A
- Absorption
- When a material takes in wave energy instead of reflecting it. Curtains absorb sound; a dark pan absorbs light and warms in the sun.
- Acoustics
- The physics of sound: how it is produced, travels, reflects, and is absorbed in a space. Tiled kitchens sound sharp because their surfaces reflect rather than absorb.
B
- Boiling point
- The temperature at which vapor bubbles can form throughout a liquid. It depends on the surrounding pressure: lower at altitude, higher inside a pressure cooker.
C
- Condensation
- The phase change from gas to liquid as vapor loses energy — the droplets that appear when steam meets a cold lid.
- Conduction
- Heat transfer through direct contact, passed from particle to particle. Fast in metals, slow in wood — which is why the two spoon handles feel so different.
- Convection
- Heat transfer by the bulk movement of a fluid: heated fluid expands, rises, cools, and sinks, forming a circulation loop. This is how a kettle heats all of its water.
- Current (electric)
- The flow of electric charge through a conductor, measured in amperes. In a kettle it flows through a resistive element and is converted to heat.
D
- Density
- Mass per unit of volume. Heating a fluid expands it and lowers its density, which is what makes warm water and warm air rise.
E
- Electromagnetic induction
- Using a changing magnetic field to drive currents inside a conductive material, heating it directly. This is how an induction cooktop heats the pan and not the surface.
- Emission (thermal)
- Hot matter giving off electromagnetic radiation. Hot enough — like a filament — and that radiation reaches visible wavelengths and the object glows.
- Energy
- The capacity to cause change. It transforms between forms (electrical to thermal to light) but the total is conserved; kitchens are full of these conversions.
- Evaporation
- Liquid escaping into gas from the surface, below the boiling point. It is why a wet counter dries at room temperature.
F
- Frequency
- The number of wave cycles per second, measured in hertz. Higher frequency means a higher pitch in sound, or a bluer color in light.
H
- Heat
- Energy in transit from a warmer region to a cooler one. An object does not "contain heat" — heat is the flow itself, driven by a temperature difference.
I
- Insulation (thermal)
- Materials and design that slow heat transfer along all three pathways — conduction, convection, and radiation. A thermos attacks all three at once.
L
- Latent heat
- The energy absorbed or released during a phase change while the temperature stays constant. Boiling water stays at its boiling point even as the burner keeps adding energy.
P
- Phase change
- A transformation between solid, liquid, and gas as particles gain or lose enough energy to change how they are bound together.
- Polymer
- A material built from long chain molecules — plastics and silicone. Low thermal conductivity and easy shaping make polymers the default for grips and housings.
- Pressure
- Force spread over an area. Differences in pressure drive flow: water leaves a faucet because the supply is at higher pressure than the open air.
R
- Radiation (thermal)
- Heat transfer by electromagnetic waves, needing no contact and no medium. A toaster browns bread mostly this way, acting first on the exposed surface.
- Reflection
- A wave bouncing off a surface. Hard kitchen surfaces reflect sound into sharp echoes; shiny finishes reflect light.
- Resistance (electrical)
- A material's opposition to electric current. Where current meets resistance, electrical energy is dissipated as heat — the working principle of elements and filaments.
S
- Specific heat
- The energy needed to raise the temperature of one unit of mass by one degree. Water's unusually high value is why it takes so long to boil.
- Spectrum (visible)
- The range of light wavelengths the eye can see, roughly 380 to 700 nanometers, running from violet to red.
T
- Temperature
- A measure of the average agitation of particles. Two objects can share a temperature and still feel different, because your hand senses energy flow, not the number.
- Thermal conductivity
- How quickly a material lets heat pass through it. High for metals, low for wood, ceramic, and silicone — the property behind most cookware design choices.
- Thermal expansion
- The change in a material's size with temperature. A bimetallic strip bonds two metals that expand differently, so heating bends it — and switches the kettle off.
V
- Vapor
- The gas phase of a substance that is liquid at everyday conditions. Water vapor is invisible; the white plume from a kettle is already-condensed droplets.
W
- Wavelength
- The distance between successive wave crests. It pairs with frequency through the wave speed (wavelength = speed ÷ frequency), for sound and light alike.
- Work
- Energy transferred when a force acts through a distance. A refrigerator's compressor does work to push heat from a cold interior into a warm room.