Demystifier's latest activity
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Demystifier replied to the thread Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?.Under a coordinate transformation ##x^{\mu}\to x'^{\mu}=f^{\mu}(x)##, the two metrics transform as $$g'^{\alpha\beta}=\frac{\partial... -
Demystifier replied to the thread Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?.How did you verify this? They do transform as tensors under coordinate transformations, but their indices are not raised and lowered in...
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Demystifier reacted to PeterDonis's post in the thread Undergrad Hawking radiation may smooth black hole singularities with
Informative.
No, because there's no white hole horizon, any more than there's a black hole horizon. It's just outgoing radiation. The portion of the... -
Demystifier replied to the thread Undergrad Hawking radiation may smooth black hole singularities.Is this something like a white hole?
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Demystifier replied to the thread Undergrad Hawking radiation may smooth black hole singularities.My confusion stems from the following. The Bardeen metric significantly deviates from the Schwarzschild only for small ##r##, close to...
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Demystifier reacted to PeterDonis's post in the thread Undergrad Hawking radiation may smooth black hole singularities with
Like.
In a Bardeen black hole solution, there is no information paradox because there is no true event horizon anywhere. The causal structure... -
Demystifier replied to the thread Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?.I believe there is no such quantity, because you study a variation of the object that defines the covariant and contravariant components.
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Demystifier reacted to anuttarasammyak's post in the thread Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor? with Like.
It is a tensor whose covariant and contravariant components are ##\delta g_{\mu\nu}## and ##-\delta g^{\mu\nu}##, respectively...
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Demystifier reacted to DanteKennedy's post in the thread High School Seemingly odd quantum tunneling with Like.
So for large objects, their wave function is so localized and are constantly being measured by their surroundings, effectively pinning...
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Demystifier replied to the thread Undergrad Hawking radiation may smooth black hole singularities.Does it shed some light on the information paradox?
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Demystifier replied to the thread High School Seemingly odd quantum tunneling.That's because tunneling is a consequence of superposition. For example, suppose that at time ##t## the particle can tunnel from the...
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Demystifier reacted to Sagittarius A-Star's post in the thread High School Lorentz Transformation of Electric & Magnetic Fields Visualized with Informative.
I tried some examples and they were correctly transformed.
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Demystifier replied to the thread Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?.3. is just a definition of the dual tensor, i.e. the rule how to raise indices in the same world. In 2. you try to compare quantities...
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Demystifier replied to the thread High School Seemingly odd quantum tunneling.No, the number of degrees of freedom is not directly related to the size of the system. It is more directly related to the number of...
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Demystifier replied to the thread High School Seemingly odd quantum tunneling.Yes, decoherence. Macroscopic objects have many degrees of freedom, which interact with many degrees of freedom from the environment, so...