Scientific Method, Universe, and the Search for Life
Science and the Heuristic Method
Science is a collective effort, not an individual one, where progress is only possible through collaboration and control by the community. The heuristic method refers to forms of work and thought that support existing mental activities.
What Makes a Scientist? How it Works
- Monitor a phenomenon, wondering about something witnessed.
- Develop a hypothesis that can explain the phenomenon.
- Design an experiment to demonstrate whether the hypothesis is correct.
- Prepare data.
- Draw a conclusion or thesis.
Pseudoscience
Pseudoscience is what is presented as scientific without being so, without being based on objective evidence, and is used to win the trust of the receiver.
The Universe
The universe is a huge vacuum in which there are millions of bodies. We see that it is divided into galaxies, where each galaxy contains thousands of stars, planets, and nebulae (clouds of gas and dust particles) that move constantly.
Dark Matter
Dark matter is matter that we do not know, does not emit radiation, and interacts gravitationally.
Stars
Stars are basically composed of hydrogen and helium, as we know from the Sun’s spectrum.
Law of Gravitation
The Law of Gravitation states that bodies attract each other, and the attraction is stronger when they are closer and have a larger mass.
Black Holes
Black holes are concentrations of matter with extremely high density and a gravitational field so strong that no light can escape. We know of their existence through X-rays. Almost all galaxies have a black hole. In the Milky Way galaxy, it is called Sagittarius A*, into which stars are falling. The point of no return is 77 million miles away.
Cosmic Events and Theories
Big Bang
The Big Bang was a huge explosion that occurred 13.7 billion years ago.
Cosmic Microwave Background Radiation
Cosmic microwave background radiation is the echo of the Big Bang.
Big Rip
The Big Rip is a hypothetical event where the universe tears apart due to the separation caused by dark energy.
Source of Elements
Stars are factories of new chemical elements. Larger stars generate carbon, silicon, aluminum, and iron. Hydrogen fuses into deuterium and tritium, releasing helium.
Supernova
A supernova occurs when gravity causes trillions of tons of matter to fall into a star’s nucleus, where extremely high temperatures and pressure cause nuclear fusion, generating the rest of the elements. The energy produced in this fusion causes an explosion that launches almost all the synthesized elements into space.
Origin of the Solar System
The Solar System formed 4.57 billion years ago when a cloud of gas and dust began to contract. This nebula eventually became our Sun and its planets. The nebula was contaminated, and it is believed that a supernova exploded near it, leading to the formation of the solar system.
Comets
Comets are distant remnants of the original nebula.
Planets
Planets formed from the initial nebula around the Sun. The first planets were in the exterior, where they have more mass because they were built with the most abundant elements of the nebula.
- Giant outer planets: Jupiter, Saturn, Uranus, and Neptune.
- Inner terrestrial planets: Mercury, Venus, Earth, and Mars (composed of rock and metal).
The Moon was formed when a minor planet collided with Earth.
Exoplanets and Conditions for Life
Discovery of Exoplanets
Exoplanets are planets that orbit stars other than the Sun. Many have been detected, including super-Earths, bodies with masses slightly larger than Earth’s.
Conditions for Life on Planets
- Distance from the star: The planet must be neither too near nor too far from its star to maintain liquid water.
- Sufficient gravity: The planet needs enough gravity to retain its atmosphere and prevent the hydrosphere from vaporizing.
- Metallic core: A rotating metallic core produces a magnetic field that protects the planet from harmful X-rays.
- Presence of a large satellite: A large satellite, like the Moon, stabilizes the planet’s rotational axis.
- Lifetime of the star: Stars with more mass have shorter lifespans.
- Existence of nearby giant planets: Giant planets can divert potentially harmful objects, protecting smaller planets.
- Situation within the Milky Way: The center of the galaxy emits more radiation, which is harmful to living beings.