[codeshaman]

A very noble endeavour indeed, but I still don't get it.

So let's say that by examining the petabytes of data that's received from the telescopes, at some point a signal is detected.

Let's say that somehow all the competing scientests and skeptics, religious and opinion leaders magically and peacefully agree: the signal is from an inteligent life form. Somewhere close, just a couple of hundred light years away ...

Then what ?

Do we build rockets to travel there ? Do we 'tune-in' and decipher the signal ? Do we send them our own signals in the hope that they are listening ?

[SCHiM]

Do you not think that actually knowing, really knowing, is a worthy cause in and of itself? To have proof that we are not alone? Even if we can't get there I think that certainty would be a very nice thing to have.

[codeshaman]

I would venture to say that most educated people allow for a pretty high probability that life exists on other planets in the Universe, given the sheer scale of the place.

In fact, a much harder task would be to prove that life absolutely doesn't exist anywhere else in the Universe.

So we instinctively believe, but we still want proof. So would the SETI thing provide that definite proof ?

In many ways this is similar to 'does life exist after death'. Either way you stand, it's impossible to absolutely prove it, but some day everyone will definetely find out ;).

[happyscrappy]

I agree that knowing is a worthy cause, but never mind getting there we will not even be able to have anything even resembling a conversation if you have to wait hundreds of years for a response.

Edit: Does anyone know the current thinking of the odds that information could be able to travel faster than light, ie a wormhole? As far as I know they are very slim.

[espadrine]

> Does anyone know the current thinking of the odds that information could be able to travel faster than light, ie a wormhole?

An Einstein-Rosen Bridge is purely theoretical, and mostly a way to understand the equation of general relativity better. The equation requires you to set a few parameters that we have no way of determining currently, and that describe the structure of the universe. By setting those parameters just right, we can imagine really strange things, such as time travel or a wormhole.

But even if those parameters allowed a wormhole, having a traversable wormhole requires exotic matter with negative mass, another thing that we have no tangible proof exists.

In other words, general relativity is so general that it allows behaviour that can't exist in the real world. Computing the odds that information could go through a wormhole is like computing the odds that God exists.

[angdis]

Well, if we do detect a signal, we're not going to just transmit "wassup?" and wait for an answer. I think it will be an interesting problem to have a conversation with other beings where the lag time is measured in decades!

[ifdefdebug]

Well galactic communication is one-way: every civilization reaching the tech level needed to participate in it just starts to send out everything they know, never hoping for anyone to reply. Additionally, every participating civilization starts relaying everything they hear from one side to the other side, so civilizations which are mutually out of range can hear from each other.

There is a galactic consent that nobody will ever be able to actually visit each other.

And of course, this is pure science fiction :)

[pavel_lishin]

Why would you wait for a response? When you send a letter, you don't send the line "Greetings from happyscrappy! How are you?" and then wait for them to reply - you go ahead and ask them questions, tell them about yourself, etc., and then wait for a reply. Or don't! Send them a letter once a week, etc.

[ifdefdebug]

Anything contradicting relativity is currently out of the scope of science and not backed by any observation whatsoever, so any travel-faster-than-light theory has exactly the odds granted to it by it's own believers, and zero for everybody else.

[laumars]

Wormholes don't contradict relativity. In fact they were predicted by relativity (or rather a solution to the singularity problem predicted by relativity).

The scientific name for a wormhole is an Einstein-Rosen Bridge - named after Nathan Rosen and, obviously, Albert Einstein who conceived the idea.

There are other suggestions for "faster than light" travel, but FTL is a bit of a misnomer because the concepts of FTL aren't about having a velocity that's greater than c (the speed of light in a vacuum), it's about warping or cutting through the fabric of space in a way that makes the distances shorter. A wormhole is just one theoretical method of jumping those distances via a shortcut.

[octatoan]

IANAP, but isn't the only argument against faster-than-light-travel the fact that it contradicts causality?

[TheOtherHobbes]

I don't see a problem there. The definition of causality is circular anyway. There's no formal mathematical self-consistent proof of causality. It's just sort-of assumed, and then there are back-arguments from relativity that say "Well, that violates something we sort of assume."

The problem is that in science, if you assume things in a naive way ("What goes up must come down." "Planets travel in circles") you're almost certainly wrong - because the details of physical reality are usually counter-intuitive and unexpected.

So what we really know is:

1. Spacetime is a thing. It has bulk properties described by GR. 2. Er - that's it.

We don't know what spacetime is made of, or what you can do with the things it's made of, or what their properties are.

So I'd classify this as "definitely not known due to lack of knowledge" rather than "definitely not proven."

Proposals like Quantum Dynamical Triangulation, Causal Sets, and Loop Quantum Gravity are beginning to ask what spacetime is made of, but they're barely in their infancy.

The one thing they have in common is the idea that there's a network of - something... - and the reality we recognise propagates across the network.

If the elements are discrete - and they almost certainly are, because of the Planck limit - there will be some moment where an element changes state.

How fast does that happen? What's the mechanism? What limits the state changes? (Adjacency? Some other property?)

It's completely mysterious, and I think it's unwise to make definitive statements about it until it stops being a mystery.

[ifdefdebug]

I don't know if it's the only one, but it is one Stephen Baxter's novel Exultant plays brilliantly with: the people in that universe discovered means to travel faster than light, but at a high price: causality was gone - and they had to get over it.

[nicboobees]

Is it worth millions of dollars to know that? Nope.

It's rich people playing with their toys.

[thebouv]

What is millions of dollars for scientific research compared to millions blown on stadiums, or billions on new jet fighters?

[nicboobees]

Stadiums benefit millions of people. Jet fighters save lives. Finding out that there's water on mars, or some single cell organisms on pluto, does nothing apart from fill a few future text books.

[rimantas]

With attitude like this we'd never have neither stadiums nor jet fighters.

[rybosome]

Nailed it. That's why it matters - without a hunger for knowledge, our species would still be living in caves, pilfering scraps of flesh from carrion. Our desire to understand ourselves and the world we inhabit has lifted us out of the darkness.

[ionised]

And there would be much rejoicing.

[stephengillie]

Since there IS water on Mars, then it's a lot more likely those future textbooks will be written there.

Edit: corrections.

[tosseraccount]

There is water on Mars. https://en.wikipedia.org/wiki/Water_on_Mars

[88e282102ae2e5b]

It would make it that much harder to justify many religious beliefs, which I predict would be a positive outcome. It's harder to be arrogant and self-righteous when you find out you're not an only child. Sure, some people would find a way to stay stuck in their ways, but not everyone.

However, the much more important thing for me is that we'd know we aren't necessarily going to run into some Great Filter [0]. I'd fret a little less about dangerous new technologies if I knew at least one case where a civilization survived.

Lastly, maybe we'd learn something from the signal itself! A new communications protocol, new music, new technologies, insight into how languages work - who knows? Finding out what we have in common with the beings who sent the signal and what we don't would teach us a great deal about what is arbitrary on our world and what's fundamental. It's like growing up in a society with extremely rigid gender roles and then traveling to a country where that's not the case - you get that "Oh I didn't realize women could even have jobs" moment, but potentially with problems that aren't self-imposed.

0. https://en.wikipedia.org/wiki/Great_Filter

[Touche]

I think it's worth trillions.

Just imagine what proof that we're not alone would mean for the world. I'm not positive it would galvanize everyone, but it would surely create new industry and untold number of jobs as we, as a world, decide to try to go and meet them.

[jessriedel]

It is definitely, indisputably worth millions of dollars to know that.

[nicboobees]

Well, agree to disagree. The average person doesn't really care if there is or isn't water on mars, or if someone spent millions of their dollars taking a photo of pluto.

Year after year the news reports another big experiement which cost millions to setup, and which claims to "give us answers as to how the universe was created". I just couldn't be less interested. It's rich people (Or taxpayer funded people) playing with their toys.

It must be great fun if space exploration is your hobby, like explorers of days gone by, but for most people it won't have any impact at all on their lives (Apart from wasting their taxes).

[pc86]

Space travel and exploration have directly resulting in many commercial products, which themselves have generated billions in revenue and tens of thousands of jobs (if not more).

Not only is your statement disappointing to hear from anyone presuming to be technically literate, it is objectively wrong.

[jessriedel]

Actually, I think you're wrong here. Space travel is a very inefficient method of R&D. Almost any other basic research has more practical benefit.

[nicboobees]

As a fellow reply states, using "Space travel" as a means for general R&D is pretty damn inefficient.

You would have a similar result if you poured money into alchemy research - lots of side products etc.

[jessriedel]

That's actually exactly my philosophy [1]. I agree with each of your examples (water on mars, photos of Pluto, early-universe cosmology). Nonetheless, the existence of extraterrestrial intelligence is in a completely different league. The random guys on the street will not only care about this tremendously, he will care for the same correct reasons that scientists care.

[1] Minus the part about it being a waste of taxes; just because people aren't interested doesn't mean it's not worthwhile, because people can be wrong.

[nicboobees]

So we find out there's some creatures on Pluto that are roughly the same as frogs. How does that impact anyones life? It'd be an interesting fact, and maybe fun if we could move some over here as pets, but beyond that, it's a colossal waste of energy and money.

[espadrine]

Let's imagine a remote island on Earth that was colonized five thousand years ago (and completely forgot about how they got there). They may spend a very long time sending and listening to sonar signals. However, we (the aliens from their point of view) use sonar for ourselves, not to detect intelligence. It would be very hard to detect intelligence from our use of sonars (which is similar to that of a few animals). Even if they did guess that we were intelligent, their understanding of who we are and how we live would be minuscule.

On the other hand, if they spent their energy sending ships, they would eventually find us, and they would learn phenomenally about technology, science and their place in the world, even before they reach us.

[pavel_lishin]

> It would be very hard to detect intelligence from our use of sonars.

Why would it be hard to determine that we're intelligent? We've clearly created some sort of apparatus for generating sonar. I would imagine that someone listening in our oceans would be able to tell fairly quickly that we're a technical civilization.

[espadrine]

> Why would it be hard to determine that we're intelligent?

Underwater sounds can come from a wide range of sources, including tectonics, natural events and animals. Those did not create some sort of apparatus. Yet, they can have a similar signature.

It is not even a hypothetical situation. A SETI lab spent a lot of time trying to figure out what a particular signature that their telescope picked up was, only to discover it was caused by their microwave oven: http://www.independent.co.uk/news/science/seti-the-hunt-for-....

[onion2k]

Let's say that somehow all the competing scientests and skeptics, religious and opinion leaders magically and peacefully agree..

That's sounds like exactly the sort of outcome we want, regardless of what else happens.

[jively]

An upheaval in the way we see our role in the universe? Re-invogorate the race to space? I think there's plenty of things that follow "then what?".

[sdrinf]

There are very few pieces of information really worthy of deliberate broadcasts across star-systems in the hopes of someone catching it. One of these few might be a full dump of neural vector-states (or functional equivalent thereof), at an appropriately low-level assembly, which when successfully executed, brings not a message, but the messenger itself.

[pavlov]

In fact, any sufficiently advanced digital program can be a "messenger" rather than a "message". But how do we know what kind of execution environment is available at the destination?

Aliens probably use Brainfuck [1], so we need a substantial increase in Brainfuck AI research. Some modern-day Kennedy needs to step up to this challenge.

[1] https://en.wikipedia.org/wiki/Brainfuck

[brianmcconnell]

A fair amount of work has already been done with algorithmic communication systems, as its a small step from a mathematical language to a general purpose programming language. Paul Fitzpatrick, then with the MIT AI lab, developed the most complete framework around the idea, CosmicOS.

[evantahler]

The answer is usually "what would Jean luc Picard do?"

[msane]

Taking the "I don't get it" attitude on this resembles a sort of classic anti-science ignorance, not sure if that's what you were going for.

[vixen99]

What we will have is a lot more experience with protocols as are required to detect such signals. Not difficult to imagine circumstances in which such capability could be highly significant or even critical for mankind or the Earth's future.

[tfm]

It's certainly difficult to imagine projects that operate on a timescale beyond a single human lifetime, but it got civilisation this far!

[neals]

Yes. Yes we will.