bhobba's latest activity
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bhobba reacted to Sagittarius A-Star's post in the thread Undergrad Why is the Lorentz Force always perpendicular to velocity? with
Like.
I think that cannot be, because Purcell does a calculation of the electric force in the rest frame of the object via lenght contraction... -
bhobba reacted to PeterDonis's post in the thread Undergrad Why is the Lorentz Force always perpendicular to velocity? with Like.
Yes, because you can express both the observer's 4-velocity and the overall EM field as covariant objects (a 4-vector and an...
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bhobba reacted to PeterDonis's post in the thread Undergrad Why is the Lorentz Force always perpendicular to velocity? with Like.
In the lab frame, yes, this is the case. But it is not the case in the rest frame ##S'## of the object. In that frame there is a nonzero...
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bhobba reacted to PeterDonis's post in the thread Undergrad Why is the Lorentz Force always perpendicular to velocity? with Like.
Which is equivalent to what I wrote in post #4, i.e., it is not just the magnetic force. So what I said in post #4 would apply if one...
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bhobba reacted to Sagittarius A-Star's post in the thread Undergrad Why is the Lorentz Force always perpendicular to velocity? with Like.
One could start from the equation for the Lorentz 4-force and from that it is rest mass-preserving. Source
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bhobba reacted to PeterDonis's post in the thread Undergrad Why is the Lorentz Force always perpendicular to velocity? with Like.
There's no way to define "Lorentz force" as being solely due to the magnetic field and have the definition be covariant. And if we...
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bhobba reacted to pervect's post in the thread Undergrad Why is the Lorentz Force always perpendicular to velocity? with Like.
It seems to me that if you define the Lorentz force as being only due to the magnetic field, the Lorentz force is perpendicular to the...
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bhobba reacted to PeterDonis's post in the thread Undergrad Why is the Lorentz Force always perpendicular to velocity? with Like.
In general this is not the case. The Lorentz force is ##F = q \left( \vec{E} + \vec{v} \times \vec{B} \right)## (modulo some constant...
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bhobba reacted to A.T.'s post in the thread Undergrad Why is the Lorentz Force always perpendicular to velocity? with Like.
Not just upward, but to the right (like it was moving before) and upward. So you have to apply the Lorentz transformation along that...
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bhobba reacted to DaveC426913's post in the thread Stargazing Meteor/meteorite made a big boom this morning! with Like.
Approx. 6ft diameter, 7 tonnes, moving at ~40,000mph.. Exploded about 30-40 miles above Valley City, OH with a force of about 250 tons...
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bhobba reacted to Andy Resnick's post in the thread Stargazing Meteor/meteorite made a big boom this morning! with Like.
https://apnews.com/article/meteor-cleveland-fireball-astronomy-89d1cd3e060774ff897512cb811710d7 Made for interesting discussions in...
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bhobba replied to the thread High School Knowledge and information in the physical world.As many here, including me, do. It's not at the HS level (it's graduate or senior undergraduate level), but if you go to a library, get...
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bhobba reacted to PeterDonis's post in the thread High School Knowledge and information in the physical world with Like.
Then you are wrong. Sorry to be blunt, but that's just the fact. I gave you an explicit counterexample. I'm not making it up; it's a...
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bhobba reacted to PeterDonis's post in the thread High School Knowledge and information in the physical world with Like.
No, @Paul Colby said that. I didn't qualify my statement about entangled particles at all in post #9--indeed, my point in that post was...
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bhobba reacted to weirdoguy's post in the thread High School Knowledge and information in the physical world with Like.
He is not rude, just straight to the point. We are not talking about opinions here, we are talking about facts. Either what you say...