Recently NASA announced that they'd 'discovered' water on (or rather under, way, way under) Mars. There followed the usual hoopla about life on other planets, we're not alone etc.

Less attention was paid to a recent paper which, using the old Drake equation, came to the conclusion that its very likely that we are alone in the Milky Way galaxy and (with slightly less certainty) probably alone in the observable universe.

The paper is called "Dissolving the Fermi Paradox" and can be found here...http://arxiv.org/pdf/1806.02404.pdf

The Fermi Paradox is the conundrum as to why we haven't seen any evidence of other advanced civilisations when, at least in the past, the Drake equation suggested that there ought to be 1000's out there.

Indeed when SETI was first established, its main proponents were pretty certain they'd find such evidence within a decade. Now, 50years down the track, they still haven't found a skerrick of data to suggest anything other than we are alone in the universe are the only species to have reach our leave of advancement. (queue all those who will show how 'woke' they are by denying we are advanced).

The new paper took the approach of allocating ranges of probability to each element in the equation based on the latest research. For example, over the past decade, biologists have increasingly opined that the origin of eukaryotic cells was vastly more unlikely than previously thought and that indeed it may have happened only once in the 4 billion year history of earth.

A few more links to go on with...
http://www.theguardian.com/commentisfree/2018/jun/27/aliens-exist-survival-universe-jim-alkhalili

I've always been a fan of the Great Filter idea...

http://mason.gmu.edu/~rhanson/greatfilter.html

Hi there MHAZE...

I had a quick look at the first reference you kindly gave us (the Fermi Paradox) a mathematical equation of determining whether we are alone, or otherwise, in our universe? A thoroughly interesting document if you can understand it, of course?

On a personal level, 'Space' if I may call it that, or 'Deep Space' to be more precise, far beyond what we here on earth, can see or imagine. On the balance of probability, should have some form of 'existence' or 'life' on them, considering the immensity of deep space, which were are told, goes on indefinitely?

Obviously I don't have the brains or imagination to grapple with such unknown quantities, or mathematical equations - being very much a pragmatists, I find it enormously difficult to embrace a topic such as this, without making a fool of myself. A very very interesting topic nevertheless, and I thank you for it.

The universe is very big:

http://en.wikipedia.org/wiki/Universe#Size_and_regions

I suspect that they probably are out there somewhere... I am less convinced of the likelihood us of ever finding them (or them finding us).

yep to ignore what we can see and know and spend billions on fantasy is the way of the god deniers.

Now I am getting really upset.

How can you people possibly suggest that Star Trek & Star Wars are not true!

//How can you people possibly suggest that Star Trek & Star Wars are not true!//

They are part of the science fiction genre. The clue is kind of in the name.

Why should we think that we're the only life form in
the universe? I believe that we could be surrounded
by other life forms - though not necessarily in the shape and
form that we may imagine.

A few thoughts ...

As we know there are few citizens of modern societies
who would utterly deny the possibility of some higher power
in the universe, some supernatural, transcendental realm
that lies beyond the boundaries of ordinary experience,
and in this fundamental sense religion is probably here to stay.
Then why can't we believe that there is also the possibility
of different life-forms being "out there?" Simply because we
haven't discovered them yet? Perhaps we're not evolved enough?

Dear mhaze,

Thanks for the link.

The fact is that the physics within our universe has been able to produce at least one intelligence capable of interstellar awareness, namely us.

Tell me if I am wrong but the Drake equation would indicate a greater chance of a solar system containing life than that life ever evolving to the point that they were capable of making others outside their systems aware of their existence.

Our own radio telescopes are only capable of detecting the signals we have been pumping into space for a hundred years at a distance of a single light year.

Given that intergalactic communication is certainly one of the great filters it would be interesting to know what likelihood that any of the 1000 civilisations in our galaxy predicted by Drake would be able to transmit an indication of said intelligence to any other capable of receiving it.

I would expect those odds would be extremely low but that would not be a reason to dismiss them even existing which is what the paper seems to attempt.

Give some thought to a question if they knew they are out there would our governments tell us? my answer is no reason, it is more than unlikely if they had a God it would be one of ours, the social impacts would be huge

How can you people possibly suggest that Star Trek & Star Wars are not true!"

Ask Sarah Sea Patrol!

Dear Shadow,

“The Australian Federal Police has referred its investigation into the media leaks from jobs minister Michaelia Cash's office about the raids on the Australian Workers' Union to the Commonwealth Director of Public Prosecutions, to determine whether charges should be laid.”
http://www.buzzfeed.com/aliceworkman/the-afp-has-referred-its-investigation-into-michaelia-cashs?utm_term=.ckNZz7WJzD#.yoxL4vr247

This will be interesting.

Ouch, sorry, wrong thread.

Eukaryotic cells are ones with nuclei and other organelles such as mitochrondria (Flora and Fauna)- prokaryotic ones without (like bacteria). So Mhaze is quoting is it is very unlikely for prokaryotic cells to evolve into Eukaryotic cells so it takes an extremely long time. Interesting. I think we have to wait for some more studies to confirm this hypothesis.

To Mhaze- Pretty robust journal article though.

Oh, BTW, those links got the Drake equation wrong. Here's the correct version:

http://xkcd.com/384/

Although I think an equation that is probably a bit more useful is the Flake equation:

http://xkcd.com/718/

Space is quite big. Time is quite long. On the one hand, it's possible that there are countless universes alongside, above and below, our own, which is big enough. On the other hand, it's possible that there have been countless Big Bangs even just in our own universe, with its bits and pieces being blasted out and then sucked back in again, over, say, thirty billion years, countless times.

So, it's possible that, somewhere out there, there is the odd planet with some form of life on it. But the chances of comparable life, life with which we can communicate on a roughly even level, that isn't, say, a billion years in advance of us, or a billion years behind, is probably a bit remote. Only a hundred years in advance or behind us, even more remoter.

Meanwhile, back in the real world, we have enough resources to feed everybody, if it were shared around. There are regions on this planet which are barely developed, given with our latest technology, if people could get hold of it. So as world population growth slows down, perhaps to ZPG by 2100, and as efficient productive technology becomes cheaper for developing countries across the world, the need to go to some other planet will diminish (like, say, growing tomatoes at the South Pole: possible but a bit expensive), along with the realisation that we are effectively alone in the multi-verse.

There's work to do on our own planet without getting too worked up about others. If they're there, and their inhabitants want to contact us for some reason, they will, in due course. If not, then no.

Joe

I find this whole topic fascinating. Especially the size of 'Space'. Many more smarter than I, understand this Big Bang; what exactly exploded? A massive planet, leaving bits of itself floating about, in what's now known as our universe? With the various constituent planets like Mars, Earth, Venus, etc. part of that huge planet that exploded causing the Big Bang?

If we were to fire a missile into space, and it never hit or collided with anything, where would it end up? If it strikes the edge of what we now know, through the immense reach of our Radio telescopes, what's the other side of it? Admittedly, almost childlike questions I agree, but are there any answers?

Canem Malum,

Re Eukaryotic cells. I first came across this when watching a talk by Brian Cox in which he finally came down on the side of us being alone in the observable universe. He mentioned that the current theory is that Eukaryotic cells have evolved only once. That is all flora/fauna have evolved from one cell that broke the code of evolving from a bacteria. I then researched it and it seems to be the prevailing view these days and the research is more around why only once. There's actually a lot out there about it...

http://www.newscientist.com/article/dn18734-why-complex-life-probably-evolved-only-once/

http://news.nationalgeographic.com/news/2010/05/100513-science-evolution-darwin-single-ancestor/

http://rstb.royalsocietypublishing.org/content/royptb/368/1622/20120266.full.pdf

That's a mere sample.

The ramifications of that are enormous. Endosymbiosis is the theory that "one Prokaryotic cell such as bacteria engulfing another Prokaryotic cell and that cell escapes digestion and therefore lives inside the cell. Now this creates a symbiotic relationship where the engulfed cell provides energy and nutrients and in return the engulfed cell receives protection." (Waggoner, 2001). So in the untold centillions of interactions where one Prokaryotic absorbed another only one ever resulted in a Eukaryotic cell.

So even if Prokaryotic style life emerged on some other planet, the chances of it advancing beyond that stage is minute.

And that's before we even begin to consider why and how single celled Eukaryotic life evolved into multi-cellular life.

" I think we have to wait for some more studies to confirm this hypothesis."

True. But at this point it seems to be, as best I can tell as a mere interested observer, that the theory is widely accepted.

So if you marry the utter unlikeliness of Eukaryotic life with theories like the Great Filter and the Drake equation, you end up, as these authors have shown, with a high likelihood that we are alone.

o sung wu,

" considering the immensity of deep space, which were are told, goes on indefinitely?"

Please note that these authors are only talking about the observable universe. They've come up with two numbers:

1. The chances of life in our galaxy - the Milky Way. That is life within 100,000 light years.

2. The chances of life within the observed universe. They make no claims about what might or might not exist in places we can't see and aren't even sure actually exist.

So, its possible to suppose that some civilisation exists in some far off (over 14 billion light years away) galaxy. But since we can't see such a place and don't know it exists, its futile to speculate about it.

______________________________________________________________

SteeleRedux,

If the chances of another civilisation existing in the Milky Way are low, the chances of such a civilisation being at a similar leave of development as us, are less likely still by orders of magnitude. Imagine where we'll be in 2000 years or 200000 years - a mere blink in time on a cosmological scale.

Current thinking is that, within the next 2000 years (and probably earlier), given how far we've come so far*, we'll be able to head off to colonise the galaxy. Guesstimates are that those endeavours will result in every habitable part of the galaxy being occupied within 250000 years.

So if a civilisation had evolved say 1 million years prior to us, that civilisation would have already reached the point where it could have and probably would have, been here.

Now I know there are all sorts of assumptions that they might be hiding or might not be interested in us or in expanding beyond their little patch. But, if the earlier Drake numbers are even close to true, that there are up to 1000 civilisations in our galay alone, then surely at least one of them would have evolved like us to expand out and colonise. But we can be pretty damn sure they haven't.

The galaxy is ours for the taking. And we'll probably take it.

/cont

/cont

* my grandfather (born 1899) could remember his mother reading him a story about how these two Americans had been able to fly a plane for a couple of hundred yards. He was still alive when Armstrong walked on the moon. Such strides in one lifetime. Imagine the strides that could be made in the next 50 lifetimes.

Umm, why are we assuming that alien life will have the same biochemistry as life on earth? Unless the panspermia hypothesis is correct, that doesn't seem like a terribly sound assumption.

Loudmouth said- "Meanwhile, back in the real world, we have enough resources to feed everybody, if it were shared around. There are regions on this planet which are barely developed, given with our latest technology, if people could get hold of it. So as world population growth slows down, perhaps to ZPG by 2100, and as efficient productive technology becomes cheaper for developing countries across the world, the need to go to some other planet will diminish (like, say, growing tomatoes at the South Pole: possible but a bit expensive), along with the realisation that we are effectively alone in the multi-verse."

Answer- I think the UN says that Zero Population Growth won't occur till 2200 (not 2100) topping out at something like 11-12 Billion- but there is a range of possible outcomes- anything could happen before then- just look at the changes in the last 150 years. But it's always about power- a Confucius scholar said that the institutions of the community are critical for its stability- ie. if the institutions are irrational then the world will become irrational. There needs to be a way of encouraging countries to engage in sane policy- the UN was supposed to do this- but being malformed- won't achieve it.

Dear mhaze,

I hardly think our carbon based forms will be exploring the galaxy but our silicone imprints quite possibly.

In my opinion it is this technology which will allow our sentience to shoot for the stars;
http://www.sciencealert.com/scientists-put-worm-brain-in-lego-robot-openworm-connectome

Just imagine your entire neural network being transferred to a chip with sensors replicating your senses. Far more robust for the huge acceleration/deceleration forces involved in efficient space travel.

It is far better than trying to shift huge amounts of food and water vital in keeping a human alive. In many ways our bodies are just vehicles for our minds. There may come a time when the type of vehicle matters little.

However we should be clear that intelligence and interstellar awareness are not the same. Imagine intelligent life forms on a planet with constant high level clouds blocking out the heavens, or even a water world. How much of human advancement has been determined by the ability to view the night sky?

So when we ask are we alone are we are generally talking about intelligent life forms. What is your assessment of the likelihood of life on other planets?

Toni Lavis said- "Umm, why are we assuming that alien life will have the same biochemistry as life on earth? Unless the panspermia hypothesis is correct, that doesn't seem like a terribly sound assumption."

Answer- With respect- perhaps the issue isn't about biochemistry but more about the complexity of the coding. How would the DNA/ coding be constructed through random natural selection for "a cell created inside another cell". Once this occurred it could be possible to modify the code for outer cell to create specialist cell walls and other structures specific to different functions such as nerve cells, epithelial cells, etc- required for higher animals. There would be presumably a path from the first single celled eukaryotic cells to more advanced structures to flora and fauna. There is talk of Gonium Pectorale a 16 cell algae (eukaryot) one of the first multicellular organisms. Eukaryotic cells appear to allow greater specialization in the outer cell- one of its functions could be as an interface between the nucleus and the outside environment.

//So, its possible to suppose that some civilisation exists in some far off (over 14 billion light years away) galaxy.//

Sorry, missed this before. Parsecs, not light years. Units matter.

http://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure

//perhaps the issue isn't about biochemistry but more about the complexity of the coding. How would the DNA...//

Carbon chauvinist.

The chances are that we would have been far more advanced and probably exploring space right now if we worked together as a species and not been held back for centuries by mindless dogma and superstition held over from the Bronze Age.

Technological advances are accelerated by wartime demands and find wider applications in times of relative peace which provides little hope for meaningful progress unless there's a dollar to be made from it.

The fact that there are people who still today believe the earth is flat and that the moon landings were faked also suggests that there will not be much significant progress for quite a while yet.

Until we churn over he last of our natural resources and convert them into landfill, there's no demand to do anything else.

Very interesting, i can say

SR,

"Imagine intelligent life forms on a planet with constant high level clouds blocking out the heavens, or even a water world"

Well let's hope they never find out about what's beyond those clouds...

"They flew out of the cloud.

They saw the staggering jewels of the night in their infinite dust and their minds sang with fear.

"It'll have to go," the men of Krikkit said as they headed back for home.

On the way back home they sang a number of tuneful and reflective songs on the subjects of peace, justice, morality, culture, sport, family life, and the obliteration of all other life forms."

http://sites.google.com/site/h2g2theguide/Index/k/krikkit

Dear mhaze,

Or that waterborne creatures are not planet bound. So long and thanks for all the fish.

"why are we assuming that alien life will have the same biochemistry as life on earth"

There are some assumptions made in this issue, but the biology of the purported aliens isn't one of them. The issue is whether there are other intelligent beings but the nature of the being is subordinate to the intelligence.

But we are assuming some things about the being. First and foremost is that, if there was such a civilisation, that it would be curious about the universe and would be expansionary.

What we know from our own experience is that we have advanced to our present state due to our curiosity, desire to learn, and ability to conceive and then implement a better existence. We also know that those civilisations which have previously existed on earth but became insular and incurious about the outside world, collapsed. Civilisation can't stand still...it advances or declines.

So if a civilisation did get to our level, its unlikely that it would just decide that enough was enough and that it should just sit back for the next 200 million years and enjoy itself. At the very least some individuals would seek new understandings and new opportunities and thus strike out in search of the other.

So the main and possibly most problematic assumption is that an advanced civilisation would have the same type of desire to create and learn and explore as we have. Since we don't see such a thing, we can assume it doesn't exist.

_______________________________________________________________

SR,

"What is your assessment of the likelihood of life on other planets?"

Likelihood of life somewhere is high.
But each stage after that becomes less likely.

The chances of finding some form that has evolved to the increasingly complex forms grows increasingly small. So the chances of life are high, the chances of multi-celled life less so etc. Finally, the chances of getting to something equivalent to a primate is vanishingly small. And I've have been for a long while of the view that nothing exists in our galaxy that has reached the level of the human brain.

Dear mhaze,

Come on mate that is just the skeptic in you protecting you from disappointment.

I'm sure there must have been a little excitement when Oumuamua was first spotted. Echoes of Rama. 10 times longer than its width.

http://www.theguardian.com/science/2018/jun/27/scientists-solve-mystery-of-interstellar-object-oumuamua

There are still a heap of questions unanswered about this object (especially its unexplained acceleration) much less about the rest of the galaxy.

//perhaps the issue isn't about biochemistry but more about the complexity of the coding. How would the DNA...//

Carbon chauvinist.
Posted by Toni Lavis

Answer-
That was the point that it was the information that is encoded in carbon is important not the carbon itself. Yes this information could be encoded in silicon. It doesn't even have to be quarternary it could be binary. Are you chauvinist against carbon- perhaps even worse-a revisionist. And how would you prove a silicon based lifeform is alive?

"Any sufficiently advanced act of benevolence is indistinguishable from malevolence- From Clarke's Third Law"