Properties of Light

Wavelengths

short wavelengths

    10^-15 m    gamm radiation
     10^-8 m    ultraviolet light
     10^-7 m    visible (purple)
     10^-6 m    visible (red)
     10^-5 m    infrared
     10^-1 m    microwaves
1 m - 10^5 m    radio waves

long wavelengths

Transparency

Facts

• Some materials are transparent and some are not

Hypothesis

Non-transparent materials are composed of chaotic "flakes", ehich doesn't allow light to pass through. Light waves are absorbed by a material, when they hit atoms of that material. Transparent materials are structured, so that light easily passes through.

Indication of Flaw in Hypothesis

Water is transparent, but seems to be as compact as possible

Information Contradicting Hypothesis

HS: atoms (fx in a salt crystal) are placed without spaces. there is no extra space through which light can pass.

- see http://www.emporia.edu/earthsci/amber/go340/visual.htm

Redshift

Redshift = doppler effect on waves in the electromagnetic spectrum sent from sources moving away from the observer