At Least 100 Billion Planets

Message boards : SETI@home Science : At Least 100 Billion Planets
Message board moderation

To post messages, you must log in.

Previous · 1 · 2 · 3 · 4 · Next

AuthorMessage
musicplayer

Send message
Joined: 17 May 10
Posts: 1847
Credit: 878,216
RAC: 78
Message 1199647 - Posted: 25 Feb 2012, 13:01:17 UTC - in response to Message 1199640.  

Any chance life started here on earth with either bacteria or viruses coming in from outer space, waking up from possible long lasting hibernation and starting evolving and replicating when once again waking up?

Bacteria are supposed to be one-celled organisms. What is the next second step following that? Am(o)eba?

Life is supposed to have started in water and later came up on shore evolving first into reptilian animals, later into mammals. The human race is supposed to have evolved from apes and as a result of this, we became an intelligent race.

My best guess is that birds did not evolve directly from fish, but from land based animals. This was really in the start of the dinosaur area. As far as I know, there were no birds before the age of dinosaurs. Maybe someone else knows more about this?
ID: 1199647 · Report as offensive
Profile William Rothamel
Avatar

Send message
Joined: 25 Oct 06
Posts: 3357
Credit: 1,341,063
RAC: 17
United States
Message 1199702 - Posted: 25 Feb 2012, 17:16:49 UTC - in response to Message 1199647.  

The birds evolved from dinosaurs. Scales became feathers.

Though there may still be some skeptics, the preponderance of evidence in the fossil record seems to support this conclusion.
ID: 1199702 · Report as offensive
Profile tullio Project Donor
Volunteer moderator
Volunteer tester

Send message
Joined: 9 Apr 04
Posts: 6661
Credit: 1,952,488
RAC: 1,082
Italy
Message 1199705 - Posted: 25 Feb 2012, 17:26:28 UTC
Last modified: 25 Feb 2012, 18:06:09 UTC

Was this the result of a global warming? I have read an article (on Science magazine) which says that in hot climates the animals' size tends to shrink, because it is easier to cool small animals.
Tullio
ID: 1199705 · Report as offensive
Profile Clyde Special Project $75 donor
Volunteer tester

Send message
Joined: 9 Aug 99
Posts: 12526
Credit: 44,846,843
RAC: 2,140
United States
Message 1199735 - Posted: 25 Feb 2012, 19:29:03 UTC - in response to Message 1199640.  

[quote]
It will be interesting to see if life developed o Mars and how long it lasted.


I hope they realize that we already brought life to the planet in the form of microbes.


Did we do that on Mars?

Those who cannot remember the past are condemned to repeat it.
--- George Santayana
ID: 1199735 · Report as offensive
Profile ML1
Volunteer tester

Send message
Joined: 25 Nov 01
Posts: 9414
Credit: 7,275,478
RAC: 928
United Kingdom
Message 1199836 - Posted: 25 Feb 2012, 23:35:15 UTC - in response to Message 1199705.  
Last modified: 25 Feb 2012, 23:36:24 UTC

Was this the result of a global warming? I have read an article (on Science magazine) which says that in hot climates the animals' size tends to shrink, because it is easier to cool small animals.

Unless you're a dinosaur with big cooling fins along your spine, or an elephant with very big ears, or humans with aircon...

But yes, having more surface area compared to mass (small) does appear to give an evolutionary advantage in high heat, and vice-versa (big) for cold.


All on just this one planet!
Martin
See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)
ID: 1199836 · Report as offensive
Profile Convergence
Avatar

Send message
Joined: 23 Jun 08
Posts: 117
Credit: 2,928,788
RAC: 0
United States
Message 1200229 - Posted: 27 Feb 2012, 2:32:58 UTC - in response to Message 1199735.  
Last modified: 27 Feb 2012, 2:33:38 UTC

[quote]
It will be interesting to see if life developed o Mars and how long it lasted.


I hope they realize that we already brought life to the planet in the form of microbes.


Did we do that on Mars?

Yes. The Mars rovers and other miscellaneous equipment that landed contained them. It wasn't intentional, though. Bacteria is everywhere here on Earth.
ID: 1200229 · Report as offensive
Profile Clyde Special Project $75 donor
Volunteer tester

Send message
Joined: 9 Aug 99
Posts: 12526
Credit: 44,846,843
RAC: 2,140
United States
Message 1200262 - Posted: 27 Feb 2012, 5:35:47 UTC - in response to Message 1200229.  
Last modified: 27 Feb 2012, 5:36:14 UTC

[quote]
It will be interesting to see if life developed o Mars and how long it lasted.


I hope they realize that we already brought life to the planet in the form of microbes.


Did we do that on Mars?

Yes. The Mars rovers and other miscellaneous equipment that landed contained them. It wasn't intentional, though. Bacteria is everywhere here on Earth.


I hope if we do find existing life (extinct life would also be great) on Mars, we can tell the difference between Martian and Earth life.
Those who cannot remember the past are condemned to repeat it.
--- George Santayana
ID: 1200262 · Report as offensive
Profile Bob DeWoody
Avatar

Send message
Joined: 9 May 10
Posts: 2947
Credit: 1,370,428
RAC: 2,470
United States
Message 1200265 - Posted: 27 Feb 2012, 6:12:06 UTC

If Mars today can support some form of life, especially bacteria and viruses, or maybe single celled life it may be hard to prove if and when life forms are discovered whether they originated there or mutated from organisms that hitched a ride on one of our landers.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
ID: 1200265 · Report as offensive
Profile skildude
Avatar

Send message
Joined: 4 Oct 00
Posts: 9529
Credit: 44,436,947
RAC: 0
Burma
Message 1200342 - Posted: 27 Feb 2012, 13:37:52 UTC - in response to Message 1200265.  

NASA is very careful about being incredibly sanitary when building probes and landers for the very reason you mentioned.
In a rich man's house there is no place to spit but his face.
Diogenes Of Sinope
ID: 1200342 · Report as offensive
Uruloki9

Send message
Joined: 1 May 09
Posts: 1
Credit: 3,624,823
RAC: 0
United States
Message 1200364 - Posted: 27 Feb 2012, 15:41:59 UTC

Wow, a lot of points to cover, but I think I will just make one regarding the drake equation.

As the one poster pointed out there are likely lots of variables. Some of those variables might make it more likely there is life instead of just less likely.

My main problem with the equation is we simply don't have enough data. Think about the "Dark Matter" factors. We humans are basically blind. We don't see at least 70% of the stuff in our universe. True intelligent life could be all around us and we simply don't have the ability to perceive it. I think of us as a form of slug in this context. (Granted that could be a little high on the scale of evolution) But, the point is we have a very limited understand of the true nature of the universe and likely are missing a few chromosomes that would make things clear.
ID: 1200364 · Report as offensive
Profile Bob DeWoody
Avatar

Send message
Joined: 9 May 10
Posts: 2947
Credit: 1,370,428
RAC: 2,470
United States
Message 1200528 - Posted: 28 Feb 2012, 4:42:20 UTC

The Drake equation was never intended to be a precision tool but mearly a means to estimate the likelyhood of other intelligent beings out there. I can remember when the variable for star systems with planets was very low and even then when all of the variables were combined the odds seemed pretty good that we are not alone. Now with the estimate for the percentage of star systems with planets has increased several fold odds wise it looking more like a sure thing.

Even so as long as there is no contact officially we are still alone.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
ID: 1200528 · Report as offensive
Profile William Rothamel
Avatar

Send message
Joined: 25 Oct 06
Posts: 3357
Credit: 1,341,063
RAC: 17
United States
Message 1200805 - Posted: 29 Feb 2012, 2:39:32 UTC - in response to Message 1200528.  

The uncertanty with the Drake equation and any estimate(including any number that I might guess at) of percentages is extremeely large. I don't think that the Drake equation tried to estimate any of the physical conditions for intelligent life: Temperature, orbit, magnetic field, gravity, etc perhaps there are a dozen or more of these.

We will get a better handle on some of these in the future.
ID: 1200805 · Report as offensive
Profile Ket

Send message
Joined: 2 Jan 09
Posts: 7
Credit: 7,959,236
RAC: 4,273
United Kingdom
Message 1201146 - Posted: 29 Feb 2012, 23:23:02 UTC

Lets make things simple and not get carried away. Whats the chances of, lets say ONE planet in the region of 300 light years or so having a intelligent race on it? Slim to none would be my guess. Do I think planets exist that are perfectly habitable but have no life beyond insect and sea life exist within that 300 light year range? Absolutely. Now lets address the "aliens", they must certainly exist in this galaxy, its just too damn big with too many stars and planets for them not to. Do I think they are within range of our feeble attempts to "make contact" let alone be near Earth? Absolutely not. Life may be abundant, but intelligent life isn't going to be like putting your hand into a bag of sweets and pulling out a fistful. The Milkyway is massive, but taking into consideration all the factors involved for intelligent life not to get wiped out or snuff itself out, would it not be realistic to think a reasonable number on intelligent life in our galaxy (weather it be as advanced as us or more advanced than us) should be put around 10 - 100 civillisations? The Milkyway is big, bug there are FAR bigger galaxies out there than the Milkyway. If the Milky way was swimming with intelligent life we would surely have solid proof of such by now.
ID: 1201146 · Report as offensive
Profile Convergence
Avatar

Send message
Joined: 23 Jun 08
Posts: 117
Credit: 2,928,788
RAC: 0
United States
Message 1201248 - Posted: 1 Mar 2012, 2:56:46 UTC - in response to Message 1201146.  
Last modified: 1 Mar 2012, 2:58:24 UTC

If the Milky way was swimming with intelligent life we would surely have solid proof of such by now.


That may not necessarily be true. We don't know how long civilizations last or how much time there is between them. We also don't know how long it takes for a civilization to become spacefaring. They may be at our stage of development, more developed but still with no means of traveling vast distances, or they may be cavemen.

There may have been advanced civilizations in the past as well, even on Earth. Earth and the universe is very old.

Space so incredibly vast that contacting other alien civilizations within any decent amount of time just isn't feasible. Even light barely crawls through space since it moves so slow. This is the main reason why I think we haven't really heard anything. Everyone is WAY out of reach.
ID: 1201248 · Report as offensive
Profile Bob DeWoody
Avatar

Send message
Joined: 9 May 10
Posts: 2947
Credit: 1,370,428
RAC: 2,470
United States
Message 1201304 - Posted: 1 Mar 2012, 9:31:37 UTC

And of course, by my way of thinking, we must consider whether or not a space faring society would want to make contact with us. I think not. And given that set of parameters I think they could remain undetected for a very long time.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
ID: 1201304 · Report as offensive
Profile Chris S Crowdfunding Project Donor*Special Project $75 donor
Volunteer tester
Avatar

Send message
Joined: 19 Nov 00
Posts: 40475
Credit: 41,357,148
RAC: 264
United Kingdom
Message 1201324 - Posted: 1 Mar 2012, 10:58:07 UTC

The way that I'm looking at it is that any signal that we detect will have taken millions of years to have reached us, and any civilisation that sent it could have long ago blown itself up and ceased to exist. I therefore think that because of the vast distances and time-scales involved, we will never make any direct contact with any ET's.

But that is not the point. The very fact that we might one day detect a signal will confirm that we are not the only intelligence in the universe, even if we cannot talk to them, which at present we simply do not know for sure. It is therefore worth while looking and why I have spent 11 years helping.
ID: 1201324 · Report as offensive
Profile Convergence
Avatar

Send message
Joined: 23 Jun 08
Posts: 117
Credit: 2,928,788
RAC: 0
United States
Message 1201332 - Posted: 1 Mar 2012, 11:57:00 UTC - in response to Message 1201324.  

The way that I'm looking at it is that any signal that we detect will have taken millions of years to have reached us, and any civilisation that sent it could have long ago blown itself up and ceased to exist.


I think you mean thousands of years instead of millions.
ID: 1201332 · Report as offensive
Profile Chris S Crowdfunding Project Donor*Special Project $75 donor
Volunteer tester
Avatar

Send message
Joined: 19 Nov 00
Posts: 40475
Credit: 41,357,148
RAC: 264
United Kingdom
Message 1201393 - Posted: 1 Mar 2012, 16:00:53 UTC

The best estimate of how far away is the observable edge of the universe, is about 15 billion light years away. The Alpha Centauri star group are 4.4 light years away. Assuming that any signal we observe won't travel at more than the speed of light, somewhere between thousands and millions seems a reasonable guess to me.
ID: 1201393 · Report as offensive
Profile Clyde Special Project $75 donor
Volunteer tester

Send message
Joined: 9 Aug 99
Posts: 12526
Credit: 44,846,843
RAC: 2,140
United States
Message 1201407 - Posted: 1 Mar 2012, 17:38:15 UTC
Last modified: 1 Mar 2012, 17:43:27 UTC

My problem with 'numbers' when it involves intelligent creatures on other planets, is a basic question:

Why would evolution produce these creatures on a significant number of planets?

Using the only life existing planet we know: Evolution seems to produce larger, smaller, stronger, more adaptable, more complicated creatures, etc.

But intelligence appears to have happened once, after a long series of lucky coincidences. On how many life bearing planets would this be replicated?
Those who cannot remember the past are condemned to repeat it.
--- George Santayana
ID: 1201407 · Report as offensive
Profile Michel448a
Volunteer tester
Avatar

Send message
Joined: 27 Oct 00
Posts: 1201
Credit: 2,891,635
RAC: 0
Canada
Message 1201409 - Posted: 1 Mar 2012, 17:43:06 UTC - in response to Message 1201393.  
Last modified: 1 Mar 2012, 17:43:40 UTC

The Alpha Centauri star group are 4.4 light years away. Assuming that any signal we observe won't travel at more than the speed of light, somewhere between thousands and millions seems a reasonable guess to me.


did they even check those Alpha Centauri star group for exoplanets ? since EVERY star are 99% sure to have planets around ?
ID: 1201409 · Report as offensive
Previous · 1 · 2 · 3 · 4 · Next

Message boards : SETI@home Science : At Least 100 Billion Planets


 
©2018 University of California
 
SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.