Oxford scientists say: Looks like no other intelligent life in whole universe (but keep looking)

[RJM Corbet]

Imo for the universe to exist at all, a lot of one-off circumstances had to occur and in conjunction with each other: the electron proton charge exactly matches and the gravitational force is exactly as it is, etc. Several other conditions too.

These circumstances did occur in conjunction and so the universe does exist. But because something happened once does not make it more likely to happen again -- much less make it inevitable -- unless we posit an infinite universe, in which case anything and everything not only does happen but happens an infinite number of times?

 

[CupofJoe]

I'm all for an infinite universe. The more the merrier.
I'll settle for infinite realities. There is so much that we don't know and even more doesn't fit what we do know. One explanation may be other realities that coincide with some dimensions of our own but not all of them.

 

[Guttersnipe]

Meanwhile, the Gwuds of the planet Seriquaan have come to the same conclusion.

 

[.matthew.]

I don't have issue with infinite universes (because I have no idea how matter came to exist in the first place).

That said, I don't agree with the idea that realities branch with decisions made etc. I know it's a popular concept, but the idea of an infinite universe being created trillions of times a second seems too far fetched

 

[Boneman]

Someone.... will find and post the Calvin and Hobbies cartoon where Calvin says:

"The surest sign that there's intelligent life in the Universe is that none of it has visited here "

(IIRC he was looking at trash piled up in woodlands, but I could be wrong )

 

[paranoid marvin]

Imo for the universe to exist at all, a lot of one-off circumstances had to occur and in conjunction with each other: the electron proton charge exactly matches and the gravitational force is exactly as it is, etc. Several other conditions too.

These circumstances did occur in conjunction and so the universe does exist. But because something happened once does not make it more likely to happen again -- much less make it inevitable -- unless we posit an infinite universe, in which case anything and everything not only does happen but happens an infinite number of times?

The thing is though that if something happens once it proves that it is not impossible; at best (or worst) it makes it highly improbable. It al comes down to how improbable. The more planets there are, the less improbable. The older the universe the less improbable. Given that there are trillions and trillions of planets out there, and that many have existed for billions and billions of years, the probability of life greatly improves.

Personally I prefer to look at the number of opportunities there are for something to happen rather than the science that says when and how it can happen.

 

[RJM Corbet]

The thing is though that if something happens once it proves that it is not impossible; at best (or worst) it makes it highly improbable. It al comes down to how improbable. The more planets there are, the less improbable. The older the universe the less improbable. Given that there are trillions and trillions of planets out there, and that many have existed for billions and billions of years, the probability of life greatly improves.

Personally I prefer to look at the number of opportunities there are for something to happen rather than the science that says when and how it can happen.

Sure. But the fact is the abiogenesis of life is not a foregone conclusion. Even where the perfect conditions exist for it to happen, it's still like winning the lottery -- with numbers far higher than that. However it did happen so obviously yes it can happen.

But the odds of someone winning a lottery twice are greatly higher than winning it once.

The great problem though is the jump from bacterial to eukaryotic cells. It is regarded as virtually impossible, if anything even more unlikely then the abiogenesis of life itself. So the jump from bacterial to intelligent life is a huge barrier.

Nick Lane"s 'The Vital Question' explains it carefully.

Again: it did happen, at least once. But neither abiogenesis nor the jump from bacterial to eukaryotic cells can just be assumed on the basis that the universe is very big. Imo

Of course, if it was put there, but ... that can quickly push beyond the limits of the forum

 

[Vertigo]

I'm in agreement with @RJM Corbet, there are just so many incredibly unlikely coincidences that have resulted ultimately with us. For example having a large enough moon to stabilise the tilt of the Earth's spin, its obliquity, which in turn stabilises potentially wild climatic fluctuations that would have made the evolution of complex life extremely unlikely. Earth's obliquity varies between around 22 and 24.5 degrees whereas for Mars "the maximum possible variation is from about 14.9 to 35.5 degrees. Significant climatic effects must be associated with the phenomenon." And there are so many more; volcanic activity, plate tectonics, Jupiter maybe shepherding asteroids, etc. etc. There will no doubt be many instances of many of these factors but how many times when they have all come together in perfect harmony?

Then for those that talk about the numbers, if you take our galaxy only a very small band is considered likely to be able to support complex life. Too close to the centre and the intense radiation would make mutation so chaotic that any sort of order evolving is extremely unlikely and too far out (as I understand it) there are too few heavier elements (down to what generation the stars are, I believe).

I think microbial life almost certainly exists elsewhere but chances of it making it past that stage is, I think, extremely small, and then to get beyond that to truly complex life (plants etc.) and then beyond that to animal life and finally to intelligent life (or maybe technological life might be a more meaningful description) is in my view vanishingly small. Taking just that last step for example, think how long Earth life was dominated by dinosaurs who showed no real signs of ever evolving technological intelligence, huge orders of magnitude greater than the evolution of humans. They just didn't need it they were already evolved to survive perfectly well without it. This to me says that there is no inevitable progress of complex life towards intelligence.

 

[K. Riehl]

I'll stick with my belief that there is life out there. Billions of years and trillions of planets make for unlikely outcomes to have a chance at reaching the level of self awareness.

I always throw out the possibility that the intelligent life in the universe is there and just using an as yet undiscovered method of communication. The future may not be in exploration but in developing an Ansible that unlocks the the key to the Encyclopedia Galactica. ( to quote Contact)

 

[Astro Pen]

It comes down to the likelihood of a first molecule of DNA cropping up. After that occurrence it is a free, if lengthy, ride to complex life and possible civilization.
I believe it was Onassis who said "Buying ships is easy, except for the first one."

 

[Vertigo]

It comes down to the likelihood of a first molecule of DNA cropping up. After that occurrence it is a free, if lengthy, ride to complex life and possible civilization.
I believe it was Onassis who said "Buying ships is easy, except for the first one."

DNA is just the program but you still need the computer before you can program it. So DNA is just one small cog in the machine. There are some fantastically complex molecules and processes going on in cells that make DNA look almost simple in comparison.

 

[Extollager]

There's a good story to be written based on the theme of what happens when society generally realizes that there are ineluctable limits to achievement and knowledge. SF tends to proceed on the basis of the idea, encouraged by our technological advances and astounding gains in knowledge, that (if nuclear war or, more recently, planetary overheating don't do us in first) the trajectory will continue till we have explored the whole galaxy and maybe more, have practical immortality, etc.; every seeming barrier, ever problem, can be overcome given time.

But in fact -- well, I start with this: for centuries there was, I gather, a tendency for the average person to get taller, century by century. The cliche is the tourist looking at the suit of armor and thinking how small the wearer was, etc. But we won't go on getting taller and taller, especially while living on earth. Again, the record for running the mile may be improved, but it will not keep on being improved forever; at some point there will be a record set for running the mile that, 50 years or more later, no one has beaten.

There's the assumption that human will live on other planets. But I wonder. Supposing civilization endures that long, say 300 years for now will humans have traveled to Mars, even? There's that matter of cosmic ray exposure. I have no objection to stories that wave that away, as a problem that will be solved; but what if it is insoluble? How will people adjust to the reality that we are not going to Mars, let alone to the stars (which has tremendous problems -- likely insoluble -- aside from cosmic ray exposure -- the oft-invoked suspended animation solution is, I suspect, a bigger problem than many people think).

And so on. I wonder what it will be like to live on earth if, 300 years from now, or even by the end of this century, it has become clear that most of the science fiction assumptions were never going to be realized.

When I discovered Geoff Ryman's concept of "mundane sf" I felt I had discovered a kindred spirit. But, again -- I'll go on enjoying stories with FTL travel, and gobs of Jack Vance colorful extraterrestrial civilizations and so on. Sure, why not? But for mental hygiene I think it's worthwhile also to bear in mind that none of it may ever happen, nothing like it. In fact the evidence tends the other way.

 

[RJM Corbet]

evidence tends the other way.

Yes. Science is often in the business of correcting common goose sense intuition. The atom is not a scaled down model of the solar system, etc. The biological organism is hugely complicated. Even a single cell is a mind-bogglingly astonishing symbiotic structure beyond all realistic coincidence. If regarded as a 'goal'.

Again: the fact is that it has originated once. Only once. All eukaryotic cells are descended from that one single original 'parent' cell.

So there can be no statistical probability drawn from a single occurrence. But of course that does not imply it will be a common occurrence, no matter how big the universe is?

 

[Justin Swanton]

DNA is just the program but you still need the computer before you can program it. So DNA is just one small cog in the machine. There are some fantastically complex molecules and processes going on in cells that make DNA look almost simple in comparison.

DNA is not actually the programme, it's the hard drive. The programme is the 4-base prescriptive language made of the nuceobases cytosine, guanine, adenine and thymine (our computer programming language has two bases). Without this 4-base programming language you don't have life. If you want an in-depth, scientific analysis of the statistical odds of such a programme arising spontaneously see here (spoiler: the odds would make the chances of life arising spontaneously on another planet utterly remote).

BTW we've had this discussion before, or maybe that was on the SFF World forum.

 

[Vertigo]

DNA is not actually the programme, it's the hard drive. The programme is the 4-base prescriptive language made of the nuceobases cytosine, guanine, adenine and thymine (our computer programming language has two bases). Without this 4-base programming language you don't have life. If you want an in-depth, scientific analysis of the statistical odds of such a programme arising spontaneously see here.

BTW we've had this discussion before, or maybe that was on the SFF World forum.

Yes, fair enough, that's probably a better analogy! But I'd still hold to the fact that I found some of the chemical processes at work in cells even more mind blowing than DNA the mechanisms for energy transfer are truly awesome. But I couldn't name them without going off and looking them up.

 

[Justin Swanton]

Yes, fair enough, that's probably a better analogy! But I'd still hold to the fact that I found some of the chemical processes at work in cells even more mind blowing than DNA the mechanisms for energy transfer are truly awesome. But I couldn't name them without going off and looking them up.

Sure, but keep in mind that that complexity - all of it - is contained in the ATGC prescriptive language in DNA. Everything is mapped out in advance in a series of instructions that are phenomenally dense, i.e. there is much, much more information in a gigabyte of DNA than an equivalent gigabyte on a PC hard drive. DNA uses complex palindromes: start in different places on the same segment of DNA and you get instructions for different and completely functional protein molecules. A bit like taking a long sentence, starting and ending in different places, and getting perfectly meaningful and completely different subsentences. We haven't begun to understand how it's done, but geneticists are looking at 'junk DNA' that isn't as useless as originally thought, but seems to contain sequential instructions for how and when sections of DNA are copied for transfer to the protein factories in a cell.

 

[Extollager]

So there can be no statistical probability drawn from a single occurrence.

I never thought of it that way (rolls eyes).

 

[Extollager]

There's a good story to be written based on the theme of what happens when society generally realizes that there are ineluctable limits to achievement and knowledge.

Has anyone written that story, or something akin to it?

Another example of limits that's occurred to me is: suppose that we do, after all, detect signals that can only be from an extraterrestrial civilization. (I don't expect that to happen, but let's suppose it does.) These must be imagined as having arrived here after an enormous lapse of time. How would society deal with it (which means various people deal with it) if it were obvious that we will never be able to decode them? We must assume that the signals are meaningful, but they will never be meaningful to us? SF people are (I think) apt to be naive about the difficulties of "translation" in the absence of a Rosetta Stone, etc. And here you would have to factor in the time element. I also have doubts about our ability to pinpoint the source, i.e. to say, "The signals are coming from a planet orbiting such and such a particular star," etc. So we have signals about whose source we cannot attain definite knowledge and whose meaning must elude us. Whew!

 

[Justin Swanton]

Has anyone written that story, or something akin to it?

Another example of limits that's occurred to me is: suppose that we do, after all, detect signals that can only be from an extraterrestrial civilization. (I don't expect that to happen, but let's suppose it does.) These must be imagined as having arrived here after an enormous lapse of time. How would society deal with it (which means various people deal with it) if it were obvious that we will never be able to decode them? We must assume that the signals are meaningful, but they will never be meaningful to us? SF people are (I think) apt to be naive about the difficulties of "translation" in the absence of a Rosetta Stone, etc. And here you would have to factor in the time element. I also have doubts about our ability to pinpoint the source, i.e. to say, "The signals are coming from a planet orbiting such and such a particular star," etc. So we have signals about whose source we cannot attain definite knowledge and whose meaning must elude us. Whew!

There's one problem with this. A signal that is strong enough to travel for thousands of light years without dissipating and getting lost against background cosmic radiation would require a phenomenally powerful transmitter, itself requiring an enormous energy source. There's no getting around it: any kind of broadcast will use some form of radiation, and radiation naturally spreads out and dissipates over a long distance. We can barely see, using powerful telescopes, the light from the more distant stars in our galaxy. But figure how massively powerful a transmitter of light a star is. How does a planetary civilisation manage - or even bother trying - to emit a comparable signal?

Edit: one presumes the alien civilisation would not transmit a focussed beam at one planetary system in particular, since they, like us, would not know in advance which planetary systems are inhabited. That means transmitting an omnidirectional signal which would require staggering amounts of power.

 

[Vertigo]

There's one problem with this. A signal that is strong enough to travel for thousands of light years without dissipating and getting lost against background cosmic radiation would require a phenomenally powerful transmitter, itself requiring an enormous energy source. There's no getting around it: any kind of broadcast will use some form of radiation, and radiation naturally spreads out and dissipates over a long distance. We can barely see, using powerful telescopes, the light from the more distant stars in our galaxy. But figure how massively powerful a transmitter of light a star is. How does a planetary civilisation manage - or even bother trying - to emit a comparable signal?

Edit: one presumes the alien civilisation would not transmit a focussed beam at one planetary system in particular, since they, like us, would not know in advance which planetary systems are inhabited. That means transmitting an omnidirectional signal which would require staggering amounts of power.

This has always been my argument against the picking up of alien signals. Our normal TV and radio signals would, so I understand, be almost undetectable beyond a few light days out certainly beyond light months out, unless as you say they were highly focused signals and how would anyone know where to focus them?