I knew that photons didn't experience time, but it never occurred to me that all of space would be contracted to zero because of this (from the reference frame of the photon I mean). Mind Blown...
I believe that thinking about space collapsing when a photon travels is less interesting than the question of why it doesn't collapse. I think this arises because we are used to experiencing time, and so we try to make sense of light's motion in terms of experiences such as ours. But since photons don't experience anything then there is no need for these comparisons. To me, the strangest thing is that we experience time in the first place. I don't see why it should exist at all. It seems very confusing and I do not understand how we can have experiences of a flow of time.
I didn't know this either but I did always wonder how if a photon did not experience time how could it have a velocity as there is a component of time in velocity. miles per HOUR, kilometres per SECOND. This explains it, there is no component of distance either. This is all very weird. lol
THANK YOU for explaining why a photons life would be "instantaneous" I had always heard that but could never wrap my mind around it, until now, so infinite thanks! You do GREAT work honestly
"Photons are timeless" What a great statement! Wraps a concept in one sentence. 👍 I hope teachers play your videos in all schools all around the world in science classes. You are an amazing teacher.
The videos on this channel are consistently (1) engaging (2) actually explain things in terms I think I understand (3) make you want to watch and understand more! Thank you.
Nicely explained! Love how you dissected the equation to reveal what why a photon has to travel at the speed of light. Want to see more dissections of equations in future videos!
Thank you very much. I didn't knew what would I do in my future, I didn't know where my interest was, but you made it particular. I am know a student of one of the best college in my country of physics. You are a very important person in my life. Thank you very much 🙏😘
From your name I am going to assume you are Indian (please feel free to correct me if I am wrong). I am also thinking about pursuing a career in physics, would you be so kind as to tell me which university are you currently attending?
@@yajursharma9305 Raman Research Institute It attracted me for it's study in theoretical physics and specifically light. It is in Bangalore (Bengaluru) which provides a convenient platform for research as progressing in a new theory you get a lot of assistance for most top colleges of India are present in Bengaluru.
@@abhijaynagal-pianomusic Thank you very much.I live in Bangalore so that's convenient. All this information is very much needed as I am about to graduate school in the 2 and half years and I would like to keep my options open.
Thankyou! This makes the Isomorphic Hologram known as "The Doctor" from Star Trek seem a lot more plausible which is a good thing as he was one of my favorite characters
Just stumbled across your channel a few days ago, but it was the best stumble I’ve had in a very long time. I view/listen to a copious and eclectic select of science-based content. Yours is absolutely stellar and very accessible to my teen children. Thank you for your efforts and fantastic content!
It’s so interesting that you did this. I’ve been stuck on this thought for weeks; the universe from a photon’s “perspective.” Every night I fall asleep trying to comprehend the timelessness. So great, thank you. Also, I was so relieved you gave us “fast fast” when the segment demanded it. For a brief moment I was worried you were gonna skip it. Don’t ever change, Nick Lucid. 💪
Nick: when something is confined, that gives it mass Me: oh, so that's why I need to get out of the house to lose mass Seriously, a video on how confinement works would be appreciated, that was a totally "mind blown" moment.
Don't make a mistake, better stay home! When you start to move outside of house then your mass will increase! Also, photons cannot exist or be confined in spacetime! You only can detect the energy of photons when they collide with matter!
I am no phisicist but if had to guess, I'd argue that the confinement is due to different reasons in the case of molecules and black holes. In black holes, what binds everything together is gravity, all you need is to have enough energy/mass in a given space. In the case of molecules and atomic particles, you have the Strong Nuclear Force and the Weak Nuclear Force, both of which are MUCH stronger than gravity, but also have MUCH smaller radius of effect. The Strong Nuclear Force keeps Quarqs together and the Weak keeps Electrons in their "orbits".
Also, electromagnetic forces are weaker than SNF and WNF but stronger than gravity, so to form molecules, you have to approach sub-particles enough for the nuclear forces to overcome the electromagnetic force that repels opposite charges.
Never thought about it, but Mass being an emergent property would mean that reality itself is an emergent property and not a fundamental one. The implications of this might mean we can at some point (if we can alter emergent interactions) alter the fabric or reality itself. A world in which literally anything is possible.
Years ago, I was on a forum talking about light, and I made very similar conclusions about light being timeless and experiencing the entire universe as a singularity. I then had a troll claim he was a physics grad and tell me that's 'not how light works'. Gotta love the internets.
I love how you brought in indeterminant forms. I might have to borrow that example next time someone wants to know why they should care about calculus. In fact, I've been tutoring a calc student about limits and we just started covering infinite limits and he really wants to understand. If I think of it, I'll recommend he watch this video to get en example of how it's useful.
You know , I love these "if" videos because I think science is all about the questions we ask and how we comprehend the data for those question , that's how science grows !!! Love the vid ♥️♥️♥️.
You are truly the best science educator on RU-vid. You don't repackage the same explanations like everyone else. Truly exceptional and entertaining content with a fresh perspective. Thank you for all your work! Take care, -E
The fact photons are spaceless and timeless kinda breaks the concepts of wavelength and frequency, at least in their frame of reference. That's what happens when you keep using classical terminology to non-classical things. Also, does a single photon travelling through a medium with a refractive index bigger than 1 makes it suddenly experience time and space, since the speed of light supposedly becomes lower? The interaction with the particles of the medium could be considered a kind of confinement then?
The speed of light doesn't change when it moves through water. The trajectory just becomes more erratic. The wave portion of the photon increases as the particle path becomes more erratic which we see as refraction, or frequency change in the case of the non-visible spectrums.
Consider that each time a photon interacts with a particle that photon is "destroyed" and an other one is "born" so there wouldn't be interactions for that photon to tick its clock. The path it's just more erratic for the light that we shine through it as a whole so for us it seems slower on average. The singles photons just get destroyed and recreated or zip through the medium at light speed, the average of those velocities is proportional of what we call refractive index
This is something I was thinking when I watched another video about the delayed choice quantum eraser: Since photons are timeless, from the "point of view" of the photon, the moment it's destroyed is exactly the same as it's created, so whether the information about which slit the photon passed gets erased or not, it doesn't retroactively change how it's entangled pair behaved hitting the screen, it just happen at the same time. Sure, the photons are traveling at c from the PoV of an outside observer, which makes it seems that one photon hits the interference screen before it's pair hit the other detectors, but to the photons all those distances are compressed to zero, and so is the time interval. Thus, there's no retro-causality, if everything happens simultaneously for the photons.
@Vilfredo Pareto Metaphysics would have some form of rules or explanations. Magic just happens because it's magic, and that's why it's magic at all. It also depends on the magic, like a witch makes a pact with black phillip and grinds human babies to fly...there's a reason to the magic, but no rhyme to it in a physical way. Most traditional magic is "Ain't gotta splain it."
I was desperately waiting for your new video. I teach physics and no one dares to mess with me for concepts in physics. It's due to your clarity in concepts.
Retire o disco da geladeira, cubra com o recheio e dobre o excesso de massa sobre as maçãs. Cubra o que ficou exposto das maçãs com o crumble, pincele as bordas com o ovo e polvilhe mais crumble sobre as bordas. Asse por 45-60 minutos em forno preaquecido a 180ºC (médio)
Loved it as always.....😇😇😇 The best part about Nick is that he doesn't go into unnecessary details and maintains accessibility...He just provides such insight that even beginners like me can cherish.... Loads of love ❤❤❤
Awesome video! I think this is great idea for a series - What if you are a photon? What if you are a black hole? What if you are a graviton? etc Fun perspectives to explore!
Cool video! -- It brings up two related questions for me though: 1) If distance and time don't exist for photons due to relativistic effects, why would anything lie beyond our light-horizon cosmologically? 2) If the cumulative expansion of SpaceTime exceeds C, how does a photon experience this given that, at literally every point along it's trajectory, both time and distance are zero? 🤔😮 I always enjoy your videos, they're fun and humorous, *tremendously* informative _while_ still remaining eminently comprehensible and accessible for laymen, well done! 😁👍
OMG this feels like an entire episode of answering one of my comment questions here. Realistically, probably a coincidence but this still REALLY made my day.
Mind blow after you explained the photon timeless/spaceless "experience". Incredible. Really makes you think if it we are only, in fact, experiencing a very small slice of what the universe actually is.
Imagine getting launched out of a star at the speed of light and hitting the eyeball of a human thousands or millions of light years away without experiencing any time at all. The experience would be nothing at whatsoever, because time and space are fundamental to experiencing anything. It's like falling asleep only to wake up many years later.
This could potentially explain: • The idea that the universe is one • The idea that everything is happening NOW and time truely is an illusion constructed by the witness • That I have little to no idea what I'm talking about
@@ScienceAsylum i can understand 0/0 and ∞/∞ and 0^0 and ∞-∞ being indetermined, but why is 0*∞ not determined as 0? and ∞^0 as 1 since we know ∞ only has all real or computable or incomputable numbers, no matter what it is, as long as its a number, shouldn't we call it 0 and 1 and be done with it? I'm sure smart people have thought this through but i cannot really get why this would be interminite. infinity is more of a concept but nonetheless, it is essentially just a over grown variable like x or y taht is just taking place of the largest number- or even could be the "constant" like e or pi but for the largest number- either way, it will still yield a number since i think we can say for sure the end of the number timeline wont end with 0 nor anything incomputable but rather a number.
@@Nosirt Let's say that that infinity can be so big that it "overpowers" the zero in the zero times infinity case. Infinity is NOT a real number, it is used in analysis that something grows without bounds. In the same way in analysis the zero is not actually zero, it is "bigger number you put in closer to zero you get" so in this context it again isn't a well behaved number. And I repeat again: infinity is not a real number, in here it is a shortcut, it can be a number but you gotta define your number system differently then (for example as transfinite ordinals or whatever) to make your operations make sense.
Question: from our point of view a photon is emitted somewhere, travels in some direction and is possibly later absorbed or scattered. However for the photon this is all a singular “event”. Does this imply that all photons are causal connections that will ultimately always be scattered or absorbed, e.g. all photons must have a destination?
My brain: how majestic and beautiful this universe is... This properties of matter and energy shaped my own structure and mind so it can wonder and explore this sea of information. My mouth: holy shieeet!
PBS spacetime mentioned the idea of mass being an emergent property due to confinement awhile ago and it completely blew my mind. Physics is _weird_ sometimes!
I had this question in my mind for a loooong time. I appreciate having an answer from someone I trust more than my intuition... But it is so frustrating! 😅 Having photons not experiencing time, I can deal with it. Having photons not experiencing space, I kind of get it. But the implication that it doesn't experience universe gets me confused, in the sense that if there is a wall, photon will be absorbed or reflected by it, it's not as if he doesn't interact with this universe. So in a way, without time and without space, there seems to be an experience of this universe! I first thought about this when presented with the double slit experiment actually, I was wondering if the fact that there is no space from photon perspective could explain something. I never reached a conclusion.
So if both photons and gluons have no mass and confined photons would have mass, maybe the Star Trek TNG holodeck makes a bit of sense after all. Holodeck matter is created with photons instead of normal matter.
"Mass is not a fundamental property." True. Energy is more fundamental, which makes it kind of ironic that the SI unit for mass is a base unit but the one for energy is derived.
Since a single photon would be weird to create an object but a lot of them could do so, could a laser beam (many photons with same polarity, phase etc) create a human being that way then?
@@matmirza5376 I think that instantaneously photons can (at least theoretically) become a positron and an electron, each of them half the energy of the photon, so if I'm not wrong, a photon can create something other than a photon. But my point is, could a lot of photons in the same state have the same effect as only one photon?
@@georgesimos4914 Well, you're not wrong. A disintegration of a photon can generate another two photons or an electron-positron pair. This last disintegration can happen if the photon has an energy of at least 1,02 MeV, the mass of the electron + the mass of the positron. Normally it occurs in the vecinities of atomic nucleus.
Is the whole energy of a photon is kinetic energy? If it is, then how the energy of light changes between deferent wave amplitude if it always at the speed of light
I may be wrong here but... the energy of light changing with wave amplitude is only true for "light" as a collection of photons, an emergent effect. For a single photon that would not be true because the energy would be E = hf, only proportional to frequency and the plank constant. This question gets to the heart of wave-particle duality. The classical wave model and particle models are both approximations of "reality". It can be argued that we don't really know what reality even is at the moment, but our best guess would be the "wave" model conceptualized in quantum mechanics.
ok, learned a couple things here, you can make a black hole with just a blob of light (no stars need apply), and we are made of gluons, which are massless (don't tell the scale that). Interesting stuff.
Great vid. I've wondered about this for a while. As a follow up, how, in a spaceless, timeless existence does a photon move through the Universe? Or is it everywhere at once? How for example can we see back in time if the photons don't move? Or if they do move, how if they don't experience time? 🤯
Photon is not moving in the photon reference point, it only moves in our reference point. It is unchanging, so from the photon perspective there is no time and space, but from ours' it is different. So, unchanging photon moves through the Universe without experiencing time, the only reason we can see it as moving because we experience time.
What would happen to the momentum of photon in a optically denser medium where the speed is lesser than speed of light? It would be counterintuitive if it would go to zero...
Saying light slows down in a material is just an over-simplification for the wave mechanics going on in that material. If you want to model light like that though, you'd have to assume it becomes massive inside the material.
@@ScienceAsylum By the way, I explained this of the light to my nephew and he asked: But how do you contained light? My brain crashed, had to be rebooted and it's still repairing some corrupted files. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-vS43ZgcQ_hE.html
@The Science Asylum - sorry perhaps my question was phrased wrong. If a photon travels at the speed of light for 2 years, from the photons perspective it is instant. No time elapsed, only 2 years to the observer. So how old would a black hole be from a black hole’s perspective?
@@freezinfire I meant it in the sense (as explained in the video) that the point of creation and destruction of the photon is the same point in both time and space from the photon's perspective
@@discretelycontinuous2059 ok, and I meant with respect to the volume of the universe (which is a lot of light years) and speed of light (only 300000000 m/s)
@@freezinfire I understamd what you meant. And certainly it is. It is interesting to think that at light speed the universe is length-contrqated to 0 and time dilated so that it can arrive at any time in the future, potentiall billions of years "in an instant" (within the photon's reference frame)
So earlyyyyy the last time....... Yeah the last time i was this early i was rooting for 100k subs And nick engages with the audience the most And his videos really get me rid of anxiety And this channel will soon become one of the best ste(A)m channels, it already is but the subs and views as well And thanks And nick is a good person from what i know , i dont need to say that but still the world needs such peeps who are good,
@@ScienceAsylum I'm a philosopher and philologist trying to understand physics, so do forgive me if this is a ridiculous question. I wonder if gluons might actually be a type of photons, or maybe actual photons. That would mean we ARE made of light.
Wow very enLIGHTening! As a hobby I read loads of books and articles on things from nuclier physics to quantum field theory to cosmology, so when I say I understood light in a new way; thats an award worthy explanation!
I haven't found a channel which explaines science topics better than this one. In particular I enjoy the pace of narration, the illustrations are fantastic... etc. etc. p.p. Yeah, using miles is a bit off for non-US citizens (ok, metric was presented in brackets), this drives me crazy in some videos, although I am crazy already... But its ok to be a bit non-metric in science ;-)
