What dipstick decided to SETI ??

440Hertz

The most likely way we’ll see signs of life is probably by analysis of the atmosphere of exoplanets using highly powerful space telescopes or detecting some artificial signal that isn’t intended for us at all, or noise being generated by technology that isn’t a signal at all. We might first see the byproducts and impact of life, not direct communication with us.

There’s also the fact that our perception of time is based on our biology and limited lifespans.

Who knows what’s out there. I mean for example, if you’ve something like an artificial life form or some kind of hybrid that has no notions of being limited by time and just maintains and repairs itself, what’s a billion years? Could be a blink of an eye to them.

I mean even our human systems aren’t limited by lifespan. Projects can span generations and knowledge passes on and is increasingly stored artificially. We’ve basically achieved some degree of timelessness even in that. Take that to its extremes and we probably become more cyborg like than we might imagine, if we start augmenting biology. We’re already doing it, just not by plugging ourselves in, yet.

You could also have the opposite, an organism evolving at the speed of bacteria, and moving at much higher speed than we do.

Our 80 to 100 years of life is an eternity to a bacteria. It’s a hundred times longer than the life of many insects and even plenty of small mammals.

You sort of have to throw all your assumptions about what life is out the window when it comes contemplating this stuff.

A probe could also be absolutely tiny. How would we recognise something the size of say a mobile phone that was capable of traversing space and looking at us? For all we know there could be loads of tech in near orbit and we wouldn’t even detect it. What it were as small as a grain of sand? That’s not impossible or even unlikely.

Intelligent life could be the size of a bee. So maybe we might be expecting the Starship enterprise to pull up, and instead we get something the size of a football.

We make a lot of assumptions based on ourselves as we’ve only got ourselves and Earth biology as a point of reference.

Smiles35

440Hertz wrote: »

There’s also the fact that our perception of time is based on our biology and limited lifespans.

I did think one time, would the size of a planet might affect lifespan. I was thinking so. Bigger planet, more resources. The creatures just keep going.

440Hertz

Smiles35 wrote: »

I did think one time, would the size of a planet might affect lifespan. I was thinking so. Bigger planet, more resources. The creatures just keep going.

Possibly, but it seems things like orbital cycles impacted how life evolved here - day / night and seasonality.

You get an optimal maximum size here - go too big and you can’t survive safely, as you need too many resources. That’s likely why the big dinosaurs died out. They couldn’t survive a change. Mammals and the dinosaurs that evolved into birds muddled through.

There isn’t necessarily an optimal minimum size though. On Earth there’s a relationship between size of a basic cell and the need for complexity. So to achieve say a complex brain and body, you need some degree of scale.

However, that’s Earth cellular biology. There’s no reason that might not have happened very differently somewhere else. It could be packing a lot more into a smaller package, or perhaps a lot less.

The answers are unknowable until we encounter even something like Venusian pond scum. At least we would then be able to extrapolate.

For example, if we found life on a planet in the solar system and even if it were only simple stuff, we could ar least then look and see if it is similar to Earth life, in which case it might be reasonable to conclude that say organisation into cellular biology is as universal a concept as organisation into atomic structures.

However, if it’s radically different, we might be concluding that the possibilities are vast and highly unpredictable.

breezy1985

Another problem is if aliens ever do pick up our signals China's 5G will kill them before they even get here for first contact : )

440Hertz

breezy1985 wrote: »

Another problem is if aliens ever do pick up our signals China's 5G will kill them before they even get here for first contact : )

Planet Gemma ?

ThunderCat

440Hertz wrote: »

The most likely way we’ll see signs of life is probably by analysis of the atmosphere of exoplanets using highly powerful space telescopes or detecting some artificial signal that isn’t intended for us at all, or noise being generated by technology that isn’t a signal at all. We might first see the byproducts and impact of life, not direct communication with us.

There’s also the fact that our perception of time is based on our biology and limited lifespans.

Who knows what’s out there. I mean for example, if you’ve something like an artificial life form or some kind of hybrid that has no notions of being limited by time and just maintains and repairs itself, what’s a billion years? Could be a blink of an eye to them.

I mean even our human systems aren’t limited by lifespan. Projects can span generations and knowledge passes on and is increasingly stored artificially. We’ve basically achieved some degree of timelessness even in that. Take that too it’s extenders and we probably become more cyborg like than we might imagine, if we start augmenting biology. We’re already doing it, just not by plugging ourselves in, yet.

You could also have the opposite, an organism evolving at the speed of bacteria, and moving at much higher speed than we do.

Our 80 to 100 years of life is an eternity to a bacteria. It’s a hundred times longer than the life of many insects and even plenty of small mammals.

You sort of have to throw all your assumptions about what life is out the window when it comes contemplating this stuff.

A probe could also be absolutely tiny. How would we recognize something the size of say a mobile phone that was capable of traversing space and looking at us? For all we know there could be loads of tech in near orbit and we wouldn’t even detect it. What it were as small as a grain of sand? That’s not impossible or even unlikely.

Intelligent life could be the size of a bee. So maybe we might be expecting the Starship enterprise to pull up, and instead we get something the size of a football.

We make a lot of assumptions based on ourselves as we’ve only got ourselves and Earth biology as a point of reference.

Well said. And of course our imaginations as to what that would look like is limited to our human intelligence. Who's to say an extremely advanced alien probe doesn't take the form of a gas for example.

breezy1985

440Hertz wrote: »

Planet Gemma ?

Jeysus could you imagine the likes of Gemma if actual aliens arrived.

A few lads from Africa wouldn't look so bad then

cnocbui

Anyone worried about unfriendly aliens paying us a visit should read the chapter on interstellar travel in the book: Thy physics of Star Trek.

It's an absolute party pooper if you harbour any notions of intelligent species zipping across space and actually physically meeting.

The gist is that the energy required for interstellar travel is so vast, that it most likely can't be done.

But what about wormholes? It looks at those too and what it would take to create them. The energy required makes that needed for interstellar travel by conventional means look like a rounding error.

We are alone and likely to remain so for as long as we exist.

breezy1985

cnocbui wrote: »

Anyone worried about unfriendly aliens paying us a visit should read the chapter on interstellar travel in the book: Thy physics of Star Trek.

It's an absolute party pooper if you harbour any notions of intelligent species zipping across space and actually physically meeting.

The gist is that the energy required for interstellar travel is so vast, that it most likely can't be done.

But what about wormholes? It looks at those too and what it would take to create them. The energy required makes that needed for interstellar travel by conventional means look like a rounding error.

We are alone and likely to remain so for as long as we exist.

Ya but I want to believe

RandomViewer

Potential-Monke wrote: »

You can relax, most sci-fi alien films based in and around now were completely off the ball with how advanced we would be at this stage. We won't encounter aliens for another few hundred years at least imo.

And if they land tomorrow, I welcome our new alien overlords.

If an alien race didn't have a n ice age or the dark ages for that matter they could have quite a headstart

EmmetSpiceland

cnocbui wrote: »

Anyone worried about unfriendly aliens paying us a visit should read the chapter on interstellar travel in the book: Thy physics of Star Trek.

It's an absolute party pooper if you harbour any notions of intelligent species zipping across space and actually physically meeting.

The gist is that the energy required for interstellar travel is so vast, that it most likely can't be done.

But what about wormholes? It looks at those too and what it would take to create them. The energy required makes that needed for interstellar travel by conventional means look like a rounding error.

We are alone and likely to remain so for as long as we exist.

Don’t put that in the ‘UFO’ thread, you’ll be scoffed at. Honestly, scoffed at.

440Hertz

cnocbui wrote: »

Anyone worried about unfriendly aliens paying us a visit should read the chapter on interstellar travel in the book: Thy physics of Star Trek.

It's an absolute party pooper if you harbour any notions of intelligent species zipping across space and actually physically meeting.

The gist is that the energy required for interstellar travel is so vast, that it most likely can't be done.

But what about wormholes? It looks at those too and what it would take to create them. The energy required makes that needed for interstellar travel by conventional means look like a rounding error.

We are alone and likely to remain so for as long as we exist.

I suspect what we might find is primitive life in the solar system somewhere.

With regard to interstellar travel, its definitely beyond the scope of physics, at least as we understand it. The issue is that at those edges of our understanding, it’s extremely difficult to prove anything experimentally. I wouldn’t think it’s likely, but at the same time, I wouldn’t rule it out. There have been plenty of times when we have discovered our grasp of physics is incomplete and physics and science in general knows that. All we can do is observe, experiment, extrapolate and model based on what we know.

The Star Trek idea is simply fantasy and has more in common with one of the great stories of odyssey. It has more in common with the history of exploration of the earth and discovering ourselves rather than space exploration. Still a great story and presents a very optimistic view of humanity, but it’s a story and it’s about ourselves.

My question is if there are civilisations out there somewhere. At what point would they give up looking? It’s quite possible that things are just so far apart that they’ll never be more than a blinking light on a graph, looking at a signal transmitted millions of years ago (at the speed of light).

We might end up knowing there’s something out there but never being able to make contact, at least at anything beyond one utterly unintelligible message every few generations.

SVI40

All alien life form will look like humans. We learned a long time ago, that God created us in his image, and since he created the universe and everything, all aliens would look like us.

QED.

biko

cj maxx wrote: »

[/https://www.technologyreview.com/2018/06/22/142160/this-is-how-many-people-wed-have-to-send-to-proxima-centauri-to-make-sure-someone-actually/
I don’t know why it not coming up as a link

The answer is 49 breeding pairs.

breezy1985

EmmetSpiceland wrote: »

Don’t put that in the ‘UFO’ thread, you’ll be scoffed at. Honestly, scoffed at.

In fairness it's like going to the Catholic thread and pointing out all the holes in their beliefs

440Hertz

SVI40 wrote: »

All alien life form will look like humans. We learned a long time ago, that God created us in his image, and since he created the universe and everything, all aliens would look like us.

QED.

Humans have an almost pathological tendency towards self exceptionalism. We like to be special, or imagine that our group is special and that the gods are smiling on us as the sun goes around the Earth to keep us warm and cozy.

It’s uncomfortable to imagine that on the big scale of the universe of things all of this that we live our lives out in might as well be a microbe on a spec of dust.

breezy1985

Only one thing is for certain and that's if aliens do exist the very first thing humanity will do is make a Pornhub category for them

Peregrinus

Peregrinus wrote: »

If the term "dipstick" must be used, we should perhaps reserve it for those who so comprehensively misunderstand the SETI project.

The focus of the project is the reverse of what you suggest; not to radiate signals outwards into space but to monitor and analyse signals from space, to search for patterns that suggests design, structure, communication, etc rather than simply naturally occurring electromagnetic and other radiation. The aim is not to be detected by our own broadcasts, but rather to detect others through their broadcasts.

As for the dangers attendant upon being detected by our own broadcasts, that ship has pretty comprehensively sailed. Ship-to-shore and ship-to-ship radio telegraphy was developed in the 1890s century, and the first signals sent by this method are still travelling outwards through space, having now (obviously) reached a distance of about 125 light years from Earth. They were weak signals with limited structure and would be extremely difficult to detect, but the volume and structuring of signals being broadcast into space increased hugely with the advent of general radio broadcasting in the 1920s, and then television in the 1950s. For decades now we have been pumping prodigious quantities of structured electromagnetic signals travelling at the speed of light in - literally - all directions from Earth. These broadcasts are not made with the object of being detected, but they are eminently detectable all the same.

What is called "Active SETI" is the broadcasting of signals with the specific hope of their being detected and successfully analysed. It does happen, but it's a tiny, tiny part of the overal SETI project. The aim is to broadcast signals which are designed to be capable of being analysed from first principles in the hope we can thereby communicate information to other cultures, without knowing what we have in common with them. For the reason just given this doesn't materially increase the chances of our presence being detected, and indeed the most likely cultures to receive and analyse these signals are cultures which have already detected our presence from general broadcasting, and are therefore paying attention to this particular corner of space.

Is there a slide deck to go with this presentation ?

Many thanks very informative

440Hertz

Probably the most positive sign of life we've detected outside of earth so far has been the phosphine that appears to be present on Venus. That, we assume, can only be generated by biological activity. So, it's possible that there is some kind of living organisms on Venus.

It's most likely that they're not very complex, but it's definitely at least a first glimpse at what might be possible in a totally different and parallel evolution, if we ever get to see what it actually is. Venus is just a tad more difficult to explore:

Atmosphere: 93 times earth atmospheric pressure. Similar to being 900m under water here.
Carbon dioxide and nitrogen atmosphere a nice day time temperature of 467ºC and it rains sulphuric acid.

The assumption is that the life might be particles floating in the mid-levels of the atmosphere, rather than something surface based. Although, you'd never know. We've some extremophiles on earth that can survive in the oddest places like vents of underwater volcanoes and even in nuclear reactors! Where there's a source of energy, nutrients and so on, life can sometimes figure out ways of extracting it.

Smiles35

You need plants for life don't you? Everything needs oxygen. So atmospheric plants as well? Reading about Venus, light does not reach the surface.

breezy1985

Smiles35 wrote: »

You need plants for life don't you? Everything needs oxygen. So atmospheric plants as well? Reading about Venus, light does not reach the surface.

Thats assuming life cant evolve on other planets using something other than oxygen

cj maxx

Mad_maxx wrote: »

more like a few thousand years , would take thousands of years to reach the nearest star ,we,ve made very little progress re_ exploring the universe

I remember an analogy from years ago. If you imagined the sun was the size of a basketball, the nearest star would be at ny or somewhere. I’m after watching a YouTube video which say that travelling at the speed of voyager 1&2 it would take 80,000 years to reach alpha proxima or centuria , the closest star.

440Hertz

Smiles35 wrote: »

You need plants for life don't you? Everything needs oxygen. So atmospheric plants as well? Reading about Venus, light does not reach the surface.

*WE* need plants for our ecosystem, but we don't know what Venusian life might need.

Even on Earth, plenty of bacteria can survive without any need for plant produced oxygen. So, it's not universally required.

Smiles35

ThunderCat wrote: »

Nevermind radio signals and the likes that degrade rapidly, it's our atmosphere that would give us away. The light from our atmosphere can be split using a spectrograph or spectroscope to show the chemical makeup of the atmosphere. We have that technology now, nevermind an advanced alien civilization. What our atmosphere tells the cosmos is that we have naturally occurring greenhouse gases such as carbon dioxide and water vapor but we also have synthetic man made compounds such as CFC's and hydrofluorocarbons. That tells anyone looking all they need to know. There is nothing we can do about it and because that information is contained in the light reflecting off Earth, it can be seen from all directions from many many light years away, maybe much further depending on the level of alien technology involved.

And that is how we in turn will end up finding signs of intelligent life in the Cosmos. The James Webb Space Telescope, due to launch in the next few years, is designed to do exactly that and will be analyzing the atmospheres of exoplanets in our galaxy.

We are 4 to 7 light years away from our neighbours in our galaxy. People have done odds of life in the universe. What are they though when they come to the universe. It's just odds on top of odds. If we find somewhere industrialised within 150 light years we'll make the effort.

cj maxx

As someone mentioned , in all probability if we find alien life it most likely be primitive simple life forms like a bacterium or virus. And in our solar system, on a moon of a planet .
As for alien travel , people have came up with various way to source the energy needs .
Dyson spheres at the like . Or that alien life has outgrown the need for physical bodies / or never had bodies and are beings comprised of energy.
Merely thought experiments imo with no basis on what we know of the universe.
But we should keep looking for sides of life

Smiles35

Think the yanks are going back to the moon to put a mass driver on it.

A. It can be used for propelling small probes just for a closer look at oxigen confirmed worlds. (The bigger more complex creatures would be on those)
B. If we do get an interactive probe kicked over to us, they are going to want it back, pronto.

JasonStatham

We need to get away from Electromagnetism in the search for extraterrestrials. We have to think outside of the box - cos if an advanced civilization doesn't use electromagnetism for communication, how on earth would they pick us up. We should think how they would communicate - and start from there.

440Hertz

JasonStatham wrote: »

We need to get away from Electromagnetism in the search for extraterrestrials. We have to think outside of the box - cos if an advanced civilization doesn't use electromagnetism for communication, how on earth would they pick us up. We should think how they would communicate - and start from there.

All very well but we can’t yet communicate using say gravity or quantum entanglement. There are possibly many other ways of sending signals that we aren’t aware of yet and using radio waves or EM generally to carry messages is just our current state of the art. Steam trains were state of the art a 150 years ago. There was a time when breaking the sound barrier was considered dangerously impossible, yet for a few decades people were zipping across the Atlantic at Mach 2 and military aircraft do it all the time.

The edges of physics are always thought experiments. We know that and scientists don’t claim them to be hard facts until they can be proven experimentally or observed and measured. We haven’t really got to that stage with faster than light travel. It’s just the laws of physics given our current understanding of them that allows us to make calculations and model things.

We are doing things today that would seem like magic to a well educated person from two generations ago.

All we can do is keep looking and not thinking too dogmatically about anything. Always approach space and the edges of science with an open mind. That’s what’s so interesting about it!

1990sman

there was some buck on something one time talking about all the nuclear bomb tests sent out some funky nuke wave into space man. (they had more technical terms)
but it made sense.

440Hertz

The biggest signals sent into space were probably military over the horizon radar and missile tracking systems, particularly in 50s, 60s & 70s

A lot of those early systems relied on extremely powerful radio pulses which were bounced off the ionosphere. Others were projected into space to detect ballistic missiles outside the atmosphere.

So for years we were broadcasting very powerful clicks and pulses of microwaves and radio waves into space.

We also beam radio waves at satellites all the time and most of that energy radiates into space, the satellite only detects the signal. So that’s likely carrying way off into deep space.

Television and radio transmission probably didn’t get very far beyond the atmosphere and we’ve moved from early technologies that used very high power centralised transmitters, to networks of smaller transmitters, to mesh networks and increasing use of satellites and then replacement of radio technology for telecommunications links with fibre.

So we’ve gone from an era of being noisy back to relatively silent in someways, but very noisy in others (links to satellites). We also now produce a vast array or far more complicated signals beamed from billions of low powered sources like mobile phones and so on. That would very likely just sound like noise and chaos.

But if you were listening to RF, I would assume we are quite détectable within about 80 - 100 light years from the planet (as that’s probably as long as we’ve been shouting loudly)

I’ve often wondered if what we should be listening for is a signal we generated being repeated and sent back? That would be the most obvious way of responding to a signal you couldn’t interpret. I wonder does SETI even look for those eg old 50s radar frequencies etc

If someone were observing they would most likely notice that our atmosphere is full of gasses that are indicative of abundant life.

That’s also likely how we will detect life on exoplanets as space based telescopes become better and more powerful.