# B What parameters of physics are most important to the existence of life?

#### Suppaman

Summary
There are laws or parameters of physics, I am told, that allow the sun to work as it does to provide us with light and heat. What attribute of physics are most important to "life" being able to exist.
The universe after the big event was a lot of lifeless stuff. However, as things settled down the rules behind the curtain were such that life was allowed to develop, they may have even been such that they encouraged the things to happen that were conducive to the process that has resulted in life. Some rule, some physics value that if it was somewhat different it is considered unlikely that life would have been likely. I am not asking what a parameter is what it is or how that parameter was established, I am interested in which parameters are most important to "life" existing. This also assumes that in a universe that is consistent from place to place that life is also likely from place to place.

Related Other Physics Topics News on Phys.org

#### fresh_42

Mentor
2018 Award
The answer to this question is more a matter of taste and opinion than a matter of fact. Life as we know it depends on so many specific circumstances, that you can run through entire quantum mechanics and astronomy and point to any single parameter. My opinion is
$$\hbar$$
since without the uncertainty principle physics would be completely different and nothing in our world would ever have happened: from stars and galaxies, to molecular chemistry for life.

#### Suppaman

I will agree, probably because it is logical. However it is not a parameter, it just is. My question was about a value that was most important.

#### BWV

The atomic number of carbon?

#### Suppaman

I think that is not a changeable parameter, is it?

Staff Emeritus
However it is not a parameter, it just is.
This is quickly going down the path of "what am I guessing?"

You need to tell us the rules first. Not just say "No, that's not it" to the responses.

#### Suppaman

As an example of a rule, parameter. The speed of light is a parameter and the rule is that you can not exceed that parameter. I have no idea if that parameter was +/- 10 percent it would affect the potential for life. Now, I am sure there are more knowledgeable people who know of the other parameters and or rules. Does this help?

Staff Emeritus
So c is a parameter and h is not? This seems very arbitrary to me.

#### Suppaman

Sorry, I missed h, I was just looking at the text. "without the uncertainty principle physics would be completely " is more than a change in value for h. Was the answer implying that the value of h is critical for live existence?

#### fresh_42

Mentor
2018 Award
Sorry, I missed h, I was just looking at the text. "without the uncertainty principle physics would be completely " is more than a change in value for h. Was the answer implying that the value of h is critical for live existence?
Yes, it is.

#### sophiecentaur

Gold Member
I think that is not a changeable parameter, is it?
But could we decide on a single parameter that is independent of the others?
I think the question in the OP is a bit too naive to warrant serious discussion - unless we are in the realms of a Sci Fi story scenario which could ignore the interrelatedness of the whole of Physics.
The speed of light is a parameter
c is far more fundamental than just being a 'parameter'. Everything starts with c.

#### pinball1970

Gold Member
Summary: There are laws or parameters of physics, I am told, that allow the sun to work as it does to provide us with light and heat. What attribute of physics are most important to "life" being able to exist.

The universe after the big event was a lot of lifeless stuff. However, as things settled down the rules behind the curtain were such that life was allowed to develop, they may have even been such that they encouraged the things to happen that were conducive to the process that has resulted in life. Some rule, some physics value that if it was somewhat different it is considered unlikely that life would have been likely. I am not asking what a parameter is what it is or how that parameter was established, I am interested in which parameters are most important to "life" existing. This also assumes that in a universe that is consistent from place to place that life is also likely from place to place.
This is far too general.
I could say the electron's charge or mass as life is just a specific chemistry and chemistry is just electrons.
You can't have life without light heat therefore you need stars therefore gravity or a few nuclear parameters are key.
Too general

#### Suppaman

Yes, we need a place for life to emerge and we had that for a billion or more years before it did. It is at this point where life started that I am looking for the key physical laws or parameters that encouraged this to happen. I am not looking for an explanation of how life started, just what was necessary for it to happen. The values of these constants, the rules that are there, in the background that allow life to get a start. Which rules or parameters that if they were not what they are the earth would just be a wet ball of rock with nothing happening.

#### Mister T

Gold Member
Some rule, some physics value that if it was somewhat different it is considered unlikely that life would have been likely.
It is best to choose a dimensionless constant, such as the so-called fine structure constant, when considering this issue. (Constants such as the speed of light $c$ or Planck's constant $\hbar$ are not dimensionless, so their values depend on conventions chosen by humans, for example, the length a meter.)

From the Wikipedia article on the fine structure constant $\alpha$:

The anthropic principle is a controversial argument of why the fine-structure constant has the value it does: stable matter, and therefore life and intelligent beings, could not exist if its value were much different. For instance, were α to change by 4%, stellar fusion would not produce carbon, so that carbon-based life would be impossible. If α were greater than 0.1, stellar fusion would be impossible, and no place in the universe would be warm enough for life as we know it.

#### Suppaman

I mentioned that part about how the sun is able to provide the energy we need in my original post. I am looking for things we had on the earth when life began. There must have been some combination of things, things governed by the rules and parameters here one this wet ball of rock. If they had not been what they are, no life. What are these laws and parameters? It may be that a lot of these laws and parameters are dependent on some other law and parameter. That would probably help science figure things out. For my question, I would like to know what the current thinking is, what do we think are the key settings of the life generator?

#### pinball1970

Gold Member
Yes, we need a place for life to emerge and we had that for a billion or more years before it did. It is at this point where life started that I am looking for the key physical laws or parameters that encouraged this to happen. I am not looking for an explanation of how life started, just what was necessary for it to happen. The values of these constants, the rules that are there, in the background that allow life to get a start. Which rules or parameters that if they were not what they are the earth would just be a wet ball of rock with nothing happening.
For life, large systems of particles and molecules rather than any one physical parameter have to be considered.
What's the most important parameter for baking a cake?
The exo planets that may be able to support life have to tick a few boxes, light / heat distance from its star, liquid water. Chemistry is the same all over the observable universe so all the building blocks for life are already there.
The earth has a moon and a tilt which are important for tides seasons etc.
Life on earth could not have got going during the bombardment period as the surface was too hot/ molten.

Water was thought to delivered via comets and asteroids.

How special is the earth is a better question.

#### Suppaman

It may be a better question but it is not my question. My question is being asked at the point where the most important step to life happens "tomorrow", standing on this wet ball of rocks at year billion, what parameters are most important to ensuring life begins.

#### pinball1970

Gold Member
It may be a better question but it is not my question. My question is being asked at the point where the most important step to life happens "tomorrow", standing on this wet ball of rocks at year billion, what parameters are most important to ensuring life begins.
According to some research deep sea vents could be the key to go from a sterile rock to the first protocells.
So liquid water, alkaline pH, heat from Geological activity.

#### Suppaman

I am not asking here how life started, we all agree it did, I am asking what laws and or their parameters were most necessary to this being a successful event here on this wet ball of rocks?

Staff Emeritus
Given that we are 20 messages into this thread and you are still telling people "that's not what I mean", isn't it time to consider if you have asked an unclear question?

#### Suppaman

Perhaps. I believe one of the things the advisors here can do for a poster is to help them ask the best questions. Can you help me properly phrase my question? What is there about " What attributes of physics is most important to "life" being able to exist." that is not clear to those who are answering? Please advise.

#### pinball1970

Gold Member
Perhaps. I believe one of the things the advisors here can do for a poster is to help them ask the best questions. Can you help me properly phrase my question? What is there about " What attributes of physics is most important to "life" being able to exist." that is not clear to those who are answering? Please advise.
The answer is there is no one parameter, life involves mass heat pressure chemistry. This involves ALL the parameters

#### PeroK

Homework Helper
Gold Member
2018 Award
Perhaps. I believe one of the things the advisors here can do for a poster is to help them ask the best questions. Can you help me properly phrase my question? What is there about " What attributes of physics is most important to "life" being able to exist." that is not clear to those who are answering? Please advise.
I suggest on all your questions you give us a multiple choice.

#### sophiecentaur

Gold Member
Perhaps. I believe one of the things the advisors here can do for a poster is to help them ask the best questions. Can you help me properly phrase my question? What is there about " What attributes of physics is most important to "life" being able to exist." that is not clear to those who are answering? Please advise.
If we're not careful we will get into yet another Top Trumps game. Which is the most important aspect of a car? 0 to 60 time? mpg? how many seats? Perhaps the number of wheels (but one would do at a pinch - or even none for a hover car) The Universe is not a good subject for Top Trumps.
There can be no isolated factor that promoted the evolution of life. Possibly a more 'discussable' question might be "discuss how many different factors do you need to get 'right' if you want life forms to develop? But that's Biology and not Physics.
The fact is that we are here and we have evidence that there has been some form of life around for a few billion years.
One extra question could be to ask why things changed to cause the totally microbial life suddenly to produce the more complex Eukariotic life. Did conditions change to introduce another vital factor which changed the 'rules' which had kept microbes chugging along fine and allowed our simple multi-celled ancestors to get started? But that again is Biology - unless there was some Physics related parameter that changed. Personally I don't like the implications of the Anthropic Principle because it just looks to me like a substitute for religion. As far as I'm concerned:

We're here because we're here because we're here because we're here.
We're here because we're here because we're here because we're here.
To the tune of Auld Lang Syne