Can you give me an example. Suppose the function is: ##f(x, y) = x + y^2##
In the non-complex case, with the data given in the previous post, I would proceed as follows:
##f(x, y) = x + y^2 = (3+(-2)^2) \pm \sqrt{0.1^2+(2*(-2) *0.1)^2}= 7\pm \sqrt{0.01+0.16}=7\pm0.41##
How can I change to polar...
If I have 2 measurements ##x = (3.0 ± 0.1), y = (-2.0 ± 0.1)## and want to calculate how the error propagates when calculating a function from those values this formula should be used: ##f(x, y) = f(x, y) ± \sqrt {(\frac{\partial f}{\partial x}*\Delta x)^2+(\frac{\partial f}{\partial y}*\Delta...
Thank you, that was what I was looking for.
So there are events attributable to climate change under some circumstances and others not. Much depends on models, observations, physical understanding of weather phenomena, etc.
Your link answers questions 2 and 3.
Does anyone have any links that...
The fact that rising temperature may cause in increase of extreme phenomena is likely, but is it true?
The increase in many of the phenomena (both in intensity and frequency) that climatologists talk about are simply not true. There is no increase in hurricanes, nor tornadoes, nor floods, nor...
1)The atmosphere is an extremely complex system, so much so that weather forecasts beyond a few days are not possible.
Why are seasonal or 10-20 year climatological forecasts reliable?
I heard from a climatologist in a video on YB (I know it is not a valid source) that weather forecasts are an...
Many people argue that we do not know how the brain works and therefore we can never reproduce a program that shows intelligence, however, this argument is just illogical. First of all, because you don't need to know how something works to reproduce it, moreover, the human brain is a specific...
Why do almost all people not think that neural networks are the mathematical model of intelligence?
I briefly explain what I understand:
-A neuron is a mathematical object that takes numerical inputs from other nearby neurons, applies a nonlinear function (combining the input with numbers...
I think the links you recommended are too advanced for me.
I am starting to study QFT, but I am also interested in astrophysics, cosmology, and black holes. In general, I am interested in a statistical mechanics book that will allow me to understand graduate level physics.
My current level is...
I just finished studying Berkeley Statistical Physics by Reif. Some things I already knew, from Tong's notes. What should I study to get on with statistical mechanics at an appropriate level in your opinion? I saw that there are various statistical mechanics textbooks, what do you recommend and...
In quantum mechanics if I repeat a measurement of the same observable in succession I get the same quantum state if it is not a degenerate state.
If I make the system under consideration interact with another quantum system and meanwhile keep measuring it what happens?
Does the system not...
That sentence is wrong, sorry, I meant to say I read online (a question on stackexchange) that quantum mechanics is related to scalar QFT in 0+1 dimensions. I would like to know more about it.
What is the Schrodinger equation in QFT? is it the nonrelativistic approximation of a Klein-Gordon scalar field? or Is there more?
I have read that the Schrodinger equation describes a QFT in 0 dimensions.
I accept every answer
References, links, notes, textbooks, papers, videos, etc. are welcome.
Vanadium 50
Excuse me if my questions are naive.
If this or other threads started by me are inappropriate, feel free to delete them.
If you think I am contributing negatively on this site feel free to delete my account.
By big picture I mean:
-the things that are there
-the relationships between things
-the fundamental mathematical topics (e.g. what group theory is for in QFT)
-what are the typical applications and problems
-how you would describe QFT in a nutshell
Your interpretations of "big picture" are also...
How much statistical mechanics do I need to know to study QFT, astrophysics, black hole thermodynamics, and other advanced topics? And where should I study it in your opinion? So far I have only read Tong's notes however I don't think it is enough. Some quantum statistical mechanics is also...
What is the big picture of QFT?
I have studied quantum mechanics from:
-Griffiths
-the first few chapters of Sakurai
-Ballentine
I have studied electrodynamics from Griffiths and General Relativity from Carroll
I have assigned level I to the question, but any answer is welcome
What should I learn to make astrophysical measurements from open data?
Suppose I want to measure the rotation speed of galaxies to generate galactic rotation curves like these: https://en.wikipedia.org/wiki/Galaxy_rotation_curve
What should I do and what should I learn?
I think I should get...
In MOND should two small masses placed at a great distance orbit faster than in Newtonian dynamics?
Would it be theoretically possible to do this experiment in the solar system, or would the presence of the sun and earth be a problem?
Can you recommend papers and books to study MOND? I know that a lot of MOND theories have been ruled out by recent observations, so I don't know where to start without wasting time studying from outdated references.
I know GR from Carroll's book and cosmology from "Physical Foundations Of...
Has it ever happened that after a discovery, data from previous experiments were analyzed and it was noticed that there was already some evidence of the phenomenon in question?
I read this tweet (I omit the author for privacy), and my curiosity led me to ask questions::
Any optimization problem is equivalent to a convex (linear) one (but infinite dimensional…). The key do perform global optimization using Lasserre’s relaxation via the problem of moment (aka...
There are many solar power plants using large mirrors on earth. Their color as seen from the satellite is blue.
(source google maps: planta solar 10 Spain)
I have another question: if I have a photo of the sky taken with a smartphone, can I get physically meaningful data from the colors in the...
Aren't the colors in this photo mainly due to the color of things? In a mirror, the color observed should be almost only that of the light scattered by the atmosphere.
No.
If I look at the mirror from a given angle I see: the light scattered by the air between me and the mirror and the light scattered by the air placed symmetrically on the opposite side. The light scattered by the latter has to go a long way before it reaches the observer who is outside the...
Because if I stand outside the atmosphere, the reflected light has to travel a lot farther, but I don't know if that is enough to make the reflection in the mirror turn red.
I expect that depending on the angle it should change the reflected color.
How often during your work do you use a symbolic calculation tool like Mathematica / Maple / SymPy? Is it worth learning(especially for a theoretical physicist)? Thank you.
How did they impose boundary conditions here if "no end" is selected?
Here: https://phet.colorado.edu/sims/html/wave-on-a-string/latest/wave-on-a-string_en.html
I would like to do the same thing without changing the wave equation of the string.
Is the bullet cluster evidence for or against dark matter?
I understand the explanation that it is evidence in favor of the existence of dark matter, and it convinces me. However, some argue that it is evidence against its existence? Why?
pinball1970
Sorry, maybe I misunderstood your message because I am using a translator.
Do you have an advanced level explanation? If yes please write it down, I will try to understand. Thank you.
Heat diffusion is caused by randomly moving particles. So there is a connection between the diffusion equation and the statistical motion of particles. Is there something similar for waves?
What prevents making a particle accelerator better than the LHC but only a few centimeters big? After all, you accelerate objects with very small masses. Are there insuperable physical limits? What are the physical limitations?
I understood that measurement is a physically vague concept (although mathematically defined as the collapse of the wave function), it happens when a particle hits an instrument, i.e., a macroscopic object. is that right? Now, if we have two particles in an entagled state and I measure one...
if I have two particles in an entangled state, I make them travel in different directions, and I measure the state of only one of them then I know the outcome of the measurement of the other.
But when I take a measurement on the first particle, what happens to the second? Does it undergo a...
Isn't the fact that the spacetime metric is not Euclidean due to the fact that there is a maximum velocity in our universe?
maximum velocity ##\implies## everyone agrees on its value ##\implies## derivation of spacetime interval (##ds^2=-dt^2+dx^2+dy^2+dz^2##)
Is this reasoning wrong? Doesn't...
I know I should not study cosmology from books that are too dated. Can you recommend an up-to-date cosmology book?
I am studying GR from Carroll's book. Do I need to study astrophysics first or other topics?
Can entangled states be generated only locally? For example if I have a particle that decays I know entangled particles can be generated.
Or can entangled states be generated even between distant particles? For example if I have one particle here and one on a distant galaxy, if I wait long...
If entagnled is any state that cannot be expressed as the product of the states of the individual particles that compose it, then yes. I used the word "weird" because I don't know if either the word entangled is valid for describing states of physically distant particles.