Recent content by henry wang

I am a poor student , can you please suggest something more affordable! Any book recommendations?

My friend is a third year Astrophysicist doing undergrad.

(Mentor note: moved here from noon homework thread hence no template) I was studying vibration of a one-dimensional monatomic chain and the textbook used periodic boundary condition (PBC). I wanted to justify the use of PBC, so I came up with this: atoms deep inside the crystal sees an...

Thank you, for your advice. I normally only greets professors in random encounters, such as in elevators, in the corridors. The questions I was asking were not related to lectures, however they are physics based questions. I guess next time I will only ask if I really can't figure or research...

I thank you Jedi master for your kind advice, from now on I shall learn to restrain the force, and not to fall to the darkside.

I am an undergrad student, I often greet my lecturers, but afterwards comes a long period of awkward silence. Also, when I ask my lecturer questions during office hours, I can't help my self but to bombard them question after questions, and they seems to be fed up with me... So how can I be less...

In an attempt to explain why a matt surface of aluminium is a better emitter/absorber of blackbody radiation than shiny surface of aluminium, my university lecturer suggested to me that: By brushing a metal surface to create a matt finish, the surface of the metal becomes rougher. Rougher means...

I am a second year Physics student, and I have a summer research opportunity on Optics (for which the topic is uncertain). The topic will probably be related to Imaging in biological systems, Analogue computation using light and, Light scattering in correlated systems, as they are the topic of...

I realized that the two measurements are not repeats since the variables were changed slightly due to human error, at the end I simply took the average of their uncertainties. Thank you very much for your help!

The measured varieble was used to calculate another quantity, the uncertainty calculated is really the uncertainty of the calculated quantity. Thank you for your help.

Homework Statement I have only repeated a measurement once, I cannot assume it is distributed as a Gaussian because there is so few data. How can I estimate its combined uncertainty? The Attempt at a Solution Total data: x1, x2 I calculated the individual uncertainties in x1 and x2 using error...

Sure thing!

Thank you so much! I changed it to radians and the error is much smaller.

The reason why error in x is so big is because inter-crystal plane distance, d, is very small and c is very large. The uncertainty in x was calculated using the error propagation equation. \Delta x=\frac{\delta x}{\delta \theta}\Delta \theta Btw, I updated the OP please check it out.

Sorry I should've specified x is just a dummy variable, it is c/wavelength with unit 1/s. The energy in this experiment is x-ray photon energy.