The Doppler effect occurs in everyday life more often than you may think. It is the change in frequency or wavelength of a wave relative to a moving observer.
In this animation a car has sound waves that it is emitting. As the car starts to move the wavelength of the wave becomes smaller on the side of the car that it is moving toward and larger on the side that it is moving away from. An observer on the left side of this car would hear it gradually become higher pitched. An observer
The gold foil experiment is the famous experiment conducted by Ernest Rutherford that we all learned about in chemistry class. This experiment proved that atoms are made up of mostly empty space. In fact 99.9999% of an atom was proven in this experiment to be empty space. Lets say we could eliminate all that empty space by condensing the parts of an atom together. How much weight could we fit in a small space such as a single teaspoon? Over a billion tons!
This idea is common when studying
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