Sun – 8 light-minutes

Ike as seen from the ISS

Mysterious Glow! UFO? Nope, Urine

Energy and Light Mr. Hibbetts Thanks to Dr. Dan Bruton, SFA

What is universe made of? Answers: Spacetime Energy Matter e.g. rock, water, air What is Energy? It is the mover of matter. Or, the ability to do work It is measured in Joules or BTU’s.

Types of Energy What are some types of energy?

Types of Energy Kinetic Potential Radiative Thermal Mass-energy And others...

Kinetic Energy Kinetic Energy is the energy of motion. Kinetic Energy = ½ mass  speed 2

Kinetic Energy Do planets have small amounts or large amounts of kinetic energy? Large Mass = Greater Energy Faster Velocity = Greater Energy The Earth: - Mass = 5.98 x kg - Average Velocity = m / s (that’s mph)

Cosmic Connections Comet Schumaker-Levy 9 collided with Jupiter. The more massive fragments imparted more energy into the atmosphere of Jupiter.

Is the kinetic energy of molecules in a substance Particles move faster in hot objects. Thermal Energy

Cool Hot

Potential Energy The energy that is stored is called potential energy. Examples: Rubber bands Springs Bows Batteries Chemical Gravity

Mass-Energy E=mc 2 Energy from converted matter Is it possible to convert mass into pure energy? Answer: Yes, our Sun does this.

Radiative Energy The energy of electromagnetic wave Also known as electromagnetic radiation Including light in all its forms

Conservation of Energy “Energy cannot be created or destroyed it may be transformed from one form into another.” Example Our Sun coverts mass energy into radiative energy (i.e. light).

Radiative energy is also known as... Light *pure energy Electromagnetic Waves *energy-carrying waves emitted by vibrating electrons Photons *particles of light

Light Photons Electromagnetic Radiation

Waves Wavelength - the distance between two successive peaks in a wave. It is measured in meters or nanometers. 1 nanometer = 1 × meters Amplitude - the maximum departure of a wave from the undisturbed state This corresponds to intensity for light.

Wave Period - the amount of time for a wave to repeat itself at a specific point in space It is measured in seconds. Frequency - is the number of wave crests passing a given point per unit time It is measured in Hertz (cycles per second). Waves

Wave Speed - is the speed with which a wave crest passes by a particular point in space It is measured in meters/second. Wave Speed = Frequency  Wavelength Waves

Shock Wave

Light and The Electromagnetic Spectrum

Rember …. Light is electromagnetic radiation. So where does it come from?

Light Comes from the vibrations of electrical charges particles Protons And Electrons

Light But what is light?... How can it be both a wave of energy and a particle of energy at the same time?...

Light It gets weirder… When directly observed light acts light a particle When indirectly observed light acts like a wave

Light So the observer influences lights behavior? According to quantum physics…Yes!

Light Solution: Light exits in packets of waves called quanta But how and why? We do not know….(yet!)

The Electromagnetic Spectrum A range of light waves extending in wavelength from radio waves to gamma rays

The Electromagnetic Spectrum Radio Waves Microwaves Infrared Visible Light Ultraviolet X-rays Gamma Rays Raging Martians Invade Roy G. Biv Using X-rays and Gamma Rays mnemonic

Radio Waves Lowest frequency Highest wavelength Omnipresent Uses?

Microwaves Highest frequency radiowaves (some don’t make a distinction) Uses?

Infrared Just below visible light in frequency Classic “Heat” vision Uses?

Visible Light Spectrum What we see Low Frequency High Wavelength Higher Frequency Lower Wavelength

Ultraviolet Higher fequency than visible light The first “dangerous” light waves Majority of the Sun’s light when it reaches earth Uses?

X-Ray Can fully penetrate most living tissue Soft and Hard X-rays overlap other forms of light in wavelength and frequency Generated from electrons Uses?

Gamma Rays Will destroy most living tissue Generated by atomic nuclei Highest frequency Lowest wavelength (about the size of an atomic nucleus) Uses?

Gamma Ray Burst in Space

Earth’s Atmosphere Transparent - the term applied to materials through which light can pass in straight lines Opaque - the term applied to materials that absorb light

Earth’s Atmosphere Transparent to visible, radio infrared (partially) Opaque gamma, X-rays, UV, Microwave