The Electromagnetic Spectrum:

{{*The entire range of possible wavelengths → electromagnetic spectrum*{{

The Sun:

In simple terms is a big nuclear furnace. Inside its core, there is an intense gravitational pressure that fuses hydrogen into helium which then releases energy in the form of electromagnetic radiation. → Photons Carry this energy in the form of waves.

Photons:

<<Formulas:<<
E=hvc=λvE= hc/ λ

E= Energy (Joules)

h= Planks Constant= 6.626 x 10 ^-34 (J x s)

v= Frequency (Hz)

λ= wavelength (nanometers (10^-9 meters))

c= speed of light = 3 x 10 ^8 (m/s)

{{Photons are particles that carry electromagnetic energy in the form of waves.{{

The more energy a photon carries the faster it oscillates.

Oscillation: to move back and forth in a regular, repeating way

 

Waves:

General Facts:

  • Wavelength is measured in nanometers (10^-9 meters)
  • {{Even though there is a wide range of types of electromagnetic waves, only some are visible to the eye→ “Visible Spectrum”{{
  • In the early 1600s scientists first learned to magnify light with glass lenses.

Parts of a Wave:

Crest: the highest point of the wave Trough: the lowest point of the wave Period: the distance between a consecutive crest and trough, measured in unit time Wavelength: the distance between consecutive waves or consecutive troughs Amplitude: the vertical distance between the crest and the trough

Frequency: the number of waves that pass a fixed point in a given amount of time.

*Higher Frequency →Louder → Brighter Light*

Lower Frequency → Quiter → Dimmer light

<<f= 1/ T<<

  • \
    • <<Frequency→Hz<<
    • <<T= period→second<<

 

Period: The time it takes for two successive crests (one wavelength) to pass a specified point.

  • <<T= 1/f<<

Types Of Waves

Transverse waves: in which the individual particles of the wave move perpendicular to the axis.

Longitudinal waves: in which the individual particles of the wave move parallel to the axis.

Types Of Electromagnetic Radiation

 

  1. Radio Waves: Heinrich Hertz proved its existence in the late 1880s.
    • They have the least energy→ and safest waves on the spectrum.
      • Longest wavelength; 1 mm
      • Lowest frequency and range→ 3 KHz to 300 GHz

     ex. T.V., FM and AM, phones, wireless computers,s and networks.

  1. Microwaves: Right after radio waves, low in energy.
  • They can be reflected by metal. Passes through glass, paper, and plastic.
    • Wavelength: 1mm to 1m
    • Frequency: 300 GHz to 300 MHz

    ex. Cell phones and microwaves <- high frequency/ energy causes any item to heat electrical and magnetic waves that are often used to heat things.

  1. Visible Light: Infrared and ultraviolet are slightly different versions of red and violet light respectively; the visible light range fits in between them.
  • A change in heat can change color.
  • Visible light can be found all around us since it comes from the sun.
    • Wavelength: 400 nm-700nm
    • Frequency: 400THz-700THz

    ex. Photography, phones, laptop, and T.V.s

  1. Ultraviolet Rays: between visible light and x-rays; towards the left.
  2. 2 types of UV:

   

  1. UVA: longer wavelengths

       1. cause skin aging and eye damage, lowering your body’s ability to fight off illness and skin cancer. 2. UVB: shorter wavelengths

  • Wavelength: 10-400 nm
  • Frequency: 800 THz

  ex. Lamps, lasers, and medication

  1. Gamma Rays: Far right of the spectrum.
  • Highest energy
  • The strongest form of radiation
    • Wavelength: <10^-12
    • Frequency: 3x 10^-18 → 5 x 10 ^22

ex. found in supernova explosions, neutrons stars, and around black holes. Can be used in medicine; radiotherapy and sterilization.