Explains what causes thunderstorms, the different types, and the effects of thunderstorms.

Read the story behind Archimedes' claim that he could lift the Earth with a lever. The author analyzes this hypothetical claim to show that it would never be possible to lift something as massive as the Earth.

Describes the three stages of a tornado's life cycle.

Provides some facts about tornadoes and describes their impact.

Discusses properties, uses, and facts about polypropylene.

Provides some common examples of chemical reactions, e.g., in respiration, rusting, and photosynthesis.

Describes the many applications of propylene glycol and potential health concerns.

Explains what is meant by the half-life of a radioactive element and how it is calculated.

Describes the different types of mechanical weathering and how each of them breaks down rocks.

Discusses how rivers form and the different types of rivers.

Explains how an air suspension system in a vehicle works, as well as the hydralastic and hydragas suspension systems. Discusses problems that could arise and what they are caused by.

Discusses the confusion around what is meant by organic chemistry and provides a list of organic compounds organized into categories and types.

Explains what a gyroscope is and the physics behind how it works.

A long list of scientists with brief descriptions of their most important contributions to science.

A list of mathematicians with descriptions of their most important accomplishments in mathematics.

Gives information about the lives and accomplishments of notable female mathematicians throughout history.

Summarizes some of the most important accomplishments of Albert Einstein.

Explains different types of pressure, the characteristics of absolute and gauge pressure, and their differences and similarities.

Discusses the characteristics of sound waves and the conditions that affect the speed of sound.

Presents labeled illustrations modeling each of Newton's three laws of motion along with explanations.

Gives brief biographical information for Robert Boyle and explains what Boyle's Law is and how to make calculations using his formula.

Discusses the two math problems that baffled mathematicians for ages, Fermat's Last Theorem and Riemann's Hypothesis. The latter is still unsolved.

Demonstrates how to divide a fraction by a whole number.

Explains what the four different types of number systems are and what they are used for. Presents the formula used to convert octal numbers into decimals and models how to apply it in two example problems.