8:00 PM - Call to order and introduction of tonight's program:

Speaker:

Dr. Daniel Rothstein, Department of Physics, Kent State University

Presentation:

"The Four 'Red' Shifts"
 

There are four types of frequency shifts in nature. One is the classical Doppler Effect in mechanical mediums, such as sound in air or in water (I will play some examples with train horns) for which it depends whether the source or the observer is moving. Another is the Relativistic (why necessary?) Doppler Effect for electromagnetic waves, which shows up in devices such as Doppler Radar, radar guns, and GPS. As astronomers we see this with light in binary stars, exoplanet detection, and the Hubble Law for nearby galaxies. The third type is the Gravitational Red Shift, which explains why light can't escape from a black hole and the apparent illusion of superluminal velocities in active galactic nuclei. The last type is the Expansion Shift, due to the expanding universe where space expands, often confused with the Doppler Effect for moving objects.

"The universe is there for us to see, but it cannot be understood without learning its language - mathematics."  - Galileo Galilei