Where Does Electric Charge Come From?

Electric charge is both a spacetime invariant and conserved over time. To understand why, we'll need to dive deep into it's connection to the electromagnetic field through Noether's theorem and quantum mechanics. Brilliant for 20% off: brilliant.org/ScienceAsylum
________________________________
VIDEO ANNOTATIONS/CARDS
What is Electric Charge?
• What is Electric Charg...
When Conservation of Energy FAILS!
• When Conservation of E...
What is a Quantum Wave Function?
• Quantum Wave Functions...
________________________________
RELATED KZbin VIDEOS
PBS Space Time on Noether's Theorem:
• Quantum Invariance & T...
• Noether's Theorem and ...
________________________________
SUPPORT THE SCIENCE ASYLUM
Patreon:
/ scienceasylum
Advanced Theoretical Physics (Paperback):
www.lulu.com/shop/nick-lucid/a...
Advanced Theoretical Physics (eBook):
gumroad.com/l/ubSc
Merchandise:
shop.spreadshirt.com/scienceas...
________________________________
HUGE THANK YOU TO THESE PATRONS
Warden of the Asylum:
[Available]
Asylum Counselors:
Matthew O'Connor, Nikolaos Vasiloglou II
Asylum Orderlies:
William Morton, Fabio Manzini
Einsteinium Crazies:
Wacky, Eoin O'Sullivan, Ken Davis, LT Marshall, Ilya Yashin
Plutonium Crazies:
Al Davis, Compuart, Ellis Hall, Kevin MacLean
Platinum Crazies:
Olga Cooperman, Rick Dinning, Kyle Bowles, Eugene Boone, Jon Adams, Mr. Orn Jonasar, Vittorio Monaco, Stephen Blinn, Mikayla Eckel Cifrese, Jonathan Reel, Volodymyr Shcherbatenko
________________________________
OTHER SOURCES
quantummechanics.ucsd.edu/ph1...
quantummechanics.ucsd.edu/ph1...
arxiv.org/abs/quant-ph/0302062
www.cbooth.staff.shef.ac.uk/ph...
web.mst.edu/~hale/courses/Phys...
www.ippp.dur.ac.uk/~krauss/Le...
physics.nist.gov/cuu/Constant...
________________________________
LINKS TO COMMENTS
• What the HECK is Time?...
________________________________
IMAGE CREDITS
Emmy Noether:
commons.wikimedia.org/wiki/Fi...

[@ScienceAsylum]

*Clarification:* When I define Noether's theorem at 1:52, the text on the screen is correct. However, there's a subtle disconnect between the broad conceptual language and the strict mathematical language of Noether's theorem that makes what I say out loud misleading. It would seem the math of Noether's theorem only applies to _continuous_ symmetries. There are _discrete_ symmetries that also result in conserved quantities, but are not due to Noether's theorem in the strictest mathematical sense. #LanguageIsHard

[@jacobkrebs5026]

Why can we apply noethers theorem, isn't it only defined on Euclidean spaces?

[@AlleyKatt]

Seems to me... if you were wanting to convey a strict understanding of Noether's theorem then you would've gone heavy on the maths. But you were going for understanding a concept, so the only way I can truly consider your words to be "misleading" is if I'm just trying to be a ∆!¢k about it.

[@erikawanner7355]

#quarantineinvariance

[@michaeldamolsen]

Nothing to worry too much about, but I applaud the fact that you mention it :) I think the video was mind blowing enough without a discussion of Ward-Takahashi identities, but maybe something for a future video?

[@yuotwob3091]

It's gone too far to go back.

[@lorenzocimino2827]

Honestly, as a Physics major, it's one of the best educational video about gauge invariance

[@davidhand9721]

You like this one more than PBS Space Time?

[@brilliaurabillah8974]

but it seems more understandable for wide (i mean people who not take physics major) audience than pbs space time

[@Familia_nepal_nepal_do_mal12]

@@davidhand9721 I think this one is better than what PBS spacetime did (and I think PBS did a good job). The lectures about this are usually terrible.

[@dannyj4858]

What are you doing knowing gauge invariance as a physics major lol

[@DANGJOS]

In what physics major are you learning gauge invariance? Seems like a graduate topic

[@constantinandro684]

I like how this channel goes into deep concepts. A lot of science channels scratches only the surface so that it's more digestible to the masses.

[@juanfromthecosmos]

We had the meme:"Actually, Quantum Mechanics forbid this". Now, we have the new one!: "Quantum Mechanics requires this!"

[@6900xx]

I came to comment section as soon as I heard him saying that 😂

[@s3cr3tpassword]

Yea he even made it into a meme format with the placement of the words and choice of fonts too!

[@jasonremy1627]

Wasn't it Gell-Mann or someone like that who said something like "That which is not forbidden is mandatory" when referring to quantum mechanics...

[@ronaldderooij1774]

It's the virus that requires and forbids everything nowadays. The universe has changed.

[@mtslybot78]

@@ronaldderooij1774 its changing. always is. the footprint left by the common experience in the moment can't be predicted, and often is not as impactful, or the impact subverts expectation, in retrospect. But I agree that 'now' is very weird. 2016 was weird, too, and it rocked the worlds collective psyche. I'm tempted to suggest that moment in recent history forced the collective consciousness to discover its ability to adapt to the unexpected, and leaves us better equipped to accept and adapt to, and/or rebuild the structure that is absent in this extended moment of human experience

[@drewkelly1955]

Anyone else lost af? I’d honestly appreciate a more in-depth lecture on this

[@polychoron]

I'm lost beyond fuck. But mostly because I can't math. All those greek symbols are just scrambled eggs. It's still very interesting, the parts I understood.

[@davidhand9721]

Watch PBS Space Time episodes on Noether's theorem. Also, same show has a good episode on this topic, called, um, quantum invariance something something... you'll see it. Much more in depth.

[@TheJohnblyth]

I think it’s becoming expected because of the format that you can slow down, pause or repeat anything that is bothersome. KZbin can let you experience it all at half the speed if you like :) I’m going to have to do that with some of the earlier videos to get a better grasp of what was presented here.

[@martifingers]

Yes, I am very lost I am afraid.

[@pronounjow]

He said this is Part 1 out of 4.

[@susmitamohapatra9293]

I see you're a fan of kurzgezagt as well 😃

[@Nevermind2010]

He is wearing a kurzgesagt t shirt

[@Helwdrokin]

is the fist thing i noticied XD

[@Helwdrokin]

there a ting i nerver white corectly

[@monikalala3810]

Where did he get the T-shirt from? Kurz gesagt, or somewhere else?

[@abhijitborah]

Birds of a feather

[@rzezzy1]

8:44 finally a counterpart to PBS Spacetime's "actually, quantum mechanics forbids this"

[@AndrewDotsonvideos]

Awesome explanation on the local phase invariance. very nice/10

[@Boog1137]

Ah the cultured one himself

[@zucc4764]

nice

[@akashdeeppaul9272]

*Watches the video lying on the couch and snacking popcorn* Nick : I don't know if you know this but humans are lazy.

[@mldag1678]

Same, I'm also SO tired so I didn't get all of it (I'll probably watch this again) but I still understood a lot of things, Nick is amazing

[@macronencer]

Yeah... this one's going to need several viewings! There has to be at least an hour's worth of material covered in under ten minutes. Still, I'm sure it's almost impossible to simplify this topic. Thank you for continuing to treat your audience as intelligent, rather than dumbing down for cheap view counts. Really appreciate that!

[@ScienceAsylum]

Yeah, this is a problem we all run into with quantum mechanics. If you remove the math from QM, there's barely anything left to talk about. That's basically all QM is.

[@spacejunky4380]

@@ScienceAsylum breaking down the math into intuition is hard to do. I follow the formulas when you explain what they are doing. When they are applied to the EMF I become lost trying to find the connections between the formula's parts and what is going on inside of the model of the field. I probably have to rewatch it to understand it better. When I really follow what's going on, I can see why you're mind is blown because I definitely have those moments too. Thank you for sharing your knowledge, I appreciate your videos.

[@guilhermesantosmacedo1694]

4:06 Oh, that's why we call magnetic potential with "A" then...

[@shayanmoosavi9139]

LOL nice one😂😂

[@Lucky10279]

Yeah that made me laugh.

[@vincelaszloszalma2103]

It was an astonishingly efficient way of breaking down the fundamentals of a very complex subject. The usage of analogies is truly enlightening, not to mention that the structure of categorization you implement is perfectly consistent. I cannot express the value of your work properly. Thank you, sir!

[@AmandaKaymusic]

Well said.

[@nadiyayasmeen3928]

I see Kuzgesagt T-SHIRT

[@Ivan___Cunha]

Great video To be pedantically precise, Noether's theorem says that every continuous symmetry is linked to the conservation of some charge, but not all conserved charges are due to symmetry. Some charges have topological nature (if there were magnetic monopoles, their charge would be topological and not a Noether's charge).

[@ScienceAsylum]

Thanks for the pedantic correction. You're not the first to mention this. I just pinned a comment clarifying.

[@yashagnihotri6901]

As much my knowledge knowledge is concerned , magnetic monopoles don't exist ! Just for the sake of keeping the divergence of magnetic field Zero .

[@michaeldamolsen]

If you really want to be pedantic, I suppose you should say "differentiable symmetry" rather than "continuous symmetry" :)

[@Ivan___Cunha]

​@@michaeldamolsen That's a second order pedantic correction XD

[@Ivan___Cunha]

@@yashagnihotri6901, As far we know there are no fundamental particle with topological charge (like the magnetic monopole), but condensed matter have plenty of topological deffects with topological charges.

[@dixshants1227]

I have been here since you were at 10k subs and even commented that you are one of the most underrated science channels. This video again just proves my point and I will see u again once u hit a million😉

[@FGj-xj7rd]

That's actually a pretty funny thumbnail. It definitely fits with the character.

[@FGj-xj7rd]

Ayyy, thanks for the heart. This heart is also invariant 😅

[@hoodedR]

@@FGj-xj7rd so what is conserved

[@FGj-xj7rd]

@@hoodedR 🥴

[@Darkanight]

it's the first time I see "definitely" being spelled correctly on youtube this month. congratz. lol

[@Zeegoku1007]

@@Darkanight Lol. How ? At least for mobile users spell correction kicks in. 😂

[@MaryAnnNytowl]

I think the cardboard look for some of those drawings is absolutely darling! Now, this video will need a couple of viewings to let it soak in, but with the rest of the explanations of electricity & how it works, it really helps, because it goes to the subject from a bit of a different perspective. Thanks so much for that!

[@Lucky10279]

“We might not know what they are, but their behavior is described by waves of probability.” Exactly! I wish people would stop saying that electrons _are_ waves when the reality is that we don’t know _what_ they are. We do know how they _behave_ though, and that’s far more important.

[@josephlombardo1246]

idk electrons are electrons, and we use the mathematics of waves to describe their behavior. there is no need to figure out "what they are," only what their properties are. there is a sense in which it's not really meaningful to talk about "what they are" beyond excitations in a quantum field. At some level you reach brute facts, and you can only describe things in terms of their properties as mathematical objects but that's just the universe for ya.

[@Lucky10279]

@@josephlombardo1246 Yes, that's what I was saying. We don't _know_ what they are, but we do know how they _behave_ and that behavior is dictated by their properties. That knowledge is far more valuable.

[@da_birdman6800]

All particles are vibrations in a quantum fabric. This fabric is a 3d+1 hyperfluid "something" The theories that describe this are called Quantum Field Theories. Particles have no actual distinct dimensions. They are not balls or any solid thing. Their physical trajectories are fuzzy and that creates probabilistic shapes that vary but the corpuscular view of elementary particles is just an illusion.

[@Lucky10279]

I can't believe I posted this only a month ago! Over the past couple weeks I've become convinced that electrons almost certainly _are_ actual physical waves in quantum fields. That's so ironic! I don't know that I've ever changed my mind about something so completely in such a short time (at least not something I've spent so much time thinking about.)

[@da_birdman6800]

I had a hard time understand physics from solid objective prospective as a teen learning about science. My biggest issue is that each time you say a particle has an exact size and shape that begs the question. Well then what defines that object? More particles? At some point things must be vibrations or motions of some medium or fabric.

[@mtslybot78]

There's a lot to absorb in this video. Concepts explained clearly infer a deeper intuition that I'm honestly struggling to process without having to pause the video. I think this will prove to be a video that is worth returning to multiple times as you incorporate all the nuance from continued study with the goal of deeper, but also more intuitive understanding. Good job!

[@adityachk2002]

Your target audience is even Smaller than vsauce, kurzegat vertasiums physics girl and others.... because you literally talk actual equations

[@manitro337]

Alas, this is the reality of true education; boring as hell.

[@chesterdomingo4590]

I acctually appreciate the presentation of actual equations.

[@mydearfriend007]

@@manitro337 it's not boring at all

[@ronanstephens1597]

PBS Spacetime is where I go to learn new things about physics. Science Asylum is where I go to learn that I have to relearn what I thought I knew about physics.

[@paulthompson9668]

Adityachk2002 He found the sweet spot between Brian Greene and Leonard Susskind.

[@xyz.ijk.]

Outstanding video!!! Seriously clear and complete and among your best.

[@DANGJOS]

Definitely your most complicated video, but also fascinating. Thanks! And I remember that dreaded A vector from Electrodynamics. Makes me want to revisit it and give myself a better understanding.

[@ScienceAsylum]

Yeah, it's definitely a "core audience only" kind of video 😆

[@rc5989]

Great video as always! Lots of great stuff packed in here. Gonna enjoy watching it several times.

[@alexsmit5430]

This is a great application of Noether’s theorem. I learned this in my upper division physics this semester so this was cool to see.

[@pleaseenteraname4824]

Anything: **is conserved** Emmy: "I have been called"

[@Zeegoku1007]

The woman I respect the most 😤🤘

[@timbeaton5045]

@@Zeegoku1007 well, it IS nice that her work has become better known over recent times. Groundbreaking stuff at the time, and underpins much of physics that we now study.

[@ailblentyn]

This will take a few views! What an interesting topic.

[@scienceandknowledgearchive8197]

Thats so great and informative. Thanks The Science Asylum

[@itaybenguigui8788]

You are the best Thank you ! Few months ago I saw Your video on The principal of least action and it got me so interested at your channel!

[@danielwalker5682]

Awe inspiring. Can't say I understood more than ~25%, but hey....I always felt there must be something that would pin down the "arbitary" extra functions on the electric scalar and magnetic vector potentials. I suppose quantum mechanics would have to come in somewhere....Keep up the great work.

[@DeclanMBrennan]

That's a fantastic explanation of phase invariance. You covered a lot of ground in a single decaminute but I found it very electromagnetically illuminating. After the little teaser, I'm hoping for a video or two on relativistic QM - a fun challenge. :-) Thanks for all the energy you put into these videos. It's time well spent.

[@ScienceAsylum]

Thanks! 🤓

[@ocnus1.61]

The quality of information and clarity despite being dificult topics (if one wants to truly understand them) is a great benefit to the youth. Thank you.

[@_Messiii]

Great video! Superb explanation!! Thank you :)

[@reinaldo3091]

5:00 Vsauce reference?

[@lyrimetacurl0]

Or... is it?

[@ShubhamRaj-mu8ol]

Who liked that he is wearing a kurzgesagt t shirt and used Vsauce's "Or is it?" at 5:05.

[@ahmadnurokhim593]

XD

[@nikolaykaloferov2894]

So complicated and also so simple(in some ways).I mean it's good to know what's around us and how it's work. Keep going ☺

[@toknowledge1371]

It's inextricably good to understand for those like me who always trying to grasp Quantum Theory from it's root. Thanks for this magnificent contribution of Explanation.

[@Mr41297]

Thanks for making that 'quantum mechanics requires this' meme so I didn't have to

[@edjanygo]

Hi Nick, I m quite impressed by this video. I ve never come accross any vulgarization articles or videos about charge, phase invariance and EM gauge. This topic is thought to be too complex or mathematical to be explained. Many thanks for the effort of busting the white lies and dubious analogies we are told to simplify our understanding of physics. As a contrary I think the difficulties, the counter intuitive concepts and fine descriptions are the heart of seeing physics as logical system.

[@larryseabrook7089]

Great job covering so many key concepts in such a short period of time.

[@ScienceAsylum]

Thanks!

[@RoXon007]

I appreciate your hard work for explaining deeply.😊

[@cherubin7th]

3:35 I never noticed this before!

[@Private_Duck]

No dislikes yet!! Edit:- This is the only video that made me scratch my head...

[@rauldumitrascu4929]

I agree. Straight to rewatching list. 😁

[@afobear]

Agreed. That was a lot of equation manipulation on the go.

[@nadavdanieli]

Yup, didn't understand a thing.

[@timo4258]

I think nobody understands why quantum mechanics rules are like they are. Hopefully one day we understand the underlying causes for all this.

[@reubenrk3406]

I wish all teachers were like you.

[@johnrowson2253]

Thanks for showing the equation

[@FundamentallyExplained]

Wow that’s a lot of mathematics covered in such a short time :O in my own videos I always end up abstracting the mathematics away a bit more for the sake of clarity, but it is honestly inspiring to see it not done like that, while still yielding a thorough and clear explanation! Awesome :D!

[@ScienceAsylum]

I don't normally have this much math in my videos. I've just been sitting on this video for a year now, tweaking it a little bit at a time and never being happy with it, so it was time to let it go. I needed to be done with it.

[@FundamentallyExplained]

The Science Asylum I hope you are nonetheless happy with how the video ended up! Not sure if it helps, but I think it is impressive to see gauge invariance, Noether’s theorem and the physical implications compressed into 10 minutes. That’s everything but easy, especially while making the explanation as understandable as possible, but I think this video does a great job at that :-)

[@ScienceAsylum]

I'm as happy as I was ever going to be with it I think. I don't think there was any way to make this an A+ topic. It's just too niche.

[@James42_]

Dang it! Why did you upload this hour?! Now I can’t sleep and late for school Tomorrow lol

[@royrosales81]

Another amazing video! Thank you for changing my world!

[@rguimatorres]

Difficult to follow, but you’re excellent explaining! Thank you, Nick! Best regards from Brazil.

[@pratyushbhattarai5632]

Not the first Not the last But when I see Nick upload . . . . . . . I click fast fast!!

[@NoNameAtAll2]

fastfast!

[@Pedritox0953]

2:20 "... my stress goes with quarantine invariance..." xD Great joke!!

[@lekhnathghimire]

2:26 best part

[@MrBananabomber123]

I always love your quantum mechanics videos.

[@benjaminbrady2385]

5:00 Hey, Vsauce. Michael here

[@melonhuskx15]

*Tesla would be proud for that thumbnail*

[@808bigisland]

Excellent! Charisma and intellect and a good sense of humor

[@EarlWallaceNYC]

Mathematically deep video. Challenging,, but worth it. I'm subscribing because of this video.

[@adityasonawane686]

It's mid night and is saw your video and was like ... Let the morning online class go to hell .... Let's watch the video 😎😎 .

[@skylorwilliams5036]

“Hopefully that ties up all the loose ends.” 😂

[@bigbadt392]

That tells u a call of duty fan n u used gen. Shepherd's dialogue

[@EnginAtik]

This video is packed with information and funny as heck. I am sure I will come back to this video many times.

[@christopheryang6416]

I am happy to learn modern physics from your video.

[@elgabacho73]

I feel smarter and dumber after watching these videos. :)

[@areallymessedupdude]

Soo true

[@nishtakasundass6669]

Relatable

[@areallymessedupdude]

I think you are an 👽 alien send to help us grow. That explains the clones 👻

[@kagannasuhbeyoglu]

Great content. Thank you👍

[@DeepakChauhan-lc7xe]

Nice explanation bro👍

[@FedericoGalatolo]

Damn, how I would love to have a deep understanding of this 😅

[@CaioEduardoG.]

Almost first... Yeah Edit: Science, Mr White

[@hawtsauce2471]

Yeah science, bitch!

[@AndreZoiaum]

You are one of the best teachers I ever saw, took me just 2 views to get something I didn't even study in chemistry

[@stefanopastore8886]

man this is one of the best videos you have ever made

[@da_birdman6800]

Nice way to precisely explain the fact that the charges of particles are really about relationships between the rotational motion of said particle & the overall motion of the local fields created by the particles.

[@mikstern5471]

Your videos are great! I would love to see one covering the topic of why spin half particles follow Fermi statistics, and integer spin particles follow the Bose-Einstein statistics. Thanks in advance.

[@c.vdheide]

Absolutely TRUE!!!!!!!!!!!!! In so many senses of the way! Brilliantly done! Brilliantly seen! Totally clear!

[@ProfessorBeautiful]

I appreciate the list of resources. Beginning Nick Lucid's book now.

[@l0_0l45]

Hell I learnt so much new stuff in this video! Please make more deep fundamental stuff like this!

[@1111boone]

I believe I understood at least 3 words this time! A definite improvement!

[@Mowxel]

I havent watched you since you had like 3k subs im glad youre doing great and only on the rise.

[@ScienceAsylum]

Where have you been? 🤔 I hope everything is ok and it's just that KZbin hasn't been showing you my videos.

[@dreggory82]

This was spectacular and magnificent

[@bend.manevitz8261]

I adore your channel, and *usually* I can follow. Not always 100%, not always first time through, but I can get it. This video, however... You need to make like four or ten videos unpacking each little bit. Please.

[@ScienceAsylum]

I agree. This needed an entire series. It's too compressed.

[@js7244]

Amazing content as always! Anyway i have to watch it a couple of times more.. It would be great if you can explain CP violation, it's still so obscure to me, please share some light on it!

[@sillypoint2292]

Hey Nick! Iam really a big fan of you. I love your videos a lot. I always wanted a teacher like you. And the way of expressing the ideas is really awesome. I always wished to see you hit 1M and grow like veritasium and physics girl . So keep hope Nick . I'll see the day when u hit 1M very soon.

[@kylorenkardashian79]

You're amazing Doc

[@lucasfreitag9794]

I can't express how nice this video is. Well done

[@ScienceAsylum]

Thanks! 😊

[@icantthinkofacoolname]

@5:17 you say something really interesting about how we don't know exactly what particles are, but we know they aren't spheres. I would love to see you make a video that explores what theories there are for physical properties of particles. Love your channel!

[@admiralhyperspace0015]

I loved the video but you just show the symbols. Show a little more of the maths. Like just putting the gauge function in and show that it doesn't do squat to the original function. And give things some more mathematical sense. We really can't appreciate these topics without the maths. But its great that you are actually covering such an important topic that others just take as a given or shrink at the requirement of explaining. I am your fan. You bring me real value and cover the best, most useful and complicated topics. Thank You.

[@jaybingham3711]

Good stuff. Thanks much.

[@constpegasus]

Great as always.

[@JavierArveloCruzSantana]

I will watch this a few more times. Thank you.

[@Lucky-df8uz]

Lol you have the impact font ready for Quantum Mechanics Requires This! Great video :O

[@66-desaikrunal71]

You deserve much more subs

[@denniscastillo427]

Excellent videos 🤩

[@mr__dev.__]

Sir , honestly I love your explanation thank you for this ♥️

[@ScienceAsylum]

You're welcome! 🤓

[@MrRogue0402]

Wow !!! Loved This...

[@e7ebr0w]

can't say I understand anything any better, but you did a great job

[@kylebowles9820]

Nice :) a Nick classic! Noether's theorem is one of the most beautiful and fundamental things in math I am aware of. I love duality

[@ScienceAsylum]

Agreed. I love Noether's theorem.

[@K-A5]

I just randomly learned about gauge symmetry last year on some podcast and I've been fascinated with it since. Are you going to do some more videos on gauge symmetry? I hope you do! Also I hope you're doing well during these stressful times

[@js7244]

I'm curious, can you share the podcast, i mean where can i get it, please?

[@michaelupdike-bz6rg]

Do more of these types of videos, please.

[@donabhishek]

I am a fan of science, you have the best way to engage even the non science people

[@arielshikoba1857]

👽The State of the 5th DImension is "Action & Cause" AKA "Effect & Affect" of the Probability of Matter (5th Dimension Light 5th DImensional Matter). And this video explains it! Bravo! 💜

[@jarno4054]

I think my knowledge is accelerating due to your vids, thanks man 😁

[@LacenWolk]

Awesome vid!

[@LuisAldamiz]

I watched it twice, maybe even thrice with so many segments I had to rewatch again and again (my mind tends to wander a lot), and I'm still sure I do not understand everything. But that's probably because you compressed a whole course on fundamental physics in a 10 mins. video. There's a lot of info on the fundaments of Reality in this short video: it's thus extremely hard for any non-specialized human being. I'll rewatch a few more times probably: it's extremely good: a very dense pack of knowledge. TY.

[@yashagnihotri6901]

Yeah , being in 12th grade right now , obstructs my limited knowledge to understand the concept of 'Gauge' included in the video rest all was a bit easier to grasp. Probably today I will read about it (Guage or whatever it is )