Where does life originate from?

[Ivan Seeking]

There is no doubt that whatever happens in the cell is just a chemistry, but we are still far from knowing all details.

[PLAIN]http://star.psy.ohio-state.edu/coglab/Pictures/miracle.gif
http://star.psy.ohio-state.edu/coglab/Miracle.html

 

[johng23]

you haven't been following the thread have you.

Sure I have, just seemed like you were suggesting that if someone's beating their wife, you should look the other way.
I guess maybe I misinterpreted it. I was assuming that it was a known fact that the person beat their wife in the past.

 

[granpa]

you've never heard that joke before?
groucho marx is famous for it.
you have heard of groucho marx haven't you?

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

A loaded question is a question which contains a controversial assumption such as a presumption of guilt.[1]
Such questions are used rhetorically, so that the question limits direct replies to be those that serve the questioner's agenda.[2] The traditional example is the question "Have you stopped beating your wife?"

 

[Borek]

No, that's classic example of the question that if you decide to answer (especially in terms of Yes/No), you always put yourself in the bad light.

 

[minorwork]

As for me, I think I can describe life as an organized set of chemical reactions whose sole purpose is to make sure that these reactions continue to exist.

What instrument measures purpose, in what units is purpose/intent expressed, and what do you use to calibrate the instrument?

Life, then, covers rocks weathering, stars aging, atoms interacting, and most anything then. Isn't that definition too broad? If you were to send an unmanned probe to Mars, what sort of sensor, what instrument, what detector would test best for life and, most important, what indication would it give for the absence of life. How do we test for past life especially in the case of Mars?

 

[granpa]

organic life doesn't have a purpose in that sense but it does have a function that it is optimized for.

(its a local optimum not a global optimum)

 

[Siv]

What instrument measures purpose, in what units is purpose/intent expressed, and what do you use to calibrate the instrument?

If we draw a line at a certain level of organized complexity that involves replication, and call all those things to the right of that line as "alive" and all the things to the left as "not alive", then that's easy. Use that very line to "measure" life.

 

[minorwork]

If we draw a line at a certain level of organized complexity that involves replication, and call all those things to the right of that line as "alive" and all the things to the left as "not alive", then that's easy. Use that very line to "measure" life.

So my Mars probe has to look for a line and find things on the right side of the line. Probably better things to look for. http://en.wikipedia.org/wiki/Life_on_Mars#Viking_experiments". One showed an increase in CO2 from Martian soil being exposed to water and nutrients. The designer of this experiment, called the Labeled Release experiment, said this indicated life. Maybe, but other scientists dispute his conclusion since the CO2 evolved could have resulted from a non-life explanation, that being the presence of super oxidants in the soil.

organic life doesn't have a purpose in that sense but it does have a function that it is optimized for.

(its a local optimum not a global optimum)

How does organic life know of this function and when it has achieved optimization?

To clarify what you mean by organic, do you mean containing the molecules that the Viking experiment did NOT detect with its mass spectrometer and gas chromatograph? Are you referring to general carbon chemistry?

I have to ask this because of the increased ability of the self-replicating programs known as computer viruses, and especially the http://en.wikipedia.org/wiki/Stuxnet" that can be said to be optimized for its function of replicating and installing a PLC rootkit in industrial software in order to cause damage to the process under the PLC's control. Can a replicating, evolving computer program be alive?

 

[Siv]

So my Mars probe has to look for a line and find things on the right side of the line. Probably better things to look for. http://en.wikipedia.org/wiki/Life_on_Mars#Viking_experiments". One showed an increase in CO2 from Martian soil being exposed to water and nutrients. The designer of this experiment, called the Labeled Release experiment, said this indicated life. Maybe, but other scientists dispute his conclusion since the CO2 evolved could have resulted from a non-life explanation, that being the presence of super oxidants in the soil.

Sure.
My point was that, any search for life should depend on how we define it.

A lot of people assume that something magical appears in an organism if its alive. Which is not true, really.

 

[LivaN]

You have already been given excellent explanations above. bobze explained it very well in post 26. You are hand waving, which doesn't belong in this forum.

No, not for my specific question. I was not hand waving, or if it appears that way it was not my intention.

granpa's post #32 put things into perspective, and #33 answers my question.
Thanks to grandpa for a good explanation.