Recent content by Markel

Ok, they seem to be available on Audible.com for cheaper, but the whole set still works out to $532.

That's great, but WOW is that expensive. The whole set must be about $1000. How is that possible?? They were originally recorded on some old cassette deck... Anyway, thanks for your help

Thanks, this is great. But I still can't seem to find the lectures which make up "the Feynman Lectures on Physics." I know they must exist somewhere...

I love Feynman's Lectures on Physics and want to go over them again, but I find there's so much of his character is lost when just reading them. I have found a few selected audio versions of his lectures, but I would like to find the COMPLETE set. I know they exist somewhere, as that's how they...

Hi, I've been put in charge of ordering some physics journals for our labs lounge. What do you recommend? We specialize in Biophysics, but a wide range of suggestions is good. Thanks!

Ha! You're right. Maybe I should stop blaming mathematica, when evidence points to human error. :) Thanks again for all your help and advice, I appreciate it!

Thanks Again! I tried using the /. (1/(1+x)) -> v idea before, and it will substitute as long as there is a (1/(1+x)) exactly in this form. But, for instance, if there is something like -2/(2+2x), it won't substitute as -2v. I'd like mathematica to do some basic rearrangements when possible...

Hi, Thanks for the Reply I'm just wondering if you can explain why you type := before your input in In[5] and In[6] ? (I'm a total mathematica Newbie if you haven't figured that out yet. Also, I have another question. I have a big long expression, and I would like to substitue in something, for...

I have determined that the problem is coming from the fact that I have some roots that mathematica doesn't know what to do with, without some further assumptions. For instance, as a test I've tried this: o = {x , y}; n = Sqrt[{x^2, y^2}]; o === n False I now have a follow up...

I'm trying to work through a derivation and am getting some funny results. For example, when trying to compare some expressions, Mathematica was telling me they weren't equal, and when I worked them out by hand, I new they were equal. I then tried something like this: ExpandAll[x] ===...

Thanks!

This is a real world application that I'm trying to figure out. I need to estimate the spring constant of a standard cover slip (used in microscopy). The coverslip is a thin glass square, dimensions 25mm x 25mm x0.15 mm. I know the Youngs modulus. How should I estimate the "spring constant" of...

Do you have much experience with this method? If so, I'd really love to pick your brain for a bit.

So the transform according to what you sent is: \sin{\omega t} \implies \frac{s}{s^{2} + \omega ^2} = \frac{1/2}{s - jw} + \frac{1/2}{s + jw} But I'm not really sure if the frequency generated by the VNA is a sine wave. Does someone know how to check this. Also, I'm still confused as...

Yes, that's right. Here's the paper where I found the model I mentioned above. My measurements are not giving physical results, and I think the problem may be how I used the frequency. http://adsabs.harvard.edu/abs/1994ITMTT..42..199A