Anyone interested in Extra-terrestrial life?

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Fnord
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16 May 2013, 9:13 pm

Sir Arthur C. Clarke made a famous observation about space explorers discovering aliens. If one considers the millions of years of pre-history, and the rapid technological advancement occurring now, if you apply that to a hypothetical alien race, one can figure the probabilities of how advanced the explorers will find them. The conclusion is "we will find apes or angels, but not men."

Why? Consider the history of Planet Earth. Let the height of the Empire State building represent the 5 billion year life of Terra. The height of a one-foot ruler perched on top would represent the million years of Man's existence. The thickness of a dime will represent the ten thousand years of Man's civilization. And the thickness of a postage stamp will represent the 300 years of Man's technological civilization. An unknown portion above represents "pre-Singularity Man", the period up to the point where mankind hits the Singularity/evolves into a higher form/turns into angels. Say another dime. Above that would be another Empire State building, representing the latter 5 billion years of Terra's lifespan.

If you picked a millimeter of this tower at random, what would you most likely hit? One of the Empire State buildings, of course. So, assuming only one civilization develops on a planet, chances are the first-in-scout starship Daniel Boone will discover mostly planets that are currently empty of alien civilizations (but they might have an almost 50% chance to discover valuable Forerunner artifacts or other paleotechnology).

As a matter of terminology, a long-extinct star faring alien civilization are commonly called "Forerunners", "Precursors", "Ancients", "Elder race", "Progenitors", or "Predecessors". Their thousand year old ruins are sobering, but their high-tech artifacts are generally far in advance of current tech levels and are of course both incredibly valuable yet incredibly dangerous. Archaeologists who stumble over such remains have a tendency to be killed by pirates, and their artifacts stolen.

If you only use the section with an alien civilization, you have a ruler and two dimes worth of apes and angels, and a postage stamp worth of near Human civilization. Ergo: apes or angels, but not men.

As a side note, one can use the time between apes and angels for the "average lifespan of a technological civilization". Insert this into the Drake equation along with a few other guesses and you can calculate the average distance between alien civilization homeworlds. (and of course the distance between Terra and the closest aliens).

Consider the high improbability that any two Earth-like planets will form and evolve to the exact and ideal conditions that develop and support carbon-based life.

Consider also the number of mass extinctions that have occurred in Earth's past. It is unlikely that the same number of these would occur on another Earth- like world at exactly the same time and with the exact same frequency.

[SPECULATION]

Finally, consider the cultural developments in Earth's history, and apply a few "What Ifs":

  • What if Democracy had never developed beyond the conceptual stage?
  • What if Rome had never fallen?
  • What if Columbus had never received any financial backing from the Spaniards?
  • What if the Nazis had developed the atomic bomb first?
Would any of one of these events have delayed or advanced human development by as much as 0.001%?

One value given for the age of the Earth is 4.567 billion years. A +/- 0.001% change would set human evolution back by 4.567 million years (Apes), or advance it by 4.567 million years (Angels).

Thus, by "Apes & Angels" one could say that any two worlds that formed at exactly the same time, and that have had billions of years to go from dust to sentient life, could differ by as much as 9.134 million years in evolution!

A divergence of only 0.000001% would still separate the two extremes by 9.134 thousand years. With this value, one alien world could have a bronze-age culture (year = 2560 BCE), while another could be far ahead of our own, both culturally and technologically (year = 6574 CE). Maybe not "Apes & Angels" but perhaps "Cavemen & Supermen"?

[/SPECULATION]



CockneyRebel
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16 May 2013, 9:14 pm

I'm very interested in extra terrestrial life. I've always had a feeling that there were many of galaxies out there in space. I imagine that there millions of galaxies and universes that have millions of Earth like planets. I'd like to see those Earth like planets in my lifetime.


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Anomiel
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17 May 2013, 2:09 am

Fnord wrote:
We know what chemistry a silicon-based life-form would need to live, but no such chemical signatures have been detected ... yet.

So let's not get ahead of ourselves here.


It would fit perfectly on Titan. :mrgreen:



Fnord
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17 May 2013, 9:58 am

Anomiel wrote:
Fnord wrote:
We know what chemistry a silicon-based life-form would need to live, but no such chemical signatures have been detected ... yet. So let's not get ahead of ourselves here.
It would fit perfectly on Titan. :mrgreen:

No, Titan's atmosphere is mostly nitrogen, with methane and ethane clouds and nitrogen-rich organic smog. It is is thought to be a possible host for microbial organic life or, at least, as a prebiotic environment rich in complex organic chemistry with a possible subsurface liquid ocean serving as a biotic environment.

Silicon, unlike carbon, lacks the ability to form chemical bonds with diverse types of atoms necessary for the chemical versatility required for metabolism. Silanes, which are chemical compounds of hydrogen and silicon that are analogous to the alkane hydrocarbons, are highly reactive with water, and long-chain silanes spontaneously decompose. Molecules incorporating polymers of alternating silicon and oxygen atoms instead of direct bonds between silicon, known collectively as silicones, are much more stable. It has been suggested that silicone-based chemicals would be more stable than equivalent hydrocarbons in a sulfuric-acid-rich environment, as is found in some extraterrestrial locations. Complex long-chain silicone molecules are still less stable than their carbon counterparts, though.

Silicon dioxide (a common ingredient of many sands), the analog of carbon dioxide, is a non-soluble solid at the temperature range where water is liquid, making it difficult for silicon to be introduced into water-based biochemical systems even if the necessary range of biochemical molecules could be constructed out of it. Another problem with silicon dioxide is that it would be the product of aerobic respiration. If a silicon-based life form were to breathe using oxygen, as life on Earth does, it would possibly produce silicon dioxide as a by-product of this, assuming that the only difference between the two types of life is silicon in place of carbon. This implies that the exhaled product, silicon dioxide, would be a solid, thus filling the respiratory organs of the organism with sand. This however would be solved if the organism lives in temperatures of several hundred to thousand degrees, where the silicon dioxide becomes a liquid. Oxygen-breathing silicon life, if it exists, is therefore most likely to exist in environments with very high temperatures or pressure.

The surface temperature of Titan has been measured at 93.7 °K (−179.5 °C). Ergo, Titan is too cold to host Silicon-based or Silicone-based life.

QED



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18 May 2013, 11:04 am

http://www.kokogiak.com/megapenny/eleven.asp
This is what 100,000,000,000 looks like. That is how many stars there are per galaxy and how many galaxies there are!! If 1 out of every 100,000,000,000 stars had a planet around it that had a civilization that would be equal to the amount of pennies on that football field!!


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19 May 2013, 11:07 am

http://www.dailymail.co.uk/sciencetech/ ... -life.html


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19 May 2013, 11:10 am

Fnord wrote:
Anomiel wrote:
Fnord wrote:
We know what chemistry a silicon-based life-form would need to live, but no such chemical signatures have been detected ... yet. So let's not get ahead of ourselves here.
It would fit perfectly on Titan. :mrgreen:

No, Titan's atmosphere is mostly nitrogen, with methane and ethane clouds and nitrogen-rich organic smog. It is is thought to be a possible host for microbial organic life or, at least, as a prebiotic environment rich in complex organic chemistry with a possible subsurface liquid ocean serving as a biotic environment.

Silicon, unlike carbon, lacks the ability to form chemical bonds with diverse types of atoms necessary for the chemical versatility required for metabolism. Silanes, which are chemical compounds of hydrogen and silicon that are analogous to the alkane hydrocarbons, are highly reactive with water, and long-chain silanes spontaneously decompose. Molecules incorporating polymers of alternating silicon and oxygen atoms instead of direct bonds between silicon, known collectively as silicones, are much more stable. It has been suggested that silicone-based chemicals would be more stable than equivalent hydrocarbons in a sulfuric-acid-rich environment, as is found in some extraterrestrial locations. Complex long-chain silicone molecules are still less stable than their carbon counterparts, though.

Silicon dioxide (a common ingredient of many sands), the analog of carbon dioxide, is a non-soluble solid at the temperature range where water is liquid, making it difficult for silicon to be introduced into water-based biochemical systems even if the necessary range of biochemical molecules could be constructed out of it. Another problem with silicon dioxide is that it would be the product of aerobic respiration. If a silicon-based life form were to breathe using oxygen, as life on Earth does, it would possibly produce silicon dioxide as a by-product of this, assuming that the only difference between the two types of life is silicon in place of carbon. This implies that the exhaled product, silicon dioxide, would be a solid, thus filling the respiratory organs of the organism with sand. This however would be solved if the organism lives in temperatures of several hundred to thousand degrees, where the silicon dioxide becomes a liquid. Oxygen-breathing silicon life, if it exists, is therefore most likely to exist in environments with very high temperatures or pressure.

The surface temperature of Titan has been measured at 93.7 °K (−179.5 °C). Ergo, Titan is too cold to host Silicon-based or Silicone-based life.

QED


It's very interesting, but I don't think you should assume Titan wouldn't be suitable.

http://astrowright.wordpress.com/2010/03/18/target-titan/ wrote:
Our current understanding of physics, chemistry, and their roles in biology suggest that an organism could survive using an entirely non-carbon-based metabolism. Silicon is a likely first place to look for alternatives. Like carbon, (the chemical backbone of life as we know it,) silicon can form four bonds, stable bonds with itself and other elements, and long chemical chains known as silanes, which are very similar to the hydrocarbons essential to life on Earth. Silicon is more reactive than carbon, which could make it optimal for extremely cold environments.

However, silanes spontaneously burn in the presence of oxygen, so an oxygen atmosphere would be deadly to any silicon-based life, and water as a solvent would be equally deadly for the same reason. So, any environment with the potential for silicon-based life would have to be very cold, devoid of oxygen and water, but with another compatible solvent, such as liquid methane. Sound familiar?

Of all places in the Solar System, Titan seems to be the only place active enough for life to currently exist. -And even though Titan is definitely an alien and hostile place, it looks like we’ve identified a way for life there, as Crichton’s Ian Malcom famously put it, to “find a way.”



Last edited by Anomiel on 19 May 2013, 11:32 am, edited 1 time in total.

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19 May 2013, 11:30 am

I do believe there's something out of space but I don't think it's aileens and I don't think they want to "invade earth". I hate they theory of the "goldilocks effect". They could be able to survive in extreme conditions.



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02 Jun 2013, 12:57 pm

^ Astrobiologists already know that, that's why they study extremophiles.
The goldilocks-zone only matter if we want to find places that can support us or life like us.
Planets with other properties could have (theoretical) silicone-based life or freaky things like earths own archaea :)



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02 Jun 2013, 1:22 pm

CockneyRebel wrote:
I've always had a feeling that there were many of galaxies out there in space.


I always shared the same feeling. Probably, it's due to that there's actually many of galaxies out there in space :lol:


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02 Jun 2013, 1:34 pm

More then 100,000,000,000 galaxies!!


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