Mechanics
What is orbit?
This phase of matter is known to expand or compress to fill the space of its container.
What is a gas?
This concept is the measurement of rate of heat transfer between an object and its surroundings; when an object and its surroundings measure to be the same, the objects are said to be at thermal equilibrium.
What is temperature?
This and many other types of waves travels at the "universal speed limit" of 299,792,458 m/s, but this one specifically stems from oscillations in the electric and magnetic field.
What is light?
The best available evidence in cosmology suggests that the universe began existing 13.8 billion years ago, with this catchy but misleading name, when in fact it was really more of an "everywhere stretch".
What is the Big Bang?
The word that describes an object's tendency to stay at the same velocity unless a force acts upon it, which Sir Isaac Newton described in his first law of motion.
What is inertia?
From the greek word for "uncuttable", this is the smallest unit of matter that retains the chemical properties of the element.
What is an atom?
This exothermic phase change is responsible for the formation of clouds and dew.
This phenomenon enables noise cancellation headphones to work, through playing the same sound as ambient noise, but shifting it out of phase. The result is that the peaks of one wave overlap the troughs of the other and vice versa.
What is destructive interference?
Named after a 18th-century Scottish inventor, this SI unit of power is equal to one Joule per second, and is also the amount of power needed to move 1 amp of current continuously at 1 volt.
What is a watt?
Acceleration measures the rate of change of this value over time, and this value itself measures the rate of change of position over time.
What is velocity?
This phenomenon allows massive objects to remain afloat in water as long as the weight of the water they would displace is greater than their weight.
What is buoyancy?
Most metals are excellent at this method of heat transfer, requiring the direct contact between the involved objects.
What is conduction?
In a standing wave, these locations experience maximum constructive interference of waves, resulting in maximum displacement relative to elsewhere in the wave.
What are anti-nodes?
Albert Einstein is famous for having developed this general version of the theory that expanded on the special case theory surrounding the behavior of matter and spacetime at extremely high speeds.
What is general relativity?
In this type of collision, kinetic energy and momentum are both conserved.
What is an elastic collision?
This phase of matter is created when matter is heated so much that electrons no longer stay bound to their atoms; in other words the atoms become ionized by the high temperature. It is found throughout the sun, and in many electronic applications.
What is plasma?
As the universe ages, the total amount of this measurement always increases. This concept is often conflated with "disorder", but is more accurately described as "everything tends toward disorder".
What is entropy?
This is the amount of time that it takes a wave to cycle, and can also be calculated as the inverse of a wave's frequency.
What is the period of a wave?
This branch of physics studies the behavior of atoms and smaller particles. Probabilistic wave functions are far better predictors of experimental outcomes than deterministic functions.
What is quantum mechanics?
This 16th to 17th century astronomer and physicist is often credited with the discovery that two objects with different mass will fall at the same rate from the same height.
Who is Galileo Galilei?
This as-of-yet undiscovered substance that does not directly interact with light is thought to be responsible for the vast majority of gravity in the universe.
What is dark matter?
The absolute temperature scale is named in honor of this 19th century British mathematician and physicist, who calculated that absolute zero is approximately -273.15 oC.
Who is Lord Kelvin?
This wave describes displacement that is perpendicular to the direction of wave travel (as in waves on a lake), as opposed to longitudinal waves whose displacement is in the same direction as wave travel (as in a spring).
What is a transverse wave?
Stephen Hawking theorized that through the process of Hawking radiation, these massive seemingly-eternal astronomical objects can take ~10100 years to evaporate to nothing, long after everything else in the universe had decayed.
What is a black hole?