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In almost every technical field, one of the key goals of an undergraduate degree is to prepare one to work as a professional in that field. Working as a professional physicist pretty much means having a PhD in physics. The key focus of an undergraduate physics degree is to prepare students to enter a graduate school program in physics. Excluding ...

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Most of the "intermediate scale" problems were solved long ago, and are now mostly the domain of engineering: application of physics to real world problems. That leaves the more interesting, "esoteric" stuff as the material at the frontier; this is where research is happening, and that becomes the material that the lecturers (most of whom are researchers) ...

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"What Einstein was really looking for was a new way to transform between reference frames that would keep the laws of electrodynamics invariant inasmuch as the Galilean transformations keep the laws of Newton invariant?" It wasn't so much about finding the transformations, because the Lorentz transformations had been known for a while at the time, since ...

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$I$ has a clear physical meaning if $I\lt 0$ – which is a significant percentage of the spacetime, so to say: $$I = -c^2\Delta t_{\rm proper}^2$$ where $\Delta t_{\rm proper}$ is the time measured by clock that moves by a constant velocity (without acceleration); and that visits the point $(x_1,y_1,z_1)$ at time $t_1$ and $(x_2,y_2,z_2)$ at time $t_2$. ...

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It's much simpler than you think! The analogy is meant to underline that if you look the wire from far away it appears a 1-d path, while if you zoom you can see that the path is actually taking place in 3-d, because the wire is an extended object rather than really a line, even though two directions are far smaller than the third one. Now the ...

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Though the question is off topic, its a rare opportunity for a young person to connect with more senior physicists, so I'll share my thoughts: There is a vast, beautiful mathematical world waiting for you to discover - you haven't even seen a deep treatment of mechanics yet. It takes a lot of work and a lot of dedication, to grasp, but we're all here ...

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No, but Newton's third law of motion implies the conservation of momentum. In other words, Newton's third law is a special case of the more general law, which is the conservation of momentum.

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What about a double-slit experiment? If your laser's spatial coherence is long enough, you should be able to place the screen far enough away to get a nice image. Or go a step further and use a ballpen spring instead of a double slit, and reproduce the diffraction image of a helix (similar to what one sees with DNA)!

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There are loads of things you can do with lasers. However, maybe this one might be of interest? It's called "Laser Audio Interferometer" I tried this and it's simple. The mirror reflects the laser beam back down the bore of the HeNe laser tube, forming a second optical cavity external to the laser. Or use a laser pointer instead; I've been told ...

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