Can Lepton's Spin be Reduced to Zero? What Happens Then?

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Discussion Overview

The discussion centers around the theoretical possibility of reducing the spin of leptons, specifically questioning what implications such a reduction would have. Participants explore concepts of spin in quantum mechanics, intrinsic properties of particles, and the nature of energy at absolute zero.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants assert that spin is an intrinsic property of particles that cannot be altered, comparing it to charge.
  • Others argue that the concept of spin is historically rooted and does not have a direct physical analogy, suggesting that the question of reducing spin may be illogical.
  • One participant mentions that particles can have zero spin, indicating that it is theoretically possible.
  • Another participant raises a related question about the implications of reaching absolute zero, suggesting that if all energy were to stop, it is unclear what would happen to an atom.
  • Some contributions clarify that while particles have spin, it differs from classical spin, and absolute zero cannot be reached due to the uncertainty principle.
  • There is a discussion about the nature of bosons and fermions, with some participants noting that bosons are fundamentally linked to energy and questioning how energy could be removed from them.

Areas of Agreement / Disagreement

Participants express differing views on the nature of spin and its implications, with no consensus reached on whether spin can be reduced to zero or what would happen in such a scenario. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Participants highlight limitations in understanding the implications of spin and energy, particularly in relation to quantum mechanics and the uncertainty principle. There are unresolved questions regarding the behavior of particles at absolute zero and the nature of bosons.

sniffer
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is it possible (just in theory) to reduce the spin of a particle to zero?

take a lepton for example - to reduce complications.

if it is, what will happen?

?
 
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spin is INTRINSIC angular momentum. You can't change spin at all ! And don't even bother picturing "spin", its nothing at all like normal angular momentum.
 
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sniffer said:
is it possible (just in theory) to reduce the spin of a particle to zero?

take a lepton for example - to reduce complications.

if it is, what will happen?

?

This question is almost a logical contradiction. You might as well ask "Is it possible to reduce blue to 24?"

The problem comes in due to the word "spin". It has been explained many times on here that this word is only historical in nature to the classical spinning motion. It really has no physical equivalent to that. Once you realize this, then you can see why your question really, even in theory, really can't be answered, at least not in a rational fashion.

Zz.
 
i know, i read this thing long ago. one qm book says electron dimension is smaller than any physical meaning, and if the physical spin applies, the speed of the circumference will exceed speed of light etc etc. spin is just intrinsic angular momentum, it's the most basic mathematcal concept in qm. i learned qm. is there for some reason "spin" property can dissapear? that's all i meant. sorry if this question sounds silly.
 
Spin is a fundamental property, like charge. If you somehow change the charge on the electron, it is not an electron any longer. Likewise with spin.

Can a particle have zero-spin ? Yes it can.
 
You can think of it this way: what we call an "electron" has spin 1/2. When you have something interact with it in whatever form you decide, that non-zero angular momentum will have to go somewhere. If it ends up in something of the same mass, you have another electron (or a positron),... otherwise, there's no electron left on the reaction (but still, the total angular momentum of the components went somewhere)... got to go!
 
sniffer said:
is it possible (just in theory) to reduce the spin of a particle to zero?

take a lepton for example - to reduce complications.

if it is, what will happen?

?

no, no and no again

Scroll down to the 'five socalled easy pieces'-entry

https://www.physicsforums.com/journal.php?s=&action=view&journalid=13790&perpage=10&page=2

marlon
 
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From what I have read, there is no 'spin', but there is energy. So this is my question. If an atom were to reach absolute zero, or some temperature that would make all energy stop. What would happen to the Atom? Would it disappear and cease to exist or what? I need this for a story I am writing and my own curiosity.
Thanks, NanLou4
 
NanLou4 said:
From what I have read, there is no 'spin', but there is energy. So this is my question. If an atom were to reach absolute zero, or some temperature that would make all energy stop. What would happen to the Atom? Would it disappear and cease to exist or what? I need this for a story I am writing and my own curiosity.
Thanks, NanLou4
1) Particles do have spin, but as others have mentioned it is a different concept from the classical concept of spin.

2) Absolute zero cannot be reached because Heisenberg's uncertainty principle forbids it.

3) If the uncertainty principle didn't apply (if Planck's constant was zero), and you did manage to reduce the energy of a particle to absolute zero, why would it cease to exist? Fermions don't require energy to exist. If you removed the energy from a boson, however, it would cease to exist, but bosons are particles like photons (light), which don't have mass. The particles that make up atoms are fermions, so an atom would continue to exist even if its energy was drained.
 
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  • #10
εllipse said:
If you removed the energy from a boson
Remove the energy from a boson ? How are you going to do that ? A boson IS energy.

but bosons are particles like photons (light), which don't have mass.

Bosons are particles with integer spin that therefore respect the Bose-Einstein statistics. Photons are bosons with spin 1 and zero 'rest'mass. However not all bosons are massless ! Eg : the massive intermediate vectorbosons that mediate the weak force. Or the pions (ie the lightest meson : a quark-antiquark-pair) that mediate the residual strong force (you know the ancient Yukawa particle)


regards
marlon
 
  • #11
marlon said:
Remove the energy from a boson ? How are you going to do that ? A boson IS energy.
Well, that was the point. As bosons try to escape the event horizon of a black hole, their energy is completely removed, correct? I guess that's along the lines of what I was thinking.

Bosons are particles with integer spin that therefore respect the Bose-Einstein statistics. Photons are bosons with spin 1 and zero 'rest'mass. However not all bosons are massless ! Eg : the massive intermediate vectorbosons that mediate the weak force. Or the pions (ie the lightest meson : a quark-antiquark-pair) that mediate the residual strong force (you know the ancient Yukawa particle)

regards
marlon
Ah, my bad. :redface: Thanks for the corrections.
 

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