What is quantum physics in simple terms or with a real-world example?
In: Physics
Real-world example? How about how solar panels work?
Light is obviously a wave. When you send it through a prism, it refracts into a rainbow (something waves do). When you send it through a very small slit, it diffracts into bands (something else waves do). Light colour is the frequency of the light (something waves have). Everyone agrees light must be a wave.
But something weird happens if you shoot light at metal. If you shoot light with a high enough frequency, electricity start flowing out of the metal. More light gives more electricity flowing out. If you lower the frequency though, at some point the electricity just suddenly stops. Once the electricity stops, you can shoot as much light as you want, you can’t get electricity to come out. With the standard “light is a wave” explanation, this phenomenon makes no sense.
Einstein figured out that light is actually made up of individual particles. More light is just more particles. Weirdly though, these particles still have colour, which we said was just the frequency of the waves… Kinda weird, but let’s keep going. So the “frequency” of these particles actually tells us the energy of each individual particle. If we assume that each electron can only interact with a single light particle at a time, then it makes sense that only high-frequency light particles have enough energy to knock the electrons. More light particles hitting the metal means more electrons get knocked out per second, so more electricity.
Put this together and you figure out that shooting a lot of high frequency light at metal makes a solar panel, and you understand why.
So light is obviously a wave, but it’s made out of small particles somehow. It’s quantized.
Quantum mechanics is what you get when you apply that logic to *every* particle. Every particle is treated as a small quantized chunk of a wave, and we can calculate how those waves change and interact over time.
Everything you ever experience is the sum of all those tiny little quantized waves connecting and evolving together.
Heisenberg’s Uncertainty Principle: taking a picture of a moving tennis ball. A still photo shows precise position, but an indeterminate velocity. Increase the exposure and a blur can be seen, which alludes to a high velocity but lower precision as to where the ball is at the time the picture is taken (quantized).
energy can only enter and exit electron in fix “quantity” AKA energy level instead of arbitrary small amount. If the incoming photon energy is too small or too large, it will just skip it.
real world example: photovolatic cell usually can only absorb a single wavelength of light. And the reverse of photovolatic cell, LED, where you apply a voltage, the electron only emit a certain wavelength of light. So technically every solar cell is a led inverse direction, and every led is a solar cell inverse direction. But usually the reverse flow efficiency is terrible compare to its normal use.
Quantum physics is the field of understanding how quantum particles behave. This generally refers to the behavior of photons (light) as well as the parts of an atom: proton, electron, and neutron. Therefore it applies to every atom, every electrical current that moves electrons around, and every light source *in the universe*.
Our understanding of it is the bedrock of how we developed modern chemistry, directly resulted in the transistor design used in every single computer today, and has unlocked deeper understanding of other fundamental forces like gravity.
At the same time, it’s also generated a lot of pop science attention because of how weird it is. There’s aspects that seem like paradoxes or impossibilities in classical physics. Electrons (in an atom) *must* exist at certain energy levels. There are relatively huge gaps between these energy levels, but because they *must* exist at those levels, they seemingly teleport back and forth between them. They can also seemingly phase through solid matter if its thin enough. You can *never* know the position and velocity of a particle at the same time. It literally acts different if we’re not looking.
There’s tons of examples, and I’d recommend just going to Chat GPT or wikipedia and getting a few.
Latest Answers