Modern

3. An experiment that determined light of frequency below a certain threshold does not excite electrons
5. A real-world example of Time Dilation
7. City in California, and experiment showing photons have momentum
9. Hypothetical subject of Time Dilation
10. "The Wave-Particle ________ of Light"
13. Allows for nuclear fusion to occur in the Sun
14. The wave-behaviour of light to bend around corners
16. The concept in quantum physics that objects cannot be seen in a natural, undisturbed state
17. An apparatus used by Michelson-Morley
18. Scientist famous for developing 4 equations describing electromagnetic waves

1. A structure that might contain a ladder
2. Einstein based his relativity development on 2 of these.
4. The interpretation of quantum physics that implies reality as a superposition of probabilities
6. Scientist famous for developing the 'wave equation' and the "cat" thought experiment. Has a questionable past.
8. The difficulty of this unit
11. Measured the speed of electromagnetic wave
12. Organization that would like to speak with Erwin
14. "Young's ______ ____ Experiment"
15. Used for internet communication worldwide