# Will we prove the existence of alien life in your lifetime?



## EricABQ (Jul 10, 2012)

Do you believe we will prove the existence of extra terrestrial life in your lifetime?

My lifetime could stretch perhaps another 40 - 50 years, and I do not believe we will prove the existence in that time. It's possible that we could send a probe to one of Jupiter or Saturn's moons and discover some life form under the ice, but government budgets being what they are, I'm not optimistic. 

I also don't expect to see any spaceships drop by anytime soon. After all, the first radio signals sent from Earth are only about 100 light years from us by now, so even if there is anyone else out there, I'm not sure how they would know we were here even if they were looking.


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## aleazk (Sep 30, 2011)

Considering the advances in medicine that will be avaiable in this century and the record of high life expectancy that my family has, I think I could live until 2080 (92 years). For me now, that seems a ridiculously far away time. I don't have a clue about how the world will be in 2080. Compare 1913 with 1980. In 1913, quantum mechanics didn't even exist (it was being developed by Bohr, Einstein and others), 32 years later they were building atomic bombs with that. Maybe some new things are being developed right now, in 2013, that will, dramatically, change the course of history in 2045!.
If something can be learned from human history, that is the fact that it evolves in a chaotic way. In chaotic systems, a slight change in the initial conditions can dramatically change the output. That's because the non-linear interactions inside the system. So, if one only knows the initial conditions in an approximate way (like in any real world situation), predictability simply breaks down, because there a lot of radically different solutions with those approximate initial conditions. 
In human society there are certainly a lot of non-linear interactions (the relation between politics, economics, society, technology is extremely complex), so, you can expect a chaotic system. Certainly we don't know all that is happening right now, so, it's impossible to make broad predictions about the future of human society.


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## ahammel (Oct 10, 2012)

It's hard to say. It all depends on how hard it is for life to originate.

If, for instance, it's pretty easy to get life on any planet that has liquid water, there's a fairly good chance that there's at least fossil life on Mars. We could stumble across that any day now.

On the other hand, if life is very touchy with respect to initial conditions, there might not be any in our solar system outside of Earth. I have no prospect whatsoever of living to see a probe shot to any other solar systems, even if it launched today, and I don't think we can count on whatever is out there screaming constantly in all directions on the handful of radio bands that we monitor. Spaceships are, of course, an even wilder hope.

So I don't think that I'll see any evidence of extra-solar life in my lifetime, but if the rest of the solar system isn't barren there's a not inconsiderable chance we'll stumble across that in the next 50-60 years.


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## elgar's ghost (Aug 8, 2010)

If life does exist anywhere else perhaps we are just too far away to ever know about it - I'd say the chances of finding out are about as likely as two insects bumping into each other after starting out at opposite ends of a mile-long field.


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## joen_cph (Jan 17, 2010)

Interviews with several scientists in the media here state that it is highly likely, even within the next 10-15 years. Recent research seems to indicate that there are at least 10 billion earth-like planets in the Universe, and just identifying a planet of some kind was a sensational thing a few years ago (currently about 2300 various ones have been identified). The methods for possibly proving life are also constantly being developed, such as the exact composition of atmospheres as seen against starlight etc.

Some of the most interesting future projects are the Nasa Kepler mission (ongoing), the E-ELT telescope in Chile (opening in 2023), the Tess space telescope (from 2017) and JWST space telecope (from 2018), future Mars and Europa-Ganymedes-Titan moon missions (maybe around 2021 http://www.guardian.co.uk/science/2013/feb/15/nasa-europa-clipper-mission-jupiter-moon, perhaps stimulated by oncoming Lake Vostok results), etc.

However being actually able to photograph not to say sample such life forms can present a much bigger problem, since earth-like planets can be thousands of light years away - or more.


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## ahammel (Oct 10, 2012)

joen_cph said:


> Interviews with several scientists in the media here state that it is highly likely, even within the next 10-15 years. Recent research seems to indicate that there are at least 10 billion earth-like planets in the Universe, and just identifying a planet of some kind was a sensational thing a few years ago (currently about 2300 various ones have been identified). The methods for possibly proving life are also constantly being developed, such as the exact composition of atmospheres as seen against starlight etc.


Oh yeah, forgot about that. We could potentially see weirdly oxygen-rich atmospheres around Earth-like planets and draw a few inferences.

The likelihood of life arising on an Earth-like planet is still a complete unknown, though, so it all depends.


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## PetrB (Feb 28, 2012)

If what my friends keep saying could be confirmed, then....


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## DavidA (Dec 14, 2012)

ahammel said:


> It's hard to say. It all depends on how hard it is for life to originate.
> 
> If, for instance, it's pretty easy to get life on any planet that has liquid water, there's a fairly good chance that there's at least fossil life on Mars. We could stumble across that any day now.


The chances of life forming even under the right conditions are exceedingly small. 1 in 20 to the power 100


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## KenOC (Mar 7, 2011)

DavidA said:


> The chances of life forming even under the right conditions are exceedingly small. 1 in 20 to the power 100


How surprised you will be when you discover that THEY'RE AMONG US!


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## DavidA (Dec 14, 2012)

KenOC said:


> How surprised you will be when you discover that THEY'RE AMONG US!


Ken, I should leave off the movies!


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## Chrythes (Oct 13, 2011)

DavidA said:


> The chances of life forming even under the right conditions are exceedingly small. 1 in 20 to the power 100


How can we calculate that considering that we don't actually know how life began and the only life forms that we do know of came into existence on this particular planet, when maybe in fact life based on carbon or water is not the only possibility?

There might be life forms made of dark matter for that matter. :lol:


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## ahammel (Oct 10, 2012)

DavidA said:


> The chances of life forming even under the right conditions are exceedingly small. 1 in 20 to the power 100


I don't know where that number came from, but I'm afraid you've been mislead.

Miller/Urey and Spiegleman's monster notwithstanding, we have nothing but wild guesses about how life originates in the first place or what the "right conditions" are. It's simply not possible with current givens to assign a probability to such a thing.

Even so, the two piece of data we do have (life originated on an Earth-like planet at least once, something on the order of 10 billion Earth-like planets in the universe) suggest your number is a touch on the pessimistic side.


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## Crudblud (Dec 29, 2011)

KenOC said:


> How surprised you will be when you discover that THEY'RE AMONG US!


Have you got a pair of those sunglasses that makes every billboard appear to say "Consume. Breed. Sleep. Watch TV."?


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## GreenMamba (Oct 14, 2012)

ahammel said:


> Even so, the two piece of data we do have (life originated on an Earth-like planet at least once, something on the order of 10 billion Earth-like planets in the universe) suggest your number is a touch on the pessimistic side.


I'm not sure that addresses the issue. The question is, given the "right" conditions, how likely will it be that life comes into being?

Saying life exists on Earth doesn't answer the question. How much of a long shot were we?

And how many Earth-like planets misses the point. What David A is talking about is the number that would be multiplied by the # of Earth-like planets. How small is that number?


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## ahammel (Oct 10, 2012)

GreenMamba said:


> I'm not sure that addresses the issue. The question is, given the "right" conditions, how likely will it be that life comes into being?
> 
> Saying life exists on Earth doesn't answer the question. How much of a long shot were we?


It's impossible to say, of course, but I'm inclined to be suspicious of any estimate that suggests that the origin of life on Earth was a long shot on the order of 1e-100. Those are "spontaneous transmutation of lead into gold" odds.

But, as I say, there's no sense speculating about the odds, since we can't estimate them with the data we have at present.


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## GreenMamba (Oct 14, 2012)

ahammel said:


> But, as I say, there's no sense speculating about the odds, since we can't estimate them with the data we have at present.


I agree with that. My main gripe is that people look at the number of planets, age of the universe, etc. and say "these are HUGE numbers. Of course life must exist elsewhere!"

But the chance of life forming at any given place and time is a very small number. We have a hard time dealing with really big and really small numbers, and a hard time comparing them.


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## DavidA (Dec 14, 2012)

ahammel said:


> I don't know where that number came from, but I'm afraid you've been mislead.
> 
> Miller/Urey and Spiegleman's monster notwithstanding, we have nothing but wild guesses about how life originates in the first place or what the "right conditions" are. It's simply not possible with current givens to assign a probability to such a thing.
> 
> Even so, the two piece of data we do have (life originated on an Earth-like planet at least once, something on the order of 10 billion Earth-like planets in the universe) suggest your number is a touch on the pessimistic side.


Of course the figures quoted by scientists are guesses. However, you not only have to take into account the molecular structure of cells but also the incredible amount of information contained in each cell. Interesting that Professor Brian Cox describes the fact of life here as 'a miracle'!


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## ahammel (Oct 10, 2012)

GreenMamba said:


> I agree with that. My main gripe is that people look at the number of planets, age of the universe, etc. and say "these are HUGE numbers. Of course life must exist elsewhere!"


That wasn't what I was trying to say. To be a bit more clear (I hope): we've observed one successful trial (life originated on Earth), and we've got evidence that the total number of trials is something like ten billion. That suggests a lower bound of something on the order of 1 origin of life per 1e10 Earth-like planets per thirteen billion years, with error bars so large as to make the estimate an exercise in futility.

Still, if somebody wants to argue that the real probability is _at least one hundred orders of magnitude_ below that, I'd very much like to see the evidence.



> But the chance of life forming at any given place and time is a very small number. We have a hard time dealing with really big and really small numbers, and a hard time comparing them. [Emphasis added]


Now you're making the opposite mistake. We don't know if the number is small or large. It's entirely possible that life has originated on _every_ Earth-like planet. We can't tell: we don't understand the process and we've only taken a really good look at one such planet (the one we're standing on).

Really, all we know about the probability of life originating on an Earth-like planet is that it's somewhere north of zero.


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## ahammel (Oct 10, 2012)

DavidA said:


> However, you not only have to take into account the molecular structure of cells but also the incredible amount of information contained in each cell.


And I must emphasize again that we know _absolutely nothing_ about the origins of cells. We can't meaningfully assign probability to it.


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## joen_cph (Jan 17, 2010)

> But the chance of life forming at any given place and time is a very small number


We don´t know that either, since we are just beginning to do research on them ... A local space scientist here, Jens Martin Knudsen, (http://en.wikipedia.org/wiki/Jens_Martin_Knudsen), used to put forward an impressively sweeping remark: that there were indications that "_the creation of life is an often-occurring side-effect of the formation of the stars_". When the discovery of alternative eco-systems began, he saw that as a confirmation - the "smokers"-ecosystem at the sea bottom, later that of bacteria living from rock and salt http://sciencenordic.com/live-bacteria-found-deep-below-seabed, http://www.darlies.co.uk/news/life-on-a-lump-of-rock-salt-may-nurture-life-on-other-planets-304.html etc. 
( http://en.wikipedia.org/wiki/Astrobiology )


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## juergen (Apr 9, 2012)

One of the least interesting questions I can imagine. There are already enough weird figures out there, I do not need more of them.


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## mmsbls (Mar 6, 2011)

The OP asks whether we'll find evidence for alien life, but until recently the research of astrobiologists focused on intelligent life. Intelligent life is vastly easier to detect through, for example, receiving electromagnetic (or other) signals. If we can find evidence of non-earth based life on other planets in our solar system, we could verify that alien life exists. Soon we might be able to find evidence of life on earth-like planets revolving around relatively nearby stars.

This thread in post #48 gives the Drake equation that precisely determines the average number of planets with intelligent life in our galaxy. Unfortunately the last 3 or 4 factors get progressively harder to estimate so people have used the equation to get numbers from 1 to 10,000s. But again this equation refers to intelligent life (of course, dropping the last 3 factors gives an estimate of all alien life).

While we don't know the likelihood of life evolving in a given environment, it evolved very early on earth. Within a couple hundred million years of conditions becoming possible (too hot earlier), life evolved here. That fact has always suggested to me that the probability is not extremely small. It's very hard to know if intelligent life is likely once life has evolved. Also intelligent life could evolve and then die out (much harder for life completely to die out on a planet).

Overall, it's very hard to guess the answer, but it's fun to explore.


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## KenOC (Mar 7, 2011)

If a popular multiverse theory is correct, then there is certainly life elsewhere. The theory says that all possible universes exist, so some certainly have life. In fact each of these universes, which are exceedingly numerous (but not infinite), exists an infinite number of times.

So there is not merely life elsewhere, there is *you* elsewhere, doing what you're doing now and thinking what you're thinking now, ad infinitum.

The article I read on this theory even calculated the physical distance from the "you" here to the nearest "you" elsewhere. The distance was, of course, exceedingly large, and impractical to traverse given the current price of gasoline...


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## aleazk (Sep 30, 2011)

DavidA said:


> Of course the figures quoted by scientists are guesses. However, you not only have to take into account the molecular structure of cells but also the incredible amount of information contained in each cell. Interesting that Professor Brian Cox describes the fact of life here as 'a miracle'!


Thank you for showing your agenda, .


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## cwarchc (Apr 28, 2012)

The issues would be distances and time required.
As was mentioned earlier, humans have only been sending out radio transmissions in the last 100 years or so


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## Ryan (Dec 29, 2012)

I f you read David Icke's books you'll know that Alien life already inhabits this planet in the form of Lizard people, all the global elite are shape shifting reptillians who control what we do and use us for their own means. It's a fascinating hypothesis that is probably true or at least 80% true.
the list of believed to be Lizard people is vast and includes people in government, royal family members, celebrities, chinese people & Ricky Martin. 
I hope this answered your question, I personally am satisfied with this conclusion. If you try to deny this as conspiracy then I will assume your a Lizard person and report you to admin, who are probably also lizard people.


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## LordBlackudder (Nov 13, 2010)

i reckon they will.


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## EddieRUKiddingVarese (Jan 8, 2013)

short response no

But are we all human? as per post #26, is that another question............


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## BlazeGlory (Jan 16, 2013)

Ryan said:


> I f you read David Icke's books you'll know that Alien life already inhabits this planet in the form of Lizard people, all the global elite are shape shifting reptillians who control what we do and use us for their own means. It's a fascinating hypothesis that is probably true or at least 80% true.


What parts of of the hypothesis do you think are the 20% that may not be true? I would like to suggest these for starters: Alien, Lizard, shape shifting reptillians.


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## tdc (Jan 17, 2011)

juergen said:


> One of the least interesting questions I can imagine. There are already enough weird figures out there, I do not need more of them.


 

In response to the op :

Yes. Obviously I cannot predict how many years I will live, but I would guess this will be proven in the near future.


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## EricABQ (Jul 10, 2012)

Here's a book on the subject I found pretty interesting: http://www.amazon.com/Rare-Earth-Complex-Uncommon-Universe/dp/0387952896/ref=sr_1_1?s=books&ie=UTF8&qid=1367537957&sr=1-1&keywords=rare+earth

Accessible enough for the novice with enough complex science for those who may be more able to follow along.

It goes into detail on why all the factors that contributed to life evolving on Earth would be very rare in the universe.


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## KenOC (Mar 7, 2011)

EricABQ said:


> It goes into detail on why all the factors that contributed to life evolving on Earth would be very rare in the universe.


"Here on Xtoxuapoon, we know that for life to evolve the molten silicon must be at just the right temperature and have the right impurities, there must be no large satellite stressing the planet's crust, and above all there must be no oxygen, not a trace. Obviously planets like ours must be vanishingly rare, so that life elsewhere, while not impossible, is certainly improbable."


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## EddieRUKiddingVarese (Jan 8, 2013)

tdc said:


> In response to the op :
> 
> Yes. Obviously I cannot predict how many years I will live, but I would guess this will be proven in the near future.


Do you mean how long you will live will be proven in the future or alien life?


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## tdc (Jan 17, 2011)

EddieRUKiddingVarese said:


> Do you mean how long you will live will be proven in the future or alien life?


:lol:

Both!!


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## DavidA (Dec 14, 2012)

KenOC said:


> If a popular multiverse theory is correct, then there is certainly life elsewhere. The theory says that all possible universes exist, so some certainly have life. In fact each of these universes, which are exceedingly numerous (but not infinite), exists an infinite number of times.
> 
> So there is not merely life elsewhere, there is *you* elsewhere, doing what you're doing now and thinking what you're thinking now, ad infinitum.
> 
> The article I read on this theory even calculated the physical distance from the "you" here to the nearest "you" elsewhere. The distance was, of course, exceedingly large, and impractical to traverse given the current price of gasoline...


It is interesting that scientists who otherwise insist that science should be experimentally verifiable nevertheless postulate the multiverse theory. There is absolutely no observable evidence for it. It only exists as the figment of the imagination of theoretical physicists.


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## KenOC (Mar 7, 2011)

DavidA said:


> It is interesting that scientists who otherwise insist that science should be experimentally verifiable nevertheless postulate the multiverse theory. There is absolutely no observable evidence for it. It only exists as the figment of the imagination of theoretical physicists.


Actually, I understand that it may be possible to get evidence supporting this theory (I have no idea how). And if nothing else, it's a great figment!  BTW scientists can postulate anything they like without breaking "the rules." Verification is another matter of course.


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## DavidA (Dec 14, 2012)

KenOC said:


> Actually, I understand that it may be possible to get evidence supporting this theory (I have no idea how). And if nothing else, it's a great figment!  BTW scientists can postulate anything they like without breaking "the rules." Verification is another matter of course.


Science is the belief in the ignorance of experts. (Richrd Feynmann)


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## ahammel (Oct 10, 2012)

DavidA said:


> It is interesting that scientists who otherwise insist that science should be experimentally verifiable nevertheless postulate the multiverse theory. There is absolutely no observable evidence for it. It only exists as the figment of the imagination of theoretical physicists.


It's one of several possible interpretations of a theory that does have plenty of observable evidence behind it. Theoretical physicists understand that. Hell, _I_ understand it and I'm only a biologist.


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## DavidA (Dec 14, 2012)

ahammel said:


> It's one of several possible interpretations of a theory that does have plenty of observable evidence behind it. Theoretical physicists understand that. Hell, _I_ understand it and I'm only a biologist.


You said theoretical physicists! There is no observable evidence for a multi-verse.


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## ahammel (Oct 10, 2012)

DavidA said:


> You said theoretical physicists! There is no observable evidence for a multi-verse.


I know! They know!

There are several possible interpretations of quantum mechanics. We can't choose a 'right' one with current givens. The many-worlds interpretation is among these.


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## clavichorder (May 2, 2011)

2001 one space odysee by Arthur C. Clarke opened my mind up to some possibilities after reading it. Asimov's novels always made me shun the probability of intelligent alien life in this galaxy. But upon reading the last of the Foundation set of 6 books, he sort of considered that a good 30,000 or more years in the future, with humanity having colonized many worlds and going through a galactic empire that fell apart, with a new dark ages, people sort of started to figure things out. And then the possibility of some intelligent life form hostile or otherwise from another galaxy was put forth. 

Asimov had a really big picture in his head, as did Herbert apparently. It would be cool if things were relatively more simple and quick like Star Trek.

I am sort of coming onto some mixed feelings about space exploration at this stage.

Anyway, I sort of hope not, sort of hope yes. I hope eventually alien life's existence can be proven. It would be great if there was a Vulcan ship waiting to make first contact with us when they believed us ready.

I confess I know very little of the current science and thinking on this topic.


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## mmsbls (Mar 6, 2011)

DavidA said:


> It is interesting that scientists who otherwise insist that science should be experimentally verifiable nevertheless postulate the multiverse theory. There is absolutely no observable evidence for it. It only exists as the figment of the imagination of theoretical physicists.





DavidA said:


> You said theoretical physicists! There is no observable evidence for a multi-verse.


I'm not sure what you're trying to say here. Scientists believe science ultimately should be based on empirical data (experimentally verifiable), but theorists create theories for various reasons. _All_ good theories are based on extensive evidence, but some theories are not developed _because of new evidence_. Examples of the latter from cosmology and/or particle physics are string theory, the Higgs field, supersymmetry, anti-matter, and the multiverse. Are you suggesting that theorists ought not create theories such as these? As an experimental physicist, I believe such new theories are critical to the ultimate understanding of reality (along with experimental side, of course).


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## EddieRUKiddingVarese (Jan 8, 2013)

mmsbls said:


> I'm not sure what you're trying to say here. Scientists believe science ultimately should be based on empirical data (experimentally verifiable), but theorists create theories for various reasons. _All_ good theories are based on extensive evidence, but some theories are not developed _because of new evidence_. Examples of the latter from cosmology and/or particle physics are string theory, the Higgs field, supersymmetry, anti-matter, and the multiverse. Are you suggesting that theorists ought not create theories such as these? As an experimental physicist, I believe such new theories are critical to the ultimate understanding of reality (along with experimental side, of course).


Think you touched a nerve there DavidA and got a pretty heavy hitting response too.

You gotta learn to love those particle/ wave like things -were made of them you know.


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## BlazeGlory (Jan 16, 2013)

DavidA said:


> It is interesting that scientists who otherwise insist that science should be experimentally verifiable nevertheless postulate the multiverse theory. There is absolutely no observable evidence for it. It only exists as the figment of the imagination of theoretical physicists.





mmsbls said:


> I'm not sure what you're trying to say here. Scientists believe science ultimately should be based on empirical data (experimentally verifiable), but theorists create theories for various reasons. _All_ good theories are based on extensive evidence, but some theories are not developed _because of new evidence_. Examples of the latter from cosmology and/or particle physics are string theory, the Higgs field, supersymmetry, anti-matter, and the multiverse. Are you suggesting that theorists ought not create theories such as these? As an experimental physicist, I believe such new theories are critical to the ultimate understanding of reality (along with experimental side, of course).


So, will we prove the existence of alien life in your lifetime?

I'll consider these above posts to be definite votes for the affirmative!!! No, wait a minute, I think they may possibly be "no" votes. Er, maybe they're "maybe" votes. Oh h**l, I don't know.


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## DavidA (Dec 14, 2012)

mmsbls said:


> I'm not sure what you're trying to say here. Scientists believe science ultimately should be based on empirical data (experimentally verifiable), but theorists create theories for various reasons. _All_ good theories are based on extensive evidence, but some theories are not developed _because of new evidence_. Examples of the latter from cosmology and/or particle physics are string theory, the Higgs field, supersymmetry, anti-matter, and the multiverse. Are you suggesting that theorists ought not create theories such as these? As an experimental physicist, I believe such new theories are critical to the ultimate understanding of reality (along with experimental side, of course).


Please note what I said. I was talking in particular of the multiverse theory and saying there is no observable experimental verification of it. Please do not extrapolate that to imply that I am saying that all the work of theoretical physics is invalid. As a trained physicist myself I would not, of course, say such a thing.
I was certainly not saying that theoretical physicists should not be allowed to theorise. That its the nature of science. But we must realise when theories are theories not established facts. A problem is that people - often through the power of the media - embrace theories as facts. At present the multiverse is a theory held by some theoretical physicists and disputed by others. It is certainly not proven fact. Let's face it, of our own universe it has been estimated we only know about 6 percent of what is up there with any degree of certainty. The rest is speculation based on our (even today limited) observations. 
The same is true of small particles. The more we know the more we reduce matter to probabilities. Interestingly when I studied physics I remember my old prof saying that nuclear physics was an expensive way of causing mass confusion! That is not to decry the amazing discoveries and incredibly ingenious theories that have been made by theoretical physicists to interpret the behaviour of matter. And the very real benefits we have from their expertise. But to recognise that with all our ingenuity matter remains enigmatic.


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## mmsbls (Mar 6, 2011)

DavidA said:


> Please note what I said. I was talking in particular of the multiverse theory and saying there is no observable experimental verification of it. Please do not extrapolate that to imply that I am saying that all the work of theoretical physics is invalid.


I think I understand. I certainly didn't think you felt that all or even some work of theoretical physics is invalid since you didn't mention anything along those lines. I was confused by the words, "interesting", "otherwise", and "nevertheless" in your sentence. I would have said, "Scientists insist that science should be experimentally verifiable _and_ postulate the multiverse theory." If you simply meant to say there is no direct evidence for the Multiverse, I agree.


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## Ryan (Dec 29, 2012)

BlazeGlory said:


> What parts of of the hypothesis do you think are the 20% that may not be true? I would like to suggest these for starters: Alien, Lizard, shape shifting reptillians.


Well it could be the fact that none of his books come in paperback. Coincidence? Or straw man argument?


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