S.E.T.I. Shouldn't we be looking for the Tetragammaton?

elivsvonchiaing

If our galaxy was a 12inch pizza, I'm fairly sure our transmissions to date would not be covered by the world's smallest coin on that pizza.

We are looking for remote life; I suspect that those that hear us can't be more than 1-2 planets (my guesstimate ) have agreed no communication until a sentient race establishes itself beyond its own planet. They have already found in the past contact is established, contact is lost, they have destroyed their planet.

We may go on to not nuke ourselves, not destroy our environment, but suffer the fate of the dinosaurs. This is currently our economic reality!

A truly evolved species will have maybe a better solution - but in the interim I think a species that develops nuclear weapons - that survives for at least 300 years (after the event) will develop a weapon that will stop any cosmic debris from - er - ending life as everyone knows it.

Such a device I think would have to yield in the 100s of Gigatons. It would probably need to be at least a four phase detonation, maybe only three.

Simply put it would need to be lattices of A-bombs enclosing H-bombs, all within a further lattice.

The search for extra-terrestrial life should pass some focus onto four-phase/three phase events in the gamma spectrum lasting between 50 and 150ns... The first peak shouldn't be before three Nano seconds, after that I'm an ignorant SOB

Capt'n Midnight

There was an interesting program on Channel 4 about Exobiology and some speculatoin that it might be convergent to some extent -science and technology is convergent in the sense that any ETs would have radar and radio etc.

about the nukes - looks like a cut/paste

Nuking comets would be unlikely to work anyway.
comets are snowballs, when you try to blow up an iceberg with dynamite all you get is an iceberg with a big hole in it. Better way would be to setup proper radar to detect them actively. in the next 300 years we should have all the large ones mapped and powerful enough radars to pick up new ones early enough that we could divert them by less violent means. I don't think ET will be using dirty nukes when they could use some form of mass drive instead.

Also considering how often we'd use nukes of that size and the short duration of the pulse and the positional accuracy of the detector it's unliklely we'd see them.

elivsvonchiaing

Capt'n Midnight wrote:

There was an interesting program on Channel 4 about Exobiology and some speculatoin that it might be convergent to some extent -science and technology is convergent in the sense that any ETs would have radar and radio etc.

about the nukes - looks like a cut/paste

Nuking comets would be unlikely to work anyway.
comets are snowballs, when you try to blow up an iceberg with dynamite all you get is an iceberg with a big hole in it. Better way would be to setup proper radar to detect them actively. in the next 300 years we should have all the large ones mapped and powerful enough radars to pick up new ones early enough that we could divert them by less violent means. I don't think ET will be using dirty nukes when they could use some form of mass drive instead.

Also considering how often we'd use nukes of that size and the short duration of the pulse and the positional accuracy of the detector it's unliklely we'd see them.

Totally agree. We probably need an orbital gun capable of delivering a device at 200 km/s. It would need to get at least 1km into a piece of iron (would still have to be doing serious RPM to achieve this). A piece of snow (comet) we really could kill - with a penetration of centre of gravity.

I personally think this is what we need to survive. We might get away without this for 10k -1M years though!

Re: SETI We need detectors that can spot signatures in the gamma spectrum that last only 150ns if we are ever going to find out if we are alone or not!

[EDIT]While I haven't explicitly stated this already - I see the role of the gun as the tracker of objects also, completely automated.

Was just looking at the capabilities of Chandra... We could get lucky here... I reckon though a much longer x-ray signature of a micro-sun would be open to hot debate though - black holes etc.

Further thoughts are perhaps signature would be much longer... The device could use "scout" nukes to drill, probably in the hundreds, these would probably be seconds apart.

Nukes are a dirty solution, but the best one we have right now, and this may still be the case in 300 years. A device that isn't big enough will leave a snowball with a big hole in it - true. Think the gun needs a choice of devices to work with and maybe even assemble on-the-fly. For it to work at all the "device" would need a tritium refinery built into the "gun" to fuel it at the last minute. Long-term it would need to do the same with plutonium. Gun would also probably need fresh tritium every 20 years - just can't see human taxpayers doing this, can only see a race that have managed to extend their longevity to several hundred years doing this... If we could detect it - it would be really exciting, even if it came from the other side of the galaxy and they're now probably gone! Don't think we could detect much further than this without a new moon (the detector) or something. [/EDIT]

elivsvonchiaing

Capt'n Midnight wrote:

.. about the nukes - looks like a cut/paste

Hmm. I did say something about this in a previous post - is that what you mean?

albertw

elivsvonchiaing wrote:

Re: SETI We need detectors that can spot signatures in the gamma spectrum that last only 150ns if we are ever going to find out if we are alone or not!

How does detecting short gamma rays help us detect ETI? I don't see the advantage of using the gamma end of the spectrum for communication. Given a sufficiently advanced race, communicating with another race, why would they use gamma rather than say lasers?

Cheers,
~Al

Capt'n Midnight

I think the point was that a civilization that used Nukes to destroy asteroids might be detectable.

Pros - Nukes generate a lot of energy.

Cons - gamma rays are kinda hard to focus onto a detector, you can't use a dish
timescale is VERY short, so you can't scan the sky cos you will miss it
as I pointed out any civilization that advanced is likley to not use nukes - at best they would be stop gap - even we would probably only use them a few times because the pressure would be there to develop a radar screen

Similar arguments can be made for Dyson Spheres, any civilization capable of making a stable one would need to have so much energy and engineering at it's disposal that they could make something better

google for fermi's paradox if you believe that we are likley to be close enough to ET to detect them. Some stars of our type a billion years older than ours exist so plenty of time for ET to have developed space travel and colonise the galaxy even at chemical energy speeds.

Capt'n Midnight

elivsvonchiaing wrote:

Hmm. I did say something about this in a previous post - is that what you mean?

where did you get the bit about four phase detonation ?

I'll say it again, you can't nuke a snowball. (without major overkill) All you do is punch holes in it. Iorn asteroids would probably not even shatter with a nuke, a nuke might work against stony ones...

solas

"I think the point was that a civilization that used Nukes to destroy asteroids might be detectable."

I honestly admit I havent a clue what half the stuff in this thread means, this is not an area I have any education in (other than the occasional documentaries)..but I remember reading somewhere years ago that if the revolutions of an asteroids/comets were decreased/increased, its magnetic field would become unstable and it would self destruct as a result/veer off course.
There was some discussion about using particular laser technology (located in thousands of specific points across the globe) which could have this effect, because of the density in space these lasers were more efficient..I dunno might have been something as simple as heating the thing up :?

Might have been a science fiction program I was watching, but sounded like a much better option than using nukes. Is this just a nice fantasy or anyone care to enlighten me?

elivsvonchiaing

albertw wrote:

How does detecting short gamma rays help us detect ETI? I don't see the advantage of using the gamma end of the spectrum for communication. Given a sufficiently advanced race, communicating with another race, why would they use gamma rather than say lasers?

Cheers,
~Al

This is based solely on the premise that an ETI have built a nuclear-based defense from inbound cosmic debris. I'm fairly sure the signatures in the gamma spectrum from such a device would be irrefutable evidence of ETI - if we could detect it.

This would be just self-defense and not an effort to contact us.

Capt'n Midnight

Lasers could be used to burn a tunnel into an asteroid, from a long distance. The material vaporised by the heat of the laser would a bit like a rocket pushing the asteroid off it's course. It would take a lot of time so there is plenty of time to scan the heavens (months or years Vs. 0.000 000 15 of a second )

Lasers are monochromatic and would stick out like a sore thumb on any spectroscope.

But there are natural gamma ray bursts, caused by stellar events as one of the early spy satellites found out. And there are cosmic rays. So how would you design a detector that can detect a spike of 150ns coming from an unknown area of the sky, maybe once per decade or even once per civilisation, ???

elivsvonchiaing

Capt'n Midnight wrote:

Cons - gamma rays are kinda hard to focus onto a detector, you can't use a dish
timescale is VERY short, so you can't scan the sky cos you will miss it
as I pointed out any civilization that advanced is likley to not use nukes - at best they would be stop gap - even we would probably only use them a few times because the pressure would be there to develop a radar screen

Still think that stop gap could be 2-5k years, so could be worth looking for, a gamma detector that can focus would be what we need to overcome here. A high temporal resolution can only help our understanding of the universe anyhow. This is something we probably need - with SETI as an afterthought.

Capt'n Midnight wrote:

Similar arguments can be made for Dyson Spheres, any civilization capable of making a stable one would need to have so much energy and engineering at it's disposal that they could make something better

Totally agree - think this is long after we have colonies on Alpha-Centauri or the closest viable alternative. Still think a race could depend for thousands of years on nuclear defence.

Capt'n Midnight wrote:

google for fermi's paradox if you believe that we are likley to be close enough to ET to detect them. Some stars of our type a billion years older than ours exist so plenty of time for ET to have developed space travel and colonise the galaxy even at chemical energy speeds.

Still think point in my original post - they have seen it all before, know that by the time the reply is received - no-one is home anymore explains this. I could be wrong.

Then again maybe there is a galactic mandate to abduct certain humans (quietly) castrate them and straighten their teeth! (Bill Hicks!)

elivsvonchiaing

Capt'n Midnight wrote:

Lasers could be used to burn a tunnel into an asteroid, from a long distance. The material vaporised by the heat of the laser would a bit like a rocket pushing the asteroid off it's course. It would take a lot of time so there is plenty of time to scan the heavens (months or years Vs. 0.000 000 15 of a second )

Lasers are monochromatic and would stick out like a sore thumb on any spectroscope.

But there are natural gamma ray bursts, caused by stellar events as one of the early spy satellites found out. And there are cosmic rays. So how would you design a detector that can detect a spike of 150ns coming from an unknown area of the sky, maybe once per decade or even once per civilisation, ???

Simple answer - I can't! But I believe it could be done. Using wave diffraction and sheer genious and a mother of an array of nano-collectors think this could be done. We would probably need an large orbital array of these...

Hopes of this seem to hinge on : there is an alien living here playing the galactic lottery and gets lucky - and is generous

Capt'n Midnight

elivsvonchiaing wrote:

a mother of an array of nano-collectors think this could be done. We would probably need an large orbital array of these...

the same amount of effort would produce a asteroid detector that would make last ditch nukes less likley to be used than slower techniques.

Again it's a 150ns event that may never happen and even if it does you are unlikely to see it above the background.

Another way to deal with asteroids it to make space stations , orbiting colonies at the legrange points or even the trojans, less likely to have the whole civilisation wiped out in one go. and then there is the option to terraform

elivsvonchiaing

Actually have given this some thought (for a change :eek: ).
The idea of an orbital super-gun was complete pants. If it could lob a few tons of payload at tens of km/s it would take decades to recover itself to Earth orbit - and would run the risk of clipping itself of a small asteroid it hadn't detected. It would also have to be deployed when the comet/asteroid was relatively close - we would not want to detonate the biggest nuke ever in our back yard - somewhere beyond Jupiter if that's an option would be best.

A civilisation capable of developing such a thing will more than likely be able to safely produce large quantities of solid anti-matter and fire shells at on-coming debris. Keep firing until there's nothing left.

What if a shell misses? Think if there was large flash on our moon for example no-one could agree that it was from such an object. Don't think a shell of 1kg would make it even a parsec before hitting enough matter to disintegrate.

I now reckon the only hope of ETI evidence from something like this is if one of nearest neighbours has to build a big nuke to do in a big rock/ice cube. Think we might see this...

Hubble just might be able to see the drilling operation; on rethink drilling a shaft with small nukes would think they wouldn't be every few seconds, but every few minutes or hours: each subsequent nuke would need to determine the effect of the previous on the trajectory and spin of the object in order to find the shaft entrance accurately.

Having life supported by our nearest neighbours seems unlikley. Having a civilisation at the same (slighty higher) technological level as us seems doubly unlikely, though. But Hell - what if?

There are quite a few threats out there - right now if we saw something that's 10 years away and its not the size of Texas more Cheyenne mountain we just might have a hope...

I'd be upset if my 15 mins of fame is in 10 million years when my fossilized remains are on discovery channel

elivsvonchiaing

Capt'n Midnight wrote:

where did you get the bit about four phase detonation ?

Think you get more yield this way. At the centre you have a whole load of fussionable material. Surround this with a big lattice of small lattices of H-bombs with more fusionable material at the core of each. Each lattice would need to be encased in depleted uranium. Whole thing encased in depleted uranium. Everything would need to know the correct time as a skew of just 1ns wouldn't give full yield I suspect.

First phase of detonation is the A-bombs in H-bombs, second phase is the H-bombs themselves. Third phase is the fussionable material at the centre of each sub-lattice. Final phase is the fussionable material at the centre of the whole device.

This is probably more uranium than we have - but others may no be so empoverished.

...and Eh, I'm not barking mad - honestly

[EDIT] 150ns wtf was I thinking? Reckon this sucker could burn for 10s of micro seconds. What I also failed to explain was the point of the four-phase, It would be modular and a bomb could be to tailor made to scale from off the shelf components (H-bombs), the only thing needed to work out is how much depleted uranium is needed to enclose each sub lattice, how much fussionable material can be burned here, likewise with the outer lattice.

A custom H-bomb with just two phase, think you would need 100s of metres thick outer uranium to get the equivalent yield.

The way I see it is... in 100 years or so we just might be able to take out something 200-300Km in diameter in rock...[/EDIT]

elivsvonchiaing

solas wrote:

There was some discussion about using particular laser technology (located in thousands of specific points across the globe) which could have this effect, because of the density in space these lasers were more efficient..I dunno might have been something as simple as heating the thing up :?

Might have been a science fiction program I was watching, but sounded like a much better option than using nukes. Is this just a nice fantasy or anyone care to enlighten me?

Captain Midnight's comment on this was good - and yours was good point also. Just now think the whole exercise is like trying to listen for the sound of a flea biting someone in Paris - from Dublin tbh. The cunning flea bite detector might work on the flat/house next door and even then there will be debate

Further thought - should hubble have a side kick - capable of identifying a quadrant/tesallation of sky worth scanning on priority basis? Just a thought is all!

elivsvonchiaing

Seen one of these. It wasn't me! (Hope this is not what its about tbh!)

Hmm can't seem to edit my posts here! Is this a pre-ban or something?
Gratuitous excuse to echo previous post - It's a big-ass sky - we should be watching everything!

keu

again I'm not an expert, but I thought hubble was being decommissioned and replaced by 2012.

Hubble is slated to be decommissioned in 2010 and replaced by the next-generation James Webb Space Telescope, scheduled to be launched in 2011. The new observatory will have a primary mirror that is 20 ft in diameter, compared to the Hubble's 8-foot reflector.

For more information on the Hubble Telescope, see NASA's Hubble Project: http://hubble.nasa.gov/ .

p.s. your funny when your drunk

Redshift

elivsvonchiaing wrote:

Hmm can't seem to edit my posts here! Is this a pre-ban or something?

There is a time limit for editing posts on boards, I think it's 24 or 36 hours or something like that. If you need something edited after that PM a Mod with the edits you want.
You are not in anyway banned BTW.

Capt'n Midnight

AFAIK To day the stongest signals being sent int o space are the uplinks to communications satellites mainly because of the tight beam. These operate on a small range of frequencies - not sure if this is because of technical reasons or not. - Would ET use signals like these and should we be looking for them or will they pass through this phase on to something new..

Multiple gigaton detonations might indicate the equilivant of WWIII a bit late then.

mr_angry

Frankly, our best chances of meeting ETI is either:

a) They show up on our doorstep via some currently unknown method of detecting and visiting habitable planets.
b) We discover a way to travel through vast amounts of space in an extremely short time, and start searching ourselves.

Even this second option is like looking for a needle in a haystack. If we look for habitable planets from Earth, we're effectively looking further and further back in time as the distance increases, and the chances of that planet still being habitable are getting lower and lower.

elivsvonchiaing

Just occured to me... if we detect a star under 10k light years away (maybe 50k dunno what's possible here) carbon burning, (silicon burning - if we are quick enough). Every telescope on and off the planet should be trained on it. Think any intelligent race would want to transmit their demise/their history etc. to the universe in this event. What we have to work out is how they would do it over the more dominant noise of their stars collapse...

SpaceJunkie

If I understand most of what is being discussed in this thread, it involves detecting Extraterestrial Life.

(My personal view...)
The first post suggested searching for short duration Gamma Radiation pulses which might suggest a civilization using large nukes to defend against cosmic visitors (ie: Comets or asteroids). The main problem with this method is energy output. Although such a pulse might be detected locally (within the star system where the blast occurs, detection beyond that would be very difficult becoming more and more unlikely the further out the pulse travels. The simple fact is, a blast of sufficient magnitude to totally vaporize the planet itself would be virtually undetectable at a cosmic distance such as lightyears. Gamma ray bursts which are barely detectable with dedicated instruments looking in the right direction at the precise right time emminate from exploding stars during supernova events. If we are looking for these events and miss more then we see, it is a whole magnitude more unlikely we would see a burst from a world deflecting/destroying asteroids.

Further, detecting any readiation emitted by a civilization depends on what type of radiation is being transmitted (higher frequencies require higher energy to reach the same distance with the same radiation density), how far away they are from us and how long ago it was sent. There is a theoretical limit as to how long ago it could have been sent. This is based on how much time it takes for the universe to cool enough to solidify into hydrogen atoms from the big bang, how long it takes for stars and galaxies to form, how long it takes for planets to form, how long it takes for a world to become life supporting, how long it takes for life to begin (if it does) and how long it takes for a civilization to evolve sufficiently to send a signal using electro-magnetic waves.

Even though there could possible be anywhere from 1 civilization to hundreds of thousands, the probability of one being within detectable reach is very improbable. It is true that the longer a civilization exists, the more likely detecting it becomes. But civilizations would have to have been around for millions of years before the chances decrease to any appreciable value. As a guideline for comparison purposes, we have only been able to transmit radiowaves for perhaps 100 years. This means that any civilization who might be able to pick up our transmissions would have to be within 100 lightyears distance. Again, very unlikely.

Lastly, if by some extreme twist of fate, there happened to be another civilization within 100 lightyears, who did detect our transmissions, it is far more likely they would come take a look before sending a "blind" response back which would take another 100 years (minimum). If they were intelegent enough to receive and decode our transmissions (radio & TV), they would know about our advancements in the area of nukes, they would know how paranoid we are as a people, how we treat each other on this ball of dust and what we have to offer them by communicating. It is clear that no highly advanced civilization would have anything to gain by contact with us. And every reason to hide their existance from detection by us.

And that would make detecting them even more unlikely....

We are a young and violent race.... I wouldn't expect a knock at the proverbial door any time soon....

Mr. Angry is right on target... (wink).

(Just my view)