Questions: One of the reasons scientists know that the universe is rapidly expanding is because the light from distant galaxies is Red Shifted, meaning that the galaxies are moving away from us. However, there are some galaxies moving toward us instead. These galaxies have their light Blue Shifted by the Doppler Effect instead. What do we know about Red and Blue light waves because of this?

One of the reasons scientists know that the universe is rapidly expanding is because the light from distant galaxies is Red Shifted, meaning that the galaxies are moving away from us. However, there are some galaxies moving toward us instead. These galaxies have their light Blue Shifted by the Doppler Effect instead. What do we know about Red and Blue light waves because of this?

Transcript text: One of the reasons scientists know that the universe is rapidly expanding is because the light from distant galaxies is Red Shifted, meaning that the galaxies are moving away from us. However, there are some galaxies moving toward us instead. These galaxies have their light Blue Shifted by the Doppler Effect instead. What do we know about Red and Blue light waves because of this?

Solution

Solution Steps

Step 1: Understanding Red and Blue Light

Red and blue light are part of the visible spectrum of electromagnetic waves. The color of light is determined by its wavelength and frequency.

Step 2: Frequency and Wavelength Relationship

The frequency (\(f\)) and wavelength (\(\lambda\)) of light are inversely related by the equation: \[ c = \lambda f \] where \(c\) is the speed of light in a vacuum (\(3 \times 10^8 \, \text{m/s}\)).

Step 3: Comparing Red and Blue Light

Red light has a longer wavelength and therefore a lower frequency compared to blue light. Conversely, blue light has a shorter wavelength and a higher frequency.