Scientific law facts for kids
A scientific law is like a very strong rule or a proven fact about how nature works. It's a statement or an equation that describes something that always happens under certain conditions. Most scientists agree that these laws are true because they have been tested many, many times and have always been found to be correct.
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How Scientists Discover Laws
Scientists don't just guess at laws; they discover them through careful observation and experiments.
From Idea to Law: The Scientific Method
The journey to a scientific law often starts with an idea called a hypothesis. A hypothesis is a possible explanation for something observed. Scientists then design experiments to test this idea.
Testing and Observing
During experiments, scientists collect information, called data. They repeat their tests many times to make sure their results are reliable. If the hypothesis is tested over and over again by different scientists and always holds true, it can become a scientific law.
What a Law Does
A scientific law describes what happens. It doesn't usually explain why it happens. For example, the law of gravity describes how objects fall towards the Earth. It tells us that they will fall, but it doesn't fully explain why gravity exists in the first place.
Laws Versus Theories
It's important to understand the difference between a scientific law and a scientific theory. Both are very important in science, but they do different jobs.
Scientific Law: What Happens
A scientific law tells us what will happen under specific conditions. It's a description of an observed pattern in nature. Laws are often expressed as mathematical equations, like Isaac Newton's laws of motion.
Scientific Theory: Why It Happens
A scientific theory, on the other hand, explains why something happens. It's a well-tested and widely accepted explanation for a broad range of observations. Theories are built on many facts, laws, and tested hypotheses. For example, the theory of evolution explains why living things change over time.
Both Are Strong
Both laws and theories are very strong ideas in science. A law describes a phenomenon, while a theory explains it. One does not "grow up" to become the other; they are different types of scientific knowledge.
Examples of Scientific Laws
Many scientific laws help us understand the world around us and even build new technologies.
Law of Gravity
One of the most famous laws is the Law of Universal Gravitation, discovered by Isaac Newton. This law states that every object in the universe attracts every other object. The strength of this attraction depends on how much mass the objects have and how far apart they are. This law helps us understand why apples fall from trees and why planets orbit the sun.
Laws of Motion
Newton also gave us three Laws of Motion. These laws describe how objects move when forces act upon them.
- The first law says an object will stay still or keep moving at the same speed and direction unless a force pushes or pulls it.
- The second law explains how much an object speeds up (accelerates) when a force acts on it, depending on its mass.
- The third law states that for every action, there is an equal and opposite reaction. This means if you push something, it pushes back on you.
Law of Conservation of Energy
The Law of Conservation of Energy states that energy cannot be created or destroyed. It can only change from one form to another. For example, the chemical energy in food can turn into the kinetic energy of your body moving.
Why Scientific Laws Matter
Scientific laws are fundamental to how we understand and interact with the natural world.
Predicting the Future
Because laws describe what always happens, they allow scientists to make accurate predictions. For instance, knowing the laws of motion helps engineers design cars, planes, and rockets.
Building New Technology
Many technologies we use every day are based on scientific laws. From electricity (governed by laws of electromagnetism) to computers (based on laws of physics and logic), laws provide the basic rules for innovation.
Understanding Our World
Ultimately, scientific laws help us make sense of the complex universe. They provide a framework for understanding everything from the smallest atoms to the largest galaxies.
Images for kids
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Scientific theories explain why something happens, whereas scientific law describes what happens.
See also
In Spanish: Ley científica para niños
