Main source of light is sunlight for our solar system

Info icon This preview shows pages 5–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Main source of light is sunlight (for our solar system)
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Secondary sources Emission from atmosphere o Aurora Emission from surface o Heat Marble in different sized bowls: Friction in bowl makes ball spiral to center; there’s NO FRICTION in space (why planets stay on their orbit) Newton was the first to discover light spectrum Mass affects time!! Acceleration=time slows down Properties of light o Light is a form of electromagnetic radiation Most of the properties of EM radiation can be described as energy (sunburn, photographic emulsions, comet tails, radiation pressure) propagating as waves (wave picture) A Wave Moves by (v) Is repetitive Has a characteristic length Einstein & Co.=light is not continuous; light is discrete!!! Einstein received his Nobel Prize for Photoelectric effect. Fascinating Characteristics of Light o Dispersion (and Diffraction) White light is separated into many components (colors) upon passing from one medium to another medium (air-glass) [fig 5.1] Dispersion by differential bending (“Refraction”) due to v<c within a medium, v=c in a vacuum. Newton’s experiment: wavelengths are fundamental for each color Dispersion by raindrops is called a RAINBOW! Energy Packet Experiments o Sometimes light behaves as if it is a flux of photons Packets of radiant energy o “The Photo-Electric Effect” (Einstein’s Nobel Prize!!) o The most basic form of materials (atoms) absorb and emit light in specific amounts Thus light can be described both as a wave and a particle This gives rise to the “wave-particle duality” of light The full Electromagnetic Spectrum (Fig 5.7) Sometimes light can be a flux of photons or a series of waves. “Light and Matter” Matter! The Nature of Light
Image of page 6
o Wave Picture Newton found that dispersing white light caused it to turn into many different colors. When a specific color was again dispersed the color remained the same, leading to the wave picture of light. o Quantum (Particle) Picture Sometimes light behaves as if it is a flux of photons, discrete packets of radiant energy Einstein found that when photons hit metal, electrons would be ejected from the metal, proving that individual photons carried energy and momentum. Quantum Mechanics describe how matter and light interact at the level of atoms and photons The atomic theory of matter o Nuclei with protons and nuetrons o Clouds of electrons at different “energy levels” or Quantum states Atomic number=number of protons Atomic mass number=number of protons+neutrons A neutral atom has the same number of electrons as protons Solid liquid gas molecular dissociation (molecules break apart into component atoms) plasma phase (free electrons move among positively charged ions) fully ionized plasma (atoms in plasma become increasingly ionized) Spectroscopy: using the features in the spectrum of light from an object to find its thermal, chemical and dynamical properties.
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern