layman: so, how do we go from newtonian mechanics to relativistic? physicist: just put in the lorentz gamma factor into every equation bro

In fact, i want more equations

His T-shirt says: "It's all fun and games until someone divides by zero"

Equations are fine! they're just more precise (and so more useful) than saying exactly the same thing, in any spoken language. Please use them often! With, of course your usual clarity of explanation. Thanks!

Earlier, I found relativistic mass concept very difficult but after watching this video, I finally understood the whole concept. You are just awesome.

1:43 i think all your viewers are "physics minded"

Fantastic video! I love that you give the equations but still make the theory easily understood for people who aren't interested in them. More formulas would be great as long as you can continue to explain the concepts without needing them.

Thank you for this video! I remember my prof at university explaning this (in 1995) and adding: "Imagine a Lorentz-Transformation of an object with mass m. Time and velocity changes under this transformation - what would identify this object as itself, when its mass would change, too? Mass needs to be invariant under Lorentz-Transformation."

Too technical? not at all! you explained the equations used in really simple terms. Bring more equations in! they don't take away they ad to it. I am a teacher my self from Finland, history thou not physics, and primary sources are always welcome. Like a historian might bring up radiocarbon dating method physics need to show what tools it uses. Not everyone might understand the whole thing, but in general scientific understanding videos, like all fermilab videos, aim is to show and tell how we do these things and how science works. Keep up the good work!

I very much love these videos in any format, so I'd do what feels comfortable for you

Important post since we hear "rest mass" too often. Thanks for giving it a rest.

Finally. I was confused af when I learned that when something move at the speed of light it should have an infinite mass, while the photons have 0 mass, and after that I thought when u move a bigger mass it would be harder to move than a lighter mass so imagine that you should move an infinite mass that would be infinitely hard, but that turned out to be not true thanks to your explanation 😃

I enjoy the more technical, mathematical, deeper discussion. Good work!

I liked the fact that this video was more technical than others. In fact, I'd like to see more equations, but this is just me. I think is not bad to put the equations as long as you explain the idea behind them. Then people that can understand the equations and the ones that don't will benefit from the videos.

Thank you for improving my understanding of physics. No problem with your use of equations. No problem with your tackling fundamental errors or explaining more deeply than popular physics explanations. Please continue to drill down into fundamental ideas, even if more equations are needed. It's worth the work.

I am a theoretical chemist earlier in my career an organic chemist and I love these explanations with more fundamentals and formulas already known and yet with a digestible way to explain them to the general public. I believe these should be taught to more people so that they now how modern World functions and spell the act of charlatans off. I love your explanations I am a fan.

I really liked this video and would love to see more similar to it. I'm not in physics but I do have a passing interest. Thank you for what you guys do

There wasn't too much math but too little, we want to see what effects the kinetic energy of a moving objects excerpts on the gravitational field, because we know gravity couples not only to the rest mass but also to the momentum (a box of gas weights and gravitates more if you heat it up because of the kinetic energy of the gas atoms divided by c²)

I'm not a physicist. I barely got through Algebra! But I know enough that I took a few minutes and worked out some examples of the equation you invited us to play with and saw you were right (as I expected you were). I learned several neat things in this video, so thank you for it. Not too technical at all. Keep up the good work!

when calculating Gamma, do you use m/s as a unit for c and v?

I'm a huge fan of the channel and I really enjoyed this video in particular. I thought you were, indeed, gental when you used those few equations. I love how much you smile throughout the videos; it brightens up my day. Keep up the great work!

Fantastic video. And i think , in order to understand these concepts this much amount of technicality is absolutely essential. I would love to see even more videos from you explaining these difficult concepts using some equations.

Yo.Can u tell me what books to read;ones that u recommend?I will transcend past normal (shall I say conventional and a traditional way regardless) but to maximize my time spent on all my self studies "emphasised" id appreciate some help to avoid erroneous intuitive way of thinking to get on with the search to intertwine one equation to embody all systems.

Hello sir, Wanted to ask what are the other applications of relativistic mass apart from using it in the momentum equation

This is the first video of yours I've watched and I found it excellent. The balance between scientifically correct and intuitively accessible content was perfect for my needs. I'm looking forward to watching more. Thank you.

sir really this video is very good and interesting like your other videos and sir please keep making videos, i know that your videos got less views than your videos deserve but I love your videos and many others like me who love Physics also love you and your videos so sir please please keep on making them..,I Love Fermilab and I want to come there in future.. and sorry sir for my bad english

Hello sir, how did the observer measure the light observation while it did not hit his/her sensors. are we assuming that the speed of observation is absolute considering the that the stationary observer has the emitter and he sensor.

Love all your videos. This was as technical as you felt you needed to make it in order to explain the concept fully. I watched it twice just to make sure I'd understood the concept of gamma in all this!

This was an excellent balance of assumption of knowledge and explanation of concepts. You produce some of the best videos on these relatively complex physics concepts. Keep it up! (and definitely don't dumb it down...)

It was not confusing at all! Please more equations in future videos. There's stuff that's meant for everyone to understand, not excluding even those who have a fear of equations, and there's some university level lecture stuff, but really no middle ground. So far I've found that Fermilab's videos have a good selection of topics, but leave at least me hoping for longer, in-depth information on the topics introduced. (Maybe consider starting another channel?)

Do electrons ever move fast enough that they require a gamma to describe momentum? The math I have been working with in my intro to quantum class uses p=mv when when working with the momentum and Hamiltonian operators. In an atom electrons don't move near the speed of light but a free particle conceivably could? Does it have something do to with the wave nature of matter or is that just because the problems we've been working with are with electrons that are too slow and the gamma can be ignored?

Now I am confused. In previous of yours that I've watched you explained that most mass comes from the fact that quarks in protons and neutrons move or vibrate at the velocities close to the speed of light and that is what increase there actual mass (which comes from Higgs field) and we normally use these masses in the Newton equation. But now you say that we cannot do this with particles having speed close to the speed of light. Can you clarify this?

Great explanation, very useful. I was not at all bothered by the (slightly) more technical nature of this one, and I think you could go even further. There definitely is a point where it becomes "math majors only," and I think PBS Spacetime has been crossing that line lately, but you're definitely doing a good job keeping it in intuitive territory.

I'm glad you cleared this up. I always had an issue with the idea that the actual mass of something grew with velocity. If that were true, event horizons would cause runaway spacetime curvature!

Dear Dr. Lincoln, I am bit confused by this video. If an object doesn't increase its' mass when it approaches the speed of light, how do you account for the weight of the proton, which I thought was due to the confined quarks moving near c (and the gluons)? If those fast move quarks don't cause the mass of the proton, what does?

Does this same concept apply to changing length with speed, is length not actually changing as well?

I thought the video was eloquent and informative, and thanks for introducing gamma

I think the base level is perfect. I'd actually enjoy more 'advanced' videos where these more basic ones are further explored. Perhaps confine the math to those 'advanced' videos instead of having to apologe for using maths in many videos?

You're very good at this. First you take up a confusing topic, one that people may not have recognized being problematic. Then you use a proper perspective and simple way to explain it. Then your speed rate of talking is perfect. Not like those video with the guy talking too fast and linking sentences together in fear you'll leave the video. You're very good at this.

So gamma factor is always there in momentum equation but changes noticeably at relativistic velocities and hence momentum is changed but the mass is always constant? Did I conclude it correctly?

Don't worry about putting ecuations in your videos as long as they are simple like this one! :-)

I prefer a little math in these types of explanations. However, I might be more math oriented than some.

These videos are great but cannot see a playlist or more importantly an order to watch videos in, you keep saying on a previous video so what is the best order to watch in

Is there an increased interaction with the Higgs field as one approaches c and if so is this a way of connecting relativity with the quantum world?

Love you sir ,you are a real gem!please continue making such great videos for curious science students!

Thanks for removing the confusion regarding relativistic momentum! ALL physics professors should ditch the concept of relativistic mass and ALWAYS include gamma when explaining Einstein's famous equation! It would make it MUCH easier for ALL students to grasp! It's quite easy for the average person to see mathematically, that as you approach the speed of light, you get closer to division by zero in the gamma term, which is ALWAYS equal to infinity.

Don’t dumb down your content for any reason... I appreciate the hard ideas even if I don’t fully grasp them immediately, and contemplating what it all means is the joy of life.

Someone please help :). He said gamma approaches infinity as velocity approaches light speed. The formula he showed isnt working. I put a huge speed in for v (I used c minus 1) but the answer is around .5. what am i doing wrong

I appreciated this video and the detail that you went into. Without the details, one cannot hope to really understand the distinction in concepts like this . Thank you very much for this.

Think you could go more technical. Videos like this, with a simple and a less simple part, would be welcome

This is excellent content. The way to really understand physics , not getting bogged down in math but using the math appropriately as needed. I’m not shying away from long advanced math calculations just expressing the right ideas first or understanding them. Love your channel . Subd. Can’t wait to watch more videos.

So if we had a proton moving at 99.99% speed of light near the earth do we use M(rest) in newton equation or M(relativistic)=[E(calculated from inertial mass)+E(k)]/c^2 in order to calculate grav force in earth reference frame? PS I didn't study physics so plz be gentle

For me it is amazing!! Keep pushing!

It wasn't really technical. I love these equations. They help you get a better understanding of what is truly going on. I like it this way, please do not fall into the trap of treating your viewers as morons. We can do math. :)

dear mr Lincoln; a) doesnt the kinetic energy not represent some mass ? I mean p=gamma*m*v and E=1/2 *gamma*m*v^2 (and therefor E=mc^2 (or its more correct version) is pretty much close the same. b) from what I understood (correct me if I am wrong) is that the mass of for example protons /neutrons ect largely is represented due to the kinetic energy of the subatomic particles that make up these particle and that, for about 98%. so that we basically can say we consist for the majority of kinetic energy, mass wise speaking… c) can we not say the more kinetic energy an object contains the harder it gets to deliver some more kinetic energy to speed things up ? because of the energy content (and therefor impulse but also mass) d) so inertia is basically the resistance of an object containing kinetic energy to gain more kinetic energy.

sir is density of a body change when mass increases in high velocity ?? and is density changes during length contraction??

Please feel free to delve deep, but beware the balrog.

Beautifully explained, as always - thank you.

I have a question about photon at rest i.e at zero deg K . I am told that mass-less photon either moves at speed of light else doesn't move at all so in Bose Einstein condensate photons stop moving but with respect to what? Does it stop moving in all reference frames like speed of light is constant in all reference frames?

I'm late to the show but since I found this channel, I've found myself watching (and rewatching) a number of videos from this series. Thanks Don! I have a question about the relationship between gamma (scalar?), mass, and velocity . Slower objects' momentum is more heavily influenced by mass. Faster objects approaching the speed of light sees gamma far exceed any significance mass has on momentum. Is there any special defining qualities of an object moving at a velocity that finds gamma equal to its mass? It would have to be travelling very fast, obviously, but I feel like it describes a unique state when gamma and mass contribute equally to momentum ..

Yes Sir we want more Math more and more equations. Great video sir.

I feel like it was not hard to follow, although I'm an electrical/software engineering student, but I have not had general physics classes in over 5 years (turns out computers dont care about gravity?)

perhaps i need to watch the update first, but wouldnt the answer be as simple as C being an asymptote of the gamma equation, which is also an exponential increase function and as a result being impossible to get at but infinitely approaching?

Thank you for the work you are putting into to make what I call your great, "Explaining Physics Series". The speed at which you explain subjects and the clarity of your explanations really makes learning easier. But it is the example of the thinking process that helps the most. Now I know why my idea of how to beat the energy generation requirement to exceed the speed of light is most likely wrong! I thought that if I used the increase in relativistic mass applied to a nuclear reaction power generation process the energy generated would approach infinity as the mass approached infinity, WaLa! Now time to reset my thinking. On the other hand if we did manage to exceed the speed of light then we would never know, we would have lost all references by which to comparatively measure the event. I think. In therms of energy I call Zero point energy and the energy at the speed of light the energy bounds/limits of our Universe. The other side of these limits exist other Universe Dimensions. Again I think. I have so much more to Learn, I need all the help I can get! Thank you for sharing your knowledge and your thinking process.

Not understanding this doesn't keep me from enjoying listening to it.

I'd prefer a bit more depth than even this to be honest, but keep it up, whatever you feel is best.

I am so glad I stumbled across this video because that has always been something I could never quite wrap my head around. I remember the very first time that I ever heard that term used. I thought to myself so if I were sped up to the speed of light then would I lbe everywhere all at once. Your explanation makes far more sense. Thank you for this video and for clearing that up.

I think that relativistic mass is a very useful concept in relativity. In SR, we have F = dp/dt where t is the proper time and p = mv in which m is the relativistic mass. The equation tells us the the larger the m, the larger the force required to produce a given acceleration. This shows that m has the meaning of inertia of a body.

Yes ! a new Don video !

Fermilab: *towards the end of the video* “but don’t worry, I’ll make a video explaining the REAL reason you can’t go faster than light” Me: *looks at recommended* “How to travel faster than light, by Fermilab” Also Me: Hmmmmmmmm...

My question might be silly, but if time "slows down" for the "frame" who wish to achieve the speed of light, then from it's perspective mass is constant and isn't it free to go faster then the speed of light?

Can anybody help, he lost me at m (crossproduct) v. v is a vector, as is \gamma. So the vector product \gamma (cross) v is clear. However, m (cross) v implies that m also is a vector, which I cannot see. Wouldn't mv be a scalar (point) product? wouldn't that mean it's E=\gamma (cross) (m \cdot v)?

I will have to watch it again, maybe a couple of times. Don't change your approach. I love that you take the time to explain these complicated science explanations of reality.

Equations is better for better understanding.

Thank you. What does gamma represent in the equation?

OMG! Thank you! I've been writing a sci-fi story about space travel and I couldn't get straight answers about relativistic mass. Specifically, did that mass only apply vs the forces acting against it or did it affect the universe around it as if it had that actual increased mass? In other words, did its gravity well increase as the speed increased? The answer means I have to do some re-writing.

Now we are owned a video that explains why is the Lorentz factor in that equation in the first place :)

I'd say if anyone really had a problem with the equations or subject matter they'd be watching something else. Do what you do.

Really good. I have a bit of equation phobia, but you explained it really well and I had this urge to hit a sheet of paper and start playing with the terms. Super cool, haven't had that urge since college!

Your explanation of the equations involved here are clear enough to make it easy to follow what you are saying without having to understand the equations. It's like discussing quantum physics - no one really undertands it but that doesn't stop us from discussing it.

High five to whoever owns the dorito with the wing. (Rx-8) Answer, the info wasn't hard to follow at all.

i want more equations

Since speed is relative, is gamma and consequentially mass it self relative? Ie: if your traveling along at half the speed of light at a given relativistic mass and an object is travelling towards you, also at half the speed of light, is your mass now infinite relative to that object since, relative to that object, you're travelling at the speed of light?

So if mass does not increase then physically what property of matter increases at relativistic speeds which makes the momentum approach infinity? Gamma is a factor which represents an increase in something, what is it that increases?

0:33 ha ha ha. "unsolicited correspondence", another words "stop sending me mail!"

Oh dear, so is length contraction even real ?

Thanks, such a wonderful explanation. I still have a question though. I really thought the relativistic mass is because of the energy of your motion (kinetic energy) being manifested into mass because of Einstein's most famous equation E=mc^2.

Please add any algebra formulas or equations that pertain to your subject, but also keep up with explaining these very complicated ideas in ways that do not need math, to understand. I once heard someone say, "If you can`t explain it simply, you do not know the subject well enough to be explaining it". I am not sure who said it and the quote may be paraphrased, but you get the idea. Thanks for the excellent videos.

Well, there goes my theory that dark matter is only the increased mass of everything in the universe moving at very high velocities.

This should be the minimum I really like this”show” but you could add more equations.

So my interest is inertia. I want to learn as much as I can about it. Any suggestions?

I would like to know what if we apply ultraviolet on a electron in a hydron Collider, it would add more speed or slow down, for me this a very important question, so I can understand mass and energy, can someone answer please.

thanks for teaching right lesson

"How about a bullet from a sniper rifle?" *Shows someone shooting an AR-15* (Love the video btw)

Hi sir I have a doubt By this equation if we are travelling with velocity v our mass increases but car, bike travells everyday thay also have thier mass but how thier mass dosnt increase ?????

So is gama correlated to time dilation?

That's not a sniper rifle. It's a normal, everyman's AR-15

I dunno, some of MY relatives are pretty massive.

Can you recommend us physics book? Or tell us which books you show in videos?

How are the values for gamma derived if v> c?