Fun Physics Fact Friday 4!

Fun Physics Fact Friday: Quartz watches are driven by an actual quartz crystal. This is thanks to a phenomenon called the Piezoelectric effect: where if mechanical stress is applied to a crystal, a small voltage is created on the surface. Conversely, if a voltage is applied, the crystal will undergo small changes or oscillations that can be measured and interpreted by the circuitry within the watch. The oscillations will remain constant as long as the same voltage is supplied from the battery and so the watch is designed interpret either electronically (for digital) or mechanically (for analog) into seconds that are presented on your watch face.


Crystals are so good at conserving the mechanical energy applied to them that a tuning fork made of pure crystal can ring for more than several minutes. This is because of how the stress that is initially applied is turned into electrical potential (voltage) and then converted back into mechanical energy, resulting in the "ringing" of a crystal tuning fork.

Fun Physics Fact Friday 3

I apologize for being a day late - I had this fact already picked out, I just for some reason thought that today was Friday. I was wrong. So ready or not, here's the next FPFF!

If you were standing at arms length next to someone and each of you had 1% more electrons than protons, the repelling force between you would be enough to lift a weight equal to that of the entire earth!

I read this one from my Feynman Lectures on Physics: Vol 2 that I got with some birthday money. I bought the entire box set and it's really nice. Back to the point: the force that you would see is called the electromagnetic force and more precisely, in this case, a Coulomb force and it is the force that is observed between two charged particles. As you may already understand from magnets, like charges repel and opposite charges attract. In your body you have, on average, 7,000,000,000,000,000,000,000,000,000 or 7*10²⁷ atoms. Each atom is composed of a specific number of negatively charged electrons, positively charged protons, and neutrally charged electrons. There is such a perfect balance within your body that you have the exact same number of electrons and protons and therefore you don't radiate a field around your body that affects others electromagnetively. But if you each had more electrons than protons, you would each have a total negative charge and repel each other.

Fun Physics Fact Friday 2!

Sorry, I forgot to post this past week's FPFF on friday. I only posted it on my twitter :/. So here it goes!

Fun Physics Fact Friday 2: Out of all of the universe, less than 5% of it is matter that we understand: atoms, particles, etc. The rest is composed of 23% Dark Matter and 72% Dark Energy. That 95% "stuff" is invisible and current experiments are being performed to try and detect Dark Matter in the world around us.

Reignited with Fun Physics Fact Fridays!

Well as at least 50% of the blogs out there, this one began and died out shortly afterward. I'm hoping to change that with a new hobby of mine: Fun Physics Fact Fridays. And yes, I know that today is sunday, but I had originally come up with this particular fact 2 days ago.

This time I worked out, using some classical particle mechanics and math to discover the proportional size of a single electron within an atom. After a little thought and calculations I have come to conclusion that if a Hydrogen atom was blown up to be the size of the Oklahoma Memorial Stadium, the single electron within that atom would be the size of a #2 pencil eraser!

Furthermore, 99.9% of an atom is pure, empty, space without any matter present at all. A frequent question is "then how come atoms don't fall within each other and collapse?" The answer is due to electrodynamics. The electrons that orbit the nucleus in atoms orbit so quickly that there appears to be just a sphere surrounding the nucleus instead of individual electrons. This is called the electron cloud. Every atom has one. Now electrons have a net negative charge and in electrodynamics, if two charges are similar (e.g. 2 negatives) they will repel away from each other. And this force used to repel atoms is so strong that the atoms and molecules never really touch each other. And on a macro scale, neither do you, since all of the electrons within your hand are repelled from the electrons in what you're "touching", you aren't actually touching the keyboard, the glass of water just before bed, or even the ground.

Well that appears to be all for this weeks physics friday! If you have any questions - I'd be happy to answer them.