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bio website lightandmatter.com
location Fullerton, California
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I teach physics at Fullerton College, a community college in Southern California. I have an undergrad degree in math and physics from Berkeley and a PhD in physics from Yale. Back when I was doing research, my field was experimental low-energy nuclear physics.


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comment Is superposition principle equally valid for both scalar and vector quantities?
@AlfredCentauri: The linearity of vector spaces as a matter of definition simply means that we have a clear definition of what it would mean for superposition to hold for a vector field. It doesn't mean that it does hold. For example, sound waves can be describes as a vector field, if you use a vector to describe the displacement. But sound waves only approximately superpose.
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comment Which nucleus is the most resilient against gamma-induced fission?
The definition in the question would include processes that I don't think any nuclear physicist would call fission, such as knocking out a single neutron. Generally we don't call it fission unless both of the products are heavier than alpha particles.
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comment Which nucleus is the most resilient against gamma-induced fission?
I don't think this is the right criterion. Being strongly bound is not the same as being non-fissile.
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comment Concerning the transtition between matter dominated universe and radiation dominated universe
@Gödel: By scale factor equations, do you mean the Friedmann equations? The Friedmann equations are simpler when there is only one form of matter present, so textbooks often present those simpler cases. That doesn't mean that realistic cosmological models only use the simpler versions.
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answered Concerning the transtition between matter dominated universe and radiation dominated universe
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comment Covariant Nonlinear Transformation in two inertial frames
Is the matrix 4x4 still if you know its solution keeps always Real? I don't understand this sentence.
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comment Covariant Nonlinear Transformation in two inertial frames
I started to think what would the matrix be for any nonlinear transformation. Matrices are linear operators. You can't represent a nonlinear transformation with a matrix.
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comment Covariant Nonlinear Transformation in two inertial frames
What book is this from?
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comment If friction disregard area, why the direction you drag a long object matters?
related: physics.stackexchange.com/a/29954/4552
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comment If friction disregard area, why the direction you drag a long object matters?
I tried the experiment with the ruler, and I couldn't feel any clear difference.
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revised Center of mass frame for massless particles
added 351 characters in body
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comment Why are objects at rest in motion through spacetime at the speed of light?
This has nothing to do with the question.
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comment What conditions should be met to notice a Doppler effect on light?
I don't get it. Where does the 3 come from?
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awarded  Nice Answer
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answered Center of mass frame for massless particles
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revised Flea jumping question
add homework tag
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comment How can Lorentz contraction be “directly” measured?
There are plenty of high-precision experiments that show relativistic effects without the necessity of accelerating anything to a significant fraction of $c$. A good example is the famous Hafele-Keating experiment.
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answered How can Lorentz contraction be “directly” measured?
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comment At what velocity does space no longer equal a vacuum?
You're referring to a science fiction novel. The physics you're describing is made up.
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revised Sound diffraction through a single slit
added 548 characters in body