Quantum Physics

Every material has a unique atomic spectra of emitted light

Today in class we studied Quantum Physics. First Mary and Bill gave a lecture on wave-particle duality, the idea that light (and particles traveling at near the speed of light) are simultaneously particles and waves, and have the properties of each. Then they talked about blackbodies and the photoelectric effect, and how those unexplained phenomena led to Max Planck proposing that light and energy are quantized (quantum physics). Finally, they talked about advances Heisenberg and Schrodinger made in quantum theory, mainly the ideas of particles existing as probabilities rather than measurable quantities.

The effect of too much CO2 and other greenhouse gases

Then Ken Landy gave a lecture about energy issues. Essentially, we are using a lot of power--way more than is sustainable for even several decades. Not only is there a finite supply of petroleum and our other main energy sources, but using them causes environmental problems and creates CO2 that contributes to climate change. He explored some other options for sustainable energy, but most are inefficient, expensive, and not viable. The best option is wind turbines, but even they aren't that great, and require a lot of space (in windy, flat areas) to make enough electricity.

What our circuits were supposed to look like

What our circuits actually looked like

After lunch, we were assigned new lab groups for the week and performed a lab to find Planck's constant. We used diodes and LEDs, finding the required voltage and wavelengths of different colors of LEDs to find the energy and frequency. From there, we found Planck's constant from the slope of the points, graphing energy against frequency. Our results were surprisingly accurate, though one of our LEDs burned out and had to be replaced, and another gave different results different times it was used.

All in all, I thought it was an interesting lab, and I can't wait until we start doing special and general relativity tomorrow and the next day.