/sci/ - Science & Math

>>5768557
No you cannot build a particle accelerator at home, unless you have good reason to do so.

If you a established physicist/engineer, you will be okay and the gov will usually leave you alone.

If you are just some regular joe, you will get stopped by the government and charged with federal crimes.

If you really want to build a particle accelerator, your best bet it to through it through a univerity or research department. They will assume the liability and take care of the legal issues. Even many physicist/enegineers do it this way.

>>5475470
Also, the water may start to get hot, you will notice this gradually, so just be on the look out. It could eventually boil, if left too long.

You are dumping a shit ton of energy into the water. Not all of it will be used to break the water bonds, some is just used up to heat the water. You will need to keep track fo the water temp and the amount of water you have before and after the experiment.

It is pragmatically easier to calculate the loss in water, than the gain in hyodgen and oxygen, even though they are the same. It is just harder to measure the gases.

Lagrangian mechanics question:

Suppose I have a system with N independent generalized coordinates <span class="math">q_k, \ k=1,...,N[/spoiler]. If <span class="math">\ddot{q}_k=0[/spoiler], then I'll define the system to be in equilibrium. I'm having trouble seeing how I can express this in terms of the Lagrangian. I suspect it'll be something like <span class="math">\frac{\partial L}{\partial q_k} = 0[/spoiler], but I can't prove it.

How do I solve this differential equation (not homework, came about in a physics problem I was doing for fun):

<span class="math">\frac{y'}{\sqrt{1+y'^2}}=\sqrt{x}[/spoiler] (y' = derivative of y wrt x)

I feel stupid 'cause this seems easy, but I can't get an answer. Help?

Here's the group website:

http://groups.google.com/group/sci-study-group

>>4549097
Well, I stand corrected. We are at 50ns with 4TeV. I imagine we will change it back to 25ns in the near future. I really don't know when, nor particularly do I give a fuck. My data collection is not effected by the decision. I always avoid going to (or joining online) the meetings that discuss those technical matters (as most physicist do). There are only a very few who actually care about minor "performace" imporvments in general (compared to the majority of physicist involved in the collabroration).

Most physicist just get there data, and leave the global problems to the actual global experts.

Here's something I don't understand about virtual work.

By definition, <span class="math">\delta W=\vec{F}\cdot\delta\vec{r}[/spoiler]. Normally, we write <span class="math">\vec{F}\cdot\delta\vec{r}= \dot{\vec{p}}\cdot\delta\vec{r}=\frac{\mathrm{d}(\vec{p}\cdot\delta\vec{r})}{\mathrm{d}t}-\vec{p}\cd
ot\delta\dot{\vec{r}}[/spoiler] and solve from there.

But couldn't we just say that <span class="math">\delta W=\delta T=\sum_k \frac{\partial T}{\partial q_k}\delta q_k,\ \mathrm{where} \ q_k=\mathrm{k^{th}} \ \mathrm{degree} \ \mathrm{of} \ \mathrm{freedom}[/spoiler]? It doesn't give the right answers, but physically I don't see why this shouldn't work.

ITT: most elegant and profound equations. I'll start.

<span class="math">\log n! \approx n\log n - n[/spoiler]

>>4126513
Why does property __"x"__ of ___insert chemicals/atoms here___ behave different then __insert chemicals or atoms here___.

To actually answer questions like that (from the ground up) is not trivial. It can be done, but it isn't usually anything alot of physicist care about or study.

See, that "math" and "procedure" for all the stuff is actually very very very basic, and can be applied to all of chemistry and atoms and shit trivially.

Basically all your are doing is Quantum mechanics. It is semi-trivial to "form" the initial equations to represent your "chemicals/atoms". It is not trivial to solve the equations (shit ton of differential equations with operators (often most of which is only numerically solvable). We usually use supercomputers to do the math, since it is so fucking long. Then it is also not trivial to use stats to obtain the bulk properties from the quantum properties. So only physicist studying that particular chemical or atoms, would likly know the answers off the top of there head.

If you want to cheat though, and make tons of shit approimations (which may or may not be justified) there is probably some very specific equations developed by chemists that only applies to the types of systems you are talking about. You should ask a chemist about that though, not a physicist.