poster: So if jellyfish and worms are not alive, what are they?
juvenissen: Good question.They are things do not bear any meaning of life. From this point of view, grass, or bacteria, or rock can be classified in the same category. Unfortunately, they are called life by scientist according to some specific criteria (debatable). If so, I can also "claim" that rock is alive by some good reasons.
poster: By the scientific definition rocks are not alive. How would rocks be categorized as alive?
juvenissen: A rock fits the majority, if not all, of the criteria used to define a life.
poster: Please outline what the criteria used to define life is, and how a rock fits the majority of them (usually it would have to fit all of them).
juvenissen: Sorry, I do not give essay as a reply here. I can answer question based on a common understanding. In this issue, for example, I can say that a rock does breath, and it can breath in air, in water and underground.
poster: A rock breathes? With lungs?
juvenissen: No. With skin.
poster: Do rocks have skin? Why does a rock need to breathe?
juvenissen:The surface. Through breathing, the surface becomes more mature. It does not need, it does. The "need" is not in the definition.
poster: You recognize the difference between breathing (respiration) and the wind blowing on something, yes?
juvenissen: Of course. Rock can breath in the ground, where there is no wind.
poster:So in conclusion: Rocks breathe through their skin, even underground. How do rocks "mature"? Did you realize that the definition of breathe is to take air into the lungs (except for the wind in a literary context). That being said, do rocks in space breathe? If so, what do they breathe?
juvenissen: Yes, every rock has a maturing process and stages. No. Breathing does not need a lung, even a rock does have space inside the rock where gas can be stored. For life lives in the air, in and out of air, by whatever mechanism, would satisfy the criterion. No. a rock does not breath in vacuum. It may breath one way (out). But that does not fit. Are you a scientist? If not, we may stop. All these talks could be very strange to you.
poster: What is this maturing process and stages? How does it breathe out?
juvenissen: Rock matured just like human. It keep changing according to the environment and it will eventually die. Material (gas, for example) leaks out of the rock. That is breathing out. I am a rock scientist. Rock is not alive (why not?). But I can try to make it fit the current definition of life. So, by the definition of life as you know it, a rock should be alive.
poster: So a rock feeds, respires, grows, reproduces, and then dies? How does it breathe in? Not by any definition I know. What definition are you using?
juvenissen: Rock does not reproduce in the normal case. But rock reincarnates. Rock breath in by absorb surrounding media on its surface.