Ch. 1 - Intorduction - Electromagnetic Spectrum Flashcards
1
Q
What is an image?
A
- A matrix of numbers
- A visual representation of an object
2
Q
Imaging Modalities
A
- A specific imaging technique
3
Q
EM Spectrum
A
Gamma - Low wavelength, high frequency, high energy
X-ray - Low wavelength, high frequency, high energy
Radio - High wavelength, low frequency, low energy
4
Q
History of light
A
Isaac Newton - 1666 William Herschel - 1800 Johann Riter - 1801 Thomas Young - 1801 Maxwell Plank - Albert Einstein Today
5
Q
Isaac Newton
A
- 1666
- Particle of energy
- Prism –> Different Colors
6
Q
William Herschel
A
- 1800
- Different temperatures for different colors
- More than just the visible colors
- There is light we cannot see –> Infrared Lights
7
Q
Johann Riter
A
- 1801
- Photo sensitive plate (silver chloride)
- Turns different shades of grey
- Outside visible light spectrum of colors would change the plate’s color - Discovered UV Lights
8
Q
Thomas Young
A
- 1801
- Light is a wave of energy not just a particle
- Double Slit Experiment
- 2 waves = deeper through and crest (bigger)
- Crest and through cancel each other out
9
Q
Maxwell Plank
A
- Black body (heat product, inside = glow) –> quantify the energy
- E = hv –> frequency (v)
- Plank’s constant (h) = 6.62610^-34 Js - The higher the frequency, the higher the energy but higher frequency light has a smaller wavelength
10
Q
Albert Einstein
A
- Maybe light is a particle
11
Q
Today
A
- Still don’t know what light it
- Both => is a particle and wavelength (behaves like both)
12
Q
Equations (1)
A
/\ = c/v
- /\ - wavelength (m) - c - speed of light = 3*10^8 m/s - v - frequency (Hz) - higher wavelength = lower frequency, lower energy - lower wavelength = higher frequency, higher energy
13
Q
Equations (2)
A
E = hv = h(c//)
- E - energy (J) - h - plank's constant = 6.626*10^-34 J*s - v - frequency (Hz) - c - speed of light = 3*10^8 m/s - /\ - wavelength (m)
