Light doesn't travel at light speed | P. Robert Nemiroff

Full interview: • Why light doesn't trav...
Featured Book: www.amazon.com/Faster-than-Li...
Professor Robert's Profile: www.mtu.edu/physics/departmen...
Not only does light not travel at light speed, it also travels at different speeds at the same time. Professor Robert Nemiroff explains why in this video. He's an Astrophysics professor who previously worked at Nasa’s Goddard Space Flight Center. For more than 10 years, he's researched phenomena that appear to go faster than light and has authored a book on the subject.

[@GreyBeardGamingYT]

YOURE BACK WHAT?! I watched you like ten years ago this is amazing. welcome back to UA-cam.

[@177Willy]

He is alive

[@TheWebstaff]

And picking up the posting interval.
OR maybe it's an AI..

[@personanonmaga5178]

😭

[@agatasowinska]

I know, right!? I was positively surprised too 😃

[@177Willy]

@@agatasowinska Tak, byłem bardzo zaskoczony.

[@lllStanlll]

Hey good to see you again man.

[@bjs301]

Great to see Sharkee back! This was always my favorite science channel.

[@OmarExplains]

Amazing video

[@coda56]

i have had notifs on for years, didnt comment on last video but im so happy your back and doing well

[@TheOriginalJAX]

Welcome back.

[@CptHer]

Wait what? You're back?! This used to be one of my favorite channels many, many years ago. I am so happy right now!

[@R3cce]

You remember his largest number video?

[@Pipehiguita]

Some of the best science explanation videos on UA-cam before his hiatus and now aswell. Great Work!

[@oleboy555]

Great format! very engaging and well edited! love that there is a longer interview available with every new topic, keep it up!
If you are worried about exposure maybe you could eventually try to collaborate with other creators.

[@bjonri]

So good to see you are making videos again! I still rewatch “what if we never travel faster than light” every now and again. Hope to see more!

[@conorhealy2763]

Oh wow, it's really nice to see sharkee again. Glad your back!

[@Ahmadmzazai]

Omg! You’re back!!!!
I was seriously concerned for your wellbeing.

[@ropesendclimbing]

Great to see you back. Keep em coming!

[@minarmiah5255]

Welcome back!

[@mihaip90]

Sharkee now that you mentioned your kid I have a feeling that he convinced you to make videos again. I gotta say that I never expected you to return, but I kept my sub cuz I liked your videos man. Keep up the good work!

[@Form_Storm]

Can you please return to your old format. I loved that a lot.

[@sylocin]

He's alive

[@boxmanatee]

About time! You've been back for months but I didn't notice!

[@TykoBrian7]

WERE SOOOO BACK!!!

[@anthonydef3000]

Duuuuuudde your back!❤

[@OcteractSG]

Thanks to time dilation, the light itself may age more when traveling through a short distance of water or air than through a long distance of the universe. Of course, no one is concerned with how old a particular group of photons is.

[@-_Nuke_-]

Wait a minute... No matter the material the "front velocity of light" is always going to be the speed of light which is equal to c = 299,792,458 m/s.
So that never changes, so information is carried AT c all the time no matter where you are.
But yes the other one which is phase velocity indeed changes.

[@lindsaytang1017]

Hello, long time no see.

[@TheWebstaff]

I've never understood that. Surely.
Nothing is still something?
The absence of something is still something.

[@eprohoda]

Like!total top travel!👋

[@HoD999x]

vsauce4 is back :D

[@tobbe7851]

Stating that shadows can move faster than light can be confusing for some viewers.
Shadows can only arrive on surfaces at the speed of light.

[@1234567895182]

Yea I'm still a little confused on that one. So he says the shadow will move back and forth on the moon faster than light. So what if I had two light sensors on the moon that are both really far from each other. If I casted the shadow from one sensor, to the other, would the delay between each sensor being detected be faster than light?
Doesn't this mean you could technically use this to send information to the moon faster than light? You have a really faster shadow maker machine on Earth pointed at the moon. The moon has an array of sensors to detect when there is/isn't light. To send information, just move the shadows across the sensors in specific order to transfer bits/data.
This just sounds wrong though but I don't know why.

[@tobbe7851]

@@1234567895182
To the person standing on Earth casting the shadow it will apear like you did something faster than light, but you have to remember that the INDIVIDUAL photons or the lack of photons can only travel at the speed of light between the sensors, and between you and the sensors.

[@ludacrisbutler]

Sharkee!

[@Petch85]

It is almost like we should not be calling c the speed of light. 😂

[@wudipest]

maybe the "c" should be attributed to the speed of "causality" instead

[@OutrageousPenalty]

PiouRRR Vakiiiumm

[@2hcobda2]

2:37

[@2hcobda2]

speeds: front, phase, group

[@2hcobda2]

5:04

[@2hcobda2]

5:41

[@2hcobda2]

6:14

[@2hcobda2]

7:18

[@CUJONFRIENDS]

Saw the notification 😁, have to wait untill I get off work to watch 🥹