ElectronSpin #QuantumPhysics #ELI5
What Is Electron Spin?
When we talk about an electron having a “spin,” it’s not like a spinning top or a rotating planet. 🪀 It’s a quantum property that’s a bit more abstract and fascinating. Let’s dive into what that means in simple terms!
Not Literally Spinning
Electron spin doesn’t mean the electron is physically rotating. 😲 Instead, it’s a way to describe an intrinsic form of angular momentum that electrons possess. Think of it as a built-in feature that helps define the electron’s behavior.
Quantum Property
- Intrinsic Quality: Just like electric charge, spin is an intrinsic property of electrons.
- Two States: Electrons can have a spin of “up” or “down,” represented by +1/2 or -1/2.
Why Is Spin Important?
Spin has critical implications in various fields, including:
- Magnetism: Explains why certain materials are magnetic.
- Quantum Computing: Utilizes spin states to store information.
- Chemical Reactions: Influences how atoms bind together.
Pauli Exclusion Principle
One of the most famous impacts of spin comes from the Pauli Exclusion Principle. 🧑🔬 This principle states that no two electrons in an atom can have the same set of quantum numbers, including spin. Thus, electrons must pair up with opposite spins.
How Do We Know About Spin?
- Experiments: Historical experiments, like the Stern-Gerlach experiment, helped scientists understand these properties.
- Mathematics: Quantum mechanics equations also back up the existence and behavior of electron spin.
Visualization and Misconceptions
🌀 Visualizing Spin: If visual aids help you, think of spin as an arrow that can point up or down.
🔄 Misconception: It’s tempting to visualize spin as literal spinning. Resist that urge! It’s a unique quantum property of subatomic particles.
Conclusion
In summary, electron spin is a fundamental quantum property that is crucial for understanding the behavior of electrons in various physical and chemical processes. 🌟 It’s not about physical rotation, but rather an intrinsic characteristic that shapes the world of quantum mechanics.
Key Takeaways
- Electron spin is a quantum property, not physical rotation.
- It plays a vital role in magnetism, quantum computing, and chemistry.
- Spin states are simply referred to as “up” or “down.”
- The Pauli Exclusion Principle hinges on the concept of spin.
Hope this clears up what it means when an electron is said to have a "spin"! Feel free to ask more questions; curiosity is the heart of learning! 🤓
The electron is not actually spinning, but some magnetic properties of the electron are what you would expect if it were spinning.
As far as I can understand from the simple english wikipedia article: electrons do have some momentum that somehow resembles spinning, but not exactly as it would be in normal physics. Also, the electron spin refers to some magnetic properties and the orientation of the electron.
If someone understands this better than me, please correct me!
Electrons don’t spin. We observe that a beam of electrons is split in two by a magnetic field so they have some kind of magnetic moment. It’s a kind of angular moment. We can even look at how energy levels work out in our calculations and comparing it to experimental results we find that some quantity is missing and if we introduce spin it fits perfectly.
If we were to calculate the spin as rotation for the electron using classical electron radius we’d get a way faster velocity than the speed of light so its not angular momentum in the classical sense and even mathematically the quantity doesn’t transform as you’d expect it to with classical intuitions in mind.
Spin is a quality that a particle has because it’s that particle. It’s linked to magnetic effects like circular currents and also comes from the QM equivalent to rotations but it’s not literally spinning like a little ball since an electron isn’t a little ball.
to quote cgp grey
> ‘Whirl around’ and ‘spin’ dont mean what you think dowm here (at the quantum level). Down here, words are meaningless. There is just math. that we are not going to do.
there are properties of electrons that are modeled by equations. we have to call this property something so we can talk about it, and the math used is similar to the math for rotational motion, so they called it spin.
at the quantum scale, the more you try to make a visualization in your mind of what is “going on” the less accurate it is. There is just math (that we are not going to do)
Spin is a property that things have. Kind of like “electric charge.” If you have something, such as an electron, it has this property that helps describe how it behaves. Two different electrons with a different value for their ‘spin’ behave in different ways (ish).
*Mathematically* this abstract property behaves kind of like spinning. Things either ‘spin’ one way or the other way, and their ‘spin’ can have different magnitudes. If you stick two things together their ‘spins’ “combine” in a similar way to how physical spinning works. So we call this property ‘spin.’ We could call it other things instead; we could call it “feeling” or anything we want to.
It isn’t actually spinning. With fundamental particles (such as – probably – electrons) they have no size, no dimension, so they physically cannot spin. They just have this property that acts, mathematically, like spinning. Except when we get into quantum mechanics the distinction between “actually is” and “acts mathematically like” becomes a bit blurry, so some things we would expect to see from spinning particles (like magnetic interactions) we see from ‘spin’.
It has an angular velocity.
Like we can measure it in the same way you meaure how fast a wheel is spinning on your car.
Why this is the case is still something to ponder, but the fact remains that it has an angular velocity.