Carbon-Based Life and the Scientific Method

Why Life Is Based on Carbon and Not on Silicon

Although silicon (Si) also has four electrons in its valence shell and is much more abundant in the Earth's crust than carbon (C), life is based on C and not on Si. This is because C-C, C=O, and C-N bonds are weak enough to form stable chains and rings, while also being able to break to make way for other molecules. This allows living organisms to obtain the energy contained in these bonds. In contrast, Si-Si and Si-O-Si-O chains are so stable that they are unalterable.

Descriptive Biology

Descriptive biology is based on the simple observation of the structure and functioning of living things, to make descriptions of what is observed. Until the 17th century, it was based solely on simple observation (human anatomy, animal and plant morphology, and animal and plant physiology) and on how to classify organisms.

Experimental Biology

Experimental biology is based on experimentation, that is, the application of the scientific method to the study of life. This type of biology starts with observation, then formulates hypotheses or models. After that, experiments are designed and conducted with objectives that can confirm or disprove the hypotheses. Results are obtained, and from them, conclusions are formulated. Possible examples include how biological characters are inherited (Mendelian genetics), how DNA contains biological information, and how RNA is involved in its expression (molecular genetics).

The Scientific Method

The scientific method is a systematic procedure that includes:

• Observation (problem statement)
• Formulation of hypotheses
• Experimentation (design of experiments, conducting experiments)
• Analysis of results
• Findings (hypothesis rejection, hypothesis admission)
• Establishment of scientific laws

Properties of Colloidal Dispersions

• Ability to present in a gel: Colloidal dispersions can be in the form of sol (liquid) or gel (semisolid state).
• High viscosity: Internal resistance to the relative movement of liquid molecules.
• High power adsorbent: Attraction of a solid surface to the molecules of a liquid or gas.
• Tyndall effect: Cloudiness appears when colloidal dispersions are illuminated laterally on a dark background.
• Sedimentation: If subjected to strong gravitational fields, the particles sediment.
• Dialysis: The separation of colloids from crystalloids through a semipermeable membrane that allows only small molecules to pass.
• Electrophoresis: Transport of colloidal particles through a gel by the action of an electric field.

Science, Technology, and Society (CTS)

Democratic societies are not passive taxpayers against the advances of science and technology, but active participants in regulating the degree to which they are applied to prevent social imbalances and to safeguard the environment (sustainable development). This includes:

• Promoting science teaching
• Encouraging scientific vocations
• Promoting the participation of specialists in humanities in scientific equipment
• Fostering democratic attitudes

The scientific method should not be an exclusive method of scientists; it can be exercised and developed as a mindset very desirable in democratic societies. One cannot act or be ignorant of the results.