Goddammm h1b visas are great for America

[Mark Celibate]

Molecular Biology BS UT Austin
Biochemistry Masters UT Austin

I was a TA and I took it seriously.
My job requires knowledge in Mol. Biology and Physics. Because these are odd partners for most people I am necessary. I got lucky and worked with really good research people (many turned entrepreneurs) who valued my persistence in figuring out stuff they did not have time for. Name gets spread about... right time right place right people I'm very lucky. The best thing that happened to me is not going forward for my PHD because my prof lost his grants due to his testicles overriding his brain. That kicked me to some fantastic people. Luck.

Yes I have tutored APC. I know the physics much better than the math. The physics largely encompasses the usefulness of finding slopes for specific realationships. (Derivatives). And finding areas under curves for specific realationships. ( Integrals) There is some calculus with extended bodies in rotation that requires some tricks with integration. And same with air resistance and capacitor charging. But it's not bad.

Without being rude, many math heads don't necessarily see the utility of what they are doing, especially in 1st year engineering physics.

The beauty of using limits to find slopes and areas is fn incredible. Also very cool with battery charging, Electric fields. The math describes the "dying off" or reaching some max value that is God like imo.

The new Physics AP1 and AP2 require some really tough concepts though. Some that APC does not touch. And yep you are right. Kids just get tossed into these classes with very little background. At least APC requires a physics prerequisite. But not for the really gifted kids. This is why I say I see a big market for the first two AP classes. I also have some software were I just write and talk on a white background so I can help some emergencies from colleague's kids on specific problems out of town. Much better than Skype.

That's very impressive tbh.

You are right about the math vs physics relationship. It's great to see the limits, definite integrals, surface integrals in action. I would like to get back to tutoring Physics C at some point but I just started a new career change so I'm busy studying all this new stuff I have to learn so it'll have to wait. I was not nearly as strong a student as you probably were so I lose it quickly unfortunately. My favorite though were the integrals with electrostatic potential (Gauss's Law, manipulating charge into charge density * volume). I always had fun with those because you had to get creative at times. Same with series in Calc BC....the students not so much

[pgardn]

That's very impressive tbh.

You are right about the math vs physics relationship. It's great to see the limits, definite integrals, surface integrals in action. I would like to get back to tutoring Physics C at some point but I just started a new career change so I'm busy studying all this new stuff I have to learn so it'll have to wait. I was not nearly as strong a student as you probably were so I lose it quickly unfortunately. My favorite though were the integrals with electrostatic potential (Gauss's Law, manipulating charge into charge density * volume). I always had fun with those because you had to get creative at times. Same with series in Calc BC....the students not so much

Gauss's Law, in APC anyway, usually ends up requiring very little calculus if you pick your Gaussian surface correctly.

And I am not smart if smart is picking up stuff quickly. I am curious and determined. I flat out worked hard. I thought about stuff at night. There were others in graduate school that were much "smarter" than I but they did not think about stuff as much as I did and were not persistent. I turned very goal oriented after being fairly disinterested in HS except about subjects I valued.

This is what gets me about education. It's the persistent kids that are curious that end up being so valuable. Kids that are "too smart" can also be super lazy.

The bolded is so similar to what one has to do to find moments of inertia in rotation. It's that same cleverness. I must be shown it first, then I catch on. And then one has to practice, actually think about some other body intensely, make mistakes, and then slap the head when you see it! That is true learning. You ponder a lot, get close, make an error, and then you see it and it really sticks.

[baseline bum]

Gauss's Law, in APC anyway, usually ends up requiring very little calculus if you pick your Gaussian surface correctly.

Yeah, if you have to do the integral the integral form of Gauss Law is pretty useless most of the time (unless for a theoretical result). Have you ever read Purcell's E&M book? I love the section he does on it. He gives the standard physical argument but gives a mathematical one for it too. A physicist on this forum recommended it to me and it's a really great read, on par with say Feynman's volume on mechanics (I still haven't read his quantum lectures, I don't know why honestly). Probably the best part of the book though is when he shows how you can infer the existence of a magnetic field from a (steady) current carrying wire by switching to the rest frame of a test particle where Lorentz contraction makes the wire charged (in that frame) and thus create an E-field. Then you transform back to the lab frame where your test charge is in motion and the Lorentz transformation implies the existence of a B-field. I always found that derivation really mind blowing since magnetic fields aren't the easiest thing to make sense of, at least in comparison to E-fields that seem pretty intuitive.

[baseline bum]

I have probably recommended that book to you 10 times now

[pgardn]

Yeah, if you have to do the integral the integral form of Gauss Law is pretty useless most of the time (unless for a theoretical result). Have you ever read Purcell's E&M book? I love the section he does on it. He gives the standard physical argument but gives a mathematical one for it too. A physicist on this forum recommended it to me and it's a really great read, on par with say Feynman's volume on mechanics (I still haven't read his quantum lectures, I don't know why honestly). Probably the best part of the book though is when he shows how you can infer the existence of a magnetic field from a (steady) current carrying wire by switching to the rest frame of a test particle where Lorentz contraction makes the wire charged (in that frame) and thus create an E-field. Then you transform back to the lab frame where your test charge is in motion and the Lorentz transformation implies the existence of a B-field. I always found that derivation really mind blowing since magnetic fields aren't the easiest thing to make sense of, at least in comparison to E-fields that seem pretty intuitive.

I have not read the book. I actually like the history books on the subjects. I read a book about Faraday and his relationship with Maxwell. Faraday was a great experimental physicist who could really not do the math. Because Maxwell understood the importance of what Faraday was doing and then could write his findings in a mathematical form we eventually ended up with Maxwells equations.

Personally i I find it necessary to go back to the very basics of what the first people were doing in order to understand the better mathematical modeling. The unifying of E and B fields was of course huge. I think I am naturally more of an experimental type than a theoretical type because I have to have a model before the math makes sense.

But honestly, you move a wire in a magnetic field and you get current flowing through a wire? That's fn fantastic. Or you find a potential difference, set a wire across it and you get a circular B field around the wire? Fn fantastic. Farmers using coils to "steal" fields from power lines, brilliant and illegal. And some of these farmers figured it out by accident with wire rolled into big spools in a storage house under a power line... The math is cool, but just the physical fact that these things happen just blows me away. And you have to orient things properly or it does not work. Then you immediately feel the vector nature of all this stuff. When you just get to play with wires and batteries and magnets and test your ideas of the fields that should be there.

Oh. The fact that the B field has to change (flux) to make current run through a wire loop... this stuff is fantastic just to play with. Or you just make charges oscillate back and forth at a certain rate and you get light or an X-ray or a radio wave... when you actually do this stuff yourself.... it's just as cool as fishing. Almost.

[pgardn]

I have probably recommended that book to you 10 times now

Its on a big list. Believe me. I will eventually get to it.

I get interested in too many things as I get older it seems.

[baseline bum]

I have not read the book. I actually like the history books on the subjects. I read a book about Faraday and his relationship with Maxwell. Faraday was a great experimental physicist who could really not do the math. Because Maxwell understood the importance of what Faraday was doing and then could write his findings in a mathematical form we eventually ended up with Maxwells equations.

Personally i I find it necessary to go back to the very basics of what the first people were doing in order to understand the better mathematical modeling. The unifying of E and B fields was of course huge. I think I am naturally more of an experimental type than a theoretical type because I have to have a model before the math makes sense.

But honestly, you move a wire in a magnetic field and you get current flowing through a wire? That's fn fantastic. Or you find a potential difference, set a wire across it and you get a circular B field around the wire? Fn fantastic. Farmers using coils to "steal" fields from power lines, brilliant and illegal. And some of these farmers figured it out by accident with wire rolled into big spools in a storage house under a power line... The math is cool, but just the physical fact that these things happen just blows me away. When you just get to play with wires and batteries and magnets and test your ideas of the fields that should be there.

Oh. The fact that the B field has to change (flux) to make current run through a wire loop... this stuff is fantastic just to play with.

I know what you mean about looking at it historically. It just blows my mind looking at this from Einstein's perspective:

(1) Galiean relativity holds for mechanical phenomena by Newton's second.
(2) The laws of physics should be simple.
(3) Then why shouldn't the principle of relativity hold for electromagnetic phenomena too? Why would mechanical phenomena ever be a special case?
(4) Then light has to have the same speed in any reference frame or the principle couldn't hold for E&M.
(5) Then we get the invariance of the spacetime interval from (4) by considering light clocks in motion vs still relative to some observer.
(6) Then we get the Lorentz transformation from (4) and (5), as well as other cool like time dilation and length contraction.

And once you have (6) you see a B-field is required to exist near a current carrying wire.

[baseline bum]

Its on a big list. Believe me. I will eventually get to it.

I get interested in too many things as I get older it seems.

Do you have any specific books you think are outstanding in various subjects in physics?

1. For newtonian mechanics I love Kleppner & Kolenkow. The problems are so much fun and it gives the best explanation of Newton's laws I have ever read. Most physics books just give you the formulas with a couple of paragraphs that essentially repeat the formulas in a long and drawn out way. It also doesn't shy away from polar and spherical coordinates, which is rare for a freshman level book. The problems are really hard though, it would have probably kicked my ass up and down the school if it was my freshman book. But sometimes you gotta get your ass kicked to learn something.
2. For a little more advanced mechanics (eg principle of least action) Taylor is really good. Much clearer and better written than Goldstein. And not chock full of errors that confuse the out of the reader like Goldstein. It's crazy how straightforward Taylor makes this subject, but it's not watered down.
3. For quantum I like Shankar. I can't front, I love the math and that's the only way I can make any sense of QM.
4. For E&M nothing touches Purcell. It doesn't shy away from math but doesn't get lost in it either (unlike say Griffiths).
5. For SR Taylor & Wheeler (1st edition from the 1960s) is phenomenal. The first couple of pages of the book talk about sacred units and how if you get rid of the idea that time has to be in the sacred unit of seconds (and express it in terms of meters) everything in SR is so much easier. It allows you to set c=1 and the transformation back to standard units is just dimensional analysis with factors of c. It's full of interesting and challenging problems, very few of which you could understand just by throwing equations at them.

[pgardn]

I know what you mean about looking at it historically. It just blows my mind looking at this from Einstein's perspective:

(1) Galiean relativity holds for mechanical phenomena by Newton's second.
(2) The laws of physics should be simple.
(3) Then why shouldn't the principle of relativity hold for electromagnetic phenomena too? Why would mechanical phenomena ever be a special case?
(4) Then light has to have the same speed in any reference frame or the principle couldn't hold for E&M.
(5) Then we get the invariance of the spacetime interval from (4) by considering light clocks in motion vs still relative to some observer.
(6) Then we get the Lorentz transformation from (4) and (5), as well as other cool like time dilation and length contraction.

And once you have (6) you see a B-field is required to exist near a current carrying wire.

It just nice to be able to appreciate some of what other people have figured out. Or some breakthrough analogy that lets you feel it. The idea of light being the constant and time and space being variable was/is something that would never have occurred to me. I always knew there was a frame of reference problem, but I would never have had the slightest idea how to deal with it. I remember when I was told what wind was as a kid. It had really bugged me. And I remember when I thought the opposite poles of magnets just squished air molecules in between them so it made them repel and pushed the air out when opposite poles attracted AFTER I found out about air. I had so many things so wrong.

I even waited outside for an airplane to land on our street when my parents told me they were going up to the sky to another place. And the They fn left in a car to go were all the planes were. An airport... Thanks for telling me. Letting me get all excited and bam, reality. Bums a little one out.

[baseline bum]

It just nice to be able to appreciate some of what other people have figured out. Or some breakthrough analogy that lets you feel it. The idea of light being the constant and time and space being variable was/is something that would never have occurred to me. I always knew there was a frame of reference problem, but I would never have had the slightest idea how to deal with it. I remember when I was told what wind was as a kid. It had really bugged me. And I remember when I thought the opposite poles of magnets just squished air molecules in between them so it made them repel and pushed the air out when opposite poles attracted AFTER I found out about air. I had so many things so wrong.

I even waited outside for an airplane to land on our street when my parents told me they were going up to the sky to another place. And the They fn left in a car to go were all the planes were. An airport... Thanks for telling me. Letting me get all excited and bam, reality. Bums a little one out.

Have you ever seen Einstein's thought experiment for why E = mc^2 should hold? It's so cool. It's based on a box that emits a packet of radiation and when you assume that packet of emitted radiation doesn't change the mass of the box you get a contradiction of the laws of mechanics (by considering the center of mass of the box/radiation system). So you have to assume it does lower the mass of the box by some mass m and then the formula m = E/c^2 for the mass the box itself loses just jumps out of the derivation. It's called Einstein's box. It's not the derivation he actually published, and it requires a result from deBroglie about momentum of radiation AFAIK (maybe Einstein had another way to show pc is the energy of radiation of momentum p? I think it was considered an experimental fact at the time), but it's still a pretty fun way to explain the most famous formula in science.

[pgardn]

Have you ever seen Einstein's thought experiment for why E = mc^2 should hold? It's so cool. It's based on a box that emits a packet of radiation and when you assume that packet of emitted radiation doesn't change the mass of the box you get a contradiction of the laws of mechanics (by considering the center of mass of the box/radiation system). So you have to assume it does lower the mass of the box by some mass m and then the formula m = E/c^2 for the mass the box itself loses just jumps out of the derivation. It's called Einstein's box. It's not the derivation he actually published, and it requires a result from deBroglie about momentum of radiation AFAIK (maybe Einstein had another way to show pc is the energy of radiation of momentum p? I think it was considered an experimental fact at the time), but it's still a pretty fun way to explain the most famous formula in science.

I have read that one but forgot about it.
But squared laws show up very often in physics so it makes since with the basic idea of spreading out. If I hold a light up to your eye 1 meter away you might say that light has an intensity of 1. If I move the light 2 meters away the photons spread you will now say I see an intensity of 1/4 of the original. Like the SA of a soap bubble that grows by 1 radius. So energy carried in a photon increase by a squared law. I have seen a number of other math and physical explanations. I have even seen one that explains the changes in the length of an object as it nears the speed of light using geometry. It was wacked but made sense. I gotta look that one up again. There are so many good modern physics explanations I just tend to forget them because they are very unique.

[pgardn]

Do you have any specific books you think are outstanding in various subjects in physics?

1. For newtonian mechanics I love Kleppner & Kolenkow. The problems are so much fun and it gives the best explanation of Newton's laws I have ever read. Most physics books just give you the formulas with a couple of paragraphs that essentially repeat the formulas in a long and drawn out way. It also doesn't shy away from polar and spherical coordinates, which is rare for a freshman level book. The problems are really hard though, it would have probably kicked my ass up and down the school if it was my freshman book. But sometimes you gotta get your ass kicked to learn something.
2. For a little more advanced mechanics (eg principle of least action) Taylor is really good. Much clearer and better written than Goldstein. And not chock full of errors that confuse the out of the reader like Goldstein. It's crazy how straightforward Taylor makes this subject, but it's not watered down.
3. For quantum I like Shankar. I can't front, I love the math and that's the only way I can make any sense of QM.
4. For E&M nothing touches Purcell. It doesn't shy away from math but doesn't get lost in it either (unlike say Griffiths).
5. For SR Taylor & Wheeler (1st edition from the 1960s) is phenomenal. The first couple of pages of the book talk about sacred units and how if you get rid of the idea that time has to be in the sacred unit of seconds (and express it in terms of meters) everything in SR is so much easier. It allows you to set c=1 and the transformation back to standard units is just dimensional analysis with factors of c. It's full of interesting and challenging problems, very few of which you could understand just by throwing equations at them.

I would read 1) first. I always look to mechanics so I feel the contrast with modern physics. I got textbooks out the gazoo I might need to load the library with the above or, I might already have some of them. Got too much on the list. I'm gonna need to live 100 years longer to understand it all. Then it will change on me.

[DMC]

Yeah all that theory is cool but when you use it to create a pulsed beam that can burn through several inches of solid graphite at over 2 MeV, that's even cooler.

[pgardn]

Yeah all that theory is cool but when you use it to create a pulsed beam that can burn through several inches of solid graphite at over 2 MeV, that's even cooler.

Actually that's probably hot. But I tend to agree. I like to see physics in action. It's one thing to say this theoretically can be done. It's another thing to do it. The engineering guys who actual create the experiments/technology have gotta feel really satisfied. I'm lucky because the simplest things freak me out. I remember getting a hand driven Van de Graffmachine and making a capacitor out of foil tapped to both sides of a plastic transparency and charging it not believing it would work (in theory it should) and shocking the crap out of myself. Delightful. Then I just made little ring capacitors out of the same material and charged them. The trick was transporting them around the room so coworkers and friends would pick them up. They just had to touch both sides of the foil plastic ring. Sometimes they would discharge them accidentally and not get shocked. Some of them would stay charged for an hour on a dry day.

Too much fun stuff to fiddle with. Good for camaraderie after a hard day of getting nowhere.

Oh btw the braking system on the baitcasters are a thing of beauty. The little "weights" you can move closer or further away from the axis of rotation is cool. The engineering of such smooth surfaces is ridiculous as well. All the new materials they have come up with for fishing line... The plastics they use to make kayaks. The amazing peddle drives with the cool chains. Who would have thought Penguin wings would work better than a little prop... not me.

[Wild Cobra]

Yeah all that theory is cool but when you use it to create a pulsed beam that can burn through several inches of solid graphite at over 2 MeV, that's even cooler.

That is one of alot of power to channel.

[Mark Celibate]

Do you have any specific books you think are outstanding in various subjects in physics?

1. For newtonian mechanics I love Kleppner & Kolenkow. The problems are so much fun and it gives the best explanation of Newton's laws I have ever read. Most physics books just give you the formulas with a couple of paragraphs that essentially repeat the formulas in a long and drawn out way. It also doesn't shy away from polar and spherical coordinates, which is rare for a freshman level book. The problems are really hard though, it would have probably kicked my ass up and down the school if it was my freshman book. But sometimes you gotta get your ass kicked to learn something.
2. For a little more advanced mechanics (eg principle of least action) Taylor is really good. Much clearer and better written than Goldstein. And not chock full of errors that confuse the out of the reader like Goldstein. It's crazy how straightforward Taylor makes this subject, but it's not watered down.
3. For quantum I like Shankar. I can't front, I love the math and that's the only way I can make any sense of QM.
4. For E&M nothing touches Purcell. It doesn't shy away from math but doesn't get lost in it either (unlike say Griffiths).
5. For SR Taylor & Wheeler (1st edition from the 1960s) is phenomenal. The first couple of pages of the book talk about sacred units and how if you get rid of the idea that time has to be in the sacred unit of seconds (and express it in terms of meters) everything in SR is so much easier. It allows you to set c=1 and the transformation back to standard units is just dimensional analysis with factors of c. It's full of interesting and challenging problems, very few of which you could understand just by throwing equations at them.

bum,

have you read the book, Quantum? A good friend of mine recommended it to me. I think I'll check it out but I wanted to hear your thoughts

[baseline bum]

bum,

have you read the book, Quantum? A good friend of mine recommended it to me. I think I'll check it out but I wanted to hear your thoughts

Sorry, I haven't heard of it. Who is it by?

[Mark Celibate]

Sorry, I haven't heard of it. Who is it by?

The book is by Manjit Kumar and focuses on the lives of Bohr, Einstein, and the other major players of the time. I'm sure it's probably a book that's beginner-friendly since my friend doesn't have a strong math or science background but I haven't read any non-textbooks on quantum mechanics either so I probably qualify as a beginner as well.

I'll keep in mind those other books you mentioned too.

[Quadzilla99]

https://www.axios.com/computer-progr...342531251.html

[baseline bum]

https://www.axios.com/computer-progr...342531251.html

Finally Trump actually doing something that makes sense.

[baseline bum]

The book is by Manjit Kumar and focuses on the lives of Bohr, Einstein, and the other major players of the time. I'm sure it's probably a book that's beginner-friendly since my friend doesn't have a strong math or science background but I haven't read any non-textbooks on quantum mechanics either so I probably qualify as a beginner as well.

I'll keep in mind those other books you mentioned too.

I'll have to check it out.

[DarrinS]

https://www.axios.com/computer-progr...342531251.html

Too bad this didn't happen sooner. My company is jam packed with those people.

[boutons_deux]

Finally Trump actually doing something that makes sense.

Tech industry didn't pay Trash, Bannon, Miller enough. Need deep deeper in their pockets.

[ElNono]

Finally Trump actually doing something that makes sense.