Recent content by Bill Foster

You all haven't identified this contraption yet?

Using the NIST database, I get the following energy levels for Ne^9. But there some some values missing (where the ? is shown). Any of you know these numbers, or where I can find them? Thanks. 1s2 1S 0 0.00000 1s2s 3S 1 7299940.0 1s2p 3P° 1 7379327.8 1s2s 1S 0 7382680.0...

I don't see how a beaker would attach to those arms anyway.

The upper arm is immobile. The chain attaches to something which leads into the box. I imagine that when the chain is pulled, it pulls that lower arm up, against spring loaded tension from inside the box. Whatever it's meant to hold, it cannot be too heavy, or the whole thing will tip over...

I'll bet some 80 year old high school science teacher knows what it is.

I'm skeptical. The notches on the arms of the C clamp look like they're meant for something like string. The arms looks like they're meant for holding something under tension. There's probably a spring inside the box providing the tension. The chain releases the tension. The chain...

Ah, of course. It all makes sense now. thanks.

I won't dispute your claim. But...HOW? And for what kinds of injuries?

http://www.stevenferris.com/whatisit.jpg Anybody here recognize this? Does it have a name? What's it used for? Thanks.

The energy solutions to the Dirac equation are E=\pm\sqrt{p^2+m^2} So I apply a Lorentz transform to that. But first, I need to expand it, right...

Combining the two equations I listed previously... \vec{F}=m\vec{a}=m\frac{v^2}{r}\hat{r} There is your basic equation for centrifugal force. Now, assume the station is rotating at some angular velocity \omega rad/sec. You'll need to convert that into a velocity: v_s=\omega r...

You'll need to know how fast the station is rotating. If it's not given, then you'll have to write the answer in terms of \omega.

\vec{F}=m\vec{a} \vec{a}=\frac{v^2}{r}\hat{r}

Since the energy solution contains a square root of the momentum (and the Lorentz transform acts on the momentum), I need to expand the function first before applying the Lorentz transform?

Homework Statement Show that a Lorentz transformation preserves the sign of the energy of a solution to the Dirac equation. The Attempt at a Solution I'm not sure how to approach this. So I apply the Lorentz transform to the Dirac equation, and work through it to obtain the energy...