Do you think ET life exists elsewhere?

[PeroK]

I would concur with Arman777 in that there are a large number of conditions that have to be met for life (of any kind) to be evolved and sustained such that it's wildly improbable that there is life elsewhere in the universe. And it's not just a large number of conditions, but conditions that must be narrowly defined too.

Astrophysicist, Hugh Ross, has done calculations that would make it more likely for a person to win the lottery 1 million consecutive times than for there to be life elsewhere in the universe. He lists 147 conditions that absolutely must be met at minimum (with possibly more) for life to develop on a planet. The odds of all of those conditions occurring in the perfect planet are 10¹⁶⁴. By contrast, he says that the total number of protons and neutrons in the universe is 10⁷⁹. And for a more intuitive grasp of how improbable those odds are, he says the probability of someone being killed in the next few seconds by a sudden reversal of the second law of thermodynamics is roughly 1 chance in 10⁸⁰. But we know that it's such a ridiculously small probability that everyone is justified in not worrying about that chance happening to them at any moment.

Essentially, Ross says, "The probability is indistinguishable from zero."

I think most people are justified in thinking we're pretty much alone. It's not impossible for other life to exist, but the odds are against it.

The flaw in this argument is, of course, that to claim that something has a probability of zero, then there must be a zero probability that your calculations are wrong.

That condition cannot be met with a subject such as alien life.

That Ross could be wrong has a non-zero probability.

 

[symbolipoint]

Would you consider unicorns possible if you lived on a world where all large mammals have a single horn on their head.

Rhinoceros?

 

[nitsuj]

I answered "probably" to the question in the title, but you didn't specify intelligent life in the title. I would say that in the next 25 years we will discover life, but will likely not ever have two-way communication with another intelligent life form.
[Late edit; fixed quote]

I agree 100% with the distinction between human level intelligence & dexterity to that of the other life we know of being significant, add to that the exponential growth in "knowledge"...

 

[Evo]

I'll repeat this here because I think it's worth considering. We may think we are at the top of the intelligence chain, but maybe not.

Even if there was "intelligent" life, that doesn't mean we could communicate with it. Maybe it's far more advanced. Can intelligence operate on more than one level? I assume you are thinking of the current human level of intelligence. We could be like chimpanzees, or less, to a more advanced species.

Maybe there are very advanced/different intelligent species out there, maybe they are ignoring us or not recognizing the signals we are sending as intelligent.

 

[phinds]

Maybe there are very advanced/different intelligent species out there, maybe they are ignoring us or not recognizing the signals we are sending as intelligent.

Evo, I don't think that's likely. I certainly believe that there could be species that are more intelligent than us but I think any that have the level of communication expertise to receive our signals is VERY likely to realized immediately that they are not random noise and have to be from an intelligent species.

 

[Evo]

Evo, I don't think that's likely. I certainly believe that there could be species that are more intelligent than us but I think any that have the level of communication expertise to receive our signals is VERY likely to realized immediately that they are not random noise and have to be from an intelligent species.

Prove it. My oldest daughter is so far off the scale, I'd wonder. But she's brilliant and gifted.

I wonder if there is intelligence we don't recognize, or wouldn't be recognized, something so alien to us. Something we can't comprehend. Why would everything have to follow our rules? I know "laws of physics", etc..., but what if communication was random? Isn't it random? Some languages are nothing more than clicks.

And Happy Thanksgiving!

 

[DaveC426913]

I'm not sure why a Christian faith would impact one's research into this area, though, Ophiolite.

Because he included the word naturally.

We already have at least one example of life arising. Since that kinda flies in the face of his assertion that it would be equivalent to ' a million lottery wins in a row', he is certainly arguing that Earth life arose the only way he sees as probable: unnaturally.

 

[DaveC426913]

Even if there was "intelligent" life, that doesn't mean we could communicate with it.

If they are as advanced as, or more advanced than us, then they will have discovered mathematics.
They will know that a circle has a radius of 2*pi. They're know a bunch of other universal constants as well.

You can establish true/false, and then you can establish a number system and formulae. From there, you can establish more subtle things, such as more than/less than.

Once you have common ground, you can begin writing a common language.
It will be simple to start, but will very rapidly bootstrap.

Robert Sawyer walked through this in his book Starplex. It was very clever.

 

[DaveC426913]

Some languages are nothing more than clicks.

The manifestation of the language is not relevant. By definition, language will have content and meaning. And we can begin a common language.

I'll see if I can scare up Sawyer's take on it. His characters only communicated with the aliens using messaged blips -essentially binary or Morse or whatever. It doesn't matter. You establish meaning jointly.

Here's one.
Also, here's one.
One <> one ... true!
Here's two.
One <> two ... false!
One and one <> two ... true!
etc.

 

[Evo]

The manifestation of the language is not relevant. By definition, language will have content and meaning. And we can begin a common language.

I'll see if I can scare up Sawyer's take on it. His characters only communicated with the aliens using messaged blips -essentially binary or Morse or whatever. It doesn't matter. You establish meaning jointly.

Here's one.
Also, here's one.
One <> one ... true!
Here's two.
One <> two ... false!
One and one <> two ... true!
etc.

But will they recognize an established language? I'm not talking about trying to set up communications. Those are two very different things.

 

[DaveC426913]

But will they recognize an established language?

No.

I'm not talking about trying to set up communications.

Right. Agree that it is unfeasible (at least in a first contact phase). So why try?

The communication of ideas is the goal, not the language itself.

 

[Buzz Bloom]

Since the "current best cosmological models of the universe indicate that the" universe is infinite, then I think the following maxim is applicable: If something can happen once, then it can happen again.

NOTE: Quoted text added above to avoid possible ambiguity.

However, regarding the Milky Way having life other than that on Earth, or any other randomly chosen galaxy, my guess is "maybe, but probably not." My reasoning is admittedly based on a controversial premise. I believe that our oversized moon played a necessary (but not necessarily sufficient) role in the pre-life chemistry that led to life, and that such a moon happens extremely rarely.

 

[phinds]

Since the universe is infinite ...

You are stating that as a fact. It is not KNOWN to be true, it just seems most likely, so basing a conclusion on it is faulty.

 

[Buzz Bloom]

You are stating that as a fact..It is not KNOWN to be true...

Hi phinds:

I am a bit puzzled by this. If my understandings below are incorrect, please correct me.

1. I understand that in principle NOTHING IS KNOWN about physics (or also about all of science), in the sense that with respect to any current "knowledge" it is recognized that new observations and better models are always a theoretical possibility. Consequently, from time to time, old "knowledge" gets REPLACED by new "knowledge". (For example, with respect to the very large and the very small, Newtonian physics has been replaced by relativity and quantum mechanics.) Therefore, at any given time, it is understood that ALL "knowledge" is TENTATIVE and is never KNOWN to be true.

2. I also understand the BEST current astronomical information fits a model in which the universe is expanding and the expansion is accelerating. Furthermore, this model requires that the universe must be infinite.

Regards,
Buzz

 

[DaveC426913]

, at any given time, it is understood that all "knowledge" is TENTATIVE and is never KNOWN to be true.

Right. So don't state it as true. An infinite universe is not the best fit model, as we understand.

2. I also understand the BEST current astronomical information fits a model in which the universe is expanding and the expansion is accelerating. Furthermore, this model requires that the universe must be infinite.

An expanding universe does not, in any way, indicate that it is infinite.

In fact, kind of the opposite. Our best current theory puts the universe at (a mere) 96 billion light years across.More to the point: regardless of its extent, it is evolving. As it expands, it is getting more rarefied. No new material is being created.

So for any event that has happened (whent he universe was all packed together), it is quite possible that it can never happen again nce the universe has spread out).

 

[Buzz Bloom]

Our best current theory puts the universe at about 96 billion light years acorss.

Hi Dave:

I may be mistaken, but I believe you have confused "universe" with "observable universe". Also, I understand that some older models had the universe expanding with the possibility that the expansion might stop and be followed by contraction. Those models corresponded to a finite universe. However, I understand that the acceleration of the expansion can only occur in GR cosmological models that are infinite.

Regards,
Buzz

 

[DaveC426913]

Fair enough. Still, the Big Bang Theory - our best understanding of creation - constrains the size of the universe.

 

[phinds]

2. I also understand the BEST current astronomical information fits a model in which the universe is expanding and the expansion is accelerating. Furthermore, this model requires that the universe must be infinite.

No, it has no such requirement. Still, as @PeterDonis often points out, our best model does suggest that the universe is infinite in extent but I don't believe even he states it as a known fact, just the most likely model.

 

[Buzz Bloom]

Fair enough. Still, the Big Bang Theory - our best understanding of creation - constrains the size of the universe.

Hi Dave:

Again this is (almost) true about the "observable universe, not the "universe. Also, with respect to the observable universe, out best cosmological models do not constrained it to any particular finite size. It's finite size continues to accelerate indefinitely at a rate that approaches exponential growth.

Regards,
Buzz

 

[DaveC426913]

... our best model does suggest that the universe is infinite in extent...

It seems I may have to go back and hit the books.

 

[phinds]

It seems I may have to go back and hit the books.

Do a search for Peter Donis' posts regarding this. He has mentioned it several times.

 

[DaveC426913]

Again this is (almost) true about the "observable universe, not the "universe.

I guess I'm a little confused as to what you're talking about.

You did say, in post 49 (point 2), "the universe is expanding". So, do you mean the universe - being infinite - is, at the same time, expanding?

 

[Buzz Bloom]

@PeterDonis often points out, our best model does suggest that the universe is infinite in extent but I don't believe even he states it as a known fact, just the most likely model.

Hi phinds:

As I understand from reading the @PeterDonis mathematical presentations about the current best model, his description of the best fit model does not specify the universe as being infinite or finite. However, I believe this is because the issue is not relevant to the math he was explaining.

I am getting the impression that the particular phrase I used in #47 may have suggested to some readers that I intended it to imply the current best model is the final model for all future time to explain the large scale cosmology. However, I think #49 makes it as clear as I can that I do not believe this, and did not intend that interpretation. However, I have edited #47 to improve understanding.

Regards,
Buzz

 

[Buzz Bloom]

You did say, in post 49 (point 2), "the universe is expanding". So, do you mean the universe - being infinite - is, at the same time, expanding?

Hi Dave:

I have edited my original post to help clarify my intended thoughts. Although I am far from being an expert, I would now phrase what you have in italics as follows to avoid further misunderstanding. To clarify, it is the scale factor of the universe that is expanding and accelerating. The variable "a" in the Friedman equation represents the scale factor.

The universe is expanding, and the expansion is accelerating. The Friedman equation (see below) together with the current best fit values of the four Ω coefficients corresponding to the current best model, implies that there is a relatively high degree of confidence that the best value of Ω_k is sufficiently negative that it specifies an open infinite universe, that is, either a hyperbolic universe or a flat universe. However, the probability is pretty small that Ω_k may at some later time, after new astronomical data is available, be part of a new best model with a positive value of Ω_k implying a closed finite universe.​

Regards,
Buzz

 

[nitsuj]

I guess I'm a little confused as to what you're talking about.

You did say, in post 49 (point 2), "the universe is expanding". So, do you mean the universe - being infinite - is, at the same time, expanding?

The universe is expanding at rates greater than c, the issue of observing it to being infinite. such a thing can only be modeled.

imo from a physics perspective if something is outside our "causal structure" what's the significance?

 

[phinds]

The universe is expanding at rates greater than c,

That is not really a correct way of stating it. Yes, things over a certain distance from each other are receding from each other at recession velocities greater than c, but that is not the "speed of recession of the universe" as you seem to believe. The universal expansion should be expressed as about (67 Km/Sec)/Parsec. This properly captures the fact that things farther apart are receding from each other faster than things closer together.

EDIT: Hm ... didn't remember the exact rate so looked it up and I think what I stated is incorrect. It should be (67 Km/Sec)/(10E6 Parsecs), or more concisely, (67 Km/Sec)/(MParsec)

 

[OCR]

Do you think ET life exists elsewhere?

Eh... ?

 

[phinds]

Eh... ?

View attachment 215729​

Hey, don't blame me for sidetracking the thread. I was just responding to a post.

 

[DaveC426913]

Eh... ?

Buzz Bloom's post #47 opened the door to discussions about the extent of the universe as it might pertain to the probability of life.

 

[DS2C]

Voted "probably". I can't prove or disprove it, but as Carl Sagan said- "If it's just us, seems like an awful waste of space." Pretty much sums it up for me.

 

[NFuller]

I believe evolving life on Earth has a possibility of $\frac {1} {10^{22}}$

How did you arrive at this number?

I find it hard to believe that the probability of life evolving on Earth is as low as you stated considering how rapidly life showed up after the crust solidified.

 

[Arman777]

How did you arrive at this number?

I find it hard to believe that the probability of life evolving on Earth is as low as you stated considering how rapidly life showed up after the crust solidified.

Observable universe have roughly $10^{11}$ galaxy and each galaxy have roughly $10^{11}$ star. So I just multiplied them and I assumed that, we are the only one in the universe since.So there's $10^{22}$ star and our solar system has the only one that contains life.So in some sense it makes sense to me (even you can multiply that number with average planet number on every star). The probabilty is referring to us that our probabilty of existence is $\frac {1} {10^{22}}$.If there's another life it will have same probabilty. My logic might be wrong and probably wrong.But even its wrong it must be really low which I am sure of it.

 

[russ_watters]

Observable universe have roughly $10^{11}$ galaxy and each galaxy have roughly $10^{11}$ star. So I just multiplied them and I assumed that, we are the only one in the universe since.So there's $10^{22}$ star and our solar system has the only one that contains life.So in some sense it makes sense to me (even you can multiply that number with average planet number on every star). The probabilty is referring to us that our probabilty of existence is $\frac {1} {10^{22}}$.If there's another life it will have same probabilty. My logic might be wrong and probably wrong.But even its wrong it must be really low which I am sure of it.

That's the known per star probability, but the OP asks about the universe. The probability of one planet with life in the universe is 100% 1/1. If a second is found it is 2/2=200%

 

[nitsuj]

That is not really a correct way of stating it. Yes, things over a certain distance from each other are receding from each other at recession velocities greater than c, but that is not the "speed of recession of the universe" as you seem to believe. The universal expansion should be expressed as about (67 Km/Sec)/Parsec. This properly captures the fact that things farther apart are receding from each other faster than things closer together.

EDIT: Hm ... didn't remember the exact rate so looked it up and I think what I stated is incorrect. It should be (67 Km/Sec)/(10E6 Parsecs), or more concisely, (67 Km/Sec)/(MParsec)

lol none of that detracts from or adds to my point.

 

[Arman777]

2/2=200%

I didnt understand this part. My previous approach was wrong. Let's suppose something similar. Image a universe has 12 planets and we can't see 9 of them. We are living one them and we know that other 2 doesn't contain any life.Whats the probability of others containing life ?

It has nothing to do with respect to the planet number. Its most likely about the circumtances that can cause to form a live. Which is tempature,water and other elements etc. And there's another thing which If you even satisfy these conditions life just doesn't pop up.

In our case we don't know these conditions and its hard to calculate the probability of it.But I believe that It would be really really low.

Probably of live=1 / (The all possiblities that can cause life)