The Stand-Up Physicist: Why Quantum Mechanics is Weird

[ChaostheClown]

You're pretty awesome. I enjoyed this, I think I'll be watching more.

[blackrad101]

Love this



[steve4961]

Why does this guy remind me of Bill Gates minus the net worth

[sweetser]

@SymmetricStrings You are correct.  I have added an annotation at 2:50, "Bad Prop! Should be h/4 pi. Thanks for being the first out of 28k people to notice.

[roskildahphreak]

This guy is pissing me the fuck off!

[Frostblock]

lame

[becomepostal]

Say no to drugs (even legal ones).

Really, 90% of people can do drugs without much trouble, glad for them, but 10% of people are really destroyed by this. When people start, they never know in which category they belong.

[becomepostal]

Difference between bizarre and weird... Now that is a creepy question.

Speaking slowly when giving important information and pivotal argument is fine. Talking slowly as if you were forcing yourself is creepy ; it looks like you are playing a trick to little children. And joking about drugs is forgetting the victims, moron.

By the way, why this "double limit" in the equation ?

Plus, we can't hear the words at 23:20 because of the bad editing (music is fine, except when it becomes a barrier).

[sweetser]

@becomepostal Call it method acting.

The double limit is needed due to math requirements. A quaternion has a place for both time and space. Time commutes (t, 0) Q = Q (t, 0) but space does not (0, R) Q != Q (0, R). If changes in R go to zero first, then changes in t, one gets classical physics. My hypothesis: if changes in time go to zero first, then changes in space, the most you can know are average changes in spacetime. That is quantum physics.

Not working with a pro video team.

[becomepostal]

@sweetser OK thank you for answering to my question, that's nice.

[XANDERXXZ]

YOU SPEEK TO SLOWLY!

[flexibartrampolin]

"here" and "now" behave very differently when projected into a first person analogy. You can impact the reference of "here", not of "now". But maybe you want to underline this very weirdness ... Another thing: I'm not a physicist, so please: is hydrogen fusion really a standard example of merging worldlines by superposition? I thought nuclei are composed of fermionic quarks. And the total number of protons and neutrons stays the same. So where's the merging? The lines are close but not the same.

[betabrain]

i smoke pot AND study quantum physics. it's mind blowing :D

[dashwood123]

At least he proved one theory, how to keep you guessing if he is crazy or normal, can he be crazy and normal at the same time, I think so. The wig element proves it.

[JoeThePhilosopher]

I'd bookmark this site but that guy is way too big a nebbish.

[datachip]

Dear Mr. MP Rock Star:

Thanks so much. That was charming and well paced for me. As someone who never took calculus, your presentation gave me a bit of a feeling for how the math works. Thank you again and please do keep up the good work.

[nandoanalog]

A bit crazy huh?

[ASKaPHYSICIST]

tell some jokes!

[2012DarkKnight]

doesn't quantum theory boil down to perspective and possibility, the perspective at which it is being looked at? which isn't predictable due to the fact that there are an infinite amount of perspectives even tho no one maybe there to view it.. and your world line should be an infinity sign x being your transition of birth and death

[CMCBrett]

It does boil down to perspective, but not so much possibility. Quantum physics can only predict an occurrence and state. It is the idea that certain properties only occur in small amounts. In quantum, your life can not be marked on any 'world line.' The atoms which build you however may do so.

[2012DarkKnight]

@CMCBrett

possibility is the effect of freewill and the kaos theory . what is this world line you refer to time is universal, thus our lifes should be looked at from an infinite position to see the overall picture. each life energy has a different life expectancy and growth rate, humans falling on the lower end of the scale when you think of the universe. Do you believe in a fully mechanized universe. or do accept that freewill and kaos have an effect on reality?

[CMCBrett]

possibility is the effect of nature; and to the point of quantum mechanics it is all atomic. Freewill is a state and privilege of the conscious which occupies your mind. Unfortunately our existence can not be seen from an infinite position because our perspective is finite. 'Life energy' holds different expectancy due to space time - note the theory of relativity.

[CMCBrett]

Freewill has the effect only reality to the extent that in which we may perceive 'reality.' The chaos theory is a well supported idea which I do believe. At any rate; the 'world line' is only a scenario created so quantum ideas may be put into perspective for someone who is new to the notion of quantum physics. You can not quantify your life; at least not at this point in time.

[2012DarkKnight]

being seen in it self, is a state of perspective. knowing our existence is finite gives us the logical conclusion that we can not say if something is infinite or not, except in mathematics is anything truly infinate

would an ant say a humans life is infinite from his perspective?? he could not say. he could assume. Freewill's actions provide the effect in reality, and this is not a privilege but a reaction to choice and belief.

[2012DarkKnight]

@CMCBrett the world line im referring to was a humans life on earth..

[8DX]

@2012DarkKnight

I don't think it's just perspective is it.. look at the double split experiment - the particle can behave as if all perspectives were happening at once.

[florencelovme]

@8DX You can also achieve what the particles does if you practice transcendental meditation.

[Torom002]

Good presentation. Though fusion is really about the strong nuclear force overcomming the weak EM force and not much to do with quantum tunneling. QT is more about a quantum particle going through a classical object. That's atleast what I've read on Wikipedia. Still, good presentation, I don't really know how correct you're on other parts in it but atleast it was entertaining.

[racsonam]

this guy is helarious

[smilingdata]

You feel insulted by his presentation, heh ?

And who are you Mr. ?

by the way, before criticizing his language make sure that yours is correct.

"i do feel sorta like...." is not English.

[NingyoAijin]

Dude... Youtube comments don't fucking need to be as concise as lectures...

[smilingdata]

We will debate your comments when you make and post your own video about the topic .

Until then shut the Fuck up !

[NingyoAijin]

what age is this video for? he is using very... umm... unscientific language here... i do sorta feel a little insulted by the language used here, but i have to give this guy credit for trying to make it easy to understand for younger people

[spleenblender]

Then stfu and stop trying to seem smart and go find a lecture to watch.

[NingyoAijin]

Youtube lectures aren't as fun or entertaining as live lectures... Also I am an aspiring theoretical physicist so I sort of feel slightly obligated to watch these lectures.

[spleenblender]

Then why are you interacting?

[theboarman]

your a fucking idiot on so many levels

[mjuad]

Absolutely brilliant. It's "you're", you fucking moron.

[Viper2026]

LOL love the epilogue :D

[Hoogliette]

thanks Doug that really brought some tricky issues to life nicely

[klavierman]

Sir, thank you so much for posting this video. It has helped me understand quantum mechanics. Observation: Your picture of the ball present in all 6 periods in time looks like a picture I saw of what a cube might look like in four dimensions.

[alliedtoasters]

What are some current or prospective applications of quantum mechanics? Why, aside from curiosity, is it important that we understand (or at least try to understand) these tiny phenomena?

[sweetser]

Electronics. Building computer and iPods with smaller circuits requires understanding how this tiny world works in detail.

The math works fine. This video hopes to provide a new reason why that math must be the way it apparently is. We do not need to understand why quantum mechanics is like this. Accept the math without question, and one can do electronics fine.

[mikestead]

Your CD player.

[becomepostal]

@alliedtoasters Are you serious ??????

Wooah, this question is even worse than the old "What are the applications of Earth being round ?"

Transistor, miniaturized radio, on-board computer in spatial devices, laser, microchip, everything that is currently electronics, personal computer, radio-telephone / mobile phone, internet, medical applications like X-Rays and Magnetic resonance imaging, Tunnel effect which permits observation and alteration of isolated atoms and leads to nanotechnology.

[alliedtoasters]

@becomepostal Thank you for your answer! Sorry you need to be a dick.

[becomepostal]

@alliedtoasters Sure. Quantum mechanics began almost a century ago, and aside from curiosity it changed the world.

There are some prospective applications in nanotechnology that will lead to new nice inventions in the years to come. Think about super-batteries, nano-robots, etc.

Furthermore, when you describe what is happening in a chemical reaction, you must take into account quantum mechanics in order to explain the behavior of electrons. Without this theory, benzene can't be understood.

[alliedtoasters]

who's the italian mathematician who constructed numbers from one and zero?

[sweetser]

Giuseppe Peano.

[becomepostal]

@alliedtoasters What's the deal ? Are you just spamming threads with quizz-like questions ?

[vetteluvnh]

You are obviously a very dedicated and intelligent physicist. Even though I didn't grasp everything in your video, I wanted to say "thanks" for taking the time to make it. I'm facinated by the concepts of QM, unfortunately I lack the mathamatical intelligence to really grasp all the formulas. So thanks again for the visuals. They're a big help for people like me.

[bajawind]

a sliver of humor would have gone a long way...

[mdiem]

Haha, stoned on physics!

I know the feeling..

[mdiem]

re: ~ 6:30

is e-hat the usual unit vector for time?

[sweetser]

Yup. In curved spacetime, if you look at nearby points in spacetime, the unit vectors for both time and space change.

[Adkit2]

So the opening hook for the standup act is a history lesson in physics? This disappoints me, I thought it was going to be funny. x.x

[Ironzealot7531]

i like physics, but hate math

this leaves me sad and conflicted

[crusifixa]

xD yeap , it use to happen to me , but when you start to get math , and like math xD it becomes a lot more funny oWo (think of math as a game , that worked for me xD)

(sorry for the bad english)

[carl77777]

You look like Bill Gates.

[sweetser]

The * is a conjugate operator acting on a differential quaternion, taking (dt, dx, dy, dz) to (dt, -dx, -dy, -dz). The inner limit in for the normed derivative used in quantum mechanics is (dt, dx, dy, dz) -> (0, dx, dy, dz). For the outer limit, the 3-vector goes to zero and does not need a *.

[EdMan2012]

this vid is boring

[Takilicio]

5/5 for me great

[70fury3]

nice job man..But since you have stopped time, or let it run down first, How can you then predict where the space the ball would be next? WIthout time to help predict it, the ball could be anywhere right???? right ?? ..............................­................. Im not a physicist my head hurts

[sweetser]

The ball will NOT go to another place next. One is looking at a collection of balls that happened to be hanging around in one place, behaving math-wise in the same way. Take a look, you catch one in one place. Take another look, at a different place. Repeat 6000 times. Now you can make odds on where it will be next. If measurement 6001 is made, there is a 20% chance it will be to the left, 30% to the right, 50% in the middle, and 100% it will be somewhere. That is the most anyone can say.

[70fury3]

Wow.. Thats cool. I actually understand what you wrote..Only...now my head really hurts!LOL! Thanks Nice video

[lightningturk]

This guy is seriously unfunny,i am both a physicist and funny he dosnt get my vote!

[Elvisleo13]

hahaha! this is hilaroius! I love this song! it is so my teacher

[SweetSoundOfGrace]

just had to think of something i recently heard being said:

'quantum physics is just a tiny part of the whole puzzle'

well, the guy did it, he explained it so that i can even understand half of it!

[MTheoryGuy]

This was great. If you don't laugh at physics its because you don't understand it. "it" being that there is nothing to understand, or so we think. I love physics, this guy was a wonderful teacher.

[harry4657]

he looks like bill gates lol

[gtssage]

Marijuana and quantum mechanics. Two great things that goes great together.

[CristianApostol]

@gtssage carl sagan would agree

[engkngorks]

you sir are a genius, i salute you, 4 dimensional can only be solved through quaternions in my own perspective, the old hidden manuscript aahhh how nice.

[macadamionsnuts]

wow this guy is funny :/

[JayashriV]

also, where can I view the other shows in this series?

thanks.

[JayashriV]

hmm... I don't really get something. firstly, where does pi come in? Secondly, is there a difference between h/4pi and h-bar/2pi? What is the difference between h and h-bar?

Secondly, why does changing the + to a - in the calculus of events equation change anything? In fact, I don't get that equation at all.

Thanks for your help. Being a 14 year old, I'm not very good at these things. :D

[sweetser]

In quantum physics, one often takes energy times time, and momentum times position, and puts that in an exponential. That can ONLY be done if the exponent is dimensionless. The units of h are those for E*t an P*x, so E*t/h and P*x/h is dimensionless. hbar = h/2 pi, so E*t/hbar = 2 pi i E*t/h. If you get n clumps of quanta, you get exp(2 pi n i). Type exp (2 * pi i) in at Google, and you always get 1. Physicists like 1's. (search for my name on YouTube, watch what interests you).

[JayashriV]

wow. simple video. but QM rocks. I love physics, I love relativity, I love QM, QED, QCD, string theory... and everything, until you come down to the complicated math.

peace

[sweetser]

Honest, the math makes it better. People have traded BS about how the Universe works ever since BS could be traded. It still goes on today. Only by using real math chops connected to Nature does the talk get to another level. Work on strings has yet to connect their math to Nature, so in my opinion is BS, done by folks smarter than I will ever be.

[cameraperson]

This is disturbing.

[XxIncompetencexX]

eehhhh dont like how he talks. totally turns me off

[adznruses]

lol

[seph77]

I dont like the hat.

[F00dTube]

Nobody cares about what you like.

[2Crystalight]

Science does not so the poor scientists any justice does it? rofl

[einstienear]

Why does this guy closde his eayes like he is half asleep? I mean, green could do better.

[will0ughby]

screw this my brain hurts, im going to bed

[WoundedEgo]

Well, I'm not qualified to evaluate your use of quaternions (sounds like a group of 4 Roman soldiers to me) but I can tell you that you are one heck of a teacher! Many thanks.

[sweetser]

Bingo, bingo. That was what the word "quaternions" meant in the King James version of the Bible. Historians think Hamilton lifted it from there. Glad you enjoyed.

[WoundedEgo]

I wish I knew what part of this was controversial.

[sweetser]

The standard approach is known as the Copenhagen interpretation. Wikipedia can introduce you to the idea if you are unfamiliar. Basically it says Nature uses probability in determining what works, yet gives no reason why probability is so central, it just is, accept that and eat your porridge.

No professionals ever bring up quaternions in discussions of quantum mechanics (OK, the one exception is Stephen Adler, but he does not do this derivative definition thing I do).

[AsgardianBeing]

I admire, that he tries to make it very clear. And achieves it pretty good. Respect!

[mnigus]

wish he wouldnt try to be funny...

[CobraActualUSMC]

Oh... Come on! We are talking about QUANTUM Mechanics here. Humor is essential. In a way, one could argue that it helps you to remember all this info. Sweester, A+. Thanks a mil.

Cobra Actual.

[mnigus]

agreed humour is a good idea. if ur actually funny.

[sharperguy]

better watch out for those MATHamphetamins

Seriously though cool video

[jomomo]

lol reminds me of bill gates.

[horderaw]

almost the way of life,i love it!!!!!!!!!!

[jdub00777]

dude, this was one of the best vids i have seen on youtube... my fav part was the end when u were like then at like 2am u get the munchies... and right as you said that i was thinking man i got the munchies and i looked at the clock and it was 2am!!!!! how weird!!! lol, good job bro!

[musicthingz]

is this guy simple , boring

[Kukident1]

damn, i cant listen to him, he talks too slow,...

[tomahawk1126]

this guy is on lsd

[SkateESA]

Also, what is the significance of pi in the uncertainty principle equation? I can begin to understand it but why can't Planck's constant stand alone in that equation?

[sweetser]

This issue has to do with phases in quantum mechanics, functions of the form exp(theta I). Euler proved exp(2 pi I) = 1. In quantum mechanics, the wave function is always getting normalized to one.

[SkateESA]

I can only hope to achieve the level of mathematical understanding to totally get all of the implications of quantum mechanics, although I can visually and theoretically understand it and am infatuated with it; I definitely begin to understand the difference between classical 3-dimensional reality and that depicted by quantum physics, and when it comes to the existential importance of numbers like pi and Euler's number in physical mathematics, the more I think about it the more sense it makes.

[SkateESA]

In the calculus of events equation, with the difference in d approaching 0 as applied to the limit-derivative equation, can the proposed 'difference in d approaching itself minus its positive approach to 0' be replaced with 'the difference in d approaching itself PLUS its NEGATIVE approach to 0"? Visually, I don't think it can be, but if not, then what does the latter represent, if anything?

[sweetser]

A friend pointed out that instead of thinking of the signs of things, what is really happening is the pesky 3-vector of space goes to zero first to make classical physics, where all events are ordered in time. If the pesky 3-vector goes to zero after changes in time go to zero, that is the stuff of quantum mechanics. I was doing something a bit too technical in the show (trying to stay on the manifold of H^1, so writing it all in terms of quaternions and their conjugates).

[idricool]

Einstein said : "God does not play dice". So therefore, the probability of things happening doesn't make sense. I've learned a lot from your video, Thanks a lot !

[ZeralTheyodine]

In "Events in Space-Time", why is it that each dimension is added to the next? Aren't you just assigning coordinates to the event?

Also: this may be me just getting ahead of my academic experience: but what's up with that superscript notation? Even a name for it would be nice, so I can slink off to Wikipedia.

[sweetser]

A plus sign can have multiple meanings. In this case, it does indicate separate dimensions that together make up a complete description of an event. If you are referring to the hats on e, i, j, and k, they indicate those are basis vectors with the size of one. Good luck with your studies.

[jeffbrown8]

this is very helpful

[idricool]

Lol I love the nerd music at the end.

[dannykanoista]

Loved it! I want more. ;)

[donegenaro]

everyone here must be more intelligent than me coz i found this the most boring vid on youtube and i watched that guy saying the war in iraq was and is good

[PornoSatan]

You're 46? You look late 20's early 30's.  :)

[Kazumaster]

A great watch :) Hats off to Doug Sweetser.

[logico9]

the world need more people like you.

BRAVO///////

[flips300021]

Fantastic!

[medici101]

sweet dude!

[twistsiwt]

Thats not Doug, thats Bill Gates!!

[alejandro15187]

crossed with woody allen

[spandulastic]

You know i seem to understand physics better when im stoned, either that or you explained it really well. Nice one Sweetser

[edimk25]

i feel the same way i think its both lol

[edimk25]

i feel the same way i think its both lol

[havesomespecks]

OK Sweetster, riddle me this. What puzzles me is the nature of energy. Energy touches physical matter and binds or repels them. They are the only two forms of energy between particles you can have except light. Now if hypothetically, energy was matter but on a different dimensional plane, you then begin to think in 3d again, ie what shape would it be an what would be its nature?

[sweetser]

Spacetime is 4 dimensional, three for space, one for time. Energy and momentum together is 4 dimensional, three for momentum in x, y, and z, one for energy. I think of momentum and energy as a sum of all the places an object happens to move: if it moves fast, it can have a lot of energy and momentum.

Mass is calculated by squaring the 4 dimensional energy and momentum.

There are many forms of energy and momentum because there are lots of ways systems moves through spacetime. Hope that helps.

[pyramidofdoom]

kind of. thats all very good for equations. but what i meant was that energy has no real physical presence in teh 3d world, yet it exists. So i wondered if energy might have a solid presence in a kind of hyperspace, that exists just beyond our comprehension of 3d space (or 4d if you include time)

[sweetser]

Every measurement is 4D, even if we separate them. Time and 3 dimensions of space make a 4D measurement. Energy and 3-momentum are the same. Square both of these, and we calculate something that does not change for all inertial observers: the interval and mass respectively.

My informal view of energy + 3-momentum is that it is a tangent space of time and 3-space.

4D is understandable and confusing (look at the quaternion animations for proof).

[pyramidofdoom]

what about gravity and magnetism though. there is energy, force and resulting momentum between them and yet there is no physical presence of it in the 4D world. I meant could there be a physical presence of it in another dimension like sub-space, and if so what form would it take, flowing liquid or gas maybe

[sweetser]

Because liquids and gases tend to gather in pools and slosh and swirl, yet gravity is a very precise response to exactly how much stuff is in a body, I don't think a physical sub-space fluid model will work. In some ways I personally would be more comfortable with a picture of some solid thing "getting the job done", but my comfort level is not relevant.

The most fundamental forces in Nature are confusing because time and space are doing math together.

[yaduke]

You are an absolute LEGEND!!! lol, far more superior then my QM lecturer. It was concise and refreshingly simple. I also loved the way you took the piss at yourself at the end..