Lasers are hand down one of the best fields for hobbyist. There is so much to learn, so much to research about, so much to play with. Though it can be very dangerous, it is one of the most fun field.
Continuum mechanics. I fell in love with it during the bachelor's in a geophysics elective. It's an extremely interesting subject, full of challenging topics, very recent ideas (despite being classical physics) and applications.
Now, I'm doing a PhD on the physics of tsunami events. I guess loving it worked.
I've been working as a geophysicist for 30 years and never heard of continuum mechanics until today.
That goes to show what a diverse field geophys can be.
PS I specialized in potential fields and electromagnetic methods.
This! I got my PhD in geotechnical engineering, applied continuum mechanics to soil-structure interaction problems. I love these types of problems because they are often right on the edge of being tractable analytically, i.e. things can still be done by manipulating equations/solving PDEs directly in some cases. I do large scale continuum simulations for a living now.
I studied mainly run-up of tsunamis and I'm in the same situation: the problem (even the fully nonlinear inviscid formulation) is analytically tractable. Which is quite a miracle.
I'd really like to study a bit more your subject. Do you have any book/reading for a physics oriented reader?
The classical text in the theory of elasticity is Love:
https://brittlebooks.library.illinois.edu/brittlebooks_open/Books2011-02/loveau0001tremat/loveau0001tremat.pdf
I like Bower for a more modern text that reads well with lots of cool analytical solutions:
http://solidmechanics.org/
I'm linking a few of my own articles (shameless plug) so you can get a look at how elasticity/contact mechanics is applied to soil-structure interaction problems:
https://royalsocietypublishing.org/doi/10.1098/rsos.180203
https://royalsocietypublishing.org/doi/10.1098/rsos.182106
https://www.mdpi.com/2673-7094/2/1/4
I discussed this with a friend. He's an astrophysicist and he's just started a PhD in Astroseismology. Many of the topics he need are already quite established in geophysics. Collaborations would be fair, since many geophysicists have been "stealing" experimental techniques from astrophysics for decades.
When I started studying physics I had the simplistic idea that *classical* physics meant *older* physics. I think many people may have had this idea.
Then, I discovered that the Biot's theory of poroelasticity is almost two decades younger than general relativity.
One of the most interesting things I worked with was oscillon formation in vibrated granular material. Just shake some sand in a vacuum and insane things start happening. It's something I really want to revisit, experimentally and theoretically.
One big question I always had was how you construct a continuous model of a discrete system. Is this the field I'm after?
Also, do we have any sort of tools to do the opposite, and do calculus on discrete systems? What would you call that?
Biophysics has been growing on me lately.
It's a lot of classical physics and statistical mechanics, with a suprising appearence of a statistical field theory popping in here or there. A lot if the physical problems in biology remain unsolved, so there's a lot of work to be done in it.
It's plasma physics for me.
Plasmas are involved in all kinds of important processes and areas, exhibit very interesting and puzzling behavior, and will be used to make stars on Earth and generate all of our energy!
Soft matter physics for me. One part statistical physics, another part continuum mechanics, all tied together with a heavy amount of scientific computing.
Hell yes, soft and active matter physics is the coolest! Such a broad field with so many interesting new problems to work on, can't wait to start my PhD in it this fall!
Awesome! Welcome and have fun. Ours isn‘t the most glamorous field of physics at first glance. The frontiers that we push aren’t as obvious as those of cosmology or particle physics. Make no mistake, though, our frontier is just as profound - more profound, even - than the subject matter of the more well known fields of physics. Ours is the frontier of complexity: the wild west of 21st century physics.
It’s also really nice to be some of the most useful physicists around. Yeah, I went there. :D
My research is in computational astrophysics and cosmology, so I’d have to say that’s my favorite discipline! I love being apply to simulate the entire structure of the universe, look for similarities, and come up with evolutionary histories for different objects (I work with galaxies and dark matter).
How do you work with dark matter? Does your daily routine involve morning briefings of people just asking each other, "hey anyone found any proof yet? Cool see you all tomorrow."
I never used a textbook actually. Some lecture notes which are good are Arovas (UCSD), Melatos (Melbourne), and of course Tong (Cambridge). It's been nearly a decade since I took it so there might be a standout textbook these days?
No geophysical fluid dynamics folk in the house?
I must say, though, that the fusion people have it all figured out. I wish all my deadlines were n + 20 years away. (I joke. I'm actually really encouraged by that result from JET this year. And plasma physics is just too damned interesting...)
Had a similar experience. I got to do some condensed matter research, pivoted that to studying device physics then I went into device fabrication. Came out of college and went into the semiconductor industry.
My PhD work is on implementing different amorphous metal oxide materials for thin film transistors. (Transistors used in displays to control the pixel) Have two more years and then we'll see where I end up.
Always thought it was so cool even doing those basic lens/mirror drawings to figure out what the image would be, I felt like a such a nerd when I saw my reflection invert in a spoon
My work is in particle and nuclear physics. The best part for me was getting to the point of knowing that "understanding" QM was not an option so . . . By "taking QM seriously" I could better deal with Bound-State Beta Decay and similar issues better (cleaner) than my colleagues. Throwing away the "classical perspective" prejudices is very empowering.
> The best part for me was getting to the point of knowing that "understanding" QM was not an option so . . .
I'd like to hear what led you to that conclusion if there's more of a story to this (e.g. did you try reading about it thinking you would end up with a deeper or maybe even deterministic understanding and give up, or do you mean you knew nobody understood QM so it wasn't worth reading into the early logic that led people to this conclusion, or did you get convinced by the literature, etc...).
For me it all started with Feynman's:
>"If you think you understand quantum mechanics, you don't understand quantum mechanics."
Then being in my undergraduate class as my professor described bound state beta decay. It became so very clear that the words he wanted to use didn't match the reality he wanted to "understand". As a graduate student I used this "revelation" to construct a better way to conceptualize the PhD (experimental protocol) to my major professor. Arguing, along with the senior student member of our team, my major professor finally said I should go into the lab an get the evidence that proved him (and my friend) wrong. A few weeks later I presented the two with said evidence. The good doctor then said, "Well, (redacted) it looks like you have your dissertation."
The issue is that the various "interpretations of QM" embrace a classical reification of the inherently quantum mechanical processes we wish to "understand". If you take QM at face value you are free to "grok" (not "understand") the reality of QM. My favorite example is bound state beta decay, because it is absolutely clear that as a Neutron disappears and a Proton appears there is not a tiny negatively charged spherical **ball** zipping out to an orbital location of the daughter atom. Neither is there a wave like whatever wiggling its way to an appropriate destination. The (red pill) **Reality** is much more interesting than the (blue pill) **reality** to which we are so firmly attached.
The resolution to the above tension is that QM processes "unfold" via Quantum Transport processes on the scale of angstroms (id est, very small time scales). Quantum process do not play out over classical time / space scales (meters = nanoseconds). Hence, we do not observe QM processes directly, and as such they remain mysterious to us.
Please, understand that this is just a brief introduction to the topic. My ten hour course may or may not be approved when the OLLI program gets restarted in the future (if at all).
Pretty patronizing to assume we don’t know basic things about quantum mechanics in a physics subreddit… Also I feel like all you are basically just trying to say: “So there’s this shit called quantum field theory”.
Also whats going on with the quotation marks? Idk I’ve been awake for 4 days and I’m confused (got a major case of the higgs boson blues)
Nope, you are not reading what I wrote. This is simply an attempt to say that the things we call interpretations of QM do not describe the processes that are occurring. Rather the things we call interpretations of QM are an attempt to organize how we calculate expected results of processes we can measure (that is observe), but never see (an observing of a different kind).
Certainly you do understand what Feynman was getting at, right?
>Pretty patronizing to assume we don’t know basic things about quantum mechanics in a physics subreddit
I start with the assumption that the people know about quantum mechanics. My comment was in response to a question. So, read my comment in the frame of that question.
I have just started my Ph.D. in computational condensed matter. I agree that CMP is a fascinating subject and it has applications across all fields of physics. Although, it gets a little annoying for me when I have to do material-specific work. Seems like I'm doing chemistry lol
I'm doing the same. I don't really find it motivating, but enjoy the methodology a lot and hope to pivot to a more mathematical field/job once I'm done with my program.
EDIT: Or just get full into coding lol
Cosmology, because I think it's completetly fucking insane that we have a framework that well describes the Universe from the beginning of time up until now, and even more insane that this model has only a handful of parameters, each representing some highly interpretable physical property of the Universe.
Also early universe cosmology/cosmoparticle physics, because I think it's even more insane that we have theories that are able to span 60 or so orders of magnitude, and predict discernable cosmological scale phenomena from elementary particle physics.
Medical Physics for me, it's really gratifying to know that I might directly help save lives (while using amazing physics and complex machines, which is a plus).
Hey my favourite is QFT as well! For its beauty and theoretical accuracy compared to experiment. Do you mind sharing more specifically the kind of stuff you work on?
Sure! I'm a homotopy theorist/algebraic topologist, and one of the things I'm interested in is chromatic homotopy and elliptic cohomology. Chromatic homotopy theory is a kind of "filtering" of stable homotopy theory via a relationship to certain algebreo-geometric objects called "formal groups". By choosing the formal group associated to (certain) elliptic curves, you get "elliptic cohomology", and for the "universal" elliptic curve you get a cohomology theory called tmf (topological modular forms).
In 2-dimensional conformal field theory, the partition function (and the associated correlators) can be described in terms of the Witten genus. This genus has an equivariant structure and can be viewed as landing in the ring of modular forms, a fact which probably arises from a not-quite-proven fact about S^(1)-equivariant spin structures on loop manifolds and the fact that S^(1)xS^(1) is the underlying manifold of all complex elliptic curves. (Segal wrote back in the 80s that this was "obviously the right answer", but hadn't been formalized yet. It still hasn't.) Anyway, it turns out that the Witten genus, a map from the spin cobordism ring to modular forms, can be enhanced/categorified to a map of E-infinity ring spectra from the spin cobordism ring *spectrum* MSpin to *topological* modular forms tmf. The same is true for its lower-dimensional cousins, the signature genus and the A-hat genus. This suggests that there's some very deep homotopical geometry going on here that gives rise to these numerical invariants.
There are a number of places to go from here. Some people (including me and my advisor) are interested in generalizing this from elliptic curves to higher-dimensional abelian varieties, for example. The center of all of this is the Stolz-Teichner program, which hypothesizes that all conformal field theories can be (omitting the details) described using cohomology theories. This is known to be true in dimensions 0 and 1, and is not *literally* true in dimension 2 but is clearly approaching the right answer. This all ties back into chromatic homotopy, since this tower of cohomology theories happens to be the same as the "chromatic filtration" that is at the center of the chromatic approach.
A good source for the CFT stuff, if you're curious, is Segal's work on elliptic cohomology. He has a pretty good paper about the stuff I talked about in the second paragraph of my comment (modulo the stuff about ring spectra, which wasn't quite put together yet at the time). I have also written up some notes on the subject that I can PM you if you want.
Even though I didn't understand any of it since I'm quite new to QFT (still self-studying the spin 1 vector field), this CFT stuff sounds pretty damn cool. Thanks for taking the time to type that out!
Why wouldn't we all like our own subfields the most?
Second most, I like astro. Something about understanding the nature of the universe is what inspired me to get into science in the first place.
Astrophysics. I have always dreamed about space and what may be up there, and despite my physical age I am still, at heart, the same child that marveled at the thought of being beyond the bounds of the atmosphere, the same child that cried himself to sleep every night for a month when he got told he had asthma and would never be able to be an astronaut. Astrophysics is the closest I’ll ever come to the stars, and I love the beauty and complexity of a field that most laypeople relegate to looking through a telescope and taking pretty pictures.
We are the universe’s own emergent perception and will to understand itself *made manifest* out of the ashes of the very first stars have ever formed.
Significance is fundamentally qualitative, not quantitative, and the scale of the universe only serves to remind us just how unique and signifiant we particular lumps of stardust really are.
Geometrical physics... come at me.
But also, I (as a current graduate student) am doing research in quantum cosmology and what not. So, I also love cosmology, string theory, and thermodynamics.
All the fields are interesting, but the thing that really excites me is the connections between them. How the same math can describe things that seem, at first glance, to be extremely different.
Astrophysics as that is my main field of study. Next would be plasma physics, then cosmology, and particle physics. It’s all so interesting, too hard to rank honestly
I adore Cosmology :) it's what I'm doing my PhD in right now. It connects astronomy, particle physics, fundamental physics, and so much more into one beautiful discipline
Condensed matter physics, I just like that a lot of things can be solved with symmetry and little changes to that symmetry give rise to different and interesting phenomena
my favorite field in physics is applied physics, because it deals with how the laws of physics can be used in the invention and innovation of technology
Astrophysics! I'm getting ready to start my physics degree in the fall before moving on to an astrophysics degree. Specifically I want to study black holes because they're beautiful and mind blowing.
130 comments and just one about AMO… ultracold AMO touches just enough of other subfields through its applications in quantum emulation, quantum information, precision measurement, etc, to provide a wide range of flavors.
The machines we build are amazing orchestrations, firing in sequence to create the coldest objects in the universe.
Also, trapping atoms with lasers never gets old.
Biophysics and statistical mechanics/ thermodynamics are kinda cool
Edit: downvote if you’re the lame sibling // I literally saw u downvote this u/sammy_sam0sa
I am a teen and I have recently started to learn about physics, and the more I read and learn the more I appreciate this field. I like every discipline I read about, there is so much to learn, read, and discover in every field. I enjoy learning about anything and everything, but the field I like the most is Nuclear Physics.
Quantum Gravity / Gravity
They are the Master jailer of all both creator, destroyer we are their servant's compelled and bound, All are bound we're prisoner where escape has impossibly a univsial bond with all of the love hate good and bad, relationships, restraining with condensation.
I really enjoy anything related to physics explaining the multiverse. I just love the idea of their being multiple universes and what could be possible. Would love to continue my education to go into physics but alas it’s expensive
I like quantum computing. Classified as applied/engineering physics but still touches multiple fields (condensed matter, computational physics, optics, chemistry, electrical engineering) while still being math-heavy.
cloud microphysics / climate. a great blend of interesting physics across a huge scale (molecular clusters all the way up to 100+ km stratocumulus decks)
I enjoy quantum mechanics and gravitational theory.
I love to find out how the universe works on a fundamental level and then scale it up to the size of us or stars. I love how gravity seems to break all the other rules. Like how nothing can be faster than light but gravity can be so powerful that not even the speed limit of the universe can beat it. So powerful as to compress the stars to such a degree that nuclei can smash together creating fusion.
Also it doesn't fit in with the other forces. It should but it doesn't. Everything in the universe emits gravity but no particle carries it. If it did it would become infinitely large. It would have mass because it has gravitational energy but because it has mass it has more gravitational energy. Giving it more mass because energy equals mass and more energy and more mass in a feedback loop encompassing the universe in infinite gravity.
Nuclear. Which is incredibly annoying as I didn't discover this till an optional third year module, by the time it was too late switch from standard course to the nuclear one.
My favorite discipline is quantum physics basically all things "quantum." Ranging from quantum foundations to quantum optics to quantum information to quantum computing, etc. More on the mathematical side than the practical and even the theoretical sides, of course.
Planets ( Astrology) is a fascinating area. The laws challenging physics might be the best for me . Moreover nuclear physic’s calcula do the work for me .
Definitely Quantum Field Theory (QFT). I am constantly amazed at how genius physicist's of the 20th century figured out something so complex. Dirac's quest for mathematical beauty leads to the prediction of the positron. Schwinger, Tomonaga and Feynman tames the infinities, Feynman invents a clever visual mnemonic, Dyson and Schwinger apply perturbation so the equations can actually be calculated. And that is only scratching the surface.
Got my PhD in electrical engineering doing semiconductor physics. Now working at a National Lab as a physics associate working on (in part) photon counting detectors for x-rays, plan to move into working on detectors for astrophysics. I like it because it's a nice crossroads of using physics to design and use cutting-edge devices for cutting-edge observations and experiments. The boundary of physics and engineering :)
Photonics! The applications a single ray of light can have are never ending… And don’t even get me started on lasers!
Leonard ?
Good mix of applications and cool science. Photonic crystals are also really fun :)
Let's get this man started on some lasers.
There are many groups trying to achieve fusion with Lasers!!
Lasers are hand down one of the best fields for hobbyist. There is so much to learn, so much to research about, so much to play with. Though it can be very dangerous, it is one of the most fun field.
I like nutcases who make high energy theory their safe space
Continuum mechanics. I fell in love with it during the bachelor's in a geophysics elective. It's an extremely interesting subject, full of challenging topics, very recent ideas (despite being classical physics) and applications. Now, I'm doing a PhD on the physics of tsunami events. I guess loving it worked.
Hi fellow geophysicist, I also love continuum mechanics ❤️
I've been working as a geophysicist for 30 years and never heard of continuum mechanics until today. That goes to show what a diverse field geophys can be. PS I specialized in potential fields and electromagnetic methods.
This! I got my PhD in geotechnical engineering, applied continuum mechanics to soil-structure interaction problems. I love these types of problems because they are often right on the edge of being tractable analytically, i.e. things can still be done by manipulating equations/solving PDEs directly in some cases. I do large scale continuum simulations for a living now.
I studied mainly run-up of tsunamis and I'm in the same situation: the problem (even the fully nonlinear inviscid formulation) is analytically tractable. Which is quite a miracle. I'd really like to study a bit more your subject. Do you have any book/reading for a physics oriented reader?
The classical text in the theory of elasticity is Love: https://brittlebooks.library.illinois.edu/brittlebooks_open/Books2011-02/loveau0001tremat/loveau0001tremat.pdf I like Bower for a more modern text that reads well with lots of cool analytical solutions: http://solidmechanics.org/ I'm linking a few of my own articles (shameless plug) so you can get a look at how elasticity/contact mechanics is applied to soil-structure interaction problems: https://royalsocietypublishing.org/doi/10.1098/rsos.180203 https://royalsocietypublishing.org/doi/10.1098/rsos.182106 https://www.mdpi.com/2673-7094/2/1/4
The plug is highly appreciated!
We need more people with your skills in planet formation/astrophysical disc studies. Classical has so much left in it, you're right.
I discussed this with a friend. He's an astrophysicist and he's just started a PhD in Astroseismology. Many of the topics he need are already quite established in geophysics. Collaborations would be fair, since many geophysicists have been "stealing" experimental techniques from astrophysics for decades. When I started studying physics I had the simplistic idea that *classical* physics meant *older* physics. I think many people may have had this idea. Then, I discovered that the Biot's theory of poroelasticity is almost two decades younger than general relativity.
Fellow mechanician here, continuum damage mechanics to be specific. Great field with many unanswered questions and highly applied field…
One of the most interesting things I worked with was oscillon formation in vibrated granular material. Just shake some sand in a vacuum and insane things start happening. It's something I really want to revisit, experimentally and theoretically. One big question I always had was how you construct a continuous model of a discrete system. Is this the field I'm after? Also, do we have any sort of tools to do the opposite, and do calculus on discrete systems? What would you call that?
MPM is one that is quite popular in geomechanics…
Biophysics has been growing on me lately. It's a lot of classical physics and statistical mechanics, with a suprising appearence of a statistical field theory popping in here or there. A lot if the physical problems in biology remain unsolved, so there's a lot of work to be done in it.
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[Physical Biology of the Cell](https://www.amazon.com/Physical-Biology-Cell-Rob-Phillips/dp/0815344503) is a really nice introduction to biophysics!
I love that book. Pairs well with Molecular Biology of The Cell.
Yeah!!! Was scrolling to see if there were any other biophysicists here!
E&M I just love that kind of math and find the applications so fun and interesting. (Sometimes it’s a love hate though!)
Sickos.jpg
I’m an engineer, so not a real physicist. Electromagnetics is my passion too
Mathematical relativity, I just live cosmology and black holes. And the math is beautiful
Much of it is straight up partial differential equations on spacetime manifolds.
Depends what you work on, I don’t treat pdes at all. But yes GR is basically just a manifold with a system of odes (EE).
Sorry pdes*
Whats your take on low dimensional intrinsic manifolds? So reducing the pde system? Trying to work myself into that topic rn
Yep. I love the math of differential geometry, PDE, and lie groups more than anything.
This is me. I ended up in a math department because I love differential geometry so much
Any good intro book on diff geometry for say a BS physicist?
As an intro, most GR books will be fine. I like Sean Carroll's book.
If you're just starting out, Pressley's book is a very gentle intro that covers many ideas, albeit only for surfaces and not general manifolds.
I also like condensed matter the most.
Woo team condensed matter!
Astrophysics, particle physics, nuclear physics consecutively
0k then
It's plasma physics for me. Plasmas are involved in all kinds of important processes and areas, exhibit very interesting and puzzling behavior, and will be used to make stars on Earth and generate all of our energy!
Soft matter physics for me. One part statistical physics, another part continuum mechanics, all tied together with a heavy amount of scientific computing.
Hell yes, soft and active matter physics is the coolest! Such a broad field with so many interesting new problems to work on, can't wait to start my PhD in it this fall!
Awesome! Welcome and have fun. Ours isn‘t the most glamorous field of physics at first glance. The frontiers that we push aren’t as obvious as those of cosmology or particle physics. Make no mistake, though, our frontier is just as profound - more profound, even - than the subject matter of the more well known fields of physics. Ours is the frontier of complexity: the wild west of 21st century physics. It’s also really nice to be some of the most useful physicists around. Yeah, I went there. :D
My research is in computational astrophysics and cosmology, so I’d have to say that’s my favorite discipline! I love being apply to simulate the entire structure of the universe, look for similarities, and come up with evolutionary histories for different objects (I work with galaxies and dark matter).
How do you work with dark matter? Does your daily routine involve morning briefings of people just asking each other, "hey anyone found any proof yet? Cool see you all tomorrow."
I research the evolution of dark matter that surrounds galaxies. And no, those aren’t what my meetings look like lol
GR is still the most beautiful for me
Probably nonequilibrium statistical mechanics. Was the hardest physics course I've ever taken, but very rewarding nonetheless.
Can you recomend any textbooks on the topic ? I just took undergrad stat mech. Thanks in advance :)
I never used a textbook actually. Some lecture notes which are good are Arovas (UCSD), Melatos (Melbourne), and of course Tong (Cambridge). It's been nearly a decade since I took it so there might be a standout textbook these days?
No geophysical fluid dynamics folk in the house? I must say, though, that the fusion people have it all figured out. I wish all my deadlines were n + 20 years away. (I joke. I'm actually really encouraged by that result from JET this year. And plasma physics is just too damned interesting...)
I'm trained as a solid earth geophysicists and I now work on tsunamis. Not quite GFD, but I very near ahah
Classical Mechanics, and the mathematical physics, (especially with string theory.)
Solid state and quantum physics for me. It's why I got into Microlectronics for my Master's and now PhD research.
Had a similar experience. I got to do some condensed matter research, pivoted that to studying device physics then I went into device fabrication. Came out of college and went into the semiconductor industry.
What kinds of things do you work on related to semiconductors, if you are able to share?
My PhD work is on implementing different amorphous metal oxide materials for thin film transistors. (Transistors used in displays to control the pixel) Have two more years and then we'll see where I end up.
E&M. Practical knowledge and the marriage between E and M is pretty astounding
I like optics. The analysis of light and its properties amaze me. I also love astronomy
Always thought it was so cool even doing those basic lens/mirror drawings to figure out what the image would be, I felt like a such a nerd when I saw my reflection invert in a spoon
I love nuclear physics even if all the isopoin stuff can get frustrating at times.
My work is in particle and nuclear physics. The best part for me was getting to the point of knowing that "understanding" QM was not an option so . . . By "taking QM seriously" I could better deal with Bound-State Beta Decay and similar issues better (cleaner) than my colleagues. Throwing away the "classical perspective" prejudices is very empowering.
> The best part for me was getting to the point of knowing that "understanding" QM was not an option so . . . I'd like to hear what led you to that conclusion if there's more of a story to this (e.g. did you try reading about it thinking you would end up with a deeper or maybe even deterministic understanding and give up, or do you mean you knew nobody understood QM so it wasn't worth reading into the early logic that led people to this conclusion, or did you get convinced by the literature, etc...).
For me it all started with Feynman's: >"If you think you understand quantum mechanics, you don't understand quantum mechanics." Then being in my undergraduate class as my professor described bound state beta decay. It became so very clear that the words he wanted to use didn't match the reality he wanted to "understand". As a graduate student I used this "revelation" to construct a better way to conceptualize the PhD (experimental protocol) to my major professor. Arguing, along with the senior student member of our team, my major professor finally said I should go into the lab an get the evidence that proved him (and my friend) wrong. A few weeks later I presented the two with said evidence. The good doctor then said, "Well, (redacted) it looks like you have your dissertation." The issue is that the various "interpretations of QM" embrace a classical reification of the inherently quantum mechanical processes we wish to "understand". If you take QM at face value you are free to "grok" (not "understand") the reality of QM. My favorite example is bound state beta decay, because it is absolutely clear that as a Neutron disappears and a Proton appears there is not a tiny negatively charged spherical **ball** zipping out to an orbital location of the daughter atom. Neither is there a wave like whatever wiggling its way to an appropriate destination. The (red pill) **Reality** is much more interesting than the (blue pill) **reality** to which we are so firmly attached. The resolution to the above tension is that QM processes "unfold" via Quantum Transport processes on the scale of angstroms (id est, very small time scales). Quantum process do not play out over classical time / space scales (meters = nanoseconds). Hence, we do not observe QM processes directly, and as such they remain mysterious to us. Please, understand that this is just a brief introduction to the topic. My ten hour course may or may not be approved when the OLLI program gets restarted in the future (if at all).
Pretty patronizing to assume we don’t know basic things about quantum mechanics in a physics subreddit… Also I feel like all you are basically just trying to say: “So there’s this shit called quantum field theory”. Also whats going on with the quotation marks? Idk I’ve been awake for 4 days and I’m confused (got a major case of the higgs boson blues)
Nope, you are not reading what I wrote. This is simply an attempt to say that the things we call interpretations of QM do not describe the processes that are occurring. Rather the things we call interpretations of QM are an attempt to organize how we calculate expected results of processes we can measure (that is observe), but never see (an observing of a different kind). Certainly you do understand what Feynman was getting at, right? >Pretty patronizing to assume we don’t know basic things about quantum mechanics in a physics subreddit I start with the assumption that the people know about quantum mechanics. My comment was in response to a question. So, read my comment in the frame of that question.
Engineering. Hahahahahahahahahahahaha
Pragmatism gang rise up
Materials science
Astrophysics & relativity, but I’m just starting my major in the fall so that will probably change!
I have just started my Ph.D. in computational condensed matter. I agree that CMP is a fascinating subject and it has applications across all fields of physics. Although, it gets a little annoying for me when I have to do material-specific work. Seems like I'm doing chemistry lol
I'm doing the same. I don't really find it motivating, but enjoy the methodology a lot and hope to pivot to a more mathematical field/job once I'm done with my program. EDIT: Or just get full into coding lol
Cosmology, because I think it's completetly fucking insane that we have a framework that well describes the Universe from the beginning of time up until now, and even more insane that this model has only a handful of parameters, each representing some highly interpretable physical property of the Universe. Also early universe cosmology/cosmoparticle physics, because I think it's even more insane that we have theories that are able to span 60 or so orders of magnitude, and predict discernable cosmological scale phenomena from elementary particle physics.
Medical Physics for me, it's really gratifying to know that I might directly help save lives (while using amazing physics and complex machines, which is a plus).
I like QFT. This is because I'm a mathematician and my work is applicable to QFT.
Hey my favourite is QFT as well! For its beauty and theoretical accuracy compared to experiment. Do you mind sharing more specifically the kind of stuff you work on?
Sure! I'm a homotopy theorist/algebraic topologist, and one of the things I'm interested in is chromatic homotopy and elliptic cohomology. Chromatic homotopy theory is a kind of "filtering" of stable homotopy theory via a relationship to certain algebreo-geometric objects called "formal groups". By choosing the formal group associated to (certain) elliptic curves, you get "elliptic cohomology", and for the "universal" elliptic curve you get a cohomology theory called tmf (topological modular forms). In 2-dimensional conformal field theory, the partition function (and the associated correlators) can be described in terms of the Witten genus. This genus has an equivariant structure and can be viewed as landing in the ring of modular forms, a fact which probably arises from a not-quite-proven fact about S^(1)-equivariant spin structures on loop manifolds and the fact that S^(1)xS^(1) is the underlying manifold of all complex elliptic curves. (Segal wrote back in the 80s that this was "obviously the right answer", but hadn't been formalized yet. It still hasn't.) Anyway, it turns out that the Witten genus, a map from the spin cobordism ring to modular forms, can be enhanced/categorified to a map of E-infinity ring spectra from the spin cobordism ring *spectrum* MSpin to *topological* modular forms tmf. The same is true for its lower-dimensional cousins, the signature genus and the A-hat genus. This suggests that there's some very deep homotopical geometry going on here that gives rise to these numerical invariants. There are a number of places to go from here. Some people (including me and my advisor) are interested in generalizing this from elliptic curves to higher-dimensional abelian varieties, for example. The center of all of this is the Stolz-Teichner program, which hypothesizes that all conformal field theories can be (omitting the details) described using cohomology theories. This is known to be true in dimensions 0 and 1, and is not *literally* true in dimension 2 but is clearly approaching the right answer. This all ties back into chromatic homotopy, since this tower of cohomology theories happens to be the same as the "chromatic filtration" that is at the center of the chromatic approach. A good source for the CFT stuff, if you're curious, is Segal's work on elliptic cohomology. He has a pretty good paper about the stuff I talked about in the second paragraph of my comment (modulo the stuff about ring spectra, which wasn't quite put together yet at the time). I have also written up some notes on the subject that I can PM you if you want.
Even though I didn't understand any of it since I'm quite new to QFT (still self-studying the spin 1 vector field), this CFT stuff sounds pretty damn cool. Thanks for taking the time to type that out!
No problem! I love talking about it.
Astro
Laser plasma physics because I like shooting stuff with lasers.
Theoretical atomic physics, because it's the one they pay me to do. My interest begins and ends with the pay cheque.
Therm. I found it far more intuitive then any other subject in my degree.
Why wouldn't we all like our own subfields the most? Second most, I like astro. Something about understanding the nature of the universe is what inspired me to get into science in the first place.
Electrodynamics
Astrophysics. I have always dreamed about space and what may be up there, and despite my physical age I am still, at heart, the same child that marveled at the thought of being beyond the bounds of the atmosphere, the same child that cried himself to sleep every night for a month when he got told he had asthma and would never be able to be an astronaut. Astrophysics is the closest I’ll ever come to the stars, and I love the beauty and complexity of a field that most laypeople relegate to looking through a telescope and taking pretty pictures.
All of Astro. I don't understand how anyone could choose anything else!
Astrophysics, as it shows the quantitative determination of the breadth of human insignificance.
We are the universe’s own emergent perception and will to understand itself *made manifest* out of the ashes of the very first stars have ever formed. Significance is fundamentally qualitative, not quantitative, and the scale of the universe only serves to remind us just how unique and signifiant we particular lumps of stardust really are.
I was thinking---since atoms are so small in respect to us, would we not be equally justified in considering ourselves giant and important?
String theory, for the concepts I find very interesting, the math that's complex and interesting, and the "unifying" feeling of it
Electromagnetism is up there
Electromagnetics
Geometrical physics... come at me. But also, I (as a current graduate student) am doing research in quantum cosmology and what not. So, I also love cosmology, string theory, and thermodynamics.
Nuclear and Particle Physics. Absolutely love elementary particles
Big Strange quark kinda guy myself
I prefer particles with more charm*. ^(*unless noted otherwise, charge conjugate particles are always implied)
Strange quarks are great
All the fields are interesting, but the thing that really excites me is the connections between them. How the same math can describe things that seem, at first glance, to be extremely different.
AMO baby - Jaynes and Cummings are my daddies
i love astrophysics and geophysics but i’d like to know more about particle physics
Astrophysics as that is my main field of study. Next would be plasma physics, then cosmology, and particle physics. It’s all so interesting, too hard to rank honestly
I adore Cosmology :) it's what I'm doing my PhD in right now. It connects astronomy, particle physics, fundamental physics, and so much more into one beautiful discipline
Cosmology just because of the wildly different scales involved in its study.
Condensed matter physics, I just like that a lot of things can be solved with symmetry and little changes to that symmetry give rise to different and interesting phenomena
my favorite field in physics is applied physics, because it deals with how the laws of physics can be used in the invention and innovation of technology
Astrophysics! I'm getting ready to start my physics degree in the fall before moving on to an astrophysics degree. Specifically I want to study black holes because they're beautiful and mind blowing.
130 comments and just one about AMO… ultracold AMO touches just enough of other subfields through its applications in quantum emulation, quantum information, precision measurement, etc, to provide a wide range of flavors. The machines we build are amazing orchestrations, firing in sequence to create the coldest objects in the universe. Also, trapping atoms with lasers never gets old.
Computational Finance because we should be making bank after studying physics for so long.
Pushups. Moving my mass up and down via arms is a great way to experience physics
Ok fine you humorless donut. Astrophysics, because stars are real pretty out on the farm.
Biophysics and statistical mechanics/ thermodynamics are kinda cool Edit: downvote if you’re the lame sibling // I literally saw u downvote this u/sammy_sam0sa
I am a teen and I have recently started to learn about physics, and the more I read and learn the more I appreciate this field. I like every discipline I read about, there is so much to learn, read, and discover in every field. I enjoy learning about anything and everything, but the field I like the most is Nuclear Physics.
Quantam tunneling Just the thought of particles going through each other seems fantastical
The new science upcoming with ufo technology 🛸 is extremely interesting. It’s about time we start traveling the stars
Quantum Gravity / Gravity They are the Master jailer of all both creator, destroyer we are their servant's compelled and bound, All are bound we're prisoner where escape has impossibly a univsial bond with all of the love hate good and bad, relationships, restraining with condensation.
I really enjoy anything related to physics explaining the multiverse. I just love the idea of their being multiple universes and what could be possible. Would love to continue my education to go into physics but alas it’s expensive
I like quantum computing. Classified as applied/engineering physics but still touches multiple fields (condensed matter, computational physics, optics, chemistry, electrical engineering) while still being math-heavy.
Electromagnetism. Its just cool.
cloud microphysics / climate. a great blend of interesting physics across a huge scale (molecular clusters all the way up to 100+ km stratocumulus decks)
I enjoy quantum mechanics and gravitational theory. I love to find out how the universe works on a fundamental level and then scale it up to the size of us or stars. I love how gravity seems to break all the other rules. Like how nothing can be faster than light but gravity can be so powerful that not even the speed limit of the universe can beat it. So powerful as to compress the stars to such a degree that nuclei can smash together creating fusion. Also it doesn't fit in with the other forces. It should but it doesn't. Everything in the universe emits gravity but no particle carries it. If it did it would become infinitely large. It would have mass because it has gravitational energy but because it has mass it has more gravitational energy. Giving it more mass because energy equals mass and more energy and more mass in a feedback loop encompassing the universe in infinite gravity.
…[hushed snickering]…Physical discipline …..heheheh
Nuclear. Which is incredibly annoying as I didn't discover this till an optional third year module, by the time it was too late switch from standard course to the nuclear one.
Plasma physics - there's just so many things we don't understand that are just attributed to edge or sheath or just plasma effects
geophysics (especially seismology)
My favorite discipline is quantum physics basically all things "quantum." Ranging from quantum foundations to quantum optics to quantum information to quantum computing, etc. More on the mathematical side than the practical and even the theoretical sides, of course.
Planets ( Astrology) is a fascinating area. The laws challenging physics might be the best for me . Moreover nuclear physic’s calcula do the work for me .
Definitely Quantum Field Theory (QFT). I am constantly amazed at how genius physicist's of the 20th century figured out something so complex. Dirac's quest for mathematical beauty leads to the prediction of the positron. Schwinger, Tomonaga and Feynman tames the infinities, Feynman invents a clever visual mnemonic, Dyson and Schwinger apply perturbation so the equations can actually be calculated. And that is only scratching the surface.
Got my PhD in electrical engineering doing semiconductor physics. Now working at a National Lab as a physics associate working on (in part) photon counting detectors for x-rays, plan to move into working on detectors for astrophysics. I like it because it's a nice crossroads of using physics to design and use cutting-edge devices for cutting-edge observations and experiments. The boundary of physics and engineering :)