1. (4) Strong nuclear force force that binds protons & neutrons
Forces of Nature
Newton's Laws of Motion
Inverse square law of forces
Fundamental forces (4)
(3) Weak nuclear force
Example:
β-decay or
top bottom quark
(4) Strong nuclear force
force that binds
protons & neutrons
in atomic nuclei
(1) Gravitational force
Example:
falling
apple
(2) Electromagnetic force
horseshoe
magnet

2. Waves
A wave is a pattern of motion that can carry energy without carrying matter along with it
Wavelength =
distance between two wave peaks
Frequency =
number of times per second that a wave vibrates up and down
wave speed = wavelength x frequency
wave speed = l * f

4. Electromagnetic Spectrum
Progression of frequency or wavelength
Radio, millimeter, sub-millimeter, microwave, infrared, optical, ultraviolet, X-ray, gamma rays
Optical/visible white light spectrum (rainbow colors):
Red Orange Yellow Green Blue Indigo Violet
[Order of decreasing wavelength, increasing frequency]

5. Doppler Shift Demonstrator
Check out the interactive website:
Click the “start emission” button, check the “show paths” button, and then click and drag the source of electromagnetic radiation “S” or the observer “O” and observe what happens. Compare the waves of electromagnetic radiation as emitted from the source to the waves as detected by the observer. Any relative motion between the source and observer causes the observer to observe a different frequency and wavelength than emitted by the source. This is known as Doppler shift.

6. Atmospheric Windows
Optical, [sub-millimeter], millimeter, and radio wavelengths
Impact on astronomy (and on human evolution!)