TED Microwaves - Veronika

RADAR technology

systems that use radio waves to detect distant objects like aircraft.

surprising applications

unexpected ways something can be used.

magnetron

a vacuum tube that makes microwaves for RADAR and ovens.

high-intensity microwaves

very strong microwave energy.

electromagnetic spectrum

the full range of light frequencies, from radio to gamma rays.

charged particles

particles (like electrons) that carry electric charge.

polar molecules

molecules with positive and negative ends (e.g., water).

frictional heat

heat produced when things rub or jostle against each other.

cavity magnetron

a magnetron with metal cavities that set the microwave frequency.

continuous stream (of microwaves)

waves produced without a break.

main food compartment

the inner chamber of the microwave where food sits.

food composition

what food is made of (water, fat, sugar, etc.).

gelatin-sugar matrix

the soft structure in a marshmallow that traps water and air.

suspension of water droplets in fat

tiny water drops spread through fat (like in butter).

ionizing radiation

very energetic radiation that can knock electrons off atoms (harmful at high doses).

non-ionizing (radiation)

lower-energy radiation (like microwaves) that cannot break chemical bonds.

chemical bonds

links that hold atoms together in a molecule.

molecularly indistinguishable

**the molecules are the same before and after

no chemical change.**

leakage

unwanted escape of energy from a device.

metal conductors

metals that let electrons move easily.

high voltages

strong electrical potential that can cause sparks.

lightning-like sparks

bright flashes similar to tiny lightning.

plasma

gas with charged particles that can glow and carry electricity.

microwavable packaging

food packaging safe for use in a microwave.

thin metal coating

a very fine metallic layer used to brown/crisp food.

an uneventful affair

something that happens with no problems or drama.

detect airplanes

find planes using sensors.

reflect off (planes/walls)

bounce back from a surface.

notice that… had melted

realize something became liquid due to heat.

expose X to Y

put something in contact with a force or substance.

kernels popped / an egg exploded

**corn burst open

egg burst from pressure.**

produce microwaves

generate microwave energy.

fields oscillate

electric/magnetic fields move back and forth regularly.

exert forces (on)

apply a push or pull to something.

jostle against each other

bump and move around, creating friction.

are ejected

are thrown out or released.

spiral outwards

move in circles that get larger.

induce an oscillating charge

cause a repeating positive/negative change.

bounce off walls

hit the walls and reflect back.

penetrate into food

go a short distance inside the food.

interact strongly with

affect a lot when in contact with.

rapidly vaporizes

turns into steam very quickly.

heat mechanically rather than alter chemically

warm by motion, without changing molecules.

designed to prevent (leakage)

built to stop energy escaping.

recommend standing (a few feet away)

advise keeping some distance.

concentrate on the surface

gather at the outside layer.

dissipates

fades away and disappears.

crisp the surface

make the outside brown and crunchy.

energetic (frequency)

carrying a lot of energy.

loosely bound (electrons)

held weakly and able to move.

high-frequency / low-frequency

many / few wave cycles per second.

metallic (cavities)

made of metal.

depending on

changing with conditions or type.

rapidly / violently

very quickly / with sudden force.

mechanically vs chemically

by physical motion vs by changing molecules.

molecularly indistinguishable

identical at the molecule level.

lightning-like

similar to lightning in look or behavior.

The higher X, the more Y

a structure showing two things grow together (correlative comparison).

So, how does it work?

a signpost question introducing an explanation.

This can have effects depending on…

cautious statement that notes conditions.

As/When (they pass/encounter)

time/condition linkers introducing a process step.

Instead of …, …

contrasts one option with another.

As long as …

condition meaning “if this is true, then it’s okay.”

limit exposure

reduce how much you are around something.

for safety and efficiency’s sake

to be safe and to work well.

strip electrons from DNA

remove electrons, which can damage genetic material.

dangerous, though it depends

risky in some situations but not all.

cavity

a hollow space in the magnetron that shapes the waves.

electrons

tiny charged particles in atoms.

magnet

an object that creates a magnetic field.

metallic cavities

the metal hollow spaces inside a magnetron.

oscillating charge

charge that flips back and forth.

electromagnetic microwaves

light waves with microwave frequencies.

pipe / waveguide

the metal channel that carries microwaves into the oven.

vibrate

move back and forth quickly.

prongs (of a fork)

the pointed metal teeth of a fork.