Why is it not possible to have waves with high frequency (high energy) and great wavelength and converse? What physical quantity ties frequency to wavelength in an inversely proportional way?

I want to measure a pulse signal using an oscilloscope. The expected rising edge of the signal is in the 1 to 5 ns scale. I have a 20 MHz oscilliscope. Is it correct that the rising edge of the oscilloscope would be limited to 17.5 ns? In other words, do I need to use a faster oscilloscope? How d...

In terms of order of magnitude, how does a the energy consumption of a typical mammalian neuron (in the brain) compare with the state of the art MOSFET?

This video demonstrates how varying color filters alter the energy of photoelectrons emitted from a light source: https://www.youtube.com/watch?v=kcSYV8bJox8 But I am confused by what these different colors having different "energies" means. Blue light is said to have more energy than red light. ...

So, my question might seem silly. I know in real life when we apply a force with our hand and push on lets say a cylinder , we know the force will be distributed over the cross section of the area, so if we had a wider area, we need more force, and if we had smaller area, then we need less force ...