Planets that can potentially support life... - Page 30

On February 27 2013 01:43 marconi wrote:
I hate to be the "conspiracy theorist" but let's analyze the situation:

All of us here ( or most of us at least ) BELIEVE that it's impossible for humans to be the only "intelligent" life forms in the universe.

If we take this into consideration, and the possibility of numerous alien species living "somewhere" in the universe, there is also the possibility that some of these alien races are more advanced than we are ( the main argument here would be that they are much older than we are, because humans have existed for a very short time according to the popular belief ).

Now if these races are far more advanced than we are, chances are they have developed faster-than-light travel and even more crazy stuff than we could ever dare to believe existed.

It might just happen that their "technology" or whatever they posses, being the ancient civilization they are, also allows them to map out the ENTIRE GALAXY ( can u believe that shit, pure sci-fi I tell ya ).

Oh and look, they find a planet orbiting a certain yellow star, in it's "habitable zone", has liquid water on it's surface, can you believe that?

Now there can be a lot of theories regarding this, but I think in the end it's safe assume that they PROBABLY know of our existence (assuming ofc we all agree that it's impossible for us to be alone in the universe). I am also relatively certain that they can avoid detection by us if the wish to do so.

If anyone here watched Star Trek, you know that the Vulcans are the first race who contacted humans, and it just so happened that they decided to wait until we developed warp drive.

Now, we didn't develop warp drive as far as I know, but we did WENT INTO SPACE. I think that's a pretty big deal for a budding race like us. Now, I'm no ET, but I'm assuming that a space-traveling race would qualify for further study, hm?

But then again, maybe I'm crazy.

On February 27 2013 01:21 Abraxas514 wrote:


http://en.wikipedia.org/wiki/Fermi_paradox

There are many hypothetical solutions to the paradox, but it seems there must be much more to the universe than we realize, or else the predictions should be visible.

(I just read through the article and it's missing the chariot of the gods hypothesis!)

On February 27 2013 01:43 marconi wrote:
I hate to be the "conspiracy theorist" but let's analyze the situation:

All of us here ( or most of us at least ) BELIEVE that it's impossible for humans to be the only "intelligent" life forms in the universe.

If we take this into consideration, and the possibility of numerous alien species living "somewhere" in the universe, there is also the possibility that some of these alien races are more advanced than we are ( the main argument here would be that they are much older than we are, because humans have existed for a very short time according to the popular belief ).

Now if these races are far more advanced than we are, chances are they have developed faster-than-light travel and even more crazy stuff than we could ever dare to believe existed.

It might just happen that their "technology" or whatever they posses, being the ancient civilization they are, also allows them to map out the ENTIRE GALAXY ( can u believe that shit, pure sci-fi I tell ya ).

Oh and look, they find a planet orbiting a certain yellow star, in it's "habitable zone", has liquid water on it's surface, can you believe that?

Now there can be a lot of theories regarding this, but I think in the end it's safe assume that they PROBABLY know of our existence (assuming ofc we all agree that it's impossible for us to be alone in the universe). I am also relatively certain that they can avoid detection by us if the wish to do so.

If anyone here watched Star Trek, you know that the Vulcans are the first race who contacted humans, and it just so happened that they decided to wait until we developed warp drive.

Now, we didn't develop warp drive as far as I know, but we did WENT INTO SPACE. I think that's a pretty big deal for a budding race like us. Now, I'm no ET, but I'm assuming that a space-traveling race would qualify for further study, hm?

But then again, maybe I'm crazy.

humans have existed for a very short time according to the popular belief

also allows them to map out the ENTIRE GALAXY

maybe I'm crazy

On February 27 2013 06:49 MrRicewife wrote:
Speak for yourself. Intelligence is random. There is just as much chance of life being unintelligent as there is to being intelligent. For eons this earth was occupied by unintelligent life. To be certain of anything involving intelligent life on other planets is asinine. I appreciate theories and good discussion but come on ... You act divine.

Or you successfully just trolled me.

On February 27 2013 07:23 Tanukki wrote:
So what would the gravity be like on a planet 3* the mass of earth? I'd imagine a bit rough? People living there must be dwarves :D

On February 27 2013 07:37 Simberto wrote:


Depends on the density, but if we assume it has an earth-like density, tripling the mass would mean that it also has a cubic root(3) larger radius. As the gravitational force on one body is proportional to m/r², the gravitational pull would increase by 3/3^(2/3), or 3^1/3. This is about 1.44.

On February 27 2013 06:49 MrRicewife wrote:
Speak for yourself. Intelligence is random. There is just as much chance of life being unintelligent as there is to being intelligent. For eons this earth was occupied by unintelligent life. To be certain of anything involving intelligent life on other planets is asinine. I appreciate theories and good discussion but come on ... You act divine.

Or you successfully just trolled me.

On February 27 2013 07:44 Hitch-22 wrote:


The assumption is unfounded on what would live there simply because they wouldn't be human (or earthborn) such that they could be EXACTLY the same as us with just simply less or more dense body masses (stronger bones or weaker depending).

Neil Degrasse Tyson has a nice rant on how he hates 'alien' movies because they make them all look like humans when they could look like anything, have imagination. Richard Dawkin's replied, however in rebuke, that it could be the case that aliens become similar to humans through the same evolutionary process, bigger brains, opposable thumbs etc are very strong evolutionary tendencies for earths enviornment and a similar one would bare the same fruit most likely followings Darwinian Theory, the strong survive while the weak die etc etc.

On February 27 2013 07:47 Tadatomo wrote:


For like 2.8 billion years we had only the most simple lifeforms(compared to what we have now). Only after 2.8 million years there was enough of time for a 'dice roll' to generate multicellular life. Now that's a whole long time. For about 1/3rd of the earth's history single celled life was the only solution needed to survival.

Then something strange happened an a plethora of complex life did evolve. Now only a small bit of biomass of this complex life actually has a brain. Most of these brains are quite simple compared to us and we are not impressed with their cognitive abilities. On the other hand, compared to our counters they are pretty smart, especially in their own way.

But we can say that only humans can be considered intelligent. Life on earth is like 4599 years without any intelligence. And then 1 million years with 1 species that has intelligence.

So I would not call it out to be 50/50 when even on earth, which might be an extremely exceptional case, intelligence is so exceedingly rare.

Maybe there is an almost endless number of extremely rare traits that can evolve. And on earth there was life long enough for one of those exceedingly rare traits to evolve. And that ended up to be what we now call 'intelligence'. Maybe on all these other planets something entirely different rare trait evolves.

Intelligence seems to be a very odd survival strategy. We still cannot explain properly why we have the ability to do develop math for quantum mechanics and general relativity. Surely we didn't use that until about 100 years ago. Yet there was some evolutionary pressure selecting these genes about 1 million years ago. All those humans who were not smart enough somehow died out. Why? It is very strange. Our brains use a lot and a lot of energy. They have a huge huge overhead.

Intelligence, as humans have it, seems to be a fluke. It seems to generally be a very bad survival strategy that somehow was a good one under odd unexplained conditions, hence it evolved the way it did.

You can argue that certain traits will be convergent. The eye is a good example. It evolved several different times. If there is life on other planets they will likely evolve eyes once life also makes the jump to complex lifeforms(and remember that was an odd thing to happen and it took a lot of time for the odds or conditions to be right)

But intelligence? For all we know it is going to be unique to humans only. No good reasons for intelligence to evolve. And remember that while we have 6 billion people right now, so we can say we are successful and indeed this has to do with our intelligence, the number of humans around the time we evolved intelligence was quite low. It took a long time for our intelligence to come up with civilization before our numbers started to boom exponentially.
With all our intelligence, humans almost went extinct about a million of years ago. And when disaster hits earth, since our body weight is too big, we will die out together with all the other larger animals. Intelligence won't have any effect.

On February 27 2013 07:50 HardlyNever wrote:


I think he was just saying that the gravity on this particular planet wouldn't be that much stronger than earth's gravity (again, assuming it has a similar density).

As to what kinds of life forms that would produce is anyone's guess. I don't see any reason to assume it would create "stumpier" versions of earth life forms.

On February 27 2013 06:49 MrRicewife wrote:

Speak for yourself. Intelligence is random. There is just as much chance of life being unintelligent as there is to being intelligent. For eons this earth was occupied by unintelligent life. To be certain of anything involving intelligent life on other planets is asinine. I appreciate theories and good discussion but come on ... You act divine.

Or you successfully just trolled me.

Even dying stars could host planets with life -- and if such life exists, we might be able to detect it within the next decade. This encouraging result comes from a new theoretical study of Earth-like planets orbiting white dwarf stars. Researchers found that we could detect oxygen in the atmosphere of a white dwarf's planet much more easily than for an Earth-like planet orbiting a Sun-like star.

"In the quest for extraterrestrial biological signatures, the first stars we study should be white dwarfs," said Avi Loeb, theorist at the Harvard-Smithsonian Center for Astrophysics (CfA) and director of the Institute for Theory and Computation.

When a star like the Sun dies, it puffs off its outer layers, leaving behind a hot core called a white dwarf. A typical white dwarf is about the size of Earth. It slowly cools and fades over time, but it can retain heat long enough to warm a nearby world for billions of years.

Since a white dwarf is much smaller and fainter than the Sun, a planet would have to be much closer in to be habitable with liquid water on its surface. A habitable planet would circle the white dwarf once every 10 hours at a distance of about a million miles.

Before a star becomes a white dwarf it swells into a red giant, engulfing and destroying any nearby planets. Therefore, a planet would have to arrive in the habitable zone after the star evolved into a white dwarf. A planet could form from leftover dust and gas (making it a second-generation world), or migrate inward from a larger distance.

If planets exist in the habitable zones of white dwarfs, we would need to find them before we could study them. The abundance of heavy elements on the surface of white dwarfs suggests that a significant fraction of them have rocky planets. Loeb and his colleague Dan Maoz (Tel Aviv University) estimate that a survey of the 500 closest white dwarfs could spot one or more habitable Earths.

The best method for finding such planets is a transit search -- looking for a star that dims as an orbiting planet crosses in front of it. Since a white dwarf is about the same size as Earth, an Earth-sized planet would block a large fraction of its light and create an obvious signal.

More importantly, we can only study the atmospheres of transiting planets. When the white dwarf's light shines through the ring of air that surrounds the planet's silhouetted disk, the atmosphere absorbs some starlight. This leaves chemical fingerprints showing whether that air contains water vapor, or even signatures of life, such as oxygen.

On September 13 2011 05:39 zimz wrote:
i always knew there were thousand if not millions of planets like earth out there like over 10 years ago. i thought it was quite close minded for many people to assume earth is exceptionally rare and maybe the only one etc.

On February 27 2013 09:47 zz_ wrote:


An earth-like planet is not exceptionally rare, but it's far from common. And (iirc) we don't know of any planet that is exactly like ours.

On February 27 2013 18:57 Grumbels wrote:
I think the following solution to the Fermi paradox is quite clever: all sufficiently advanced civilizations are intelligent enough to not advertise their existence to the rest of the universe out of a healthy sense of paranoia.

It's a good thing probably that the world has protocols for this and doesn't allow amateurs with a fascination for space to basically create a giant homing beacon for a possibly predatory race of star travelers.