Question

Classify each of the following statements as a hypothesis, law, or theory. (a) The force acting on an object is equal to its mass times its acceleration. (b) The universe as we know it started with a big bang. (c) There are many civilizations more advanced than ours on other planets.

Short answer

(a) Law, (b) Theory, (c) Hypothesis.

Step-by-step solution

Understanding Scientific Classifications

In science, statements can be classified as hypotheses, laws, or theories. A hypothesis is a proposed explanation made on the basis of limited evidence. A law is a statement based on repeated experimental observations that describes some aspect of the world. A theory is a well-substantiated explanation acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation.

Classifying Statement (a)

The statement '(a) The force acting on an object is equal to its mass times its acceleration' relates to a quantifiable and frequently observed phenomenon. This is known as Newton's Second Law of Motion, which is based on consistent empirical evidence. Therefore, it is classified as a law.

Classifying Statement (b)

The statement '(b) The universe as we know it started with a big bang' is a comprehensive explanation of the origin of the universe. It has been tested and supported by a significant amount of observational data and scientific research. Therefore, the statement is classified as a theory, known as the Big Bang Theory.

Classifying Statement (c)

The statement '(c) There are many civilizations more advanced than ours on other planets' is speculative and not currently supported by direct empirical evidence. This is a proposed idea that could lead to research. Thus, it is classified as a hypothesis.

Key concepts

Hypothesis

A hypothesis is a starting point in the scientific process. It is a proposed explanation for a phenomenon, based on limited evidence. Think of it as an educated guess. Scientists use it as a basis for further investigation. A hypothesis must be testable. This means there must be a way to prove it true or false through experiments or observations. For example, the statement about civilizations on other planets is a hypothesis. We don't have direct evidence to support or refute it yet. A good hypothesis paves the way for new research. Experimentation validates or challenges the hypothesis. Ultimately, a hypothesis may evolve into a theory if supported by consistent findings.

Scientific Law

Scientific laws describe relationships observed in the natural world. They are statements based on consistent, repeated observations. Unlike hypotheses, laws describe what happens, not why it happens. They are often expressed with mathematical formulas. An example is Newton's Second Law of Motion: \( F = ma \) where \( F \) is force, \( m \) is mass, and \( a \) is acceleration. Laws are considered universally true under specific conditions. However, they do not provide explanations for why these relationships occur. For an explanation, one must look at a theory. Scientific laws help predict future events and are integral to understanding basic scientific concepts.

Scientific Theory

A scientific theory is a well-substantiated explanation of an aspect of the natural world. It emerges from repeated testing and confirmation through the scientific method. Unlike hypotheses, theories are supported by a large body of evidence. They help explain why something happens, often combining various laws and facts. The Big Bang Theory is an example, explaining the universe's origin. Theories are constantly scrutinized and can be refined as new evidence arises. They provide a framework for making predictions about unknown phenomena. Theories are different from laws as they explain the underlying reasons behind observations.