The Best and Worst Prediction in Science

The best and worst predictions in science are both based on the same underlying physics

Special thanks to:
Prof. Sean Carroll
Prof. Brian Schmidt
Prof. Stephen Bartlett
Prof. Geraint Lewis

Patreon supporters:
Bryan Baker, Donal Botkin, Tony Fadell, Jason Buster, Saeed Alghamdi, Nathan Hansen

Virtual particles are a way of talking about fields and their interactions as though particles are doing all the work. This is why there is some controversy around using the term 'virtual particles'. Some people think the term is useful, especially since in calculating with Feynman diagrams you draw all the particle interactions that are possible (and then do the calculations to get the right answer). While others feel this terminology is misleading because virtual particles don't behave like real particles and can't be observed.

[tumbsor]

2:03 '' Take a picture where i look like i'm doing something''

[BrendanBeckett]

Hmmm, yes, I understand some of these words.

[jamcdonald]

I love it how Physics has so many "We are 99% sure that the value is x, and 98% sure the value is y, the only problem is they are very different values, both calculated with high accuracy"

[amehak]

"not only is the universe stranger than we imagine, it's stranger than we can imagine."

[juliep.]

College math class throwback. Just nod and try to look smart, it'll be over soon.

[thehotyounggrandpas]

I aint no scientist but I have some time off work next week and I've decided to solve all these problems, so fingers crossed.

[janandreslotsch]

When I first saw this video I was still in highschool and I thought this is a fascinating effect I never really learn more about. Now I'm studying physics and in three days I'll have my first exam on quantum mechanics.

[legoshaakti]

6:36 I love how absurd the calculation of 10^112 ergs is. That’s about 5*10^35 (500 000 000 000 000 000 000 000 000 000 000 000) times the estimated mass-energy equivalent of the universe.

[MyChico]

To everyone saying this sounds weird, remember this 8-minute-long video is a summary of several thousand-page-long books.

[Rman]

omg, that vibration in a field graphic is by far one of the clearest and most mind blowing things I've seen in a long time...

thanks guys.

[anarchy]

Macroworld: Theory doesn't always match up because of friction
Nanoworld: Ok, so friction is out of the game but now you gotta deal with virtual particles
Thanks universe

[magicstixr]

"My electrons move funny because a ghost comes and shakes them...."

Virtual particles in a nutshell...

[savvyno.]

I had completely forgotten what was the title of the video at the end of 3 mins.

[SirNobleIZH]

Wait... I think I know a solution:
Rather than there being separate fields for things like electrons and positrons, what if instead those were just bumps in opposite directions in the same field? Like an electron is a bump up, and a positron is a bump down? That would explain the excess energy from our calculations, and also explains why when they meet they annihilate. Like how when the crest of one wave meets the trough of another and they cancel out.

[bl]

5:46 I commend and applaud you for making this visualization, since i first understood fields, this was what i envisioned - thank you for making this graphical interpretation.

[doggonemess]

The universe is made of tiny colorful flavored balls. Combine them into new and interesting flavors! Amaze your friends and family!

[MarkCliffeIsGay]

Virtual particles? Psh. We need to build a wall around each nucleus.

[GzzLuiz]

It's amazing that year by year, you post things about more deeper fundamental concepts. This just keeps me excited. Thank you very much. Keep up the great work!

[Jobobn]

Great video! One minor critique I would have: I really feel like you should have brought up the Casimir effect in regards to virtual particles. I realize its a bit of a lengthy explanation to break down the experimental apparatus and whatnot, but I've always felt that it does the best job of helping get a real-world "feel" of virtual particles existing.

[pierrecurie]

Being super pedantic, I'll mention that what Sean said near 4:05 is not quite correct (but nobody really cares).

1) While it's true that there's exponential decay from higher powers of alpha, there's factorial growth from the fact that there's a LOT of more complicated diagrams. Since factorial growth overpowers exponential decay eventually, this sum is infinite. In simpler sums, mathematicians can use Borel summation to map the sum to a finite number.

2) Each of the diagrams with a loop in it is actually infinite. There's a dodgy process called renormalization that deals with these infinities in a systematic way.

#2 is a fundamental part of QFT. Nobody ever talks about #1.