Comment

Comment by Nader Khouzam on August 8, 2011 at 6:01pm

Glen, I find it hard to conceive for life to suddenly emerge on a planet fully formed without the capability to reproduce.  It would not last for very long.  I agree with you that we do not fully understand the mechanisms that lead to life.  We have just begun our journey!

Comment by Glen Rosenberg on August 8, 2011 at 5:42pm

Nader,

Is it possible that life could emerge fully formed, no replication mechanism, immutable and intelligent or not? I acknowledge that life is limited by the laws of the universe but how much do we really know to confidently project the formula and the limitations?

Comment by Nader Khouzam on August 8, 2011 at 7:04am

Glen,

DNA is not universal. As I mentioned earlier, life in the universe can arise from either carbon or silicon based compounds since they can form large molecules.  Such molecules can code for protein synthesis.  As per Sagan, I agree that the evolution of such carbon or silicon based molecules can yield a multitude of living organisms.  I also agree with you that life does not necessarily have to be biotic.  I watch scifi movies and there is no end to human imagination.  We imagine that intelligent life could arise in the form of robotic civilizations.  However, it is difficult to conceive that robots could evolve from other organisms without an organic component.

Comment by Yusuf Said on August 8, 2011 at 3:41am

Amino acids do not store information. The first life on Earth started with RNA as it has catalytic and information storage capacity. Life on Earth uses 20 amino acids and 4 different nucleotides, but it should be noted that there are more than 20 amino acids and 4 nucleotides, we and the rest of life on Earth simply use those 20 and 4 for life. So to answer a question asked earlier no DNA is not universal. While we have a systam of A-T, G-C a quaternary system of two sets of bonding nucleotides it is possible to have three or four complementary pairs which can be used as a genetic code. Of course those nucleotides would create different codons perhaps utilizing different amino acids. Also there is no guarantee that life even functions the same way if it exists elsewhere, but it would need to follow some sort of information storage molecular system followed by a coding process to code for catalytic molecules to carry on cellular function.

Comment by Glen Rosenberg on August 7, 2011 at 11:20pm

Nader,

Is DNA universal? The script. Why? Do we have a sufficient basis to assert life cannot emerge in our universe in an utterly unique way? If we are in a multiverse does it follow that the building blocks in other universes will be different because the physical laws and chemistry are different? Sagan wrote about the endless variations that evolution can produce but I have never encountered a scientist who seemed to think  that genesis can occur in some way we cannot forsee. Other than abiogenesis, of course.

I basically agree with your take on religion.

 

Comment by Nader Khouzam on August 7, 2011 at 10:57pm

Glen,

I agree that life on earth is not a model for life elsewhere.  Evolution certainly has taken different paths on different planets.  I also agree with you that religion is used to control the masses of weak minded individuals.  religion offers them comfort, forgiveness of wrong doings and best of all eternal life in a paradise environment.  It promises the weak minded more that atheim can, therefore it is more popular.  Religion is also used by people to justify their lifestyle.  People can feel that they belong to an "exclusive" club where they call themselves "saved" and call others "damned".  They feel that they belong to a fortune 500 organization where take advandage of privileges such as a forgiving master, so they can do as they please and get forgiven later. Humans on earth are still primitive in my own account and many more years of evolution are necessary before they can judge each other beyond race, religion, gender, etc.  I wish I was born a few thousand years from now.

Comment by Glen Rosenberg on August 7, 2011 at 10:26pm

Nader,

If there ia a way of ascertaining or verifying the issue of life elsewhere I will wager generously on the affirmative. (SETI is a longshot.) But I would not be so quick to assume that the life on earth paradigm is the one and only.

I'd also wager that the great religions will utilize the knowledge to enhance their position and continue their dominion over the masses. And even if the grand poobah of extraterrestrials visits and imparts knowledge of the universe the puppeteers will proclaim it is indeed the devil incarnate.

Anyways I was not arguing the building blocks idea, rather the "geocentric" idea.

Comment by Nader Khouzam on August 7, 2011 at 9:57pm

Glen, It is a fact that amino acids- The building blocks of proteins are found in meteorites that impact the Earth.  The amino acid test is very easy to do and I have done it many times.  When we place the amino acids in a vile and shoot them in a high velocity chamber, we actualy make proteins in the lab !!  This is enough verification for me.  Regarding genesis of life, I strongly believe that liquid water is key to the formation of polypeptides and carbon based life as we know it.  It is very posible that on other planets that are located in the habitable zone where liquid water exists, life can take hold using carbon or silicon, the second best bond forming element in the universe.  Keep in mind that life is tough and extremophiles live in acid, extreme temperatures and even in nuclear reactors.  It is thus very plausible that life already exists out there but we have not yet found it.  Yusuf, you brought in the Drake equation which equates the likelihood of intelligent life being found in the universe.  Lets take it one step at a time.  For us scientists, life can be a bacterium living in underneath the polar ice caps of Mars or deep below the ice of Europa.  Intelligence takes a lot of time to evolve and assumes that the parent star can live long enough to support evolution on the host planet.  We all know that frustrations such as impacts by asteroids, radiation, etc.  can either wipe out life or eliminate it, thus it takes a long time for inteligence to emerge.

Comment by Yusuf Said on August 7, 2011 at 8:31pm

There is no factual evidence of any other planets which support life in our galaxy or universe for that matter. The Drake equation set forth by SETI the search for extraterrestrial intelligence postulates the likelihood of extraterrestrial life with the following equation. 

Here N stands for the number of possible worlds in our galaxy which support or are capable of supporting life. R is the average time for star formation, f sub p is the number of those stars which support planets, n sub e is the number of those planets which can support life, f sub l is the number of planets which will actually support life, f sub i is the number which go on to support intelligent life, f sub c are the number of those civilizations which actually go on to create technology which is detectable radio for example, and finally L is the amount of time that civilization has been transmitting signals. The galaxy is vast and it could take hundreds if not thousands of years for any such signal to either reach another civilization sent by us or vice verse. The idea of intelligent life other than our own elsewhere in the galaxy is a fascinating prospect but we must face the possibility that we are entirely alone. In science nothing is certain or fact as it is subject to change with new evidence. Right now science does not say one thing or the other on the existence of extraterrestrials as there is no evidence either way. However, we can postulate the likelihood of extraterrestrial intelligence.  

Comment by Glen Rosenberg on August 7, 2011 at 5:35pm

Nader,

How is it a fact without verification? And is it reasonable to assume that the genesis of life on earth is the only way life has or will be generated elsewhere? Even on earth life is sustained in a way that would have been thought to be impossible before its recent discovery at the floor of the ocean. So if life can be sustained in a different way maybe it can originate in a different way.