Is there life in the universe, and if so has it visited Earth?

[DaveC426913]

the basic scientific principle that anything is possible until proven not

Sorry but this is not a scientific principle.


In fact, the most pertintent scientific principle might be Occam's razor: which model fits the facts with the least exceptions. Since there are zero facts indicating ET life, the implication would be that it's not out there until more compelling evidence shows otherwise.


Also, evolution has absolutely nothing to say about the creation of life on another planet. Evolution only acts on existing life. Evolution and creation are apples and oranges.

 

[D H]

Given the vastness of space I cannot rule out the existence of life on another planet.

We aren't talking about life here. We're talking about intelligent life. I would argue that even if primitive life is somewhat abundant, complex life will be rare and intelligent life, extremely rare. If the closest extant intelligent life is in some nearby galaxy or even more remote than that it doesn't really matter if that life exists. We are essentially alone.

If one believes in Evolution then one must believe in the basic scientific principle that anything is possible until proven not and no one has categorically proven life does not exist elsewhere in the Universe.

The first step is a non sequitur, the second clause is a falsehood, and the third clause is a red herring.

 

[baywax]

Yes, I think its a case of "if you say its out there you have to prove what you say" and not "I think its out there now prove me wrong". This is because when you make a statement as monumental as " there is life on 51 Pegasi" you don't just leave it up to someone else to prove it or to prove you wrong... you prove it for yourself and others.

So, get to work!

 

[D H]

Yes, I think its a case of "if you say its out there you have to prove what you say" and not "I think its out there now prove me wrong".

The first statement is a basic scientific principle. The second statement, which is essentially the same as engineroom's "the basic scientific principle that anything is possible until proven not" is the basic principle upon which crackpots operate.

Science underlying operating principles are similar to those of law. In both law and in science the burden of proof lies with the claimant. In both law and in science, placing the burden of proof on the claimant keeps claimants honest and helps reduce the number of frivolous claims.

 

[towerdp]

We aren't talking about life here. We're talking about intelligent life. I would argue that even if primitive life is somewhat abundant, complex life will be rare and intelligent life, extremely rare. If the closest extant intelligent life is in some nearby galaxy or even more remote than that it doesn't really matter if that life exists. We are essentially alone.


The first step is a non sequitur, the second clause is a falsehood, and the third clause is a red herring.

I would disagree with the fact that it would be rare to find "intelligent life" it struck twice on our planet. Us as humans have the ability to adapt and make somewhat sense of what's going on around us, and dolpins our other intelligent life form on Earth doesn't have the structure we do, but there brains are indeed intelligent. Like us they can be asked to create a new trick/movement that they have not been trained to do.

 

[Ivan Seeking]

2) Evolution: If one believes in Evolution then one must believe in the basic scientific principle that anything is possible until proven not

As stated already, you are way out of bounds with that one.

 

[D H]

I would disagree with the fact that it would be rare to find "intelligent life" it struck twice on our planet.

Dolphins, chimpanzees, and crows are all very smart, but do they qualify as "intelligent life"? It depends on your definition of "intelligent life". Do dolphin, chimpanzee, or crow have anything approaching the ability to receive signals from or send signals to other stars? Are there dolphin, chimpanzee, or crow cities? towns?? hamlets? Humans have been "intelligent life" for 5,000 years or so if intelligence is couched in terms of the demonstrated ability to form a civilization, and for less than 100 years if intelligence is couched in terms of the ability to receive signals from or send signals to other stars.

Dolphins and crows in fact exemplify the rarity of intelligent life. While they are very intelligent animals, their evolution has pushed them down a path that precludes the ability to advance beyond that stage.

The pre-conditions for life have to be right. Most star systems are inimical to life: they are too close to the galactic core, binary stars, or have hot jupiters. Of those that remain, an earth-like planet must form that escapes the run-away global warming of Venus thanks to a freak collision with a Mars-sized object and escapes the run-away cooling of Mars thanks to being a bit larger than Mars. Of those that remain, primitive life has to form and live through disasters such as the Late Bombardment. Of those that survive this, complex monocellular life has to form and escape its own pollution (Snowball Earth). Of those that survive this, multicellular life has to arise. Then pre-intelligence (dolphins, crows, hominids) has to arise. Then intelligence has to arise -- and not kill itself off. Intelligent life is, IMHO, exceptionally rare.

 

[vivesdn]

National Geographic november issue features some photos of The Cave of Crystals. On it, sveral crystals of selenite have grown up to 10m long and upt to two meters thick.
Conditions required: a cave in limestone, below water level, kept warm (112ºF) by an underlying magma chamber, undisturbed for hundreds of thousands of years.

Undisturbed: no water movement, no pH changes, no temperature changes, ..
And of course, water saturated on calcium sulphate. For 600000 years.

What would have been the probability of bus size crystals forming naturally?

Life on universe? That's easy? Intelligent? A matter of time.
Visited earth? This one is slightly more difficult.
Proofs? Not available (yet?).

 

[CEL]

...
What would have been the probability of bus size crystals forming naturally?
...

The probability of an event that has occurred is 1.

 

[Hanfonius]

I keep finding the words, 'The basic scientific principle that everything is possible until proven not.', and I cannot help but consider it accurate.

While it is misused in the sense of, 'I believe in UFO's - you prove me wrong.', how can it conceivably be wrong when used in the sense of, 'therefore, I shall attempt to prove it right, then present it to my peers for validation.'?

The von Daniken approach illustrates the former, and perhaps Gallileo the second.

The scientific mind must necessarily examine the unorthodox views of the day. Isn't that what most of us are doing right now in this section of the site?

 

[D H]

I keep finding the words, 'The basic scientific principle that everything is possible until proven not.', and I cannot help but consider it accurate.

Pearl S. Buck was not a scientist. You can find some very pithy statements about the impossible by politicians, philanthropists, writers, and scientists. You can even find mathematicians who recommend thinking of six impossible things before breakfast. You will not find something stating that "everything is possible until proven not" is a basic scientific principle.

 

[Hanfonius]

Pearl S. Buck was not a scientist. You can find some very pithy statements about the impossible by politicians, philanthropists, writers, and scientists. You can even find mathematicians who recommend thinking of six impossible things before breakfast. You will not find something stating that "everything is possible until proven not" is a basic scientific principle.

I had never heard of Pearl Buck - I guess this shows a local of formal education!

OK, so the offending words here are 'basic scientific principle'. If semantics can be bent slightly, and another phrase inserted to substitute three words, do you consider my assertions to be valid? Perhaps 'The enquiring mind will consider everything possible until proven not.'?

 

[vivesdn]

what would have been, not what is.
If 10 years ago (the cave was discovered on 2000) one crazy scientist would have said that 10m crystals were possible, I'm sure you would not assumed a probability of 1.

By the way, if the probability of an event is not zero, you cannot say that it was one just because it happenned.
I mean that the probability to get one specific side of a coin is 1/2. And when you got one of the possibilities, that event had still 1/2 of having occurred.

 

[CEL]

what would have been, not what is.
If 10 years ago (the cave was discovered on 2000) one crazy scientist would have said that 10m crystals were possible, I'm sure you would not assumed a probability of 1.

By the way, if the probability of an event is not zero, you cannot say that it was one just because it happenned.
I mean that the probability to get one specific side of a coin is 1/2. And when you got one of the possibilities, that event had still 1/2 of having occurred.

Wrong! The a priori probability of getting a tail when tossing a coin is 1/2. If you toss a coin and get a tail,the a posteriori probability of getting a tail in that trial is 1. It does not change the a priori probability for the next toss, that is still 1/2.
The probability of finding 10 m crystals in any cave on Earth is 1, since those crystals have been found. The probability of finding similar crystals in another place is nonzero. I cannot calculate what it is, since I am not a mineralogist.
The probability of life existing in the Universe is 1, since we know that life exists on Earth. The probability of life existing elsewhere is nonzero. Even not being an exobiologist, I would say that it is somewhat high.

 

[gareth]

Wrong! The a priori probability of getting a tail when tossing a coin is 1/2. If you toss a coin and get a tail,the a posteriori probability of getting a tail in that trial is 1. It does not change the a priori probability for the next toss, that is still 1/2.
The probability of finding 10 m crystals in any cave on Earth is 1, since those crystals have been found. The probability of finding similar crystals in another place is nonzero. I cannot calculate what it is, since I am not a mineralogist.
The probability of life existing in the Universe is 1, since we know that life exists on Earth. The probability of life existing elsewhere is nonzero. Even not being an exobiologist, I would say that it is somewhat high.

According to the findings of quantum physics, is there not a non-zero probability that everything will occur? It's just a matter of time, whether we're still around to witness the event or not is a different matter.

This has got me to thinking though, someone mentioned something a few posts back about imagining something that is not possible.

I find this hard. Our thinking and perception of things is built from our daily experiments (life), so this is all we can imagine. We live in a 4D world, how can we imagine something that is not possible if we have no experience of it. It's like trying to imagine living in a 10dimensional universe, you simply can't.

So how can we imagine something that is not possible? The thing must be built from our prior building blocks of knowledge (time, space, matter) anything we imagine will just be a certain arrangement of these elements which has a nonzero probabilty of happening.

So not only is everything possible, but things are possible that we can't even possibly comprehend.

 

[DaveC426913]

Dolphins, chimpanzees, and crows are all very smart, but do they qualify as "intelligent life"?

Dolphins and chimps are mammals, just like humans. I would categorize intelligence as a trait of the mammalian order. I would count that as a single instance of the rise of intelligence.

Birds, OTOH, are a second instance.

 

[DaveC426913]

I keep finding the words, 'The basic scientific principle that everything is possible until proven not.', and I cannot help but consider it accurate.

It is certainly commonplace these days, what with 'Power of Attraction' and other such woo-wooism rampant these days.

But it has nothing to do with science.

 

[Hanfonius]

I find this hard. Our thinking and perception of things is built from our daily experiments (life), so this is all we can imagine. We live in a 4D world, how can we imagine something that is not possible if we have no experience of it. It's like trying to imagine living in a 10dimensional universe, you simply can't.

So how can we imagine something that is not possible? The thing must be built from our prior building blocks of knowledge (time, space, matter) anything we imagine will just be a certain arrangement of these elements which has a nonzero probabilty of happening.

So not only is everything possible, but things are possible that we can't even possibly comprehend.

This is so thought provoking. Our building blocks of knowledge are growing rapidly each generation, and this must serve to increase our scope of imagination. This is where the science fiction writers dwell - but much of what they imagined has become reality. Perhaps just around the corner, we will discover anti-gravity, matter transfer, warp drive, free and clean energy, even perpetual motion.

Many of the young people entering into the sciences today will be fortunate enough to work within fields way beyond what we think of as impossible dreams.

 

[Ivan Seeking]

We have to be careful when we consider possibilities, as opposed to known violations of the conservation laws, causality, etc. For example, there is no reason to believe that a perpetual motion machine would ever work because we have well tested theories that tell us why they don't. But, might it be possible that some unknown effect or phenomenon could appear to be perpetual motion? Could something fool us for a time before we began to understand it? I don't see how this can be ruled out. But, we would still expect that energy is conserved over the entire system.

Unlike a perpetual motion machine, the existence of which would violate the known laws of physics, the WARP drive foks are trying to exploit known physics to discover loopholes, if you will, that might allow us to work around limits that were only assumed to be absolute. And while other complexities may arise that makes the idea WARP drive implausible or impossible, the idea itself is not one that assumes a magical solution from the netherworld, as does the notion of a perpetual motion machine.

 

[gareth]

We have to be careful when we consider possibilities, as opposed to known violations of the conservation laws, causality, etc. For example, there is no reason to believe that a perpetual motion machine would ever work because we have well tested theories that tell us why they don't. But, might it be possible that some unknown effect or phenomenon could appear to be perpetual motion? Could something fool us for a time before we began to understand it? I don't see how this can be ruled out. But, we would still expect that energy is conserved over the entire system.

Unlike a perpetual motion machine, the existence of which would violate the known laws of physics, the WARP drive foks are trying to exploit known physics to discover loopholes, if you will, that might allow us to work around limits that were only assumed to be absolute. And while other complexities may arise that makes the idea WARP drive implausible or impossible, the idea itself is not one that assumes a magical solution from the netherworld, as does the notion of a perpetual motion machine.

Yes, the conservation laws etc. are our (current) reality. Can we imagine a perpetual motion machine? (the one Lisa makes on the Simpsons usually springs to mind)

What I'm really asking is can we imagine breaking one of our conservation laws? A machine that spins faster and faster? Easy to imagine, but the science behind it is currently unimaginable. That's why we still fill our cars with dead fish.

 

[CEL]

According to the findings of quantum physics, is there not a non-zero probability that everything will occur? It's just a matter of time, whether we're still around to witness the event or not is a different matter.

I am not an expert in quantum physics. Where does it state that everything has non-zero probability of happening?
Anyway, even if something has a non-zero probability of occurring, this does not guarantee that it will occur sometime.
Remember that the Universe will not last forever. First it will cool down, then the black holes will evaporate and finally the protons will disintegrate. This will take around $$10^{80}$$ years. A very long time, but not infinite.

 

[Ivan Seeking]

Yes, the conservation laws etc. are our (current) reality. Can we imagine a perpetual motion machine? (the one Lisa makes on the Simpsons usually springs to mind)

What I'm really asking is can we imagine breaking one of our conservation laws? A machine that spins faster and faster? Easy to imagine, but the science behind it is currently unimaginable. That's why we still fill our cars with dead fish.

There are some funny things that happen at the quantum level [and in places like black holes] but these do not generally extrapolate to the normal, macroscopic world around us. As for some of the strange stuff that does in principle extrapolate from the quantum realm to the macroscopic, as is mentioned in the post above, the scales of time involved make it unlikely that such an event would ever be observed over the entire life of the universe. And even then, if some strange event did occur at large scale, it would only be once. So the short answer is no, we do not expect violations of the most basic principles - the conservation laws. Instead, we seek to expand our base of knowledge using what we already know, with reasonable certainty, to be true.

 

[WaveJumper]

I voted yes to the question whether intelligent has visited us, but there is something that boggles my mind. At least on 3 occasions I've seen fighter jets being scrambled to down said UFO's(belgian triangle comes to mind). What is with our military? Do we want a war we can never win? What if those said aliens used their super weapons and annihilated a part of the US or the whole of it? If they have enough energy to cross galaxies, it stands to reason that they might very well have capabilities to annihilate us. What gives us such tremendous courage to shoot missiles at something that could potentially destroy whole countries? I couldn't fire a missile at an UFO even if i had to go to jail upon landing. Do we have proof that what our fighter jets are trying to down, has done anything wrong or bad to us? What is the hostility for? IMO, we firing missiles at an UFO is like the tribesmen of the Amason throwing stones at helicopters. I would argue that if those were real highly technological space ships that we name UFOs, we are coming across as the laughing stock of the galaxy with the kind of weapons we are trying to use unsuccessfully on those rare encounters.

 

[Ivan Seeking]

By definition, the object is unidentified. The job of the AF is to protect the airspace of the respective country, and that's what they're doing. Also, often, it is only in retrospect that an encounter appears to be anomalous. In spite of the many conspiracy theories, the government probably doesn't understand the phenomenon any more than the rest of us.

I am also pretty sure that we've never downed an alien spacecraft , so if we are throwing stones, there appears to be no harm done.

 

[baywax]

By definition, the object is unidentified. The job of the AF is to protect the airspace of the respective country, and that's what they're doing. Also, often, it is only in retrospect that an encounter appears to be anomalous. In spite of the many conspiracy theories, the government probably doesn't understand the phenomenon any more than the rest of us.

I am also pretty sure that we've never downed an alien spacecraft , so if we are throwing stones, there appears to be no harm done.

A not so remote possibility is that these unidentified craft are man made and commandeered by the elite force of a scheming rogue nation with ambitions to control the entire human population.

If this is the case, these "ufos" are extremely vulnerable to projectile points (bullets) and so when you see gun laws prohibiting guns to most citizens, this is when the invasion is imminent. Canada has such laws and there are a slew of those floating tea saucers up here.

 

[Ivan Seeking]

A not so remote possibility is that these unidentified craft are man made and commandeered by the elite force of a scheming rogue nation with ambitions to control the entire human population.

I would debate that point in cases where the performance envelope of the intruder appears to be far beyond any human technology. We can't know the precise characterstics of the most advanced crafts, but we have a pretty good idea about the approximate limits of performance and technology. The Iran '76 event would be a good example - the first link in the UFO Napster. And being that this occurred over thirty years ago, we can have pretty good confidence that this was not a [earthly] technology from that time.

However, the AF responds because it is assumed that the UFO is a potential enemy craft, not aliens.

 

[Proton Soup]

I would debate that point in cases where the performance envelope of the intruder appears to be far beyond any human technology. We can't know the precise characterstics of the most advanced crafts, but we have a pretty good idea about the approximate limits of performance and technology. The Iran '76 event would be a good example - the first link in the UFO Napster. And being that this occurred over thirty years ago, we can have pretty good confidence that this was not a [earthly] technology from that time.

However, the AF responds because it is assumed that the UFO is a potential enemy craft, not aliens.

i just read the ufo00020.pdf, and everything about it screams 'unexplained electromagnetic phenomena'. maybe something like ball lightning. instrumentation/radio interference is repeatedly described as a function of proximity to the phenomenon. locals described noises like that of lightning.

 

[Chronos]

No compelling evidence [e.g., downed space craft] of alien visitation. Perhaps it is because interstellar travel is as prohibitively resource and time intensive as our own primitive science suggests. In that case, there may be billions of advanced civilizations in the universe that are just as stuck in their own neighborhood as us. That, to me, is the most logical explanation for Fermi's paradox.

 

[Ivan Seeking]

i just read the ufo00020.pdf, and everything about it screams 'unexplained electromagnetic phenomena'. maybe something like ball lightning. instrumentation/radio interference is repeatedly described as a function of proximity to the phenomenon. locals described noises like that of lightning.

Perhaps, and that is an explanation that I too have suggested, however it is not entirely consistent with the report.

 

[Ivan Seeking]

No compelling evidence [e.g., downed space craft] of alien visitation. Perhaps it is because interstellar travel is as prohibitively resource and time intensive as our own primitive science suggests. In that case, there may be billions of advanced civilizations in the universe that are just as stuck in their own neighborhood as us. That, to me, is the most logical explanation for Fermi's paradox.

Again, perhaps, but citing Fermi's paradox while denying the potential authenticity of alien spacecraft reports is a bit paradoxical in its own right.

 

[baywax]

No compelling evidence [e.g., downed space craft] of alien visitation. Perhaps it is because interstellar travel is as prohibitively resource and time intensive as our own primitive science suggests. In that case, there may be billions of advanced civilizations in the universe that are just as stuck in their own neighborhood as us. That, to me, is the most logical explanation for Fermi's paradox.

I'd say if they could get here they're here already and completely assimilated in a way that we can't see... like very advanced and efficient camouflage.

 

[CEL]

No compelling evidence [e.g., downed space craft] of alien visitation. Perhaps it is because interstellar travel is as prohibitively resource and time intensive as our own primitive science suggests. In that case, there may be billions of advanced civilizations in the universe that are just as stuck in their own neighborhood as us. That, to me, is the most logical explanation for Fermi's paradox.

It all depends of the longevity of technological civilizations. I believe that in the next century we will be able to find habitable planets in neighbor star systems.
If there is interest, colonizing expeditions could reach such planets in 10 to 20 years. With the head start in technology, such colonies could reach other star systems after one or two centuries and so on.
If our civilization lasts enough, in one million years we could colonize the Galaxy.
The fact that the Galaxy does not thrive with alien civilizations suggests that either we are alone or that civilizations don't last that much.

 

[DaveC426913]

The fact that the Galaxy does not thrive with alien civilizations suggests that either we are alone or that civilizations don't last that much.

The third possibility is that the galaxy is thriving but not in a way that's visible to us. The classic "quarantine" hypothesis.

 

[baywax]

I would debate that point in cases where the performance envelope of the intruder appears to be far beyond any human technology. We can't know the precise characterstics of the most advanced crafts, but we have a pretty good idea about the approximate limits of performance and technology. The Iran '76 event would be a good example - the first link in the UFO Napster. And being that this occurred over thirty years ago, we can have pretty good confidence that this was not a [earthly] technology from that time.

However, the AF responds because it is assumed that the UFO is a potential enemy craft, not aliens.

Yes, but completely isolated tribes in Brazil have no experience with a "performance envelope of (an) intruder (that) appears to be far beyond any (tribal) technology" when they see a helicopter buzzing them. I'd further this idea by saying 1. Developments since the first Foo Fighter (1933) may have gone beyond what we're used to... 2. Developments based on downed extraterrestrial vehicles may result in these "ufos".

 

[gareth]

The theories about the UFO phenomena been due due man made craft got me to thinking;

Science, and in turn technology is based on constantly buliding on other peoples work. Could there really be a research project (that would have to involve some pretty interesting stuff) be going on that is so big it has managed to engineer one of these crafts (if they are crafts of course)?

It would have to be very secret, and only known to a very select group of people. It seems unlikely that with all the mainstream science going on at the same time some of the ideas would have cropped up here and there.

Basically what I'm saying is, if we did build such objects, we got help.