to various papers:
http://academic.research.microsoft.com/Paper/10465109

Most of the rest on the Web seems to be fluff.

 

[KJbushway]

Maybe this is stupid. But I would like to think that the universe throws a clause for traveling the stars. A civilization has to come together in order to combine their knowledge and explore the stars, which to me means they had to become peaceful first. Bigger help the smaller.

I think that Alien tech would surprise me, how they are built and powered. But the names or machines I don't think would surprise me too much.

 

[sojourner]

The universe doesn't care about the civilizations in it. Or anything else for that matter.