Recent content by marcusl

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    Affordable way to remove potassium from off-grid water?

    You should have a sample of your water tested so you know what you’re dealing with. Right now you are just guessing at what an appropriate solution might be.
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    Other Difficulty Finding a Position After Physics Bachelors Degree

    The administration has instigated a huge ramp-up of weapons procurement (especially since you-know-who apparently shot off most of our inventory of missiles and other armaments). I've read that it will take years to build new facilities to meet the demand. At this time, then, engineering jobs in...
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    Other Difficulty Finding a Position After Physics Bachelors Degree

    The job market is terrible and AI has wiped out entry level jobs. What hasn’t changed is the need for networking. In a 40+ year career, I worked at two startups, 2 small companies (~120 people) two large companies (~25,000) and one multinational (110,000 employees), not in that order—and was...
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    Graduate How many interpretations of QM do you speak?

    I’m a lurker in these interpretation threads—I like the discussions even though I often don’t understand a lot of what’s being discussed. My undergrad text was Merzbacher, which I didn’t like because it kept circling back to the same topics instead of dealing with them once and for all. Grad...
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    Undergrad How do bar detectors work in gravitational wave detectors?

    The most sensitive Weber bar, designed at Stanford, used a 4800 kg aluminum cooled to 2 to 4K to reduce thermal noise. I forget its longitudinal resonance frequency--something in the neighborhood of 1 kHz. The amplitude of longitudinal ringing was amplified by coupling it to a light diaphragm...
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    Unknown apparatus - vacuum tube of some kind?

    That tubing is pretty small to pull a meaningful vacuum, so I vote for pressure—but not very high or the fittings would fly off. Maybe it’s a water flow tube and the disks measure conductivity or voltage breakdown through the open slots?
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    Undergrad An intuitive reason for the definition of temperature via entropy and internal energy?

    dS=dE/T. At low temperature, systems are highly ordered and a small energy input results in a relatively large increase in disorder. At high T systems are already disordered, so a small energy increase doesn’t change the entropy much.
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    Engineering Second degree for engineers for more job opportunities?

    WWGD, you have addressed many of the post replies at great length, but the OP is long gone. BTW, note that he/she kept talking about companies, interviewers, job market, etc. but never once looked at their interview performance or addressed any in my post. I guess it’s easy to blame the world...
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    Two A/D use cases for Radar

    1. Yes, counting ADC clock cycles is equivalent to measuring time. Keep in mind that many pulse waveforms exhibit range-Doppler coupling, so a target's motion can change its apparent range. This is universally taught in radar courses, so I'm sure that is covered in a different part of your...
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    Other Struggling with illness and existential despair

    You’ve been seeing the wrong therapists, then. Keep looking until you find one who works for you.
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    Other I would like to get recommendations for graduate level physics books

    Most self-study efforts are aborted, no matter how confident the self-student is at the start. You even say in your post that you might not make it through your curriculum. I wouldn’t waste time on planning the graduate curriculum until you are nearing the end of your extensive undergrad review...
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    How to measure the diameter of a shaft without a caliper?

    Harbor Freight has plastic composite digital calipers for $9.99. (They even have plastic manual-reading ones for $1.99!) Plenty accurate for your needs. Calipers link
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    Other I would like to get recommendations for graduate level physics books

    Go through your seven review books first. You will then be in a much better position to evaluate what level of graduate text, and what style of exposition, works best for you going forward.
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    Math Math major jobs in the space industry

    Pure math probably not much but if you are applied, you might have a shot. Numerical methods, writing or improving complex simulation codes for structural, thermal or electromagnetic systems, optimizations and, of course, anything AI.
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    Undergrad How RF pulses synchronize proton phases in MRI

    Information on spin dynamics is also in these classic texts: Abraham, Nuclear Magnetism Slichter, Principles of Magnetic Resonance EDIT: Spell check miscorrected the first name. It’s Abragam, not Abraham.