Appendix E: Glossary of Terms
This glossary covers many of the foundational terms you’ll encounter throughout this book. However, science is filled with unfamiliar words, especially as you explore more advanced experiments or dive into adjacent topics. If you come across a term not listed here, try asking ChatGPT for a definition or an explanation in plain language. It’s a great way to get instant, personalized help—whether you’re reviewing for class or just satisfying your curiosity.
- Acceleration – The rate at which an object’s velocity changes over time, typically measured in meters per second squared (m/s²).
- Albedo – A measure of how much light a surface reflects. A higher albedo means a surface reflects more light.
- Amplitude – The maximum extent of a vibration or oscillation, measured from the position of equilibrium.
- Angular Size – The angle an object appears to take up in the sky, usually measured in degrees, arcminutes, or arcseconds.
- Apparent Magnitude – A measure of how bright a celestial object appears from Earth.
- Calibration – The process of adjusting or marking a measuring instrument so that it gives accurate results.
- Capacitance – The ability of a system to store electrical charge, typically measured in farads.
- Center of Mass – The point in an object where its mass is evenly distributed in all directions; the balance point.
- Centripetal Force – A force that keeps an object moving in a curved path and is directed inward toward the center of rotation.
- Conductivity – A material’s ability to allow the flow of electric current or heat.
- Control Variable – A variable in an experiment that is kept constant so that the effect of other variables can be observed more clearly.
- Decibel (dB) – A logarithmic unit used to express sound intensity or signal strength.
- Density – Mass per unit volume of a substance, often expressed in kilograms per cubic meter (kg/m³).
- Diffraction – The bending of waves around the edges of an obstacle or aperture.
- Electromagnetic Spectrum – The range of all types of electromagnetic radiation, from radio waves to gamma rays.
- Energy – The capacity to do work; it comes in many forms, such as kinetic, thermal, electrical, and potential.
- Frequency – The number of occurrences of a repeating event per unit time; in sound, it determines pitch.
- Gravity – The force that attracts two bodies toward each other, proportional to their masses and inversely proportional to the square of their distance.
- Gyroscope – A sensor used to measure rotational movement around an axis.
- Hypothesis – A proposed explanation based on limited evidence as a starting point for further investigation.
- Infrared Radiation – Part of the electromagnetic spectrum with wavelengths longer than visible light; often experienced as heat.
- Inertia – An object’s resistance to a change in motion.
- Kelvin – The SI base unit for temperature, where 0 K is absolute zero.
- Kinetic Energy – The energy of a moving object, proportional to its mass and the square of its velocity.
- Latitude – The angular distance of a place north or south of the Earth’s equator, measured in degrees.
- Longitude – The angular distance of a place east or west of the Prime Meridian, also measured in degrees.
- Lux – A unit of illuminance, representing one lumen per square meter.
- Magnetometer – A sensor that measures the strength and direction of magnetic fields.
- Mass – A measure of the amount of matter in an object, typically measured in kilograms.
- Momentum – The product of an object’s mass and velocity; a measure of how hard it is to stop a moving object.
- Parallax – The apparent shift in position of an object when viewed from different angles, used to determine distances in astronomy.
- Period – The time it takes for one full cycle of a repeating event, such as a wave or oscillation.
- Photon – A quantum of light or other electromagnetic radiation.
- Potential Energy – Stored energy due to an object’s position or configuration.
- Precision – The consistency or repeatability of measurements; distinct from accuracy.
- Reflection – The bouncing of light or sound waves off a surface.
- Refraction – The bending of a wave as it passes from one medium to another with a different density.
- Resolution – The smallest measurable change in a quantity that a sensor can reliably detect.
- Sensor Fusion – The process of combining data from multiple sensors to produce more accurate or comprehensive measurements.
- Signal-to-Noise Ratio – A measure that compares the level of a desired signal to the level of background noise.
- Spectroscopy – The study of the interaction between matter and electromagnetic radiation, often used to identify substances.
- Surface Tension – The elastic tendency of a fluid surface that makes it acquire the least surface area possible.
- Temperature – A measure of the average kinetic energy of the particles in a system.
- Torsion – The twisting of an object due to applied torque.
- Uncertainty – The estimated amount by which a measured or calculated value may differ from the true value.
- Vector – A quantity that has both magnitude and direction (e.g., velocity, force).
- Voltage – The electric potential difference between two points, measured in volts.
- Wavelength – The distance between successive crests of a wave, often used in the context of light or sound.