What is Life?

This is a hard question, but to answer it we can define boundaries to help determine the answer to this question.

Biology is the scientific study of life. The cell is the basic unit of life & every organism consists of one or more cells. But despite tremendous diversity, coding instructions of all living organisms are written in nucleic acids. We could define life by listing its basic components, but still more is necessary.

We designate an organism as "life" via these five criteria, of which scientists have settled on, and these qualities are in combination creating life:

1. Organization: (ex: atoms make up molecules)
2. Energy Use: (ex: humans use energy to live)
3. Maintenance of internal constancy: (ex: your kidneys regulate water balance by adjusting the concentration of your urine)
4. Reproduction, growth, and development: (ex: germination of acorns)
5. Evolution: (ex: increasing numbers of bacteria survive treatment with antibiotic drugs)

Can we create life synthetically? Ie: on our own? Yes. Look up the Craig Venter story. It's a big read, and super interesting!

Life is Organized

The atom is the smallest unit of a type of pure substances. These come together to make molecules. putting these together gives an organelle, a membrane-bounded structure that has a specific function within a cell. For example, chloroplast.

When you put together enough organelles, you get a cell, the fundamental unit of life. But that's not the end of it. You can put together cells to make tissues, a collection of cells. Then putting these together to make organs that are structures consisting of tissues organized to interact an carry out specific functions. For example, a leaf.

These organs go together to make an organ system that connect the organs physically and/or chemically to function together. Putting these together to make an organism, the actual alive thing.

Now the organisms combine to make a population that's local, then into a community that occupy the same region. Then they combine to make an ecosystem, then into a biosphere.

Emergent Properties

Emergent Properties are new complex functions that arise at each level of organization. This doesn't have to be biological in nature. But usually they are. For instance, you can combine skin cells together to make sheets, then into the form that they are on our bodies to make our skin organ.

Emergent properties result from all forms of organization. One block from a cinder-block wall doesn't form much, but put them together and you have a functional wall of many uses.

An example is the Massive Engine. Look it up for a cool example of this!

Life Requires Energy

Energy comes from the sun, and certain organisms convert this light into chemical energy. These are called producers, extracting energy and nutrients from the non-living environment. There are consumers who eat the producers. There are decomposers that obtain nutrients from dead organisms and/or organic wastes.

Every time something consumes some other thing to get its nutrients, there's an associated "heat tax" with it.