Exploring Theories and Laws. How are these four concepts related to each other?

Exploring Theories and Laws

How are these four concepts related to each other?

Common Descriptions• Facts are indisputable, proven, known to have

happened

• Hypotheses are educated guesses, hunches, unsubstantiated claims

• Theories are unsubstantiated ideas, opinions, unproven explanations

• Laws are proven theories that have withstood repeated testing over time, rules that must be followed, a piece of enacted legislation

HYPOTHESIS

THEORY

L A W (fact)

When proven that it always works

When supported over time

From Where Do These Ideas Originate?

Theories in Media

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.

Student & Teacher IdeasA 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.

Jigsaw Activity

• Read your article.

• Discuss the authors’ definitions and examples of scientific fact, theory, law, and hypothesis.

• How are these similar/different from the commonly used/Helen Curtis’ definitions of these terms?

• Be prepared to briefly share with the class.

List examples of scientific theories and laws….

Theories Laws

Theories LawsTheory of Special Relativity:

The speed of light in a vacuum is constant regardless of the motion of the observer or the motion of the light source. Explains the relationship between mass and energy.

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

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

Ideal Gas Law: PV=nRT

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

Electromagnetic Field Theory:

A change in an electric field produces a perpendicular magnetic field. A change in a electric field produces a perpendicular electric field. Explains the way in which charges and currents interact.

Ohm’s Law: V = IR

Describes the relationship between the voltage (V), current (I), and resistance (R).

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

Law of Superposition:

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

Theories LawsTheory of Special Relativity:

The speed of light in a vacuum is constant regardless of the motion of the observer or the motion of the light source. Explains the relationship between mass and energy.

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

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

Ideal Gas Law: PV=nRT

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

Electromagnetic Field Theory:

A change in an electric field produces a perpendicular magnetic field. A change in a electric field produces a perpendicular electric field. Explains the way in which charges and currents interact.

Ohm’s Law: V = IR

Describes the relationship between the voltage (V), current (I), and resistance (R).

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

Law of Superposition:

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

Theories Explain Observations

Theory of Plate Tectonics: Earth’s crust is divided into plates that move.

Explains why earthquakes and volcanoes occur in certain zones.

Electromagnetic Field Theory: A change in an electric field produces a perpendicular magnetic field. A change in a magnetic field produces a perpendicular electric field.

Explains the way in which charges and currents interact.

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.

Which Came First?General Theory of Relativity: Law of Universal Gravitation:

Chromosome Theory: Law of Independent Assortment:

Kinetic Molecular Theory: Boyle’s Law:

Which Came First?

General Theory of Relativity:

Einstein: 1916

Law of Universal Gravitation:

Newton: 1687

Kinetic Molecular Theory:

Bernoulli, Clausius: 1738, 1857

Boyle’s Law:

Boyle: 1662

Chromosome Theory:

Thomas Hunt: 1910

Law of Independent Assortment:

Mendel: 1866

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

Stephen J. Gould

Scientific 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 Theory: A general principle supported by a substantial body of evidence offered to provide an explanation of observed facts and as a basis for future discussion or investigation.

Lincoln, Boxshall, and Clark (1990)

Scientific Law: A scientific law is a description of a natural relationship or principle, often expressed in mathematical terms.

Is there a hierarchy among the four original concepts?

•Facts

•Theories

•Laws

•Hypotheses

Facts

Hypotheses

Theories

Laws

Lead scientists to develop

Which, when supported by experiments, become

And, eventually proven, become

More absolute

Less absolute

Facts

Hypotheses

Theories

Laws

Lead scientists to develop

Which, when supported by experiments, become

And, eventually proven, become

More absolute

Less absolute

HYPOTHESIS

THEORY L A W

HYPOTHESIS

THEORY L A W

•Concise, descriptive principal

•Based more on observation

•Explanatory principal

•Based more on inference

Mystery Tube

So How Do We Teach This?

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

String Theory

?

Mystery Tube

So How Do We Teach This?

Post-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.

Laws and Theories

• Based on evidence• Can change

with new evidence • Cannot change into each other

• Based primarily on observations• Holds for specific

conditions• More descriptive• Answers “what happens?”

• Relies heavily on inferences• Generalizations• More explanatory• Answers “How does it happen?”

Laws Theories