How fast do neutrinos travel? | Even Bananas

Pound for pound, of all the particles with mass, #neutrinos are the fastest, almost traveling at the speed of light… but not quite. So exactly how fast are they? Neutrino physicist Dr. Kirsty Duffy and Durham University neutrino theorist Dr. Jessica Turner discuss how fast the elusive neutrinos can travel. #evenbananas #fermilab

Links:
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Neutrino Oscillations episode:

All Things Neutrino:

Fermilab physics 101:

Fermilab home page:

Production Credits:
Host: Kirsty Duffy
Creator: Lauren Biron
Guest: Jessica Turner
Writers: Lauren Biron, Kirsty Duffy, Ryan Postel, Emily Driehaus
Science Advisors: Andre De Gouvea, Charlie Borwell
Director/Editor/Animator: Ryan Postel
Camera/Audio Production: Luke Pickering
Illustration Designer: Diana Brandonisio
Theme Song: Scott Hershberger

[petyrkowalski]

A neutrino. Knock, knock. Who’s there?

[ThomasJr]

After watching tons of these videos, I now can follow them much more easily. Hard work pays off.

[HP-HP-HP]

Yay, it's Dr. Duffy! I learned something new and I hope to see more videos from you!

[joseraulcapablanca]

Thanks Doctor Duffy and Jessica, keep up the good work.

[ohdogwow]

I love how her excitement for this subject matter is so strong the pupils of her eyes feel no need to interact with her eyelids. It's great! :)

[djgruby]

An excellent video on this very exciting topic. It was the first explanation of the neutrino oscillations I've heard that helped me to somehow grasp the idea of them switching flavour as we observe them.

[bigsarge]

😄 Fascinating and informative as always, thanks!

[TheyCallMeNewb]

The first bonus fact has greatly knocked me around. No acceleration in the massless photon I could appreciate, but how does a massive (even when tiny) particle have no need at all of acceleration?

[Brett]

How is Nutrino Formed? How Photon get Pragnent?

[YossiSirote]

Three questions on neutrinos:
1. Why does the oscillation of masses not violate conservation of mass? Does this mean that different mass neutrinos travel at different speeds?
2. Is there a CMB equivalent in neutrinos? Have we/can we observe it?
3. All neutrinos are left handed. But they travel slower than the speed of light. If we travel faster then a neutrino will it appear right handed?

[jonwesick]

Since neutrinos travel slower than the speed of light, you can define a reference frame that travels faster than them. From that reference frame a left-handed neutrino would appear to be a right-handed neutrino. I'd be interested in a video on this.

[neIntangible]

When a neutrino/photon is created, what causes it's direction path to travel this way or that?

[Nilcha-]

How many wavelengths long is a photon? Just one wavelength or multiple?

[bjornmu]

OK so the neutrino form Andromeda arrived here 40 µs after the photon. But it would also be interesting to know how much time passed for the neutrino? 🤔

[OldGamerNoob]

If mass is given by a particle's interaction with a field, does it just ATTEMPT to go at the speed of light and sort of zig-zag back and forth with the field waves/particles along the way?
Is that oscilation back and forth at light speed the timer that causes time dilation for objects traveling at different sub-light speeds?

[MrPerfs]

How ironclad is the case for neutrino oscillation requiring rest mass? Like are there alternative theories where neutrinos travel at C but still produce the observed oscillations? If so, how seriously are they taken?

[radekc]

So, how sure are we that photons travel at c? If the only clue to neutrino's mass is oscillation, then photon's lack of oscillation is not exactly a proof that it doesn't have, for example, the same mass as neutrino.

[evans]

I have a question, due to length contraction wouldnt the "experience" of a photon be that its source and destination are also same place?

[jimdo]

they change wave length when they changes color. So can the wave length actually be speed then?

[kevinderrick]

I'VE ASKED THE FOLLOWING ON SEVERAL PHYSICS SITES, WITH NO LUCK:
Photons always travel at c and express this regardless if you travel toward or away from the source. The energy difference is expressed in a frequency shift.
DO NEUTRINOS TO THE SAME THING?