PeroK's latest activity
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PeroK replied to the thread Undergrad What empirical observation supports the axiom of continuous spacetime?.Ontology is philosophy, not physics. No it's not. Everyone knows GR can't be the whole story. There's an explicit singularity in the... -
PeroK replied to the thread Undergrad What empirical observation supports the axiom of continuous spacetime?.PPS you can use calculus on population studies, for example, even though an animal or human population is ultimately discrete. You... -
PeroK replied to the thread Undergrad What empirical observation supports the axiom of continuous spacetime?.It isn't. No one has found a way to make a discrete theory work. The continuum is simpler mathematically and thereby the default... -
PeroK replied to the thread Math Math major jobs in the space industry.Most people these days would refer that question to an LLM. -
PeroK replied to the thread Undergrad What empirical observation supports the axiom of continuous spacetime?.Because it makes the mathematics easier. -
PeroK reacted to PeterDonis's post in the thread High School Can a black hole become a white hole? with
Like.
We have a theoretical model of white holes. That model is what @Ibix's post was describing. Please be aware that personal speculation... -
PeroK reacted to Ibix's post in the thread High School Can a black hole become a white hole? with
Like.
We have mathematical models, the ones you are relying on when you talk about white holes at all. They look nothing like the FLRW... -
PeroK reacted to member 775858's post in the thread High School Can a black hole become a white hole? with
Skeptical.
How would we even know anything about whiteholes? No one has observed one yet. I will be greatful if you can explain what happens to all... -
PeroK reacted to member 775858's post in the thread High School Can a black hole become a white hole? with
Skeptical.
[Moderator's note: Spun off into a new thread due to topic change.] Is it possible that everything consumed by a black hole is so... -
PeroK reacted to SmartyPants's post in the thread High School Taking a limit and getting the wrong answer...don't know why with
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Yes, I went ahead and calculated the limit using Taylor series the other night...it's alot easier this way than trying to simplify... -
PeroK replied to the thread High School Taking a limit and getting the wrong answer...don't know why.Here's a solution using Taylor Series: $$\tan x = x + \frac{x^3}{3} + \dots$$$$\sin x = x - \frac{x^3}{6} + \dots$$$$\tan x - \sin x =... -
PeroK replied to the thread High School Taking a limit and getting the wrong answer...don't know why.Here's something interesting, and possibly useful: In this case, we needed ##t'''(0)##, where ##t(x) = \tan x##. Note that: $$t'(x) =... -
PeroK replied to the thread High School Taking a limit and getting the wrong answer...don't know why.You can apply L'Hopital directly. Let ##t(x) = \tan x## and ##s(x) = \sin x##, then: $$t'(x) = \frac 1 {\cos^2 x}, \ t''(x) =... -
PeroK replied to the thread Undergrad Is this proof "by contradiction" or "by contrapositive"?.It's explicitly a proof by contradiction. But, a specific type of contradiction is to contradict the initial hypothesis. That means that...