Adapted from work byRandy Bell

Oregon State University

Scientific Theories & Laws

How are these concepts related to each other?

Common ideas

Speculation

Fact

Mystery Tube

Mystery Tube

Mystery Tube

Law of StringsWhen any short string is pulled, the long string shortens by an equivalent amount.

String Theory

?

Develop Your Own Model

PlanThen buildTry it out… does it work like the Mystery

Tube… A little bit? A lot? Completely?

Share Your Model

Describe what the inside of your tube looks like

What was your reasoning for this configuration?

To what extent does your model work like the mystery tube?

Competing Scientific Theories/Models

Common ideas

Speculation

Fact

From where do these ideas originate?

Laws in Media

Explicit Instruction

Answer:A law is something that can be measured or observed to be true. A theory is something that can only be assumed to be true based on the best available knowledge. A theory can eventually, though not necessarily, become a law after time and scrutiny.

HYPOTHESIS

FACTS

THEORY LAW

Potential Progression of Scientific Ideas

Explanatory

A theory cannotbecome a law

Descriptive

Can come before a theory… butA law cannotbecome a theory

Good starting place (sometimes)

Proposed answer toresearch question: Testable!

Scientific Fact: “In science fact can only mean confirmed to such a degree that it would be perverse to withhold provisional consent.”

Stephen J. GouldScientific Hypothesis:1. A proposed answer to a research question

2. A tentative explanation for an observation or phenomena that can be tested through experimentation

Scientific Facts and Hypotheses

Scientific Theories & Laws in the Standards

Theories LawsTheory of Plate Tectonics: Earth’s crust is divided into plates that move. Explains why earthquakes and volcanoes occur in certain zones.

Newton’s Laws of Motion: Describe the relationship between the forces acting on a body and its motion due to those forces.

Cell Theory: Identifies cells as the fundamental unit of structure and function in living things. Explains that new cells are formed from other existing cells.

Ideal Gas Law: PV=nRT

Describes the relationship between pressure, volume, moles, and temperature of a gas.

Darwin’s theory of natural selection: Explains the diversity of life in terms of competition, survival, and inherited traits.

Mendel’s Laws of Inheritance: Describes how hereditary characteristics are passed from parent organisms to their offspring.

Atomic Theory: All matter is composed of elements made up of atoms. Explains why matter is conserved in chemical reactions.

Law of Superposition:

Describes the general principle that in undeformed layers of rock, the oldest rock will be at the bottom.

Theories LawsTheory of Plate Tectonics: Earth’s crust is divided into plates that move. Explains why earthquakes and volcanoes occur in certain zones.

Newton’s Laws of Motion: Describe the relationship between the forces acting on a body and its motion due to those forces.

Cell Theory: Identifies cells as the fundamental unit of structure and function in living things. Explains that new cells are formed from other existing cells.

Ideal Gas Law: PV=nRT

Describes the relationship between pressure, volume, moles, and temperature of a gas.

Darwin’s theory of natural selection: Explains the diversity of life in terms of competition, survival, and inherited traits.

Mendel’s Laws of Inheritance: Describes how hereditary characteristics are passed from parent organisms to their offspring.

Atomic Theory: All matter is composed of elements made up of atoms. Explains why matter is conserved in chemical reactions.

Law of Superposition:

Describes the general principle that in undeformed layers of rock, the oldest rock will be at the bottom.

Theories Explain ObservationsTheory of Plate Tectonics: Earth’s crust

is divided into plates that move.

Explains why earthquakes and volcanoes occur in certain zones.

Cell Theory: Identifies cells as the fundamental unit of structure and function in living things.

Explains the structure of life and where new cells come from.

Darwin’s theory of natural selection: Explains the diversity of life in terms of competition, survival, and inherited traits.

Explains the fossil record and how species can change over time.

Atomic Theory: Matter is composed of discrete units called atoms, as opposed to the obsolete notion that matter could be divided into any arbitrarily small quantity

Explains why matter is conserved in chemical reactions.

Theories Explain LawsEinstein’s General Theory of Relativity:

Explains gravity in terms of space-time curvature and that space-time is curved by matter.

Law of universal gravitation:

Describes the relationship between mass, distance, and the force of gravity.

Chromosome Theory: chromosomes are the basis for all genetic inheritance. Explains the mechanism underlying Mendel’s laws.

The law of independent assortment: Describes the principle that traits are passed on to offspring independent of each other .

Kinetic Molecular Theory: Matter consists of tiny particles in constant motion, whose speed is proportional to the absolute temperature. Explains gas laws.

Boyle’s Law:

Describes the relationship between pressure and volume of a gas when temperature is held constant.

BEFORE Instruction (WRONG)Quotes from Students &

Teachers“A scientific law is a theory that has been proven over and over by different scientists.”

“A scientific law is definite, and nothing is named a law unless scientists agree that there is no question to its being true. For example, scientists are open to finding new information about the atomic theory, but Newton’s law of motion has been tested enough times that scientists are certain it is true.”

“Newton’s 1st Law is proven and through various testing and experiments it has come to be known as a proven law. Theories, however, have not been proved enough to be changed into laws.”

AFTER InstructionQuotes from Students &

Teachers

“Scientific theories never turn into laws.”

“A scientific law is often mathematical and is used to describe a pattern found in nature. A theory is used to try and explain the ‘why’ of a pattern or occurrence.”

“A scientific law is a statement describing how something works. A scientific theory attempts to explain something that cannot be directly observed. Laws are usually something that is observable. Theories are based on inference, an effort to explain something.”

Scientific Theory & Law Extension

Individually: Write a list of key ideas

or create a Venn diagram focused on scientific theories and laws.

Consider how they are similar and different.

What Qs remain for you about scientific theories and laws?

Group: Discuss your ideas with

your group, adding to and modifying your list as needed

What does the Mystery Tube activity tell us about what science is like?

What does the Mystery Tube activity tell us about what science is like?

A scientific theory and law cannot become the other.

Why? They serve different purposes.

Neither is absolute.Both have exceptions

and can change (but don’t have to change).

Scientific knowledge (including theories & laws) is evidence-based.

All aspects of scientific work are creative… Developing Qs Developing procedures Problem solving Data interpretation Development of models