A neutrino walks into a bar. Someone asked him if he wanted a pint. The neutrino said, "No thanks, I'm just passing through!"
@mentalimage22415 жыл бұрын
That's hilarious
@justincotra68513 жыл бұрын
great lecture was impressed by the clarity of the SM
@Emcee_Squared5 жыл бұрын
Questions: 1. We know neutrinos are almost as fast as light, but what is their official speed? Has it been measured? 2. Does a neutrinos speed change as the neutrino oscillates into higher mass generations? 3. The tau neutrino is very heavy, and it travels at relativistic speeds.. Does that make it a good contender for dark matter? 4. If it doesn't get it's intrinsic mass from the Higgs field, then where does it's mass come from?
@BrunoPST20105 жыл бұрын
I'm gonna try to help a little bit with the questions: 1. Since neutrinos have mass, it does not make sense to ask what is their "official" speed, since speeds below the speed of light are not absolute -- for massive particles, there's always a reference frame in which the particle is at rest. 2. The thing is precisely that, rigorously speaking, the flavor neutrinos propagating in free space do not have well-defined speeds; what happens is that its components (the mass eigenstates) propagate at different group velocities because of their different masses, and that's what causes the oscillations in the first place. You'd have to think of neutrinos as wave packets in this approach, in order to make sense of the oscillation behavior. 4. The mechanism by which neutrinos acquire mass is not contained in the Standard Model, so the official answer for that would be that we simply don't know. However, there are some proposals, the most famous of which is the so-called see-saw mechanism. About the 3rd question, I really don't know anything specific, but neutrinos are indeed one of the candidates for dark matter.
@Emcee_Squared5 жыл бұрын
@@BrunoPST2010 Thanks for taking the time to answer these questions. With regard to the first question, I ask that because Dr. Stefan mentions in the lecture above that we can detect the neutrinos a few seconds before we can detect the light from a supernova, so I imagine the speed at which these neutrinos travel at must be fairly steady, just under the speed of light. And the fact that they have no Higgs interaction may also play a role in this. I will have to look up this "see-saw" mechanism and research some of the current hypotheses for how they obtain mass.
@BrunoPST20105 жыл бұрын
@@Emcee_Squared Indeed, the typical speed at which neutrinos are emmited in these processes is very close to the speed of light, precisely due to their small masses; but I imagine that neutrinos arrive earlier than light from the supernova has more to do with the fact that whereas the photons are constantly being scattered inside the supernova -- which effectively "traps" them and make them take longer to leave it -- the neutrinos almost don't interact and just fly off instantly.
@Emcee_Squared5 жыл бұрын
@@BrunoPST2010 Yes, that is how I understand it too. The photons "bump" into a lot of things as they make their way out of the star, but the neutrinos go through without touching a thing. That, and the fact that they travel at near light speed, means they are detected even before the light. It's pretty amazing.
@MrAlRats5 жыл бұрын
@@Emcee_Squared Neutrino emission occurs during the core collapse while light is produced when the shock wave reaches the surface of the star.
@GratefulFrog4 жыл бұрын
Thanks again Stefan for the great presentation. You are an inspiration speaker and teacher! I wish I could remember the relationship between DUNE and the Swindon magic-roundabout! Cheers!
@Do_Odles5 жыл бұрын
Lovely lecture, great speaker -thank you
@relaxingnature26174 жыл бұрын
The only thing more abundant than neutrinos is the amount of times this guy said ah ah ah ah ah ....
@Ouvii5 жыл бұрын
A scientist concludes their experiment shows that neutrinos travel faster than light. The bartender says "we don't serve faster than light particles here" a neutrino walks into the bar
@feelingzhakkaas5 жыл бұрын
great lecture and excellent presentation ...very beautiful
@Bobby-fj8mk4 жыл бұрын
I can't see any useful information that will ever be gained by studying the neutrino except to satisfy our curiosity. On the other hand - studying the electron led to millions of applications and has helped us in almost every part of our lives. Can neutrino research ever be justified?
@JohnPKING-nj8nc3 жыл бұрын
"Can neutrino research ever be justified?"
@amirsadeghi9888 Жыл бұрын
what about the people that are in the path of the neutrino burst? Shouldn't this be done in remote areas???
@justincotra68513 жыл бұрын
seems logical that stuff ie particles of energy get smaller and smaller as processes on the big scalehappen over time, however does it nececarilly play a role just because it exists?
@kaushaltimilsina77275 жыл бұрын
Wow! Incredible!
@xSUBIACOx5 жыл бұрын
Love how he had to convert worldwide metric, into silly American imperial measures so you lot could understand, lol. "Here Chuck, what's that 'metre' thing he just said?" "Fucked if I know, Meryl!"
@tumbleddry28875 жыл бұрын
yeh....one more embarrassing thing we have to deal in the US with these days
@MCToon5 жыл бұрын
I think we should all switch to livestock based units. Starting the length. One sheep is the average length of all the sheep in Scotland. It can get re-evaluated every 10 years. Mass is measured in German Shepherds. Average mass is all shepherds in Germany. Not just dog based shepherds. Volume is measured in Male Spring Break using volume. All other units are available for definition.
@1st_ProCactus5 жыл бұрын
@@MCToon Americans wont get it. It has to be 'football fields' and 'empire state buildings'. Power is measured in DVD players.
@1st_ProCactus5 жыл бұрын
To me, seeing those wigs pick up a shovel full of dirt and throw it back down is a big slap in the face to the people involved with actually making the device.
@WilliamLeeSims5 жыл бұрын
I know this is silly, but Dune has a great logo. It's filled with subliminal outreach.
@rafihussain5 жыл бұрын
Good luck. Fermi lab
@khalifaofthemosthigh68535 жыл бұрын
They are planning to use Neutrio as a specialized refined fuel to initiate time travel.
@cherryg.30425 жыл бұрын
Khalifa Of The Most High who is they? ASA
@thetherorist92445 жыл бұрын
....the mathematics show that you are trying to witness the future by measuring the distance between photons and neutrinos....bet you wondered how I know this?
@paulcalhounwaser79713 жыл бұрын
Physicists have observed tachyons, so they are no longer “hypothetical.” Most physicists do not know it, but all neutrino speed measurements have yielded average speeds slightly faster than the speed of light. And the neutrinos’ rest mass-squared has been measured from neutrino oscillations, and they are negative. The square-root rest masses are thus imaginary. According to special relativity, positive relativistic mass must always travel slower than the speed of light. Conversely, negative relativistic mass must always travel faster than the speed of light. Thus, neutrinos have negative relativistic mass and negative-imaginary rest mass. Neutrinos are tachyons and cannot rest but must travel faster than the speed of light in a vacuum. Although we would measure neutrinos time as going slightly backward rather than stopped like light, they do not actually go there at all. Everything we see and measure is in the past, but nothing goes there. There is no “tachyonic antitelephone.” I have uploaded several papers on all these properties to Academia.com.
@johnfarris61525 жыл бұрын
You want to really mess with their minds, just say "On Earth as it is in Heaven."
@jerrygundecker7435 жыл бұрын
a neutrino just flew past my ear. It missed my by that much. Whew! That was a close one.
@rkpetry5 жыл бұрын
*_..."neutrino...out...instantly" [_**_12:43_**_] but not straightly-scattering thousands of times..._* *_...tbd why is the neutrino only affected by the weak force yet it bounces on electrons..._*
@jelinlikeafelin5 жыл бұрын
Electrons also interact weakly
@barbarian11112 ай бұрын
200 feet capsules filled with Liquid Argon minus 300° underground what could go wrong 😂 🕳
@scottanderson81675 жыл бұрын
Didn’t he give this talk a couple years ago?
@yootoob60035 жыл бұрын
You know how it goes, giving talks at symposiums and conferences... Just rejig your last .ppt you presented at a previous symposium...
@scottanderson81675 жыл бұрын
Yoo Toob that makes sense.
@douglasgreene51975 жыл бұрын
I think I understand the standing wave within a wave. Seems obvious.
@laralara67992 жыл бұрын
@23:00 @41:00
@sakadabara5 жыл бұрын
おっばいチョコ
@executivesteps Жыл бұрын
Uh!
@xSUBIACOx5 жыл бұрын
Of all thosse 1,000 scientists ~ Not one African???
@3Space1time5 жыл бұрын
First
@philipsmith790410 ай бұрын
If neutrino can pass through lead for a year without being stopped , why can the deep n trap only capture 1 per hour instead of millions of them ?