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Ask Slashdot: How Would You Explain Einstein's Theories To a Nine-Year-Old? 293

SiggyRadiation writes: A few days ago, my 9-year-old son asked me why Albert Einstein was so famous. I decided not just to start with the famous formula E=mc^2, because that just seemed to be the easy way out. So I tried to explain what mass and energy are. Then I asked him to try to explain gravity to me. The earth pulls at you because it has a lot of mass. But how can the earth influence your body, pull your feet to the ground, without actually touching you? Why is it that one thing (the earth) can influence something else (you) without actually being connected? Isn't that weird? Einstein figured out how energy, mass and gravity work and are related to each other. This is where our conversation ended.

Afterwards I thought: this might be a nice question to ask on Slashdot; how would I continue this discussion to explain it to him further? Of course, with the goal of further feeding his interest in physics.
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Ask Slashdot: How Would You Explain Einstein's Theories To a Nine-Year-Old?

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  • I Wouldn't. (Score:5, Insightful)

    by Anonymous Coward on Thursday January 18, 2018 @07:21PM (#55956515)


    • Relativity might be a better place to start, or just tell the kid humanity is destined to be crushed in a black hole if it is lucky to survive that long.
      • Re:I Wouldn't. (Score:5, Interesting)

        by VernonNemitz ( 581327 ) on Thursday January 18, 2018 @08:48PM (#55957023) Journal
        Einstein is famous for more than just Relativity stuff. He got a Nobel Prize for some work in Quantum Mechanics (explained the photo-electric effect). He may also be famous for popularizing the use of "thought experiments" in physics --he's certainly famous for thinking of some very insightful thought-experiments, that guided his mathematical efforts. And he is certainly famous for promoting the notion that all aspects of the physical universe can be described by a few fundamental equations (even though the notion is still waiting to be proved true).
        • by WarJolt ( 990309 )

          Einstein had no idea how gravity works like the article suggests. Theoretical physicists have some ideas, but no consensus yet.

          Also, the article neglects to mention that Newtonian physics explains gravity as a force that pulls you towards the earth. That particular contribution predates Einstein by quite a bit.

          • I was going to say something similar.

            Einstein's Special and General theories don't really explain gravity. Nor does our current understanding of quantum mechanics.

            There are theories -- there always are -- but there is no solid evidence to support any single "grand unified theory" theory yet.
      • by Evtim ( 1022085 )

        Special relativity is a great "click-bait" because I yet have to meet a (layman) person who does not go wide-eyes when you mention time dilation (most people think that time is a convenient notion invented by humans that does not "really exist as a thing" anyway). It's a great narrative - everyone intuitively understands the Galileo transformations, no problem there. Build it up with few examples (cars, trains) and the go to "let's see what happens when we try to measure the speed of light from different in

    • Re:I Wouldn't. (Score:5, Insightful)

      by 0100010001010011 ( 652467 ) on Thursday January 18, 2018 @07:39PM (#55956657)

      They don't need the math, just the high level concept. Just like we do with every thing else you teach them.

      Use a trampoline. Roll balls around each other and each other.

    • by zifn4b ( 1040588 )


      Correct. In order for someone to grasp the subject matter they need the knowledge foundation that his ideas were built upon. How would you explain the inner workings of the internal combustion engine to a 9 year old? You can't. How would you explain fractional reserve banking or the differences between Capitalism and Socialism to a 9 year old? You can't. What you can do however is gradually educate your kids on the foundation concepts that those higher level ideas are built upon which is supposed to b

  • by AHuxley ( 892839 ) on Thursday January 18, 2018 @07:30PM (#55956583) Journal
    Has some of the history of the atomic age and the science, math. []
  • by eyepeepackets ( 33477 ) on Thursday January 18, 2018 @07:31PM (#55956587)

    ...wait until you get the pleasure of trying to explain how "gravity" warps space, which is supposedly nothing at all, and how nothing can be warped. Then there is the whole issue of time versus timing in the context of perception, etc. Not a pleasant place to be if you want the kid to think you are not just another nutter.

    • by Anonymous Coward on Thursday January 18, 2018 @07:47PM (#55956713)

      General Relativity took me 5 years to get my head around as an adult. I taught my daughter, now 11alot about current cosmology. She now has nightmares about asteroid hits and the heat death of the universe, But she loves maths and wants to be an engineer, so I've done pretty well.

  • Newton. (Score:5, Informative)

    by msauve ( 701917 ) on Thursday January 18, 2018 @07:31PM (#55956589)
    "Einstein figured out how energy, mass and gravity work and are related to each other. "

    That would be Newton. Einstein tweaked Newton to cover the extremes.

    To acquaint someone with Einstein, start with some of his thought experiments [] which break Newtonian physics.
    • Re:Newton. (Score:5, Informative)

      by dfsmith ( 960400 ) on Thursday January 18, 2018 @08:25PM (#55956913) Homepage Journal

      Newton didn't get the energy part.

      Einstein (as I understand it) and the rest of the physics world had a problem in that Maxwell's Equations did a really good job of describing electromagnetism. However, the wave equation that pops out does not account for the velocity of the observer. This implied that the speed of EM radiation (light) is constant for ANY observer: oh dear. Einstein (and Lorentz) hypothesized that time didn't have to be the same everywhere, and came up with Special Relativity to describe it. And, remarkably, SR was shown to be accurate. It's also how energy gets mixed in with mass.

      A handful (nearly two hands full) of years later, Einstein published General Relativity as a description of why acceleration looks the same as gravity. (Inspired by Newton's F=(constant)*Ma=GMm/(rr).) He did this by hypothesizing that distance is not the same everywhere. And, remarkably, GR was shown to be accurate. (He needed some help from other mathematicians, because the math is hard for warped spacetime.)

      Maybe the above is not quite kid-friendly, but Einstein challenged the ideas of classical physics (time and space being "flat"), and got it right. Or at least the next-level-of-right.

      • by msauve ( 701917 )
        "Newton didn't get the energy part."

        Of course he did []. Perhaps you're referring to Mass-energy equivalence which is, as I said, at the extremes.
        • by Boronx ( 228853 )

          That equation is wrong. He didn't get it.

          • It's close enough for "lies to children", which is how Terry Pratchett and his co-authors of "Science of Discworld" described educational simplifications.

            I've explained some aspects by walking children, and physics students, through the "ladder paradox" described at [] .The principle of simultaneity which is key to understanding it is often glossed over by many people trying to understand the event. The idea that the time of events depends on the observer so deeply is _enormou

          • by msauve ( 701917 )
            You're unfocused and pedantic. The discussion is about Einstein, and that means a differentiation between Newtonian and Einsteinian physics. Anything before Einstein was Newtonian, even if Newton himself didn't fully develop the math and formulae. Fact is, the math came out of Newton's Laws, so he did fully "get it" in concept, even if not fully developed in detail.
  • There's always this: []
  • by MAXOMENOS ( 9802 ) <maxomai&gmail,com> on Thursday January 18, 2018 @07:36PM (#55956619) Homepage
    If he's pretty smart, then you might be able to hand him a copy of Einstein's Relativity: The Special and General Theory. This is a layman's-level introduction that avoids the weeds of Riemann geometry and the like. The math will still be above his head (unless your nine-year-old understands college-level algebra), but he should still be able to get the concepts from reading this.
    • by evought ( 709897 )

      If he's pretty smart, then you might be able to hand him a copy of Einstein's Relativity: The Special and General Theory....

      Indeed, I started that way, myself. Between his thought experiments and illustrations, Einstein did a very good job of bringing the extreme conditions he was talking about down to things you could imagine. I also read a number of Asimov's non-fiction books between 4th and 7th grade (my parents had a very good library downstairs). Today, I have a tabletop illustrated edition of Hawking's A Brief History of Time and The Universe In a Nutshell which I have worked through parts of with our daughter (now 13). Th

      • Read him: Flatland: A Romance of Many Dimensions. Its an old novella that got rediscovered when Al was becoming famous, because it had a 2d dimensional characters that discover a 3d world, and many of the ideas also could be extended to thinking about being a 3d entity living in 4th dimensional space-time.

        He can wait until 4th grade before you show him the field equations and teach him PDEs....
  • Disclaimer: I am not a parent.

    Einstein discovered a way to describe how the Universe and everything in it works, in mathematical terms.
    Using the math he created, people can predict how things in our Universe should work, before they even try to do something.

    That'd be my opening shot, anyway. Beyond that it'd depend on what the 9-year old asked me about.
    Someone (who is a parent) once told me that if a child can ask a question, then they're probably ready for the answer. So I'd let the child drive the conversation, as opposed to drowning them in a bunch of information.

  • by aberglas ( 991072 ) on Thursday January 18, 2018 @07:40PM (#55956671)

    You do not really understand it.

    Two twins orbit around each other and then meet. They are both older than each other. Warping fundamental concepts of time and distance to make speed do weird things. As to General Relativity, those pretty pictures you see on TV are nothing like what it really is.

    Newton is hard enough. Maybe by 16 a kid might be able to really understand it if they are smart.

    Some things just cannot be explained in a meaningful way.

    • by kenh ( 9056 )

      Some things just cannot be explained in a meaningful way.

      What? Examples?

    • by Pfhorrest ( 545131 ) on Thursday January 18, 2018 @10:28PM (#55957595) Homepage Journal

      Two twins orbit around each other and then meet. They are both older than each other.

      Sounds like you're the one who doesn't understand relativity.

      Two twins are set into motion relative to each other, and then left to coast inertially like that. Time passes. Each twin thinks more time has passed for the other than for themselves since they were set into motion. Neither is objectively correct; a third observer could find the same amount of time to have passed for both, or any different ratio of time to have passed for either, depending on how that observer is moving.

      But then the twins are set back into motion toward each other. Again, after being set into motion like that, they disagree about how much time is passing for each other, but then, so does every other observer, and about everything else in the universe too. Observers in different states of motion disagree about how much time is passing how quickly where.

      The twins come back together and are brought to a stop relative to each other. They have definitive ages relative to each other that they both agree on, as does every other observer in the universe.

      The trick is that when they're being set into motion apart, turned around and sent back together, and stopped at the end, time is also passing differently for each of them not just because of their different states of motion, which nobody can agree upon, but depending on whose motion is being changed how much, which is something that every observer can agree upon even if they can't agree on the absolute measure of that motion. (That is, while observers may disagree about which twin is stationary and which is moving, they will all agree that one twin is moving more [or less] now than it was before).

      If one twin stayed in the same state of motion the whole time, while the other got sped away, turned around, and then stopped when he got back, then the one who stayed behind is older, and everybody agrees.

      In your scenario, it sounds like they both underwent the same acceleration, just mirrored from each other, so both would be the same age when they came back together, and both would agree on that, as would every other observer in the universe.

      Other observers moving differently than the twins would disagree on what age they are, but they'd all agree that they're the same age as each other, whatever that age is.

  • Watch season 1 of Genius [] on the National Geographic channel.

    Your nine year old will learn about a lot more than just Einstein. But it does a decent job of visually explaining some of his breakthroughs.

  • I started to say it would depend on how bright the nine-year-old was, but since he's already asking, it means he's curious and that's the best time to teach a child about something. One of my teachers used to say, "Seize the moment of excited curiosity."

    I have seen a few books (and own a couple of them) written on the subject specifically targeted to young people. Just a quick search on Amazon yielded this one - "Albert Einstein and Relativity for Kids: His Life and Ideas with 21 Activities and Thought Expe
  • Some simple thought experiments, exactly the same as those that Einstein used, would be a great place to start. Specifically, using train cars, and lights, and clocks, and bombs. The most fundamental thing to understand is that WHEN something happened depends on your perspective. That's the fundamental idea, and if you can help your kid appreciate why cause and effect can appear to be different for the same event, that will get him interested.

    I think it will also keep his interest to focus on the provocativ

    • I came to post this. I worked through the train thought experiment with my oldest when she was nine or ten, and she got it. She asked just before bedtime, and I think that we talked for maybe half an hour. She went to sleep disagreeing with our conclusion, but a few days later she mentioned that yup, the train gets smaller as it goes faster!
      • by robbak ( 775424 )
        That's a good idea - quite often the best way to understand it is to use the thought experiment that the original person used. So just like Newton's Canon is the best way to get a grasp of orbits, Einstien's train is a great handle to get to grips with Relativity.
  • by istartedi ( 132515 ) on Thursday January 18, 2018 @07:50PM (#55956735) Journal

    I wouldn't try to do it directly. Plenty of other people have covered these areas, and on a level that makes it accessible. For time dilation, Carl Sagan's original Cosmos series had an excellent depiction of time dilation and travel approaching the speed of light. IIRC, part of it was based on a "what if" scenario in which c was something you could approach by peddling a bicycle really hard. When you returned from the ride, all your friends were grey-haired old people.

    I'm sure there is some other good programming out there.

  • by david_thornley ( 598059 ) on Thursday January 18, 2018 @07:55PM (#55956761)

    Special Relativity can be comprehended by a reasonably intelligent people who knows some algebra, and it introduces some fascinating concepts. General Relativity is much more complicated. The explanations I've seen involve either a lot of hand-waving or tensor calculus. Start with Special Relativity, and leave the General Relativity stuff for later, if ever.

  • by CaptainDork ( 3678879 ) on Thursday January 18, 2018 @07:58PM (#55956779)

    There are two: Special relativity and General relativity.

    Associate the "S" with speed and the "G" with gravity.

    Neither is noticeable to you because objects would have to be moving super fast or an object would have to be immersed into a very strong gravity.

    As an object approaches the speed of light, as compared to us standing still, that object gets very heavy, a clock on it would run very slowly, and the object would become shorter.

    A very large gravitational field does about the same thing.

    Einstein also discovered that mass is frozen energy and both are the same thing, similar to water and ice.

    It's more complicated than this simple description and I can help if you'd like to learn more.

    Have your mother bring me a beer.

    Thanks, kid.

  • by Stormy Dragon ( 800799 ) on Thursday January 18, 2018 @07:59PM (#55956785) Homepage

    "Everything should be made as simple as possible, but not simpler." -- Albert Einstein

    • This quote does not appear to have been written by Albert Einstein. He has said something similar, but it is more likely that this quote comes from someone who was paraphrasing Einstein or some other person like William of Ockham or Bertrand Russell.
  • How I would explain it is in a condescending and patronizing manner. For good measure, I would end with, "DUH!" and maybe a flick of a finger to their forehead.

    I'm really good with kids, so good that it's intimidating to parents which is why nobody asks me to babysit their kids. ;)

  • Einstein was famous because he was good at PR. He wasn't the most capable Physicist, but he was good at discovering things to work on that would get him attention.

    Now for what he is famous for, it's clearly relativity. The ideas behind special relativity were not new when Einstein proposed his views (Lorentz and Poincare were arguably first), but Einstein was probably the first to completely embrace relativity and the invariance principals.

    Unfortunately, it's really hard to do relativity justice w/o appreci

  • by kenh ( 9056 ) on Thursday January 18, 2018 @08:11PM (#55956851) Homepage Journal

    Afterwards I thought: this might be a nice question to ask on Slashdot; how would I continue this discussion to explain it to him further? Of course, with the goal of further feeding his interest in physics.

    He hasn't shown an interest in physics, he's shown an interest in a famous name he's heard (likely) repeatedly.

    You should learn not to read too much into everything a 9 year-old says.

  • Wrong answer (Score:5, Insightful)

    by turbidostato ( 878842 ) on Thursday January 18, 2018 @08:16PM (#55956869)

    By your own account, your son is not asking you about relativity: he is asking why Einstein is so famous (and he is 9 year old).

    The proper answer is, then, because he ranked to the top of his field, just like (put here whatever TV competition he is fan of, Disney young singers or whatever). When you get to the top of your field, you get famous. Full stop.

    Now, if you really want to introduce him into Einstein's, I can tell how I introduced myself, but I was eleven or twelve back then, which I think makes the situation a world apart.

    I happened to start thinking about the relativity principle, the original one, Galileo's (no memory of how I stumbled onto it, though) and felt fascinated by the old man in his ship, trying to decide from within his cabin if the ship was moving or not. From there I moved to the "known fact" that nothing, and I mean NOTHING, can go faster than light in a vacuum (you can disgress a bit here talking about Mach's aether and Michelson-Morley experiment if you want to), and how would the world look like if that were true (I probably had read some of the old mental experiments about trains and watches coming and going, but I've forgotten when or where, probably because all this became obscured on my memory by my read, years later, of both Russell's 'ABC of Relativity' and Einstein's 'The meaning of Relativity' -*you* should read them and you would probably wouldn't be asking this question.

    Once I got satisfied about special, I moved to the general starting also on"known" facts (taken by me as granted, back then): energy and mass are somehow equivalent (E=m*c^2) and gravity and acceleration look very much the same but can they in fact be set appart? (hint: gravitity looks "spherical" from the perspective of an observer under a heavy field). Oh, another interesting fact: there can also be black holes under newtonian physics, as long as C stands constant and nothing can run faster than light (in a vacuum -oh! and why does light runs faster in a vacuum than through transparent matter? does something can go faster than light -on said matter? Mr Cerenkov left a message).

    The fact is, that though you cannot *demonstrate* Einstein's Special or General theories of Relativity without advanced maths (you can't demonstrate Newton's either), you can *exhibit* them on a credible manner, specially the special one (pun intended), on a two dimensional field, just using basic geometry, so a child can have a grasp of them.

  • I'd get them a copy of General Relativity For Babies. [] I've also gotten my nephew Quantum Physics For Babies. The entire series is wonderful.
  • The earth pulls at you because it has a lot of mass. But how can the earth influence your body, pull your feet to the ground, without actually touching you? Why is it that one thing (the earth) can influence something else (you) without actually being connected?

    A famous analogy is a ball of modest mass (such as a soccer ball) held up by a stretched bedsheet, held firmly at both corners. The soccer ball dimples the bedsheet and induces a curvature around it. If you were to drop a smaller ball (such as a ball bearing) on the bedsheet, it would roll towards the soccer ball even though they don't touch each other. You could even get the smaller ball to "orbit" the larger one if you gave it just the right velocity in the right direction.

    The bedsheet is like spacetime:

    • held firmly at both corners

      Duh, at all four corners. Sorry.

    • "...You could even get the smaller ball to "orbit" the larger one if you gave it just the right velocity in the right direction."

      Oh, but the little ball *always* end up going towards the big one, but I read the Moon is getting further from Earth with time, not nearer.

      And where do the Earth and the Moon rest upon? I can't see any stretched bedsheet beneath them -or are they elephants, all the way down?

      And what the hell has all this to do with Einstein? I thought Newton settled all that!

  • by thestuckmud ( 955767 ) on Thursday January 18, 2018 @08:22PM (#55956897)

    Explain that Einstein grew up in a time when physicists were looking for the materiel makeup of the universe, referred to as "ether", but they had so far failed to provide an explanation. Famously, the Michelsonâ"Morley experiment showed no changes in the speed of light moving in different directions, which makes no sense if Earth is moving through the ether.

    Einstein had the brilliance and audacity to reject common sense models of the universe and ask what would it be like if the speed of light really is constant: That the photons leaving a headlight on a moving train move at the same rate whether we measure them standing on the train or on a platform at the train station. From there, using wonderful "thought experiments," relativity was born.

    Next, you can introduce concepts like red/blue (doppler) shift, time dilation, and the effect acceleration has on changing otherwise invariant properties of physics (special relativity).

    I think it is informative to explain the awesome scope and mathematical complexity of general relativity, which re-imagined the universe as a four dimensional space-time whole. That even Einstein had welcome help with the mathematics. That today's physicists have yet to resolve this apparently correct theory of the large with quantum mechanics, the physics of the very small. And that black hole, which were only things of science fiction when I was a kid, offer the best promise of tying these together of anything in the cosmos.

    • Morley continued the experiments after the famous one you're referring to and found proof of a dynamic aether. They couldn't detect the aether in the famous Michelson-Morley experiment because the experiment was only designed to detect a static aether. Aether moves with matter, and likely causes inertia, it doesn't just act as some thing we are experiencing drag from (think trying to measure the wind while you're a feather being blown around by it and only able to "see" a few micrometers from the surface
      • My first thought on reading your post defending ether (aka aether) was "don't feed the trolls". The fact that observers moving at different velocities observe the same beam of light traveling at the same velocity (C) easily disproves classical notions of ether, dynamic or otherwise. In order to be consistent, your dynamic aether will have to obey exactly the space-timer warping properties of general relativity and thus cannont be detected or falsified.

        However, your comment raises a crucial point about p

    • Einstein had the brilliance and audacity to reject common sense models of the universe and ask what would it be like if the speed of light really is constant

      A constant speed of light was proven over a decade before Einstein published. What he did was figure out how to reconcile that with other physics equations by dilating time and space to maintain the consistent equations.

  • Universes Speed Limit, do not exceed.

  • by JBMcB ( 73720 ) on Thursday January 18, 2018 @08:33PM (#55956947)

    Outsource it to Carl Sagan: []

  • He does terrible things to Cats!

  • Best to tell him that all we have is theories - but that we don't really know. For example, there have been many proposed alternatives to General Relativity. The most intriguing IMO is Erik Verlinde's. Note that the predictions of GR have been verified within long ranges and large masses (but not short ranges and small masses), but the interpretation of curved spacetime is not proven - it is just a mathematical construct that fits the observations. Also, Special Relativity postulates some things that are no
  • Annus mirabilis (Score:4, Interesting)

    by langmick ( 863824 ) on Thursday January 18, 2018 @09:26PM (#55957247)
    I would ask my nephew that when he was around that age, he starts at MIT next year at 16. I would explain to him that in one year, Albert Einstein changed the face of the world, and made all our lives better. He used his imagination to do it. He wasn't the best mathematician, in face, there were better ones hot on his heels, but he had the ability to imagine how little things work as well as the entire universe. He then set out to prove it. I think kids respond to encouraging their creativity with stories like Einstein's and how he built his ideas on other's ideas. Exposing them to Julius Sumner Miller, Brian Greene and Richard Feynman is also a lot of fun, because they had lots of fun with science. I enjoy talking to kids about science, and seeing their eyes light up. These videos are pretty good. []
  • ok so I'm having fun with the word... Maybe the situation of how he attained a "rock star" status. He presented new theories that got attention from all the best scientists around the world. Some of that will get into regular media. He promoted peace, he had that charm that attracted lots of ladies, his attitude was playful brilliance (didn't bother to have neat haircut and wear snooty suits like many other eggheads). Everyone recognizes the famous equation, much less understand what it means. I read somepl
  • Was literally a case where he had to be forced to unlearn what he knew that was wrong. It was funny in many ways I had trotted out animations showing reference frames shifting but he was thoroughly stuck on a Newtonian space time but could accept time dilation without realizing it's just another dimension.

    Probably would have had an easier time with a 9 year old. If they could grasp the concept of the Lorenz Transformation the rest follows easily.

  • Watch the old Carl Sagan Cosmos episodes together.

    And you could 1985 "Insignificance." []
    But watch that on your own, for pointers.

  • Show him the failure point of Newton.

    Tell him about Mars, Venus, Jupiter and how they follow orbital mechanics. Tell him how by noticing small errors in movement they were able to find Neptune ( Tell him they noticed the same thing for Mercury but couldn't find any new planet to explain it. Tell him why: Mercury is so close to the Sun that time slows down.

    Then, tell him about GPS and how those very precise clocks are faster than the ones on Earth. Without Ein

  • I think it's a fair thing to say that nothing can interact with another thing without "touching" it. I think that's the very point -- just because you don't see it, nor feel it, doesn't mean that there isn't some mechanism of contact.

    "How things are connected" is easy when it's strings and cups -- indeed, the traditional string-and-cups telephone is easily experienced, understood, and built by a five-year old.

    But "how things are connected" when the cups are you and a planet, and the string is invisible and

  • I'd consider just covering more detail of gravity. If you can get some volunteers to stretch out a bedsheet and place some balls of varying masses on it, then roll smaller balls around them that may help 'set the stage' for future concepts. I'd cover the Einstein aspect by just saying he figured out a lot of *how* gravity works and its effects. Give it a couple years to get into special relativity and such.

    If they are interested in games, get them to try out Kerbal. Great way to really get to understand

  • like the eternal mysteries of how coat hangers multiply in the closet and why socks always disappear in the dryer.
  • Specifically this one:
  • To understand how forces act as a distance, you have to understand gauge bosons (aka exchange particles). The Standard Model of Physics defines these for the electromagnetic interaction, the weak interaction, and the strong interaction. It is highly believed that there are gauge bosons of gravity as well (called gravitons) but this has not been proven yet.

    Elementary particles interact with each other by the exchange of gauge bosons, usually as virtual particles.

    For more info see this web page [] and for ton

  • I don't think it would be as hard as you might think PROVIDED you really understood it yourself. Of course, this applies to anything you wish to teach to anyone.

    The problem with relativity is that it is so counter intuitive to everyday experience and to the classical physics you've been taught that you have to unlearn much of it first. That may make it easier for younger people to understand -- they don't have as much to overcome as they would later.

    Like most EEs, I was taught classical electromagnetism, fi

  • Of course you should teach kids stuff like this; it's 100 year old science. At some point kids need to be learning these concepts or the weight of science that needs to be learned as an adult will be too large.

    I would start with a small adaptation of the description that Einstein uses to describe relativity to non-scientists:

    When you're in a car, and you speed up, what do you feel? What do you feel when it stops? Imagine you're in a car (or roller coaster, or rocket ship) that is always speeding up really,

  • First play him some insane clown posse and then get a couple of long wires and show him how a magnet works.
  • fake news (Score:5, Funny)

    by bugs2squash ( 1132591 ) on Friday January 19, 2018 @01:51AM (#55958447)

    I once read an account of a thought experiment where there are a line of cows side by side with their noses all touching a long, straight fence. The farmer attaches an electric fence shocker to one end of the fence and it makes all the cows jump as they feel the shock.

    The farmer sees the cows jump one after the other as the electricity reaches each nose

    But to a visitor from a nearby city, who happens to be standing at the other end of the fence at the time, the cows all seem to jump up in unison, since the light bringing the image of the far cow arrives at the same time as the electricity arrives to shock the nearest cow.

    When the farmer and the passerby meet they find they have different first hand accounts of the same events, proving to the farmer that city folk are ignorant of country ways, and proving to the city slicker that country folk tell tall stories

  • I've had my kids watch the TV shows Eureka [] before they were 9. So my kids already new what force, energy and mass were. It makes having these discussions much easier.

    E=mc^2 makes sense if they know what energy is and they understand the units

    relativity needs a lot of math to explain properly but I think I did a better job with my youngest son. The speed of light is actually the speed of causality. Every observer sees this speed the same even if they are moving re
  • When my daughter was asking how people could stand on the "downside" of the earth, I compared the earth and stuff to magnets. The larger the objects, the stronger magnet. We never got into energy, but I would compare energy to velocity: Throwing a piece of pebble at someone hurts. The harder (=faster) it's thrown, the more it hurts. But the same goes if the pebble is changed to a larger stone. That would hurt just as much even if it's thrown at a lower velocity. The same goes if you accidentally drop it on

  • To a nine-year-old I'd say he was the most woke dude of his time. Only instead of woke, he was brilliant, which people valued back then.

    He wrote tracks nobody expected that got the most upvotes. Only instead of tracks, they were scientific papers and instead of upvotes they were experimental confirmations.

    He withstood persecution from neo-Nazis who spoke against him at marches with tiki torches. Only instead of neo-Nazis, they were actual Nazis and instead of tiki torches, they had panzer divisions and a Lu

  • by MagicM ( 85041 )

    I would get "Who Was Albert Einstein?" by Jess Brallier from the library and give it to them. The whole "Who Was" series is great, as is the "What Is/What Was" series.

  • Get him a Netflix subscription and put Cosmos on.
  • A User's Guide to the Universe by Dave Goldberg and Jeff Blomquist is a great high-level introduction to a lot of this stuff, with weird but relatable examples included, and covers a lot of interconnected topics.

You know, Callahan's is a peaceable bar, but if you ask that dog what his favorite formatter is, and he says "roff! roff!", well, I'll just have to...