T Nation

SETI Project . . .


#1

Ok, we have 2 options.

Either, there's intelligent life out there, or there isn't. If they're not out there, it's a waste of money.

But if they ARE there, we have 2 options. They are either dumber than us, or they're smarter.

If they're dumber, we don't want to have anything to do with them.

If they're smarter, they'll find us before we find them.

Scratch the project, give me 10% of the money you saved and I'll move on to the next problem.


#2

Well first of all, SETI isn't very expensive compared to many other probably useless projects the government throws money at. They have some time on big antennaes and a bunch of underpaid post-docs manning them. Not a lot of money involved.

Of course, it is likely a waste of time. If we pick up a radio signal, well, it is going to be from a few light years away at best, to possibly hundreds of light years away. So there's no way we're going to ever get to wherever they are broadcasting from since we don't have the technology (and won't have the technology for anything other than really slow space travel for a long, long time--we can't even get a person back on the moon at the moment). If we sent a signal, it will take years, to hundreds of years (or thousands) to reach them. So what, we're going to have a conversation that spans thousands of years? Both civilizations are likely to destroy themselves, cut funding, or whatever in that span of time. And, in the event they are way more advanced than us, they're not going to use radio signals anyway--or at least they might have possibly figured out some faster-than-light communication scheme that our stupid brains can't comprehend.

So, yes, it is probably pointless. The most it can tell us is that we're not alone. If they could tell us that much, it is probably worth the little money that is spent. If it never tells us anything, well, your tax dollars are supporting a few post-docs, maybe summer salary for a professor--I wouldn't quibble over that given all the other pork our tax dollars fund.


#3

"Everything that can be invented has been invented." --Charles H.
Duell, Commissioner, U.S. Office of Patents, 1899.

^^^^^You remind me of that guy. ^^^^^


#4

http://www.newscientist.com/article.ns?id=dn2796


#5

Unfortunately, no information can be transmitted FTL using that technique.


#6

SETI was cancelled by the government years ago. It survives as a privately funded project.


#7

Replaced by the STI project.

They are still searching.


#8

True, but it goes to show that it could definately be possible. We used to think it was impossible, not we can speed up and slow down light/electrons. Next thing you know we'll figure out how to beam people up to starships like Star-Trek. One of the few things I actually look forward to as I age is the emerging technology. I want a fucking space ship before I die!


#9

Unfortunately, it shows no such thing. Other experiments have been done where the speed of light was exceeded (superluminal ultrasounds: http://www.acoustics.org/press/150th/Mobley.html). The only common point to all those experiments is that no information can be propagated faster than light.

If we ever manage that, then we'd have a real breakthrough. The current experiments, while cool, amount to no more than parlor tricks. Cool to do, but with no practical applications. The techniques used don't lend themselves to future improvements that would allow information to be propagated.


#10

I didn't intend the article I posted to directly show that faster-than-light-speed information propogation was plausible. However, it does go to show that what we once thought impossible or very technologically far off could really be just one breakthrough away.


#11

Hmm, I'd like to see the proof of how this works. I'll have to ask my TAs or something.

Also, note that you can theoretically get a location no matter how far, within any time span, no matter how short, in YOUR frame of reference. IE, you could reach Andromeda in a year, your time. This is allowed in relativity because time is dilated and length is contracted for a moving reference frame. To an outside observer, you are approaching, but never reaching, the speed of light. That is, you cannot transmit information faster than the speed of light (to a stationary observer). Viewed from your own reference frame, what happens is that the length between you and the distant location is reduced by Lorentz contraction, and also your clock runs slower than outside clocks.


#12

FTL information propagation would enable causality to be violated, so it isn't just a problem of technology. It would allow information to be sent back in time from/to a fixed location, and introduce similar paradoxes as would "travelling backward in time".


#13

I do not believe that current experiments are parlor tricks for a couple reasons:

1) Although information cannot be transferred distances of meters in the electrical signal FTL experiment, perhaps shorter distances are possible. From the article, the pulse peak travels FTL, but not the total energy, conserving relativity. This necessarily means that the pulse becomes drawn out and distorted. But we don't know the rate at which it is distorted. It may be possible to transmit information over mm or cm. A limited amount of distortion might be overcome through mathematical procedures, allowing very short distances to be covered. And in any case, the rate of decay may be neglible over microcircuit distances. Yes I'm talking out my butt because I'm not a physicist/mathematician, but then again, you never know. I'm just throwing ideas out.

If I'm reading this correctly, this experiment is not simply a personal/outside reference frame problem as boomerlu alluded to. In the reference frame problem, the person feels like they are to the destination instantly because time slows down at high % of c. They do not actually move faster than c. The observer sees them go at c, and time moves more quickly for them. At no point do either of the observers actually percieve themselves or the other to travel FTL. It's a time thing. The pulse peak IS in fact travelling FTL.

2) Absolutely every technological breakthrough that started with theoretical manipulations has gone throuigh the "parlor trick" stage before becoming useful. Quantum physics? Planck's blackbody radiation solution (which gave birth to quantum) was considered by many, for years, to be just a trick of the mathematics to work the problem out. Not until later did they actually "figure out" quantum (Not today either).

3) The distance covered is a very real breathrough. Up to this, all pulses were very, very limited in distance. 120 meters is huge, as is the fact that they did this without huge expense.

4) Just because relativity may turn out to be violated, it does not necessarily mean that it is useless. Newtonian physics anyone? Not that I'm implying it will be...but it does breakdown near black holes, as far as I'm aware. Maybe there are other instances where relativity is "broken". Maybe not.

Yes, I realize the causation problem is big (well, huge). That's why I'm going to be very interested to hear/read/see more.

Cool stuff.


#14

1) The thing is, is FTL travel for mm, cm distances even useful? Light travels so fast that it is considered instantenous anyways. Optical networking/computers anyone? It may eventually be useful, I don't believe it is useful at this point.

I need to read the acoustics article more carefully, but if I'm interpreting what i've seen so far correctly, it is the interference that travels FTL? Not light itself?

2) Haha, or Bohr's model of the atom? "Proof by...it works...." And the fucker got a Nobel for it too! Hell, relativity was practically a mathematical "parlor trick" with no practical uses at first (who the hell was going to travel at .5c in 1905 anyways?). Now it's the basis of modern physics.

Actually, a lot of modern physics is math. It's crazy how much of it is mathematical theory without being tangible. The current theory of mass is that it's given by a scalar field!

3) Hmm...Morse Code? While the information takes time to decode, traversing the distance is the main issue for something like a remote spacecraft.

4) If relativity can be broken, I think many people would rejoice. Oh sure the scientific community at large might not react well at first since it's such a central and built in tenet to our understanding the universe.

Just because we think causality is important doesn't mean violating it is a bad thing. Being able to violate causality is a necessary condition for time travel.

Also, Google quantum teleportation. Spooky.


#15

Actually, for large distances such as the ones involved in space travel, light is incredibly fucking slow. That's the problem.

If we could reach a good percentage of it (say, 99.99999% of the SOL) then space travel would be doable, because of the time dilation effects on those traveling at those speeds, but it would make coming back to Earth unnecessary, as centuries might have elapsed here.

If you have to go slowly, then you either freeze yourself for the duration (à la Nostromo in the Alien movie) or have "generation ships" where people will live for many generations before reaching their goals. (Fairly common in sci-fi stories, but not in movies).

Reminds me of a science-fiction story where the first expedition to a faraway planet arrives only to be greeted by humans, because in the intervening centuries of "Earth time," someone has figured out how to travel faster than light and the planet has been colonized for a couple of hundred years when they finally reach it.

Of course, in the stories, they generally avoid dealing with the causality problems of FTL travel.


#16

If FTL information propagation is possible, then I would highly suspect, and hope, that it is SR rather than our concept of causality that is not correct. Thinking about the latter makes my brain hurt and causes* a vague feeling of hopelessness in me.

  • Assuming there is such a thing as a "cause".

#17

If you ever see the headline "Physicist wins state lottery jackpot for 3rd time in a row" you can start worrying.


#18

Yeah, I totally realize that, but the guy was talking about mm and cm scale distances.

The problem with traveling with the .999999c spaceship is that you have no guarantee that the planet you reach is going to be remotely the same once you reach it, since it ages much faster than your travel would. I guess this is the same problem with cryo and generation ships though.


#19

Math and philosophy make my head hurt more....mainly because they don't deal with reality.

I think one of our math TAs proved that if you use one orange, you can peel it such that you can cover the entire surface of the earth with just one orange.


#20

That's not too bad. On a geological scale, a few hundred or thousands of years is not much.

Unless the place gets hit by a comet or an asteroid while you're on your way, it should be similar enough when you arrive.