Light as Particles; Telescopes

What is the traditional view of light?

Light is usually thought of as a kind of wave.

Who adopted the particle view of light?

Isaac Newton.

What experiment did Thomas Young conduct in 1801?

Young's Double-Slit Experiment.

What is an interference pattern?

Alternating bands of light (constructive interference) and dark (destructive interference).

What phenomenon did Heinrich Hertz discover in 1887?

The Photoelectric Effect.

What does the photoelectric effect demonstrate?

Light falling on a metal plate generates a small electric current.

Who proposed revisiting the particle view of light to explain the photoelectric effect?

Albert Einstein.

What is 'wave-particle duality'?

The concept that light sometimes acts like waves and sometimes like particles (photons), depending on the situation.

What question did Louis de Broglie pose in 1924?

Does matter sometimes act like waves?

What did experiments with electrons demonstrate?

Electrons can also exhibit wave-like behavior, producing interference patterns.

What happens when a measurement is made on electrons passing through slits?

The electrons behave like particles instead of waves.

What is quantum mechanics?

The science of the very small, dealing with phenomena at the atomic and subatomic levels.

What are the three functions of telescopes?

Magnifying, resolving, and brightening.

Who invented the refracting telescope?

Hans Lippershey, likely in 1608, and perfected by Galileo Galilei.

What problem is associated with refracting telescopes?

Chromatic Aberration.

Who invented the reflecting telescope?

Isaac Newton in 1668.

What is the solution to the problem of refraction degrading optical images?

Placing telescopes on tops of mountains.

What is the Hubble Space Telescope known for?

Being an artificial satellite that operates above the atmosphere.

What major problem did the Hubble Space Telescope face upon launch?

Spherical Aberration.

What mission corrected the Hubble's spherical aberration?

The 1994 C.O.S.T.A.R. mission, which provided corrective optics.

What is the primary function of the James Webb Space Telescope?

It is primarily an infrared instrument.

What are Lagrange Points?

Positions in space where gravitational forces balance, allowing spacecraft to maintain position with minimal fuel.