Recent content by sir_manning

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    Melting/freezing point depression of water vs. other liquids

    I think I know where I've gone wrong, just in case someone comes across this post in the future. The Clausius-Clapeyron equation only applies in the case of a flat boundary between two phases. In the macroscopic world, the discrepancy is so small it can be ignored. However, when deriving the...
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    Melting/freezing point depression of water vs. other liquids

    Hey I'm trying to derive the Gibbs-Thomson equation for the freezing/melting point depression of liquids inside a confined space, such as a cylindrical pore. This has been observed for many liquids, such as water, benzene, heptane, etc. Basically my question is, why does water, which expands...
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    Need verification of physics phrase for novel

    I think it sounds just fine with the minor changes suggested by Dipole: "According to Classical Physics, at any given time you cannot be at more than one position in three-dimensional space." It's not going to be for a classical mechanics textbook, after all!
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    Chapter in MSc/PhD thesis for general public

    Hey I'm writing up my thesis at the moment and I'd like to include a chapter that is a summary of my project intended for the general public. This would use simple language and probably focus more on background topics instead of my specific results. I think it would be a good exercise in...
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    How to find the number that's evenly divisible by a set of numbers from 1 to n?

    Phrased another way, your problem is to find the lowest common multiple (LCM) of a set of numbers from 1,...,n . Luckily, there is an easy formula to get the LCM for two numbers a and b from the greatest common divisor (GCD): LCM(a,b) = |a*b|/GCD(a,b) . I say luckily because finding the GCD is...
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    Sphere-Packing porosity development

    This might be helpful: http://en.wikipedia.org/wiki/Kepler_conjecture "Experiment shows that dropping the spheres in randomly will achieve a density of around 65%". I think how much they settle down would depend on the size of the balls and the diameter of the bucket.
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    Lab report writing software? (Mac)

    Sorry, one more thing. If possible, get away from Excel and learn a data analysis language/package that can make some sexy graphs. R, MATLAB, Gnuplot, Root, etc. are all excellent and are very useful to know in general anyway. Finally, I once tried to do everything in Maple (it has a worksheet...
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    Lab report writing software? (Mac)

    I use LibreOffice (seems faster over OpenOffice or NeoOffice) to write up technical stuff on my Mac. It has an integrated TeX-like formula editor and is free. The drawbacks are that its spreadsheet program isn't great, and copy/paste from other spreadsheets (like Excel) don't work that well. The...
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    Understanding Integration: A Simple Explanation

    By being very careful with your minus signs! What did you try? Remember that 'a' is a constant and you are integrating with respect to 'x'.
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    Proving Inequality: Solving Im(z) and Re(z) with Triangle Inequality

    Sorry, I see that you did write \left| sin z \right| = \frac{e^{i(x+iy)} - e^{-i(x+iy)}}{2i} . However, I don't understand how you came up with your answer: where did the absolute value signs in \left| \frac{e^{y} + e^{-y}}{2} \right| emerge from? You can't just insert them. And how did you...
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    Proving Inequality: Solving Im(z) and Re(z) with Triangle Inequality

    It will be easier to break this into two problems. First prove that \left| sin z \right| \leq \frac{e^{y} + e^{-y}}{2} , then prove that \left| sin z \right| \geq \frac{e^{\left| y \right|} + e^{- \left| y \right|}}{2}. Also, use \left| sin z \right| = \frac{e^{i(x+iy)} - e^{-i(x+iy)}}{2i} .
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    Speed of Dark: Beyond Light & Time

    This is exactly like asking: -what is the speed of silence is and why doesn't it overtake sound? -what is the speed of no traffic and why doesn't it overtake traffic? etc.
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    Proving Inequality: Solving Im(z) and Re(z) with Triangle Inequality

    Don't forget about the reverse triangle inequality: |x - y| >= ||x| - |y||
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    How to find a function from real data?

    This sort of analysis is carried out all the time in many subjects (physics, economics, cognitive science, etc.), hence there are multiple techniques. Generally in physics, one at least has an idea of the form of the function and therefore just plays with the parameters until a good fit to the...
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    If you could do it again, *when* would you?

    I went to university right after high school because I knew exactly what I wanted to study (physics). Although I don't regret that decision, I do sometimes think that taking a year off first to travel would have been very rewarding. Working and living abroad while relying completely on yourself...
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