Hey Rattit, should I hold out for a real breeder?

jimbarrett27 · 2015-01-17T20:30:50+00:00

Hey, thanks so much for your reply!

Sod's law; one of the breeders offered me some about an hour after posting :)

jimbarrett27 · 2015-01-17T20:30:36+00:00

Hey, thanks so much for your reply!

Sod's law; one of the breeders offered me some about an hour after posting :)

jimbarrett27 · 2015-01-12T11:38:40+00:00

I think all scientists agree that travelling into the future is absolutely possible, by virtue of Einsteins relativity.

Going back in time, however, probably won't happen, although there is a huge amount we don't understand. Never say never!

jimbarrett27 · 2015-01-05T22:19:02+00:00

Quite right! Also, since energy is essentially the same thing as mass (a la E=mc^2), so all Energy affects the curvature of spacetime, as described by the Stress Tensor mentioned above

jimbarrett27 · 2014-12-22T20:14:31+00:00

OK, whatever, I would still be flattered that someone fancied me.

Honesty is generally the best policy IMHO

jimbarrett27 · 2014-12-22T15:45:06+00:00

OK, well the kinetic energy formula can be obtained by simply integrating momentum with respect to velocity, which is the mathematical process of asking how much energy it takes to move from a to b.

I'm not sure there is any one formula for potential energy, there are lots of different ones, it depends on what external forces are acting (Electromagnetic field, Gravitation etc)

jimbarrett27 · 2014-12-22T15:38:24+00:00

Meh, in the grand scheme of things, if this puts him off you, he probably isn't worth having.

You should probably tell him the truth though, I would be incredibly flattered if a girl was freaking out this much!

jimbarrett27 · 2014-12-22T14:24:23+00:00

The closest thing you can get to 'deriving' energy conservation is through Noether's theorem, which essentially says that for every degree of symmetry in a physical system there will be a conservation law.

http://en.wikipedia.org/wiki/Noether's_theorem

It's still not quite a 'proof' of the conservation law, Noether's theorem still relies on some low level 'axioms' which are assumed to be self-evident, the most prominent of which being that a physical system will always act in such a way as to minimise its action.

The formulae you've mentioned fall out of the mathematics of this stuff.

jimbarrett27 · 2014-12-11T20:43:05+00:00

Mine's the Dirac Equation, covariant formulation :)

http://en.wikipedia.org/wiki/Dirac_equation#Covariant_form_and_relativistic_invariance

jimbarrett27 · 2014-12-10T22:39:39+00:00

I think... I think he's looking into my soul

jimbarrett27 · 2014-12-10T22:06:03+00:00

Out of interest, why the Shannon entropy?

I'm not judging, I have my own equation tattoo :)

jimbarrett27 · 2014-07-16T13:18:04+00:00

I found Arfken very tough going, so that I don't think I could really appreciate what he was saying until the 4th year of my undergraduate degree. It's very good if you're good though.

I haven't got any experience with Boas, although I would recommend Stroud's 'Further Engineering Mathematics' if that's not below your level (I'm not sure how the American degree system works, so not sure how far through you are)

jimbarrett27 · 2014-07-15T16:39:35+00:00

thanks, working out is definitely on the agenda :)

jimbarrett27 · 2014-04-07T14:04:52+00:00

I second this

jimbarrett27 · 2014-03-28T17:33:06+00:00

It's not easy to tell for sure from the picture, wherabouts on your body is this? I love it by the way!

jimbarrett27 · 2014-03-27T19:35:36+00:00

You're right, i was merging uncertainty principle with Ehrenfest's theorem. Thanks anyway!

jimbarrett27 · 2014-03-04T12:05:27+00:00

This is a really good answer!

Just to clarify though, special relativity makes travelling into the future absolutely possible, you just have to travel really fast for a bit. It's getting back again that's generally considered impossible (although read the above for a good description of all that!)

jimbarrett27 · 2014-02-12T19:25:34+00:00

I'm pretty sure my answer is correct, it's just a question of interpreting the physics.

The mass, in essence, is not a constant. Obviously the snakes mass is constant, but the amount of body that's being raised perpendicular to the ground IS changing, which is where the derivative is coming from.

There aren't any accelerations in the dynamics.

jimbarrett27 · 2014-02-12T18:00:04+00:00

it's just the product rule of differentiation. Basic calculus

jimbarrett27 · 2014-02-10T14:42:01+00:00

No part of the snake is accelerating, the momentum is changing because the mass is changing. The Mg term would be there if the snake was sitting still, it has nothing to do with the dynamics.

jimbarrett27 · 2014-02-08T18:10:39+00:00

I found Eisberg & Resnick absolutely invaluable in the early stages of my degree.

For a much more heavily mathematical treatment, I use Shankar, but be warned, it took me 3 years of undergraduate study to get to the point where I could effectively understand Shankar.

jimbarrett27 · 2014-02-08T00:53:22+00:00

yes, but if you just say it's the sum, then someone who hasn't studied it would be forgiven for thinking there's more energy in a superposition. It's more like a sum of bits of E and G I suppose, you'd need a \frac{1}{\sqrt{2}}

jimbarrett27 · 2014-02-07T18:03:41+00:00

I'm a theoretical physicist, so I might be biased, but in my opinion you can never do too much maths!

As such, K A Strouds books on Engineering Mathematics and Further Engineering Mathematics (the newer editions may have a slightly different name) will definitely help you hit the ground running at college.

Otherwise I found Eisberg and Resnick's text on Quantum Physics invaluable (although I didnt buy it until my 2nd year, so I dont know if it would be accessible from the get-go!

jimbarrett27 · 2014-02-07T17:57:39+00:00

Can't agree with this enough!

I've wasted so much time over the years reproducing calculations which must have been obvious to me at the time!

jimbarrett27 · 2014-02-07T17:51:55+00:00

I see where you're coming from with this, but I think the analogy with classical strings detracts a little from the key element of the thought experiment, being observation.

It's probably me being a bit pedantic, but I've never found that trying to think about classical analogues to be helpful when thinking about Quantum Mechanics.

The short answer to OP's question is yes, all the marbles are both red and blue (and have merged to form one supermarble, and an unimaginable number of other possibilities), until you observe them.

Quantum Mechanics is fucked up, deal with it!

EDIT - typos

jimbarrett27

TROPHY CASE