Particle Physics (17 of 41) What is a Photon?
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- čas přidán 19. 05. 2015
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In this video I will introduce photon as a piece of energy, having no mass traveling at the speed of light, acts like a particle, having momentum, and having energy that is quantized.
Next video in the Particle Physics series can be seen at:
• Particle Physics (18 o...
Your my hero. I need this for a class right now but I'm going to do this, the E&M playlist, and review with you over the Summer. I've always hated school but with you I actually get to sit down and enjoy the material. I've set up a channel under a different name and I'm hoping to have a laser done by the end of the Summer AND be able to explain why it works.
Man, keep up with the good work. The content and structure of your lecture was amazing!
Such a great place to come when it's summer. Your videos are clear and easy to understand. Thank you.
Well done. Clear and concise without mind-numbing 'higher' mathematics. This video really helped me clear up several photon concepts I obviously missed in classes so many years ago, that I have questioned ever since. Thank-you and carry on...
Learning new concepts makes life interesting. I never get tired of it.
Thank you this explains so much right now. Are we experiencing a Photon event right now?
Wonderful! Oh thank you for this. This is the best physics lecture I have ever had. My interest and love for the subject is rekindled because of my chance discovery of this video.
At the end... I LOVE the little blooper moments--you should do this in all that actually contain them--I know I come up with many in "live" lectures: They actually bring up good points that otherwise drift away into the ether (why do we use that expression still?) If it cuts too deep into the time available, then cut out some of the live calculator button presses! Then maybe one dedicated video...remember Walter Lewin's "dotted line" video?
Wow this is a great video, thank you so much for posting.. It helped that I had basic college courses on some of this and that I brushed up on it today, but I like the way you break it down and luckily thus far everything makes sense.. I can't wait to see your other videos
Thank you and please dont stop.
Stfu he's the one helping
Manchester United that’s what she said 🤷🏾♂️
*UH* *UH* *UH*
*DONT STOP*
@Michel van Biezen
At 11:56, you pose a question on how many oscillations of an atom does it take to emit a photon - and then you said you'll get to that later. What's the answer to that? I went to your next video and you described how photons are emitted in discrete energy packets by equally discrete electron energy level "jumps" in the atom. How does the thermal vibration frequency of the atom relate to electron energy level jumps? Does thermal vibration cause electron energy level jumps? Or are electron energy level jumps and thermal vibration two different ways to create a photon? If the former is true, how is the relationship of (photon freq = atom oscillation freq) maintained if the atom oscillation is not quantized? Or is the atom oscillation quantized?
You answered your question with your last statement. The oscillations are quantized. We have videos in the quantum mechanic section that explains that in a lot of detail
That's crazy. So the model I had in my head of atoms in a material vibrating at arbitrary intensities and with the vibrations scaling up smoothly with the material heating up, was wrong. Do vibrations relate to a physical movement of the atom in spacetime, or are the vibrations, in this sense, a more abstract concept than simply movement? Also just want to say thank you so much for creating all this educational content - and believe me, I'm well on my way going through them all.
One other thing you might find interesting and is critical in understand the architecture and dynamics of matter in our universe - all matter distributed over the size spectrum is partitioned into quantized levels of interaction bounded by large matter/energy barriers enabling composite objects like photons to be very stable forcing interactions to occur between them instead of decaying to their component particle systems. This is why there are finite sets of stable matter systems within unstable systems (subatomic particles, atomic particles, atoms,...)
Fascinating! And mind boggling numbers and concepts of the Universe.
Thank you, professor. You’re a natural explainer and teacher.
N. DeGrasse Tyson once said the best teachers should be the first people to be cloned…everyone remembers the good teachers they’ve had growing up 👏🏼👏🏼
Thank you for your nice comment. We are glad you are enjoying the videos.
I liked the bloopers at the end😊 thank you for the amazing videos... keep up the great work professor!
one thing to ask.....
How does photon / light reflect??
Like as we see in normal things Newton third law of motion is the reason of reflection of an object.... But we see microscopically the protons of both objects repels each other.. So this is actual reason of reflection......
Now if photon does not have mass and charge how it can repel .... ??
So basically my question is how reflexion occur in photon / light...
Michel can you please make a clarification on this point what is the nature of energy ,is energy a sort of wave ,why do you keep reffering to a photon as a chunk of "energy" or a piece of energy,is this "equivalent" to speaking of an electromagnetic radiation.
Einstein received the Nobel price for discovering in 1905 that electromagnetic energy (such as light) is made up of individual chunks of energy we call photons. (See the "photoelectric effect experiment")
@ ~ 11:30 I think that 10^12 or one TERA is now common enough to be expressed using the word "TERA". So, nowadays Tera-Hertz or, back on subject: "600 THz" would be the norm, not 600 x 10^12..OR 600EE12.do most agree?
What does the term "photon can actually bump it like a billiard ball bill bumping another billiard ball and making it move" mean?
Thank you so much. I made a huge step forward in understanding.
Excellent explanation, thank you, and you have another subscriber.
Wonderful series, thanks. A wave in the water uses the water as its medium. What is the analogy for a photon moving through the vacuum of space? Would you say the "space-time-fabric" is the medium for the light wave?
That is a good way of stating it.
the electromagnetic wave which is greatly used for communication is consist of a lot of photons and propagate like a water wave in the pond or a single photon only ?????
They are comprised of an incredible number of individual photons; together they form electromagnetic radiation.
So, a scale would actually read a small amount if a moving photon hit it, but it wouldn't be weight that is actually measured, perhaps momentum or impulse?
Scales read a force (like weight), not mass. When a photon hits a scale there is change in momentum which is impulse. And impulse = force x time.
I have a question . If Photon is a particle like electron and proton So what is its charge ?? And is photon attract or repel by any charge??
No, photons do not have mass and do not have charge. A photon is not actually a particle but it acts as if it does. (there are other particles with mass that do not have charge)
if photon is a vibratıng massless wave propagatıon ,My question is,why does a photon never stop vibratıng while passing through in the unıverse which is being ın absolute zero condıtıon ,that ıs, -273 degree or 0 K.?
Thanks.. Stay blessed.
Love your videos, very helpful. Most surprising to me in this video is the number of photons hitting a square meter of the earth per second though. 3.42 x 10^21 is big number no doubt but it's 100x less than a mole. I would have have expected it to be a much larger number given how small a photon is relative to everything else in that square meter. Perhaps this is because we were only dealing with one wavelength of light in the example and there are many different wavelengths hitting each square meter simultaneously?
No, it is the total number of photons per second per square meter. Nature has many mysteries.
m=mo/square root 1-v2/c2. mass variation formula. Is this valid for photon?
No. Photons always travel at the speed of light.
Hello Michael. hoping you can point me to one of your many videos that would explain the concept of the "Photon Gas" I am seeing it being used in the sense the Photon gas actually has a temperature. This seems absurd to me. My understanding it is a useful concept when used in astrophysics.
We don't have any videos on photon gas. A photon gas is a theoretical CONCEPT and is used in some advanced method of thermodynamics and astrophysics.
nice. the right kind of approach and video.
i apreciate the work and seriosity.
i like the tone and the pace of speech.
i can really understand the topic.
other video creators and channels just keep on machinegunning the freaking text as if it was a race or something and it always starts and ends with follow and subscribe orders.
R E S P E C T !!!
thank you Sir !
(eddie)
Eddie,
Thank you for the feedback. We appreciate it.
God bless you.
when i was in school i only had poor marks but now as a grown up i m devorating those vids.
really love the quantum stuff and also the new branch quantum biology.
i turned 41 last last sunday
Thank you. You are still a "youngster" in my book. Keep up the learning and enjoy.
@4:50 you are explaining the formula to determine the energy in a photon from the sun.
You arrived at the number 1.6 x10-19j
Is that number Phi?
Or is that just a coincidence?
I am asking because I have always been amazed at how 1.618 or close to that seems to factor into a staggering number of calculations.
Some aspects of geometry physics seem very mysterious, obviously.
Thank you for taking the time to post this, not everyone finds this sort of thing fascinating, but from those that do, we salute you.
That is just coincidence in this case. The energy of a photon only depends on its frequency. (or wavelength)
I really appreciate you answering what must have seemed like a rather ignorant question.
Maybe by the time I get through all your videos I will have an actual question for you.
;)
Please what happens for the energy and momentum of a photon when entering water or any medium
The energy of a photon is: E = h f Thus the energy of a photon only depends on its frequency. And since the frequency of a photon doesn't change as it enters a medium with a different index of refraction, the photon retains its energy. Since the momentum of a photon is: p = E/c , and the average speed of a photon slows down in a medium, it would "appear" mathematically that the momentum increases. But the experts cannot agree on this as there is another theory that shows that the momentum decreases, and then there are valid arguments that indicates that the momentum of photons do not change in between the many interactions with the electrons in the medium. And then there is the concept that a "photon" in a medium may not be an entirely correct concept due to the many interactions it undergoes in the medium.
Michel van Biezen thank you very very much for your answer . Ithink l am very lucky l am a teacher from Iraq thank you again
Sir how is the frequency of photon and the frequency of its container electomagnetic wave related....i mean what is the relation between both the wave frequencies?
The electromagnetic wave is not a "container" of photons. The accumulation of photons IS the electromagnetic radiation, and yes, they have therefore the same frequency.
Thank you sir.....doing great job....
Very well done. I'm enjoying your content. Thanks
Glad you enjoy it!
Sir as oscillating... is one vibration give us one photon ?.. How we will find no of photons. If you had already explained that in your videos please give me reference. So that i can find the video to watch and understand and one more thing, to enjoy......
You can find some of the answers in this playlist: PHYSICS 65 PARTICLE PHYSICS and in this video: Particle Physics (27 of 41) What is a Photon? 11. Volume (Density) of Photons
Ok.Thank you sir for helping...
Your owrk is very nice ! I´ve whached some and thye were all very very good !!! It Helped me a lot !!!
Great series thanks. And nice to be at a level where it doesn’t have to be viewed speeded up!
(‘Yellow’ photons is good, though I imagine that most of the photons in the universe are invisible. Maybe not.)
photons are invisible until they enter the eye, the those in the "visible" range are visible
How big is the energy bundle photon
Easy to understand. Thank you. Some kids hate school because they are not thought in a way they can understand this and that.
When electric charge oscillates in free space photons emerge from space, they stretch with expanding space, lose their energy to space & ultimately dissolve back into space. Could the photons be made of Space itself. If so the entire Matter & Energy could have emerged from Space.
Photons don't "emergy" from oscillations. Oscilating charges cause the existing electric field to oscillate
How did you get the 1361 W/m² value?
That is a known value which was measured by satellites.
I am into quantum photonics and i appreciate your videos
Great subject to get into. Glad you found our videos!
very informative. Thank you.
As stated, a photon consists of oscillations of the electromagnetic field. Oscillations are a function of time. When an electron moves from a high energy orbital down to a lower one, it emits a photon instantaneously. Being that it's instantaneous, how can oscillations be created in zero time?
As far as I understand, nothing happens in "zero" time. However many "events" in physics happen in very little amount of time, sometimes in less than 1 billionth of 1 trillionth of a second. In our world that appears instantaneously.
I was more referencing plank's constant rather than the amounts of time perceivable to a human.
If an electron doesn't move instantaneously, then it must spiral down to the lower energy level instead of just jump, creating the constituent oscillations of the photon. But then doesn't that contradict the plank length? If the plank length is the smallest possible time/energy interval possible in the universe and a photon represents a plank length sized chunk of energy, then a photon must be created instantaneously because time cannot be divided into a smaller quantity to be summed together to create a photon. Spiraling would take more than a plank length's amount of time, thus suggesting that the electron does in fact jump.
Am I understanding this correctly?
The explanation I've come up with is that when releasing energy, an electron quantum tunnels to the lower energy orbital, leaving a packet of energy behind (photon).
Additionally, I think there is corollary to the vibrating(hot) atom causing back and forth motions of an electron and the electron creating a stream of ripples in the EM field. The corollary is that the presence of energy itself distorts the EM field and causes ripples. If this is true, than that is how a packet of energy could manifest as a set of ripples without actually being the result of a physical electron oscillating back and forth.
I don't have the tools to test this hypothesis. Could you discern whether my conclusions are valid or not?
Thanks =)
This was very helpful!
Consider every object in this universe consists of a visible part with constituents ultimately made of photons and an invisible part with dark matter constituents ultimately comprising photons (simplified explanation). This means every object can be considered to be has a matter density field with visible and invisible components. It is the invisible components of an object's matter density field (mass, charge,..) that conveys forces at what appears to be at a distance from an object and is responsible for entanglement. The structure of space as the mass density field is the resultant of every object's mass density field which extends about 10^14 km / kg beyond the visible part of the object.
Great video!
But Sir i think that this (3.42X10^21 photons/sec.m^2 ) amount of photons is only referring to the light having wavelength of 500nm. So sir what about other wavelength of EMR falling on same unit area?
Yes, that is correct. We used the most common wavelength of sunlight as an example to approximate the number. If you want to calculate the exact number you will have to integrate over the blackbody radiation curve of sunlight.
@@MichelvanBiezen oh then it will be so much more photons falling on per unit area..Wow!!! Awesome! thank you so much Sir. I enjoyed your classes.. You make it so simpler n now going to watch from start. Got one subscriber..:-)
Enjoy and welcome to the channel.
@@pemchen It will not be more. He considered that all 1361W/m^2 where photons at 500nm but there will be much less of those photons as the 1361W/m^2 is the energy for photons all all wavelength and most of this power is photons in the infrared. You will need to integrate and you will see how much photons of each wavelength but you will use the amount of power for each for example just around 2W/m^2 for 500nm and you will need to integrate all that to get the total but since 500nm is around the middle of the visible spectrum there will not be that much more photons when you integrate.
Mike here and thanks Mike:)
The photon is a linear electric motor, propelled to slide through the weightless vacuum, from which the electromagnetic force.
I wouldn't call a photon a "linear electric motor".
La linkul de mai jos este postat un pdf cu deducerea tuturor parametrilor fizici ai structurii dinamice a fotonului, aflat in translatie (propagare) prin vidul cosmic=materia primordiala inponderala a universului.
At the link below, a pdf is posted with the deduction of all the physical parameters of the dynamic structure of the photon, in translation (propagation) through the cosmic vacuum=the weightless primordial matter of the universe.
@@MichelvanBiezen www.astronomy.ro/forum/viewtopic.php?t=16743&postdays=0&postorder=asc&start=0
Assalamu alaikum,
I want to ask u about a simple pendulum.
Is there any relation with gravity ? for stop a Simple pendulum.
Thank u!
I think what you are asking is: " is gravity responsible for slowing down and stopping a pendulum"? If that was the question, the answer is "no". If here was no friction and no wind resistance, the pendulum would keep swinging forever due to gravity.
@@MichelvanBiezen oky, please can u recommend me any video lecture for better understand.
You can take a look at this playlist: PHYSICS 16 SIMPLE HARMONIC MOTION AND PENDULIM
Thank You Professor...
🙏🙏🙏🙏🙏
so, then, heat is made up of photons (heat dissipation = vibrating atoms have electromagnetic radiation = the photons leaving the object) therefore heat is electromagnetic radiation as well? heat energy is the same as the energy of llight?
so, the reason we don't see heat is because their energy (frequency) is too low?
+1 sub. you answered my question, 3 others I wasn't particularly asking now and like 8 i didn't know to ask!
Glad we were able to help.
Interesting stuff but the math you presented exceeds my pay grade as a truck driver. Sometimes I equate my truck as a giant photon moving at 70 miles an hour delivering goods to mostly an unappreciative universe. I wished I had taken math more seriously in school. Thanks for the post.
I had to laugh when you wrote " unappreciative universe". Yes, people do not realize how the world would litterally stop if people like you didn't transport all the goods we use on a daily basis. My hat off to you. We need individuals like you.
What is source of electric field of photon produced by oscillating electron? Electron never loses any of its electric field. What happens to photon's electric field when it is absorbed by electron.
When an electron emits a photon it definitely does lose energy, (othewise the electron cannot emit a photon). When an electron absorbs a photon, it will have increased energy.
@@MichelvanBiezen Thanks for reply. Photon has both energy & momentum. A mass bearing object in motion also has energy & momentum. When such object transfers its energy & momentum its mass remains intact. Similarly a photon should be transferring its energy & momentum to electron but its electric field should remain intact. My question was what happens to electric field of photon.
Since the energy of a photon is solely a function of its frequency: (E = hf where h is Planck's constant), a photon will either be completly absorbed and ceases to exist, or it will change its frequency if only part of its energy is given off (like with Compton scattering).
According to Einstein's theory, E = mc2, Energy has mass in it. If m is 0, there is no E. Therefore, a photon has to have a minute amount of mass, which also explains why it can have momentum.
I respectfully disagree
Plancks' constant is not 'joules per second'. It is joule second. Two different things.
You are correct
Photons are bubbles of inflated space, -they get emitted in a variety of shapes and sizes, but they are just pockets, or bubbles of less dense space.
if photon doesn't have a mass how can it have a momentum. please explain
The oscillating electric and magnetic field of the photon interact with the electrons and nuclei of atoms, causing a force interaction that acts as if it has mass.
photon is what controls everything...you,me...everything! it is what lights up those images in your head and controls your body.
Very good explanation! Thanks 👍 a lot!
Glad it was helpful!
Please note that 300 million m/s (3x10^8 m/s) is a little over light speed Michel rounded it to 3x10^8 m/s just to save time.
The actual speed of light (in a vacuum of course) is roughly 299,792,458 m/s according to the internet.
dur
I think a photon has some properties of mass. It is affected by gravity, has Kinetic Energy, can produce electron & positron both mass bearing particles. Concept of massless photon comes relativity. Is there any conclusive evidence that photon has no mass. Electron & positron produce photons, both Electron & positron have mass. I think 1 directional motion of photon is due to its mass since electric & magnetic flux only oscillates in opp. directions. Particle like action of photon is due to its mass. Wave behaviour of photon is due to Interaction b/w fluxes. I know this is not what current thinking is but I am curious about photon having no mass. I think all stable particles must have mass, electric & magnetic charge.
Photons do not have mass, and do not have kinetic energy. But yes, they do have mass like properties and they do have momentum. They are essentially chuncks of energy, but the energy is a function of their frequency (not velocity or mass)
@@MichelvanBiezen Thank you for clarifying. Since photons have no mass, during annihilation rest mass of electron and positron must be covering into energy of oscillating electric and magnetic fields following E=mc2. Do we know how does this transformation take place?
No, we do not know how matter transforms into energy.
Photons have mass? How else could they interact with for example the gravity from black holes?
+Johanbogeberg No, photons don't have any mass.
+Michel van Biezen but you can in deep hubble images see that galaxies and dark matter bends light. Black holes are also known to bend light. I was sure the reason for this was that light has a tiny tiny mass
+Johanbogeberg Gravity bends space which photons travels trough.
I see, so there's a denser space where there's gravity, making the time slower? Which then makes the light to refract - because it's "traveling slower through gravity"? What about electric and magnetic fields, can they alter the directions of the photons?
No, photons follows the curvature of spacetime which again is impacted by gravity (although there is refraction due to earths atmosphere).
As far as I know, neither electric or magnetic fields can alter the direction of photons since light has no electric charge. (Well if you enter quantum mechanics and look into very very strong fields it can happen but that is something else).
By all means, I am no expert so I might be wrong as well :)
If a photon reflects from a mirror at 0 degrees then since it changed its direction to the opposite it would have had to been at zero velocity at some point. At this point how does it continue to exist to reflect if a photon that doesn't move doesn't exist? Clearly they do exist at zero velocity to do a turn around at 0 degrees. Right?
Any object spends zero time at the turn around time, and therefore is never at zero velocity. The speed of light remains the same through the collision, only the momentum switches direction.
Photons are not things. The Newtonian corpuscle idea is just as dead today as it was in Newton's time. Photons don't have positions and they don't have velocity. They don't move along a path. All of that is just bullshit in the minds of those who didn't listen carefully in high school when we explained to them that a photon is simply a small amount of energy. :-)
what is the moving mass of photon?
A photon does NOT have mass. It interacts with particles as if it does, in that it has momentum and can transfer the momentum to another particle.
This interests me, as it is said (and taught in college physics) that the "REST mas" of a photon = 0, implying that a moving photon actually has non-zero mass...
wow, you are a so good teacher
Thank you! 😃
Quantized disturbance in free space propagating at 'c' indefinitely, starting from near the Graviton and ending same.
3.9*-19J
Nice lecture ! Always heart breaking to see profesionnals use "sec" for Second SI unit, which is actually "s" only. Having γ used for photon instead of "photon" would have been great also. All this, does not help the public audience to get used to standardized units to ease things for everybody on a middle term basis. Meanwhile, Km, Kph, sq m & al will still be there 😒
thanks keep uploading please
I`m not a scientist obviously , but I just don`t get it , if photon has no mass how can it have energy ? what happened to E=mc ,
+Brunon Dziedzic
A photon is the essence of what energy is. The energy that we receive from the Sun is in the form of photons. Each photon carries a quantized amount of energy from the Sun.
energy doesn't have mass. e.g. heat is a kind of energy, when the heat reaches you, you just feel it, you won't gain mass.
Michel van Biezen that was a simplistic explanation. Thanks man.
You got it right. There are no photons and for the reasons you state.
But, when you go outside and see the sunlight and even the warmth of the Sun on your skin, it sure seems like it must be energy, huh? Actually, light is NOT energy...or photons...or waves. Wait a sec! How can it have a wavelength if it's not waves? Easy. It has a varying intensity with a specific period between repetitive parts of that variation which can be plotted as a wavy-looking line. But, it's not a wave and doesn't exist as any sort of wave mathematics or wave analog (such as ripples on a pond which also can be better explained as something other than waves).
The sunlight does NOT come as energy. The warmth we feel is from energy that's already there in the matter that makes up our skin (and all other matter). Parts of the sunlight provide a "signal" (for lack of a better word) that changes the rate at which the particles of the matter move. When the speed is felt as warmth, it's a "signal" at a wavelength and intensity (amount of variation) that speeds up the particles of the matter of our skin.
Obviously, there's some sort of relationship between the rate of the "signal" and the speed of the matter particles and you can find people asking the question around the internet of what that relationship is. Sadly, since "light" and "electromagnetism" are so poorly understood, I have yet to see a satisfactory answer.
Some of our nerves respond to matter particles moving at "warm" and "cold" rates (faster and slower). I don't think we are able to feel infrared wavelengths directly but feel the change in particle speed.
When the matter resonates strongly with other rates the "signal" changes, it can re-radiate those "signals". If the rate (frequency/wavelength) is within the range that stimulates color receptors in our eyes, we see them as colors.
Always be suspicious of explanations that violate the laws of physics...as you were and unlike the presenter of the video who obviously doesn't question anything he's mrmorized in the science and physics classes he's taken.
its E=mc^2
Luv the topic. Gonna go buy a text on particle physics.
It is a very fascinating topic indeed. 🙂
You are doing a great service. I love your videos
Plz tell me how & where I can send my donations
FYI....I am here just to seek knowledge
Thank you. Glad you found our videos. 🙂
www.ilectureonline.com/donate
www.patreon.com/user?u=323607
@@MichelvanBiezen
Done
Vibrate the side of a round bucket of water. . ..Because photons are input +1=0 now -1 output 3D wave centers of pure Vibration continuously coming into +1=0 now -1 out of existence.. . .
All the elementary particles are composite particles composed of dark matter particles smaller in size than photons (i.e. You can't detect them with photons). Photons do indeed have mass just too small to measure - they are deflected (interact) with large mass density fields (i.e. Large curved spaces of mass). If photons had no mass, they would NOT interact with mass fields at all and thus their trajectories would not be altered.
How is this photon particle generated by applying heat?
From the atomic perspective, every atom becomes an oscillator and the oscillation (caused by heat) will send out photons.
so every atom has photon particle and by the applying heat they release that
Not exactly. Photons are energy. As the atom vibrates, it loses energy by emitting photons. They convert kinetic vibrational energy into photons (energy).
I love the ending of the video 😊😊
😄😄 Yes, each video doesn't go as smoothly as you may think....... (that was funny!)
@@MichelvanBiezen That ending was as beautifully light as light - or as a photon should I say? 😊😊 Thanks for your videos ...
Thank you for explaining about photons🥰
Happy to help!
Photons is any energy pack With 0 charge, spin of one With two possible orientations and 0 restmass..I wish more teachers Would focus more on the core of the sience
One question here..... If photon has no mass why black hole makes it sink down ??
That was the big conclusion Einstein realized when he formulated the general theory of relativity: that light was affected by gravity.
Michel van Biezen..... Yes, ok I get it....... Fake illusion = Gravity makes light also curve but actually it is curve of spacetime fabric.... Thanks for replying.....
Answers to your questions can be found here in this playlist: PHYSICS 66 - QUANTUM MECHANICS
Why can't you weigh an atom before and after absorbing a photon and determine the weight of that photon?
Since E = mc^2 The energy amount of a single photon is so small that you cannot measure it.
@@MichelvanBiezen Okay then how about moles of photons and moles of atoms until you get a measurable response. We can measure energy from light in this way. If we can determine a single photon is being ejected during the double slit experiment then we can determine X moles of photons. Even if we needed to use X moles of light sources to achieve this all ejecting a single photon. Then just divide by the same amount of moles to get to a energy of a single photon. We somehow know that blue light has more energy then red light and the only way to know that is to know that a single photon of blue light has more energy than a single photon of red light once you work backwards to a single particle from an experiment. I don't look to math formulas to tell me what is possible but to my imagination as you can see, imagining experiments just like the early scientist. I am not 100% convinced that the formulas are complete and feel like they are missing some terms or are only true in finite circumstances. Just like the speed of light is not c. It is the refractive index. Even space is only 10-9 torr of a vacuum and is therefore a medium. You are brilliant but I would like to see videos and answers explained verbally if possible and not just rely on the math which is just a human construct. You are one of the few that responds to comments and are in the right spot to answer such thought experiments.
I know I will be attacked for my statement but I will share it anyway.Light does not consist of photons and has no speed. It has a rate of propagation and it depends entirely on the medium it goes through. Light is waves or disturbances that are completely invisible until they encounter a target....
Thank you sir
Thanks
there a other think also going on on earth
this professor is 3x10^8. time better than my teacher how teach the same thing in my school 😂😂😂😂😂
Hi Michael, how can I imagine a piece of Energy (Photon)?Energy is not a physical number. It is only a calculation number (in my opinion).
We have placed satellites into space with "solar sails" and the photons coming from the Sun striking the sails caused the satellite to accelerate. And satellites in space need to be adjusted from time to time as a result of the Sun's photons striking them and moving them from orbit.
@@MichelvanBiezen Thank you, Michael
ok, that proves that they exist. But I cannot imagine, what they are (a particle with a mass of 0 is hard to understand), how they look, how they transport energy (in my opinion energy per se does not exist, it needs differences of a charge or a velocity or similar). And on the other hand: where is the wave in this context?
Olaf from Vienna/Austria
A photon with enough energy can collide with an electron in a metal and deposit the energy the photon contains to the electron, such that the electron can pull away from the electrical attaction to the metal and give the electron a velocity as it flies away from the metal at high speed. Only energy can do that, nothing else.
@@MichelvanBiezen Hi Michael, thank you again. Yes, you describe the photo effect and I agree, that must be because of energy. But what I don’t understand is, how is it in space.
The energy must come sun and earth. But how?
OK, you say, a photon is a quantum of energy. In Wikipedia is written, a photon is a type of elementary particle that serves as the quantum of the electromagnetic field. But how can I imagine an electromagnetic field in that giant space?
But in relation to your description as a piece of energy: I don’t think energy exists as a physical property. If you imagine the heat flow through a wall. There are only temperature differences and the heat capacity of the wall. The energy flow is simply a calculation value, nothing real.
Olaf
When heat enters an object, it causes the vibration of the atoms to increase in both magnitude and frequency, making the object hotter. Therefore energy is storen by an object through the vibrations of the atoms. When you place a hot object in contact with a cold object, the vibrations of the hot object cause the vibrations of the cold object to increase. When the objects are at a distance from one another the energy is transferred from the hot object to the cold object via the electromagnetic radiation.
do photons have no mass even when they are moving at the speed of light
Yes, photon do not have mass under any circumstances
No
How its possible ,photon of no mass but momentum?? then photon is a matter or energy or wave??
A photon is essentially a "piece of energy", but it has NO mass and yes it has momentum. When a photon "bumps" into an electron it will transfer momentum to the electron.
Can I know what will be the condition of bumping of photon into an electron. And how it is possible ??
Any example ?
thank you ,for your reply
A photon is an oscillating electric field. When it gets close to a charged particle like an electron, the electron will be pushed by the force that exists when a charged particle is in an electric field and it will be pushed by the changing magnetic field.
Ask yourself this: why should there be a lower limit to the matter size spectrum in our universe ending in photons? Adhering to this belief will not lead to the understanding of the structure of Dark matter and explain the numerous other existing mysteries and paradoxes in contemporary physics. On the contrary, understanding that all "visible" elementary particles are composite systems of matter will lead to the origin of the matter in our universe from the Big Bang as well as explain why and how the Big Bang actually occurred.
h is not J/s which was verbally said when introducing what h is
Yes, it is J x sec
Thank youu!!!!!!!!!!!!! MAY Allah keep you Blessed
Thank you. May Allah bless you and your family as well.
If you say so, or whatever story you choose
It's interesting that a particle can violate all the laws of physics and still be considered not just real by physics 'experts' but, also pretty easy to define and describe. I'm thinking that maybe some attitude and aptitude adjustment might be in order..
I'm guessing you don't have much of an eye for irony.
Brilliant
They have no mass but they can bump into another particle and has a momentum???
Then don't "bump" in the traditional sense, but they can indeed impart momentum on other particles (and yes, they don't have mass).
If light is em wave then what is the role of photon
It was discovered that light (and E&M ratiation) has dual properties at the same time consisting of wave like properties and particle like properties. Experiments can be done to show that both are true at the same time. Einstein received his nobel prize for showing that light has particle like properties in the photoelectric effect.
@@MichelvanBiezen so its not discovered?
@@MichelvanBiezen officially
Yes it was discovered, and multiple experiments have shown it to be correct.
@@MichelvanBiezen then why does every one say that em radiation are stream of photons and not changing electric and magnetic field (google)
There are two equations one of which is on the white board at the very beginning of this presentation which immediately contradict the statement that a photon has no mass. E=hf and E=mc(2) the first equation shows that frequency is equivalent to energy(mass) and of course the second shows that indeed Energy is most definitely equivalent to mass. you don't have to believe me simply listen to the people who derived these equations Messr's Einstein and Plank and also Sir Roger Penrose. If a photon has frequency then indeed it has mass this is irrefutable.
The fact that photons don't have mass yet they can bump into other particles and make them move makes things really really weird
Nature is full of surprises.
Wish my teacher taught like this
Photons have "mass", which is the same thing as energy, waves on the aether.
"Particles" don't physically exist, photons and matter are wave movement on the aether.
A photon IS momentum in one direction.
"Photons move at the speed of light", so photons move at the speed of photons, lol.