# Search PBS Space Time

## Results

### 2022-04-27: How the Higgs Mechanism Give Things Mass

• 02:31: ... wavefunction from one point in space to the   next - local phase - doesnâ€™t affect measurable  quantities - only relative phase ...
• 03:09: ... that the laws of physics are invariant  under changes in local phase. The set   transformations that can change local phase ...

### 2020-11-04: Electroweak Theory and the Origin of the Fundamental Forces

• 05:42: So there we go - we insisted on a symmetry - that the Schrodinger equation is invariant to changes in the local phase of the wavefunction.
• 06:20: ... is the magnitude of the wavefunction, and the rotation amount is our local phase ...
• 08:50: ... in the Schrodinger equation so that it would no longer be invariant to local phase ...

### 2018-11-07: Why String Theory is Right

• 08:35: ... the Schrodinger equation that fixes these phase differences preserving local phase ...
• 11:07: ... as local phase invariance required us to add the electromagnetic field to the ...

### 2018-07-11: Quantum Invariance & The Origin of The Standard Model

• 05:16: This position dependent phase shift is called a local phase shift, instead of a global phase shift.
• 05:21: We'll try this because, well, we already know that the magnitude squared of the wave function should still stay the same under local phase shifts.
• 05:38: ... if we do a local phase shift, say, only this point here, only that location changes, as if it ...
• 05:50: If you allow this sort of local phase shift, you can change each point in a different way and really mess up the wave function.
• 06:08: Among other things, messing with local phase really screws up our prediction for the particle's momentum.
• 06:19: Change the shape of that wave function with local phase shifts and you actually break conservation of momentum.
• 06:26: Local phase is not a gauge symmetry of the basic Schrodinger equation.
• 06:38: Just for funsies, maybe we can change the Schrodinger equation to find a version that really is invariant to local phase shifts.
• 07:34: ... we've discovered that the only way for particles to have local phase invariance is for us to introduce a new fundamental field that pervades ...
• 08:24: Any particle that has this kind of charge will interact with and be affected by the electromagnetic field and be granted local phase invariance.
• 08:35: In order to have this particular type of local phase invariance, particles must possess electric charge.
• 08:48: In this case, the symmetry is local phase invariance and the conserved quantity is electric charge.
• 09:41: It turns out that local phase invariance is just the simplest of the larger suite of gauge symmetries of the standard model.
4 result(s) shown.