Red Shift 46Afa1

1. Let's start by understanding what red shift means in astronomy. 2. Red shift occurs when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum. 3. This usually happens when an object in space, like a galaxy, is moving away from us. 4. The formula to calculate red shift $z$ is $$z = \frac{\lambda_{observed} - \lambda_{rest}}{\lambda_{rest}}$$ where $\lambda_{observed}$ is the wavelength we detect, and $\lambda_{rest}$ is the original wavelength emitted. 5. Important rule: The greater the red shift, the faster the object is moving away. 6. This is a key piece of evidence for the expansion of the universe. 7. In entertainment videos, red shift can be explained visually by showing light stretching as objects move away, changing color from blue to red. 8. This helps viewers understand how astronomers measure the speed and distance of galaxies. Final answer: Red shift is the stretching of light to longer wavelengths as objects move away, indicating the universe is expanding.