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Evolution on earth vs around the universe


raizen27
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So I'm always hearing that humans are such a young species and that there's probably much more complex life out there in the universe somewhere. I always agreed with that statement and didn't think anything of it until recently..

I thought, there has been life on earth for billions of years now and it's only now that intelligent beings are coming about, meaning that it takes a long time for evolution to figure it out. Give or take a few million years, who knows if any other species could do it much faster? You don't just pop into existence as galaxy roaming super aliens. Chances are that if there is life elsewhere, there are just a bunch of dinosaurs having the time of their lives on some huge super earth with all the leaves imaginable. Or that they didn't even make it that far at all. On the other hand there could be another species somewhere in nearly the exact same place technologically as we are, there's infinite room for possibilities, really.

Any way you look at it, it seems that we could be the farthest ahead, or at least close to the front of the pack on those terms, provided there's anybody else out there to compete against at all.

 

Thoughts? Comments? I'd love to hear opinions on this from people

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I see no reason to assume we are at the front of the pack, a few million years difference could make us so advanced we would be god like but there is no reason to assume intelligence wasn't possible during the time of the dinosaurs, near the end quite a few species were developing signs of large brains, gripping hands, the asteroid was just bad luck. Take out that asteroid impact and a tens of millions of years old civilization of some species of dinosaur could be in control. If we take the idea of mediocrity seriously then we should be about average but millions of year old civilizations are not out of the question. the real question is "where are they"...

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haven't read this yet, but very interesting topic

 

So I'm always hearing that humans are such a young species and that there's probably much more complex life out there in the universe somewhere. I always agreed with that statement and didn't think anything of it until recently..

I thought, there has been life on earth for billions of years now and it's only now that intelligent beings are coming about, meaning that it takes a long time for evolution to figure it out. Give or take a few million years, who knows if any other species could do it much faster? You don't just pop into existence as galaxy roaming super aliens. Chances are that if there is life elsewhere, there are just a bunch of dinosaurs having the time of their lives on some huge super earth with all the leaves imaginable. Or that they didn't even make it that far at all. On the other hand there could be another species somewhere in nearly the exact same place technologically as we are, there's infinite room for possibilities, really.

Any way you look at it, it seems that we could be the farthest ahead, or at least close to the front of the pack on those terms, provided there's anybody else out there to compete against at all.

 

Thoughts? Comments? I'd love to hear opinions on this from people

if you remove anthropocentric,

then what is real ?

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As Moontanman said,

where are they?

Stars found so far tend to have a litter of planets, with estimates of 1012 planets in our galaxy. And, astronomers have observed many stars much older than Sol. It is incredible that intelligent life would not exist in the Milky Way. Folks at SETI believe there are at least 106 earth sized planets, but no one knows how many are habitable. SETI is currently searching for signals coming from stars within 1000 light years of Earth, which is a tiny fraction of stars in the galaxy.

 

Given these estimates are accurate within a factor of 10, it seems reasonable to me that we will find intelligent life by the end of the century. Otherwise, technological civilizations are either extremely rare or exterminate themselves quickly.

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i always keep this thought in my head,

from star trek, first contact.

in it the scientist has to do the warp drive for the aliens(vulcan)to see intelligence,

in the movie if he did not do this,

the the aliens passing by would not have made contact due to believe of primitive species(humanity).

i always wonder if this is a possibility.

 

edit-

 

i also have the thought that carl sagan and the government came across something to this effect.

Edited by krash661
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i always keep this thought in my head,

from star trek, first contact.

in it the scientist has to do the warp drive for the aliens(vulcan)to see intelligence,

in the movie if he did not do this,

the the aliens passing by would not have made contact due to believe of primitive species(humanity).

i always wonder if this is a possibility.

 

edit-

 

i also have the thought that carl sagan and the government came across something to this effect.

It is unlikely that a civilization could envelop an entire planet in stealth. And, it is unlikely a civilization would deem it necessary to do so.

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It is unlikely that a civilization could envelop an entire planet in stealth. And, it is unlikely a civilization would deem it necessary to do so.

you think nasa is transparent ?

 

or did i not understand your comment ?

 

think about carl's book and the movie contact (1997)

 

 

edit-

 

and if i did misunderstand your comment then,

there are individuals that are less fortunate in knowledge than me.

they try to "contact" / talk to me every day.

 

i simply ignore them.

 

there are two different worlds here,

public eye and behind the scenes.

 

oh well.

i guess it's what you have access to.

Edited by krash661
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you think nasa is transparent ?

I do not understand your question.

 

Radio, television, and telephone signals emanate from the earth 7x24 and travel into space in all directions. Those signals can be picked up by civilizations on other stars if anyone is listening. Moreover, a powerful telescope on an exoplanet can detect signs of life from light reflected from the earth into space, such as oxygen in our atmosphere produced by plant life and green reflected into space from leaves of plants.

 

As long as we transmit radio, TV and cell phone signals, and as long as light is reflected from the earth into space, we are detectable by alien life. And, ATM no technology exists or has been proposed that is capable of hiding signs of life in all of the EMF (radio and light) signals leaving the Earth.

 

I have no more access than any other citizen.

Edited by EdEarl
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I do not understand your question.

 

Radio, television, and telephone signals emanate from the earth 7x24 and travel into space in all directions. Those signals can be picked up by civilizations on other stars if anyone is listening. Moreover, a powerful telescope on an exoplanet can detect signs of life from light reflected from the earth into space, such as oxygen in our atmosphere produced by plant life and green reflected into space from leaves of plants.

 

As long as we transmit radio, TV and cell phone signals, and as long as light is reflected from the earth into space, we are detectable by alien life. And, ATM no technology exists or has been proposed that is capable of hiding signs of life in all of the EMF (radio and light) signals leaving the Earth.

 

I have no more access than any other citizen.

the problem here is,

it's obvious you do not understand anything i said.

simple.

 

edit-

 

knowledge is the treasure.

anything less than what already exist,

is primitive.

Edited by krash661
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I do not understand your question.

 

Radio, television, and telephone signals emanate from the earth 7x24 and travel into space in all directions. Those signals can be picked up by civilizations on other stars if anyone is listening.

 

Actually no, this is one of things that gets told over and over but in reality the interstellar medium absorbs the broadcasts from earth well within the confines of the local area around the Sun well before the nearest star could listen in to I Love Lucy. The fact that the radio telescope at Arecibo could detect itself across the known universe (one of things claimed over and over as well) does not pertain to passive listening but instead assumes a intentional very powerful signal.

 

Military radars are about the only signals likely to be detected across interstellar distances and in fact signals similar to military radar have indeed been detected from areas closer to the center of our galaxy than us but did not repeat and so were not candidates for evidence of ET even though such radars on Earth would be unlikely to be repetitive in the way a radio broadcast would.

 

Moreover, a powerful telescope on an exoplanet can detect signs of life from light reflected from the earth into space, such as oxygen in our atmosphere produced by plant life and green reflected into space from leaves of plants.

 

This is not quite possible yet but is in the realm of possibility.

 

As long as we transmit radio, TV and cell phone signals, and as long as light is reflected from the earth into space, we are detectable by alien life. And, ATM no technology exists or has been proposed that is capable of hiding signs of life in all of the EMF (radio and light) signals leaving the Earth.

 

I have no more access than any other citizen.

 

 

As I said this is a mistake idea.

Edited by Moontanman
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As long as we transmit radio, TV and cell phone signals, and as long as light is reflected from the earth into space, we are detectable by alien life. And, ATM no technology exists or has been proposed that is capable of hiding signs of life in all of the EMF (radio and light) signals leaving the Earth.

As I said this is a mistake idea.

Why do you say it is a mistaken idea, insufficient power due to distance attenuating the signal, absorption of the signal by interstellar matter, or noise from other sources hiding the signal? What is SETI searching for with radio telescopes?

 

Many radio frequencies penetrate our atmosphere quite well, and this led to radio telescopes that investigate the cosmos using large radio antennas. Furthermore, human endeavors emit considerable electromagnetic radiation as a byproduct of communications such as television and radio. These signals would be easy to recognize as artificial due to their repetitive nature and narrow bandwidths. If this is typical, one way of discovering an extraterrestrial civilization might be to detect non-natural radio emissions from a location outside our Solar System.

From: http://en.wikipedia.org/wiki/Seti#Realized_Interstellar_Radio_Message_projects

 

Military radars are about the only signals likely to be detected across interstellar distances

Some of the most powerful military radars, now abandoned, were on the DEW line. Their peak (pulse) output was 160KW with a 400W average. Now that satellites provide the military with early warning, powerful military radar is not nearly as important as it once was.

 

On the other hand, clear channel radio broadcasts of up to 100KW continue today, and that is continuous power, not a microsecond pulse as radar uses. Moreover, the military prefer to use stealth, but radar provides a beacon for enemies to track ones location, which is another reason the military need to avoid powerful radar signals. Thus, the military use spread spectrum transmissions that transmit a signal on several frequencies simultaneously, with the frequencies continuously changing. Only a receiver programmed to receive the same sequence of frequencies can detect such signals. Low total power, spread spectrum radar and communication provides stealth and avoids high power on any frequency. These techniques will prevent SETI from detecting military signals, even from Earth.

Edited by EdEarl
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Why do you say it is a mistaken idea, insufficient power due to distance attenuating the signal, absorption of the signal by interstellar matter, or noise from other sources hiding the signal? What is SETI searching for with radio telescopes?

 

From: http://en.wikipedia.org/wiki/Seti#Realized_Interstellar_Radio_Message_projects

 

Some of the most powerful military radars, now abandoned, were on the DEW line. Their peak (pulse) output was 160KW with a 400W average. Now that satellites provide the military with early warning, powerful military radar is not nearly as important as it once was.

 

On the other hand, clear channel radio broadcasts of up to 100KW continue today, and that is continuous power, not a microsecond pulse as radar uses. Moreover, the military prefer to use stealth, but radar provides a beacon for enemies to track ones location, which is another reason the military need to avoid powerful radar signals. Thus, the military use spread spectrum transmissions that transmit a signal on several frequencies simultaneously, with the frequencies continuously changing. Only a receiver programmed to receive the same sequence of frequencies can detect such signals. Low total power, spread spectrum radar and communication provides stealth and avoids high power on any frequency. These techniques will prevent SETI from detecting military signals, even from Earth.

 

 

http://zidbits.com/2011/07/how-far-have-radio-signals-traveled-from-earth/

 

 

 

While it’s interesting to imagine how far our radio signals have traveled into space, it’s extremely unlikely that an alien will be able to catch the latest episode of ‘I Love Lucy’. This is thanks to the inverse square law. In Layman’s term, it’s a form of signal degradation.

As radio signals leave earth, they propagate out in a wave form. Just like dropping a stone in a lake, the waves diffuse or “spread out” over distance thanks to the exponentially larger area they must encompass. The area can be calculated by multiplying length times width which is why we measure it in square units – square centimeters, square miles, etc. This means that the further away from the source, the more square units of area a signal has to ‘illuminate’.

 

Another way to think of it, is that the strength of a radio signal will be only 1/4 as great once you are twice the distance from the source. At ten times the distance, the strength of the signal would only be one hundredth as great.

Because of this inverse square law, all of our radio signals become indistinguishable from background noise at around a few light-years from earth. For a civilization only a couple hundred light-years away, trying to listen to our broadcasts would be like trying to detect the small ripple from a pebble dropped in the pacific ocean off the coast of California – from Japan.

 

 

There is also the problem of interstellar dust and gas absorbing the signals.,

 

I think the DEW line would have directed most of it's energy around the curvature of the Earth and not directly out into space and was designed to specifically do just that.

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I think the DEW line would have directed most of it's energy around the curvature of the Earth and not directly out into space and was designed to specifically do just that.

True, the only radar I know of intended for use outside the Earth's atmosphere is Arecibo. Although, AFAIK they have not transmitted in many years.

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I see no reason to assume we are at the front of the pack.

 

None whatsoever. I would say it's just the opposite. Our Sun is a fairly young star. Somewhere out in the universe there surely is, or was, an intelligent species that arose before our own Sun was even born.

 

However, ...

 

It is incredible that intelligent life would not exist in the Milky Way.

 

I disagree. From my own rare Earth point of view, I would find it quite incredible if intelligent life did exist somewhere else in the Milky Way. Note well: I said rare Earth, not unique Earth. To think that we are the sole intelligent life form in the universe is, to me, a ludicrous proposition.

 

To think that we are essentially alone in the universe is not so ludicrous. Suppose there are a million or so truly Earth-like planets in our galaxy, but suppose the odds of intelligent life arising on a truly Earth-like planet is a one in a billion chance. That means that not only are we the sole intelligent life form in our galaxy, we are most likely the sole intelligent life form in our galactic cluster. These low odds would still mean that there are hundreds of millions of other intelligent forms in the universe. It would also mean that each and every one of those civilizations is essentially alone in the universe. By essentially alone I mean that we will never communicate with one of those other intelligent life forms even though there are hundreds of millions or more of them out there.

 

That intelligent life is extremely rare is, to me, the easiest answer to the Fermi paradox. We can't see ET and ET hasn't been here because the nearest ET is so ridiculously far away that communications and travel are impossible.

 

 

The fact that the radio telescope at Arecibo could detect itself across the known universe (one of things claimed over and over as well) does not pertain to passive listening but instead assumes a intentional very powerful signal.

 

You didn't say so, so I will. Those claims are pure nonsense. Locally, electromagnetic signals fall off in intensity inversely proportional to distance from the source. That alone will make any signal eventually become undetectable. Further afield there's interstellar / intergalactic dust that can obscure the source. Even further afield, there's the huge problem of the expansion of the universe. Unless an intelligent species somehow learned to harness the broadcast power of an active galactic nucleus, the redshift and consequent reduction intensity that results from expansion will hide even the most powerful of signals.

 

Here's what SETI itself has to say on this issue (http://www.seti.org/faq#obs12):

If an extraterrestrial civilization has a SETI project similar to our own, could they detect signals from Earth?

 

In general, no. Most earthly transmissions are too weak to be found by equipment similar to ours at the distance of even the nearest star. But there are some important exceptions. High-powered radars and the Arecibo broadcast of 1974 (which lasted for only three minutes) could be detected at distances of tens to hundreds of light-years with a setup similar to our best SETI experiments.

 

Becase it is extremly hard to accurately pinpoint the statistical value of lifes origination, it is yet nearly impossible to know how rare/frequent life is in the universe.

 

Exactly. We are doing statistic inference from a sample point of one, something that is always a bit dangerous. While I am of the personal opinion that intelligent life is extremely rare, that is just an opinion. The true answer is that we just don't know (but knowing one way or the other is a worthy pursuit).

Edited by D H
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my question is, why does it have to be earth like,

it's possible that only humans need an earth like planet,

and not necessarily other species that exist.

 

thinking above anthropocentric

Edited by krash661
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my question is, why does it have to be earth like,

it's possible that only humans need an earth like planet,

and not necessarily other species that exist.

 

thinking above anthropocentric

 

 

We only have one data point, no trends can be postulated from one data point, it's possible that silicon life exists in the methane lakes of Titan, I'm not going to hold my breath for it and one of Saturn's moons, the name escapes me right now, has geysers that shoot organic particles out into space. It's just simply too early to rule out the extremes but like DH I am betting that complex multicellular life is uncommon in the universe but i would take the bet that bacterial type life forms are quite common, even in our solar system...

 

DH, did you read my link? It graphically illustrated the point of signal lost and due to distance and why it's unlikely we would detect anyone who wasn't intentionally broadcasting a high powered signal... and yeah i should have pointed out the Arecibo example is mostly urban legend...

 

There also might be life that doesn't conform to our definitions of life as well, maybe an entire planetary ecology made up of one life form that has no cellular structure comes to mind but is of course pure speculation...

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like i said,

 

thinking above anthropocentric

an·thro·po·cen·tric

 

an·thro·po·cen·tric [ànthrəpə séntrik]

adj

1. treating humans as preeminent: regarding humans as the universe's most important entity

2. from point of view of humankind: seeing things in human terms, especially judging things according to human perceptions, values, and experiences

anthropocentric responses to the condition of animals

 

 

 

 

-an·thro·po·cen·tri·cal·ly, , adv

-an·thro·po·cen·trism, , n

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We only know of one planet with life, we cannot objectively say if this is an example of the norm or if it is an extreme example that has occurred no where else...

when we is used are you referring to humanity ?

 

if so then again,

 

like i said,

 

anthropocentric

 

edit-

 

if you remove anthropocentric,

then what is real ?

Edited by krash661
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when we is used are you referring to humanity ?

 

if so then again,

 

like i said,

 

anthropocentric

 

edit-

 

if you remove anthropocentric,

then what is real ?

 

 

Like i said, it's all we have, our point of view is the only one we have knowledge of, the only one we can have knowledge barring some contact of extraterrestrial nature. I do not see your point.

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