What does a theoretical physicist do?

In this video I answer a question that I get a lot: "What does a theoretical physicist do?" How does it work? Do we sit around all day and dream up new particles?
Theoretical physics is a job very similar to any other. You get an education and then you put your knowledge to work. In physics as in all disciplines in science, most of the research is understanding what other people have done. But physicists do many other things besides their research: They teach, mentor, organize conferences, sit in committees, do public outreach (!), or perform administrational functions.
Where physics is special is in the amount of mathematics that we use in our work.
Support me on Patreon: / sabine

[@aplacefaraway]

"What does a theoretical physicist do?" This is one of the many unsolved problems in physics.

[@babyrazor6887]

Nice one! x 100

[@user-hr8pz6lh5w]

they teach Thermonuclear hydrodynamics.

[@rickh3714]

CERN has just announced that it's laboratories will close down as of tomorrow . "All knowledge of the physical Universe has been achieved and no scientific work beyond general Earth-keeping need be done" said the Head of CERN in a teary speech delivered to the U.N yesterday. Predictions for the year this will happen? The LHC will be converted into a luge run for the * * * * * Winter Olympics she also stated.

[@Joeyd1184]

work at black mesa? idk

[@nickmerix2900]

They screw up real physics

[@bobtimster62]

Einstein was once asked by someone, who apparently did not know what theoretical physics was, where his laboratory was. He proudly held up his pencil. Another time he was asked what his most useful tool was. His response was that it was his wastebasket.

[@einsteindrieu]

Like that !

[@arpanroy213]

Ki

[@psibarpsi]

Where did you get that info?

[@bobtimster62]

@@psibarpsi I read it in several places. Unfortunately, I can't remember where. You might find it in some biographies of Einstein. I'm not sure.

[@BruceWayne-us3kw]

I’m kinda skeptical that Einstein ever said that. There are lots of things people claimed that he said but many of them are false.

[@MICHAELYEPES]

"Physics is the only thing you can really understand; it's the rest of the world that doesn't make sense."

[@NicleT]

MICHAEL YEPES one of the most important quote from this video! It reminds me that even if I have glasses to see the world, it is fundamentally out of focus.

[@jpp9876]

That's because the laws of physics are very dependable. But also very unforgiving.

[@darxray]

It’s so weird that some scientists are constantly trying to devalue the experience of other people

[@DangDatsCrazy]

​​@@darxrayThe point is based on the notion that everything else does ultimately depend on physics. So to understand anything truly and fully, you will have to understand the physics behind it. No devaluation, no selfishness, just a thought provoking idea.

[@Thulesmann]

Physicists and Mathematicians have my highest respect. They are at the cognitive upper limit of human intelligence at this point in our evolution. I have a sense of awe when I contemplate their high intellects and their self-discipline, work ethic and ability to focus, and their idealistic hunger for the knowledge that can create a better world for all of us.

[@sneakylemon8513]

I dunno dude. I'm busy with my BSc in maths and physics. People still call me stupid all the time 😂 maybe one day when I have a phd they'll stop. I remember once when I was at school my science teacher called me an airhead, to which I pointed out that I get the best marks in his class. He just laughed and said I must have cheated. I know he was kidding but it kinda stung.

[@Thulesmann]

@@sneakylemon8513 Your science teacher was a jerk to belittle you like that. Go for the PhD. if that is your goal and don't let such negative people stop you.

[@Pclub4ever]

@@sneakylemon8513 Don't let other people dictate what you think about yourself. Get your education and focus on yourself. You'll have the last laugh. You got this.

[@carti8778]

@@sneakylemon8513 people won’t care much even if u have a phd. I will defend my phd (theoretical physics)in sept this year and life is still the same. Also , i don’t wanna continue in academia bcz there are very less permanent positions and the pay in postdocs is ridiculously low. I am planning to switch to data science/machine learning so i prepare for it alongside my phd. I know u are excited now ( i was too during bachelors) but this enthusiasm won’t be the same in grad school. Currently, U need a minimum of 2-3 postdocs (6 years) after a phd to apply for a good permanent position

[@sneakylemon8513]

@@carti8778 that's pretty sad. Yeah, my plan is actually just to finish my BSc and then do an HDE and become a highschool maths teacher. Then go overseas a bit to make some real money and then settle back in my home town and just do what I love. I've been a tutor for like 10 years and a substitute teacher for 2 years and I just love working with the kids. They're such fascinating beings 😂

[@bhangrafan4480]

Years ago I worked in Universities doing molecular biology research, but there were physics and maths departments in these places, and I always loved these subjects. What I saw of the physicists (theoretical ones) was each was locked in a little tiny office with a desk and a computer, and spent all day on the computer running simulations and doing calculations. It seemed a very isolated life compared to experimental work in a large open plan laboratory complex.

[@justaracoonchillinginatoilet69]

yoo ive seen you on the hippiearab podcast channel before. guess we have similar interests. damn the internet is a small place

[@itslogical3884]

Why were they locked in the office? So they can focus better, or to prevent them from escaping to the biology dept.

[@dominiksrokowski8913]

Merry Christmas! and well deserved holiday! Please bring us more of you next year!

[@petarcuric5003]

Thank you for the video❤️!!! I was wondering that question in the past few weeks!

[@angelgavieiro]

I loved the final statement... that must be the reason why I watch physics youtubes, they make sense in comparison to the rest of my day... even when I am not fully (or even partly sometimes) understanding them!

[@ngdnhtien]

I can't thank you enough for making this video, Dr Hossenfelder. It helped, a lot!

[@musicalBurr]

Nice work Sabine! Save the best comment for last! (Eminently quotable) You are a great performer and know how to put on a good show, setting aside your math and physics prowess. I get so excited when I see there's a new video from you - never disappoints! Thanks again. James.

[@olivierjung913]

Frohe Weihnachten und rutsch gut ins Neue Jahr mit deinen Lieben ; )

[@cymoonrbacpro9426]

I Love your work and honestly! Thank you

[@donald-parker]

From the great philosopher YB: "In theory, there is no difference between theory and practice - In practice, there is."

[@youmaycallmeken]

He (also) said "I never said half the things I said." Quote Investigator: There is no substantive reason to credit Berra, Einstein, or Feynman. The expression was coined before Einstein had reached his third birthday and before the other two were born. quoteinvestigator.com/2018/04/14/theory/

[@ErvinKrauss]

Hello Dr. Hossenfelder - thank you for these great videos. Your explanations are clear and succinct. I'm able to follow ideas that would otherwise escape me. Tschüss. -Ervin

[@europaeuropa3673]

I like your videos because your voice is clear and very easy to hear with the background noises usually present where I live. However, not all of your subject matter is easy to understand...........sometimes I have to make an effort to think about it.

[@gsalien2292]

Hope your Holiday is perfect! Thank you for the video!

[@jaykay2218]

GS Alien damn it you genius

[@DIGtotheIT]

Great video, as per usual 🙂

[@mahaabdelmoneim7635]

May you enjoy your vacation. Thanks for your video :)

[@user-ox5nw7gn6d]

Thank you for this video Dr. Sabine Hossenfelder.

[@hankseda]

Happy Holidays! Hope you enjoy a big rise in your potential energy.

[@derdagian1]

Right, through out, word by word, succinctly, and concise! Thank You Or, detect gold in Alaska

[@captainoates7236]

Sabine is the best at the public outreach part. My presence here is living proof.

[@skydebnath2593]

The last line made my day... It gave me a confirmation that I am on the right track.... Thank you very much

[@willemvandebeek]

Merry Christmas, Sabine! :)

[@mrtubeyou77]

Thanks! Very interesting and useful!

[@sergeyyatskevitch3617]

Great insight, especially about the importance of being good at Math (diff equations, group theory, stochastic systems, etc.). This is why you can meet theor physicists anywhere from the Perimeter Institute to the high-frequency trading shops. To rephrase, learning math is more interesting than learning how to code. Although the latter is needed as well. Cheers!

[@nrv8013]

I do really love this channel! How honest Dr Sabine is absolutely refreshing and new in the actual context of science communication! But I would like to ask a question, that is why the new fashion in theoretical physics is to talk about many universes and the anthropic principal to our universe; the 5 or 6 hypothesis for many worlds interpretation....black holes that may create new universes... Is that physics or philosophy? Shouldn't physics by about the fundamental questions that have not been answered yet? Or are those questions to difficult to the current means / money in disposal to science?

[@hen2005]

Excellent video. Thank you.

[@ibji]

Congrats on reaching 50k subs.

[@dancasey9660]

Trying to build on or improve what was discovered by previous generations. Sounds about right!

[@alexanderjohnson2309]

This was great... thank you!

[@isabelab6851]

I enjoyed this video...I knew some physics students in college (I have a math major) but went to the dark side of business...but it is interesting to hear where it is today. I am reading your book and I hope that science reaches back to the scientific process. Otherwise I think that they risk losing credibility in the eyes of lay people that think that it is mumbojumbo, crazy talk🤣🤣😂😂 😎

[@upasanapanigrahi4796]

Thank you for showing direction.

[@richardduke9788]

Sounds easy ! Read books , go to meetings, talk to people - but you have to be able to connect the dots between all of that information .

[@PauloRenatoRodriguesprr]

Merry Xmas and Happy New Year!!!

[@stueyapstuey4235]

0:57 'depends strongly on the field' and (ahem) the funding...

[@assiavladimirovna8905]

I read this comment exactly at the time she said that I was like wow lol

[@jaykay2218]

You don’t really need much funding for theoretical physics

[@Brassard1985]

Yep

[@davew4998]

@@jaykay2218 If you want to eat you do.

[@ameerkherbawi8466]

@@assiavladimirovna8905 lmao me too

[@semmering1]

Dear Sabine, physics is the only thing that can be understood, it´s the rest of the world which is often not logic and understandable. That is the best statement I ever heard so far from you. You speak straight out of my heart...

[@c4t4r4c]

it's the rest of the world that doesn't make sense :D :D :D on point!

[@TheSimonScowl]

@Hell Fridge: " At least there's a tiny chance for the textbook :D" Not if it lives in Texas!

[@thePronto]

And seems to make less sense every day...

[@TheSimonScowl]

@Hell Fridge I suppose there COULD be states as backwards as Texas in other continents. I'm not putting money on it though.

[@TheSimonScowl]

Alabama, Oklahoma, Mississippi, Ohio, North Carolina, South Carolina, Florida, Georgia... are not far behind (#5 is my home state).

[@massecl]

It doesn't make sense for her because she doesn't understand it, and she dismiss any people who is able to understand it. It's a very egocentric stance, one of the most annoying trait of today's scientists.

[@jefitnick2237]

Thank you very much for your video

[@cmilkau]

That sounds like an amazing occupation, all of it.

[@kenmcnearny2727]

The concepts of physics seem intuitively easy to understand oddly though I find the mathematics impenetrable. Oppositional movements of discrete bodies evolving into vectors of motion as they effect one another are easy and pleasant to visualize mentally but the math goes down like a sandpaper sandwich. Funny how people are different like that. And thank you for evoking a pleasant memory of a co-worker and doctoral candidate explaining that writing a doctoral thesis is as simple as taking a body of knowledge and rearranging it in a unique way. Anyone can do it really (not their first day of course) she said with a smile.

[@einsteindrieu]

Me as a Scientist worked on trying to figure out Einstein's Time slowing down as you speed up.Now that teaches me something that is a conversion of energies.There's a give and take working on this mass.This is where the start is to figure out what time is.

[@scudder991]

Sabine, i love your explanations and deeply respect your knowledge of theoretical physics. Is there a hypothesis that explains why the smallest magnitude charge for leptons is 3 times the smallest magnitude charge for quarks? If that was not true, then most elements could never be charge-neutral, and chemistry would be radically different (or impossible).

[@MichaelZeng-hn5my]

Sabine Hossenfelder explaination on theoretical physicists do is clear n amazing. She is one of the finest best teacher lecturer in the sciencetific areas. She should appeared more on the internets channels will assist young sciencetists to think widely on physics. I always watch her programmes with alots of intesrests in physics.

[@run1492]

Great video Sabine, that was awesome ! Imagine for a moment that someone (a friend of mine, we usually say) dreams about making a little progress in some OPEN problem in theoretical physics or biology ... She/He has basic university knowledge in math and physics, and by discovering such a problem, she/he will be able to learn, dream, having a good time, and grow in self-confidence... What would be the concrete path / websites / books / "existing open problems web-based index (just joking)" to start ? Could you be a little bit specific, please ? BIG THANKS !

[@carpo719]

So, not much? :) Thanks Sabine, appreciate your concise videos

[@johnnyb8629]

I totally agree with your final statement, religion, human behavior, the human brain, all are things that seem like we will never understand really. physics, absolutely, and will lead us to achieve the highest levels of technology eventually. personally, I have difficulty with calculation, i can do it when it's applied to something i can see but learning it in abstract was always really hard for me and therefore i could never justify the time and effort to go very far with it. I live very close to Fermilab and I grew up in and around the lab complex and so I grew up following the achievements in particle physics my whole life. When i hear people tell me that they do nothing there that applies to everyday life , i like to point out that the people who work their , work with the most power life altering technology ever in human history. It's those people who brought us the nuclear age, the nuclear bomb, electronics, nuclear medicine, nuclear imaging, etc etc... people are ignorant. This is why public engagement from the physics community is of the utmost importance and I would propose the lack of this is why the high energy physics program in the US has been cut so much in the last few decades and we are no longer in the head of the field and why the SSC was scraped and the LHC is the world leader in high energy physics.

[@BillyLapTop]

Wonderful amount of information and inference revealed between the lines. Good explanation.

[@bestowicprimer8835]

You mean the point of administration emphasized, not normal "programing" what kinda shit is going on here and observations are not matching the math in cosmology !! It's the universe is wrong not the math. Dark matter is real the math says so!!! Geeze ok look here I saw the upset scientists when the blackhole reveal I heard them use undertones and push secret only great minds would hear literally reading between the line mentioning hawking again and again. Is the world just not ready for the neo world? I'm sorry they got to u.

[@BillyLapTop]

I found between the lines, currents of liberation from established dogma.

[@bestowicprimer8835]

@@BillyLapTop maybe perhaps it's to intentional develop unrest and talk about these topics but being a hidden evil to a brink

[@bestowicprimer8835]

Or her job made her do it... hell PBS even started declaring their opinions as such when making a video instead of calling more observed but less mathematical theory as complete bolagne... anton is on board it seems with supporting tree and not touching "climate change" just like the states controlling the spread of information dividing the masses with fear shame and sex.

[@ravichanana3148]

Apart from picking an existing problem, one can discover new science also while exploring science and technology.

[@manoo422]

The problem is that almost no one (outside of the field of science) understands what a 'theory' means. Almost everyone (i.e the public) think its just an 'idea' you came up with that day!

[@WestOfEarth]

Or they think 'theory' is synonymous with 'guess'. How many times do you hear someone say 'It's just a theory'?

[@massecl]

@@WestOfEarth A theory is based on a set of premises, or axioms. They are guesses, and can never be totally verified. The theories are periodically replaced by better theories, that may or may not contain the previous one as a limiting case, they are not persistent. You have been indoctrinated in thinking that theories are truth because there is some vested interest behind, but science is mainly doubt and humility.

[@massecl]

@@WestOfEarth Who are you?

[@pronounjow]

"BUT THAT'S JUST A THEORY... A GAME THEORY!" Sorry, I'm referencing another KZbin channel's closing line as a meme.

[@GrouchierThanThou]

@@massecl Nope. Theories are not guesses. From Wikipedia: "Scientific theories are the most reliable, rigorous, and comprehensive form of scientific knowledge." Knowledge and truth are not entirely synonymous, obviously, but they are certainly terms that are closely related to each other. Knowledge and guess on the other hand, are almost diametrically opposed to each other in meaning.

[@stevewilson8267]

I very much appreciate your understanding (& music too) possibly comment on Salvatore Pais and his patents and later possibly Kenneth Shoulder’s Electrum Validum. To me this EV seems an answer to things. Do you lecture in USA?

[@discogodfather22]

Hey Sabine, could you do a video on the recent news about Axions and the lithium decay research going on? A new Boson? A fifth force?

[@ivanfromunion3513]

Me: "You have me! I AM GOING TO BECOME A THEORETICAL PHYSICIST!" Sabine: "You get an education" and "You have to understand the mathematics"... Me: "AS SOON AS I FEED THE CAT."

[@BenReillySpydr1962]

You could just put it in a box and move on

[@mihirmyatra1302]

@@BenReillySpydr1962 it won't die until you see it. Don't see it forever ;)

[@TheRealBoeJiden]

Mihir Myatra Schrodinger called he wants his experiment back 😅

[@TheLJShow-ys8wr]

@@mihirmyatra1302 Box gotta block the smell.

[@davew4998]

@@mihirmyatra1302 Maybe.

[@mydumbass5133]

Thank you I needed to know cause of school

[@thePronto]

So being a theoretical physicist is very similar to running a business. You have to understand what has already been done, separate out what hasn't been done and figure out what you can get done with your limited resources. The two things I think you left out, in both domains :-) are: figure out what you can get funding for, and figure out if anyone is going to be interested. They might be the same thing, but not always.

[@jessedaas6365]

Well said.

[@Higgsinophysics]

Perfectly explained

[@Kiky_MedPhysicist]

thank you very much maam

[@touhoulinuxfan8399]

“What does a theoretical physicist do?” *Sometimes* they fly around with tau cannons and HEV suits

[@cdl0]

Nice explanation, except the only point I would disagree with is on condensed matter, where you will find significant separation between people who do experiments and those who do theory, where the latter are much fewer than the former. There are a few individuals who do both, but they are quite rare. You can also draw some distinctions between those whose main job is developing new theory, or making improvements to existing theory, which is mainly mathematical work; those who build complex software packages to implement the theory as some kind of numerical approximation, which is part mathematics and part computer science, and the individuals who mainly dedicate their time to doing the calculations using these packages, and interpreting the results. Almost invariably, everything is a joint effort among all the participants, who, hopefully, all know what they should be doing. :-)

[@zoebettina]

Somehow that was the best explanation of theoretical physics I've ever heard

[@machinelearning171]

What a nice description of theoretical physicist’s working philosophy, well, I think that applies to all fields except politics, thanks

[@yogeshmalviya306]

Last line was epic ☺️

[@talldarkhansome1]

I love the accent. Love the common sense. Love the intellectualism.

[@MrSiah007]

My fascination with this and my lack of ability to comprehend this level of mathematics is such punishment to me lol it’s like growing up loving music but it being able to write or play it.

[@Paul__3mwn]

Refund specifics and anticipated actions: let's get into the nitty-gritty

[@derwissenskiosk8041]

The last sentence: Oh thats what I thought in school about Langurage and Politics compared to Ph Ch ans Math...

[@sensorpixel]

Watching this while doing theoretical physics. This is self-referential and I should focus. Anyways. Merry Christmas! :)

[@12jbiswajit]

Thank you very much Ma'm. Liked your inspiring words for reserach in theoretical Physics. Ma'm can you guide me for doing research in Physics. How to put the first step. I had completed MSc in Physics. Now I am a teacher in Physics for 14 years. Late to start research.

[@vitor4944]

they run around with a crowbar smashing aliens heads

[@paulfrancis8836]

A good physicist only talks to someone long enough to tell them they are wrong.

[@Forever._.curious..]

"Physics is only thing we can understand and rest of the world doesn't make sense" , well said

[@davidschneide5422]

I like that Sabine spends some time teaching during pauses from fantasizing about new particles.

[@jwb52z9]

The people who tell you they don't understand Physics are also probably people who don't understand math very well either. I'm one of them. Academic related information just doesn't typically stay in my memory for long enough for it to do me any good. I seem to have a memory with no rhyme or reason for what stays and what doesn't. The only thing I have noticed over my lifetime is that the more I actively try to remember something, the worse I am at doing so.

[@RonLWilson]

Having come from an engineering rather than a physics background I can see a number of similarities between theoretical physics and engineering R&D. For example both rely heavily on math, though perhaps somewhat different branches of math. Both rely on modeling. Both deal with ever complex problems (e.g. for engineering, self driving cars). So while math makes a great foundation it seems to also be in some ways a limiting factor in that it is so hard to learn the math and once one has learned it hard to follow complex calculations. I keep thinking there must be a better way one that builds upon that math but adds to it as well. Math is sort of like DOS. What would be cool if one could come up with something more graphica that preserves the underlying math but provides a more graphic and less symbolic depiction of the thing it is modeling. Graphs/plots plots are a strat in that direction but it seems that there could be more. For without that we might reach a limit where even the smartest people can't advance in that the complexity in doing so is simply so overwhelming for even the best and brightest to master, not to mention lessor mortals.

[@metakatana]

The problem is the loss of precision in graphical descriptions. Drawing is just an approximation or a sketch of whatever you're describing. While with symbolic descriptions, we can accurately and precisely describe things that are impossible to draw. For example, how exactly can you draw a 10-dimensional vector space? With symbols, we are able to perfectly describe it without loss of precision. But depicting it graphically is useless for us, we cannot visualize 10 dimensions. We cannot accurately draw y=x^2 on a sheet of paper. But with symbols, we can describe every single (x,y) perfectly. I think graphical depictions help a lot with developing intuition for abstract concepts and I agree that they should be used more. However, for the reasons stated above, they cannot replace symbolic representations. Some people also find symbolic descriptions easier to work with than graphical descriptions. As for calculations and computations, I believe that the computer is currently our best tool.

[@RonLWilson]

@@metakatana What you are saying is typically true but not necessarily true. I am thinking that one can develop methods (perhaps yet to be invented) that employ graphics that do not lose any precision from the symbolic representation and in fact in one sense is more precise in that it more precisely connects wit the thing being modeled. For just what did X stand for anyway in that equation. The graphical solution could show just what that x is referring. Also just what assumption went into that equation? You have to read the accompanying text to find out those things so mathematics alone does not tell the whole story, it just shows the mappings between variables. A paper with just equation would typically be pretty useless and would ebeds words as well, so any mathematical formulation in one sense is incomplete, even if precise.

[@metakatana]

@@RonLWilson Also, no one claimed that mathematics is complete. In fact, with Kurt Gödel's Incompleteness theorems there shall always be a bigger picture in the game of mathematics.

[@rclrd1]

@@metakatana Visual imagination is an important component in the thinking of many mathematicians and theoretical physicists. This often takes the form of rough sketches (not accurate diagrams...) that help them to grasp the meaning of the symbols and equations. Mathematics is more than juggling with abstract symbols. Examples are Faraday’s ‘lines of force’, Feyman diagrams, Penrose diagrams, etc. Of course, in higher dimensions it gets problematic but intuitions drawn from the three-dimensions we are familiar with still help.

[@RonLWilson]

@@rclrd1 I think perhaps the issue here may be a bit in the semantics of what is a graphical solution. That might mean a plot but I am using the term more abstractly. For example consider a circuit diagram. One can from such a diagram write equations for currents and voltages but without the circuit diagram one would be pretty hard pressed in understanding those equations other than for a very simple circuits. Also consider Feynman diagrams. Or one could even consider the game of chess. One could play that using symbols, King's Knight to Queen's Bishop 4, but a chess board and pieces really help, even if playing N Dimensional chess. So by a graphical solution I am not just meaning a graph as in a data plot but graphical like circuit or feynman diagrams form which one can write equations but also conveys what those equations represent.

[@EngGear]

I didn't forget to subscribe.

[@faraany3k]

So just chill mostly.

[@soldtobediers]

Sabine 3:16 to 4:30 Just as echoes of past math teachers notes had demanded... ''Show all you're work'' 4:30 ''Theoretical Questions Are mankind's constant pioneering vacuums Which are found creeping into All of Creation's empty spaces.'' -122019

[@MrClaudiograssi]

Generally the thing a theoretical physicist is best at is causing the Pauli effect :-)

[@SabineHossenfelder]

Ha!

[@extradimension7356]

You just have to send said sensitive equipment "Good vibes" (not too many sideways judgmental looks in its general direction) ... Ever noticed that computers fain failure when one is the most stressed out or a ridiculous deadline is looming. Perhaps theoretical physicists are a stressful presence in a hands on laboratory ;-).

[@Finnec123]

And most of us have no clue what that is.... 😒

[@sergeyyatskevitch3617]

This is what maintains a healthy balance between the number of theoretical physicists and the number of experimental physicists. Another application of the Lotka-Volterra model :)

[@nfazal4065]

Hoodbhoy is considered one the 100 most influential people in the world like Lisa Randall. Hope to see your name in that list soon(if you keep it up-that is an incentive for you. Prof.Dr.Fazal

[@onethreefiveeye]

Happy vacation to you... und überhaupt. 🍀

[@SabineHossenfelder]

Thank you :)

[@WestOfEarth]

Now I understand where my deadpan, understated sense of humor comes from. It's cultural. But regarding theoretical physicists, do you spend time just sitting or walking in contemplation?

[@floatthecreek]

This theoretical physicst, Sabine Hossenfelder, makes my heart skip a beat because she is not only brilliant, but is equally beautiful. Love you channel Doctor!

[@JohnVKaravitis]

Your "love" is unrequited. Deal with it, son.

[@toddq6443]

I admire her mind so much that she could look like Joseph Carey Merrick and I would still find her beautiful. TNQ

[@barryhornby3303]

Speaking of being on vacation and theoretical physics, perhaps one of these physicists could take up the phenomena of time compression while on vacation!

[@oliverkrenek3216]

The joke at the end killed me.😝😝

[@zetadroid]

I approve the choice of the seeley-dewitt expansion of the heat kernel

[@extradimension7356]

As to 4:20 That's why publicly funded research is so important as it can be put into the public domain... I wonder what the ratio of research (commercial/ private and governmental) is under "Lock-and-key" vs. "Public domain" is ? Big science perhaps being slightly better at sharing ?

[@ceeaki22ndcentury]

Everything humanity discovers about space is weaponized and used for control. Until we have the information we're just dogs chasing our tails.

[@I_hunt_lolis]

What does a theoretical physicist do? Clearly pushing carts and buttons all while running around in a secret underground research facility whacking interdimentional aliens with a crowbar...

[@iruleandyoudont9]

Sabine, can you tell me what would happen if we had a set of concentric charged spherical plates, like nesting dolls, and analyzed the Casimir effect? would it amplify the force to pull apart, say, an atom or a cluster of atoms in the center? could that central atom then undergo stimulated emission to release photons? would the electrons then jump back up an orbital since the Casimir effect has not diminished as a result? the surface area of the outer shells would be greater than the inner shells which is the basis for why I think the forces would be amplified to pull the center outward in every direction. I don't know how many layers you would need.

[@bernhardschmalhofer855]

The Casimir effect is pretty small. So if the plates are charged the electrostatic forces would overwhelm the force from the Casimir effect.

[@iruleandyoudont9]

@@bernhardschmalhofer855 uncharged then. I thought they were typically charged for some reason my mistake.

[@bernhardschmalhofer855]

@@iruleandyoudont9 In the uncharged case I would assume that nothing special would happen. That's because the range of van-der-Waals-forces is pretty small. The situation might be more interesting when you substitute the concentric spherical plates with layers of graphene. If you want to pull apart atoms, then I have an alternative suggestion. Light a candle. The flame is a plasma and can be influenced by electric and magnetic fields.

[@iruleandyoudont9]

@@bernhardschmalhofer855 well the idea is to pull apart the atoms using the vacuum forces from the Casimir effect since they shouldn't diminish when we stimulate emission. the idea is more to use the central atoms like springs, we're stretching them to add potential to force the electrons up an orbital, then stimulate emission so they drop down an orbital releasing a photon, and then they go back up because the Casimir effect vacuum forces are still pulling just as hard

[@bernhardschmalhofer855]

@@iruleandyoudont9 Yes, that sounds like solid state physics. You can look up photon phonon interactions.

[@zacheryp813]

Is it possible to test theoretical physics theories? (Im really dumb)

[@Philiptanzer]

I wonder if I may ask a question about Quantum vs Newton/Einstein, why do so many physicists favour Quantum? I know very little about the physics, but I know a little about the maths. From what I know (which is admittedly little) our equations for big things are consistent with continuitity and convergence (they *need* these mathematical theories) but the very little I know about Quantum involves ignoring convergence (I've seen them discard non-convergent infinite series in the equations, and I've heard the phrase "don't think about just calculate" was used popularly). So my question is why do physicists seem to want to go with the Quantum side (looking to expand it to gravity for example) when it ignores a pretty fundamental theorem? Just when I see someone replace an infinite non-convergent series with a number I get a scream of *"WHAT HERESY IS THIS??!!"* in my brain, has this been solved?

[@filename1674]

Because they believe that quantum physics works differently. They tend to observe about small things and ignore the bigger things which the big thins is the product of small things.

[@Philiptanzer]

@@filename1674 Big things from smaller things I accept, but why does ignoring convergence get a free pass? It is a fundamental theorem and I just want to understand if this issue has been solved or at least why it is something that they are happy to live with.

[@cmilkau]

What do you mean by "favour"? Both are fully accepted and well-tested theories. They are not really contradicting each other. It's more like, their limits don't overlap. As you said, one works for big (gravity dominated) structures and the other for small (and also high energies, it does include special relativity). For gravity interacting with quantum effects (like black hole horizons should have), we have no theory. We can take the equations of the theories we do have and apply them outside their tested domain, which is called extrapolation. In this case, that extrapolation produces nonsense. So we need a new theory. We could make a third one, maybe we should, but most physicists prefer a single theory. That single theory would then have to match what we already know, so it has to be BOTH quantum and fully relativistic.

[@Philiptanzer]

@@cmilkau But there is a contradiction, either convergence is a fundamental theorem or it can be put aside when it is inconvenient. This willingness to put aside convergence is what I mean by favouring.

[@marcossidoruk8033]

@@Philiptanzer can you please use specific terminology, there is no theorem named "convergence" that is just a word that can be used in many ways inside the field of mathematics. For example, an infinite sum may be convergent under certain sumation criteria, and on the other hand the limit of a function is said to be convergent if it can be proven to have a certain value that satisfies the formal definition of a limit. Now that being said, I don't know what do you mean by "ignoring convergence" as I said before convergence is just a word and I don't know what you could mean by ignoring it.

[@physicsouruniverse2798]

yes you are right

[@SergioTorres-zz5vl]

Dear Sabine, I have a question for you: what do you think about Alexander Unzicker’s claims that the Higgs discovery is a fake? He is allover KZbin basically saying that physicists are impostors, wasting money and deceiving the public. Is he correct? Thanks (I discuss your videos with my students and you have good analysis, your opinions on this matter should help clarify to young students how science works, physics in particular). Thanks

[@richardsammut1339]

Has anyone else just been watching big bang theory and wanted to google what does Sheldon actually do all day

[@spookd8700]

When do we start talking about resonance cascades

[@17ultralimited69]

And do peer reviews of other colleagues work.

[@vintologi]

I remember when i was a teen i had an idea "matter as a curvature of space" but i quickly ran into the problems you mentioned (conflicts with observations, math contraints) so i had to give up on that (people far smarter than me have already looked into that).

[@jaykay2218]

darwinian vintologi lulz

[@brianlaudrupchannel]

I always just imagine an equation on the white board that they have been trying to work out for 10years and have a lot of tea breaks

[@ZJProductionHK]

Do u sit around all day dream up new particles. This line lmao. What i laugh even most is that she didnt laugh when she said this line

[@silverphoenix_1756]

3:13 the main reason why this profession seems interesting to me the most.