# All Questions

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### What does “although electrons enter and leave the diode, charge is carried by holes in the p-type region” mean? [closed]

I read this in an electronics book but I couldn't understand it: The flow of current through a forward-biased diode may be summarized like this. Electrons pass from the external circuit and ...
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### Can a planet form before the parent star ignites?

I'm unable to find an answer to my questions via my searches. This questions pertains to the timeline of a star system creation. My question: During the creation of a star system, can satellite ...
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### How is light created?

I'm very curious about how light is created. I'm trying to get back to some type of real understanding about why everything on the sub-atomic level vibrates and the implications for the ...
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### Do systems with level crossings have unstable eigenbases?

It's folklore dating back to von Neumann and Wigner that time-dependent Hamiltonian systems tend not to have level crossings of their energy eigenvalues. However, we can of course consider smoothly ...
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### what would be the maximum depth of tunnel? [closed]

Perhaps more of an engineering question, but with the subject recently in the news about hyperspeed maglev tunnels I'll chance it here. Say you set up a network of line of sight underground tunnels ...
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### Is there a fundamental difference between the statistical methods of science, comparing medicine to physics?

Is there a fundamental difference between the statistical methods of science, comparing medicine/biology with small sample sizes(n < 10^2 or 10^3) to the statistics applied in Quantum Mechanics (h: ...