PeroK's latest activity
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PeroK reacted to renormalize's post in the thread Graduate Can a causal or time-like structure emerge without assuming a metric? with
Informative.
@OmniThoughts, by joining this forum you agreed to abide by all the rules stated here... -
PeroK replied to the thread High School Is there anything in the Universe that is not fundamentally made up of matter?.There is matter, antimatter, radiation, possibly dark matter, possibly dark energy, spacetime (if you count that as something)...
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PeroK reacted to Borek's post in the thread High School Is there anything in the Universe that is not fundamentally made up of matter? with
Like.
So helium-4 atom doesn't occupy space? -
PeroK reacted to DaveC426913's post in the thread High School Is there anything in the Universe that is not fundamentally made up of matter? with
Skeptical.
While not definitive, one might make a good start by grouping all things into either fermions or bosons. Fermions obey the Pauli... -
PeroK reacted to Dale's post in the thread Undergrad Electric Field of Uniformly Charged Infinite Plane with Informative.
By “usual” I meant “usual for the infinite plane”. Most people, when solving the infinite plane problem, implicitly choose a boundary...
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PeroK reacted to Dale's post in the thread Undergrad Electric Field of Uniformly Charged Infinite Plane with Informative.
I don’t think they did go awry. It is a valid solution to Maxwell’s equations. It is just a different boundary condition than usual.
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PeroK replied to the thread Undergrad Electric Field of Uniformly Charged Infinite Plane.The horizontal component is zero, by symmetry. I've not got time to do the asymmetric calculation now. I'll do it later. Although...
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PeroK reacted to Vincf's post in the thread Undergrad Electric Field of Uniformly Charged Infinite Plane with Like.
Hello, The sum you're showing is a Riemann sum. The Riemann sum is $$\sum_{n=0}^\infty f(x_{n})(x_{n+1}- x_{n}) $$ with the function...
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PeroK replied to the thread Undergrad Electric Field of Uniformly Charged Infinite Plane.Re the above identity for ##\pi##. $$\int_0^{\infty} \frac 1 {1 + x^2} dx = \bigg [\tan^{-1}(x)\bigg ]_0^{\infty} = \frac \pi 2$$And ...
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PeroK replied to the thread Graduate Horizontal component of the electric field of an infinite uniformly charged plane.I've started a new thread on how to do this properly...
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PeroK posted the thread Undergrad Electric Field of Uniformly Charged Infinite Plane in Electromagnetism.Here is a valid derivation of the electric field for an infinite plane, based on the result for an infinite wire of uniform linear...
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PeroK replied to the thread Will anyone alive today see a permanent colony on the Moon or Mars?.To many of us Elon Musk (and his kind) are the catastrophe that will destroy life for the vast majority of humans. There would be no...
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PeroK reacted to Baluncore's post in the thread Will anyone alive today see a permanent colony on the Moon or Mars? with
Haha.
That can be achieved with LSD, or the hallucinations of AI, without any need to contaminate Mars with the human epidemic from Earth. -
PeroK reacted to Ken Fabian's post in the thread Will anyone alive today see a permanent colony on the Moon or Mars? with Like.
My pessimism is mostly grounded in resources and economics, at both ends - Earth and 'colony' - but don't dismiss other concerns like...
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PeroK replied to the thread Graduate Horizontal component of the electric field of an infinite uniformly charged plane.You should be able to use any shape (except mathematically pathological ones) and the integral convergence should work. The infinite...