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Ask Slashdot: How Would You Explain Einstein's Theories To a Nine-Year-Old?
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.
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.
next.
Which is why he needs to get interested soon before he notices the opposite sex.
Has some of the history of the atomic age and the science, math.
http://www.pbs.org/program/ura...
Domestic spying is now "Benign Information Gathering"
...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.
Everything in the Universe sucks: It's the law!
"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.
"National Security is the chief cause of national insecurity." - Celine's First Law
There's always this: https://youtu.be/MTY1Kje0yLg
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.
Finding God in a Dog
"Things just happen, what the hell".
(c) Terry Pratchett, "Hogfather"
Every red light turns green, if you drive fast enough.
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.
Asking why someone is "famous" does not convey an interest in physics or science or anything else. Seems like a normal nine-year old's inquisitive nature.
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.
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 Experiments". I know there are others out there.
Let the kid read one or two of those books and then have a discussion with him to see how much he learned. If he's a bright as I suspect he is, I think you'll be surprised.
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 provocative aspects of that. Relativity DOESN'T behave the same way that the normal world does, and that's intriguing to people of any age that take the time to think about it.
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.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
I thought the following "Which way is down" video really opened my eyes and helped simplify concepts about relativity. It's relatively short and it mostly keeps things simple, yet goes pretty deep.
https://www.youtube.com/watch?v=Xc4xYacTu-E&feature=youtu.be
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.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
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.
It little behooves the best of us to comment on the rest of us.
Now go play with your Nintendo Nano
-- Tigger warning: This post may contain tiggers! --
"Everything should be made as simple as possible, but not simpler." -- Albert Einstein
First of all, your kid is amazing. I love his curiosity about the world. To a nine year old, "imagination" is more important than "theories". I would answer the question this way... Einstein used his imagination to visualize how the universe works. He could imagine time, speed, distance, and scale in a way that enabled him to formulate mathematical models of how these things were related. Based on Einstein's understanding of the universe, inventors have created amazing things like: smart phones, Google maps, and atomic energy. Einstein is famous because he used his imagination to find a new way of looking at the world. Einstein once said, "Imagination is more important than knowledge". Try to remember that when you are bored at school. Remember to imagine.
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. ;)
Anons need not reply. Questions end with a question mark.
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 appreciation of exactly what energy and momentum are and the insight that radiation can possess inertia. Of course you can short cut this all into the final insight that E=mc^2, but I'm not sure that is much better than teaching history by memorizing dates and reduces this from a scientific explanation to simply a historical explanation (basically Einstein is famous, like Michael Jordan is famous, but he's a famous scientist).
General relativity is even more complex. The beauty behind the discovery of general relativity is that the math actually works out (which is no mean feat). One can always propose an elegant theory, but if it turns out to be inconsistent with the math, it is just an idea, not a theory. Hilbert and Einstein both worked furiously to work out the math ahead of the other, but it is generally acknowledged that the earlier works of Einstein were likely the insights that motivated the solutions discovered by both men.
Everyone should be respected as an individual, but no one idolized. It is an irony of fate that I should have been showered with so much uncalled for and unmerited admiration and esteem. Perhaps this adulation springs from the unfulfilled wish of the multitude to comprehend the few ideas which I, with my weak powers, have advanced. -Einstein
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.
Ken
- He is coupled with atomic energy (and atomic bomb) research.
He wrote a letter to FDR that inspired the Manhattan Project, suggesting that the US beat the Germans to the first functioning atom bomb.
Ken
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. http://amzn.to/2Df5RKb 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: the presence of mass causes it to curve in such a way that other masses in its vicinity tend to be drawn towards them. I think that may be as far as you want to go with a 9-year-old without looking up lessons on the internet.
If it weren't for deadlines, nothing would be late.
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.
https://www.youtube.com/watch?v=mnJuKXhFaQ8
Universes Speed Limit, do not exceed.
For General relativity anyway. It always bothered me when I was thinking about gravity that it was supposed to be 'acceleration' and acceleration always seemed to imply speeding something up, giving it energy. Then I remembered that a centrifuge has a gravity like force but it doesn't expend energy.
The other thing, browse youtube videos together with your son, see which ones seem to work for him, maybe with some explanation from you.
In theory, theory and practice are the same; in practice they're different. (Yogi Berra & A. Einstein)
Outsource it to Carl Sagan:
https://www.youtube.com/watch?...
My Other Computer Is A Data General Nova III.
Source: Disruptive: Rewriting the rules of physics
author's website
"If you can't explain it simply, you don't understand it well enough.""
-- Albert Einstein
He does terrible things to Cats!
Truth isn't Truth - Guliani
Just start with Minkowski, Lorentz, Riemann, Gauss, and Mach. Start with their work and move on from there. Also maybe learn you're an idiot for trying to make your normal kid into a genius, people aren't equal, they are either smart enough to get there on their own by that age or they're normal (though if your genes played into it, the kid might be retarded.)
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 not proven - only the effects are proven. Even quantum mechanics postulates a foundational equation ("operator correspondence") that is just a guess that works. Bottom line: we don't really know. I strongly recommend the book Doubt and Certainty, by George Sudarshan and Tony Rothman - in that book you will see how little we really know. Tell you son that we have guesses that work, but don't know how the Universe is truly constructed.
Einstein changed the way we looked at gravity. Because before we thought of it in a very 'Newtonian' way. That gravity simply pulls us and that works for simple examples. But Einstein's gravity is not like that at all. Einstein gave us gravity as a function of geometry, and if you google 'blackhole space curve' and look at the images you will understand. Gravity creates a hole and if you are near/close to it you fall in. The falling is gravity, it changes the vector for an object at rest in a given location based on the mass of nearby objects.The physical Earth is in the way of us falling to the core so we simply stand on it, but the pressure in the core of all the mass on earth trying to squeeze lower is huge. -- This may lead to other questions but those are trivial and left as a exercise to the reader. ;-)
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. https://www.youtube.com/watch?...
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 someplace number of people that really know the General Theory of Relativity is about 20 (I assume these people can do the math and have intuitive feel for it).
mfwright@batnet.com
Richard Feynman, the late Nobel Laureate in physics, was once asked by a Caltech faculty member to explain why spin one-half particles obey Fermi Dirac statistics. Rising to the challenge, he said, "I'll prepare a freshman lecture on it." But a few days later he told the faculty member, "You know, I couldn't do it. I couldn't reduce it to the freshman level. That means we really don't understand it."
So as a non-musician if I was trying to explain why a particular piece of music was brilliant would my first thoughts really be that the best thing I could do would be to attempt to sing or hum it to the unlucky victim? Similarly, as someone who is neither a physicist or educator should I really think that I might be the best person to explain Special Relativity and its consequences? Instead, might it not be a better approach to work through one or two existing high quality resources with them?
I'm sure there are others, but in terms of a recommendation I found the Cox and Forshaw book "Why Does E=mc^2 (And Why Should We Care?)" https://www.goodreads.com/book... good. I also think it could possibly be something that a bright 9 yr old might enjoy reading and understanding with their dad.
Eventually he'll figure out that the opposite sex is also indistinguishable from magic.
I've fallen off your lawn, and I can't get up.
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.
"Hey kid, here's Google..."
Table-ized A.I.
Watch the old Carl Sagan Cosmos episodes together.
And you could 1985 "Insignificance." https://www.youtube.com/watch?...
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 (https://en.wikipedia.org/wiki/Neptune#Discovery). 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 Einstein, we couldn't have a GPS.
ID: the nose did not occur naturally, how would we wear glasses otherwise? (apologies to Voltaire)
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 you can walk through it, now that's a mighty different game. That said, the players are the same. Bigger cups, thinner strings.
So that's the space where I'd describe most famous physicists living. Things interact because they are connected. That's the easy part. But it's about how those things are connected. That's often the very spooky part!
The thing is that it's not just a physics thing. Every problem-solving professional lives in a solution space that's all about how things are connected. Plumbing is all about interactive connections. So is network programming. So is telecom, and social conversation.
You and I are connected right now, through a highly latent, very long distance, overly abstracted connection. And yet, as far apart as we are, my finger touches a plastic key, that ultimately touches a contact which in turn touches (and diverts) an electron that ultimately produces a relay-race of electrons that reach the lightbulb in your monitor, that propels a photon directly into your eye.
It's really cool that my fingertip is capable of shoving a photon into your eyeball. It's certainly the result of a great many connections -- but each one of them is definitely direct contact.
(you're going to give me the poetic licence to say that waves (radio, compression, sound, et cetera) are the result of contact at the particle or molecular level)
And so, I'm going to further say that electromagnetism, and quantum entanglement, and other spooky actions at distances are also the result of contact, simply contact that we've not yet discerned. Perhaps we're back to strings? Maybe they're looped?
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 how gravity 'works' in relation to space travel.
Not even sure the exact age, but quite early on. I used to play a lot with the Lorentz equations, seeing how much my mass would increase the closer I got to the speed of light, or how thin I would appear, etc. It was great fun. And I've explained Relativity to my own kids at younger ages. Maybe I didn't get into the math behind it as much, but, you know, many feed their kids all of these fantastic fairy tales, when actual reality itself can and is more bizarre than any fairy tale -- and actually is reality, after all.
like the eternal mysteries of how coat hangers multiply in the closet and why socks always disappear in the dryer.
Talking to people who actually met the man I got the image Einstein is not only great because of theoretical mind, communication skills or persona with the press. He shared and encouraged others to go far beyond his discoveries with every conversation, every letter, and every coauthorship.
Most people seem to be missing the major point, Einstein was the last of the classical physics school and the first of the quantum school. In modern sports terms, he changed the game and set the precedent for being brilliant and scientifically open in the modern world. And when I say game, I mean every one of physical sciences of the 20th century has a tie back to one of his two papers.
General Relativity is the end point of classical physics, it was due about the time Albert published. General relativity was the endpoint of the enlightenment, inevitable conclusion involving scalars, Maxwells Equations, newtons calculus, and gauge theory.
Near nothing in classical physics describes accurately the photoelectric effect on the photon hitting a conductive surface knocking off one or more free electrons in units or quants of energies. Expermentalists had led the way, Einstein seemly described the theory effortlessly. In the years from first publication of photoelectric effect to shell states an atom, describing the geometry of chemistry, was mature in less than 15 years.
Both papers were backed up by solid observation within 15 years so by his late 40s had two games changer papers very few theoretical misses in the meantime with his other endeavors. He immigrated to the US at the time basic science became the basis of a nation becoming a superpower.
Not many people get to participate in the end of the road of the basis for classical physics, and the starting of quantum physics. Einstein was one of the primary figures of both, did it out of obscurity while underemployed and published both papers, provided a credible defense of both in less than 5 months in 1905. Then most of all was open and giving in the support who took the quantum out of his hands and moved it far forward of Einstein's abilities.
In the era of 1930-1949 he supported fully, through support filled letters and editing, suggestions people who eclipsed his mathematical and theoretical acumen for publication. There were many personalities in the same time period that were quite diffrent from that.
Specifically this one: https://www.goodreads.com/book/show/1567832.The_Time_and_Space_of_Uncle_Albert
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 tons of detail see this video.
The first gauge boson theory, quantum electrodynamics for the electromagnetic field, was the work of Dirac in 1927. It did use some work by Bose and Einstein on the statistics of photons though.
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, first in high school, then in lower level undergraduate physics, and finally in much more detail in junior level EE school classes. We were also taught relativity, but as a separate topic within physics. Had I been taught relativity first, and then been taught electromagnetism in the relativistic way I think it would have actually have been easier and more satisfying. I would have learned that there really isn't such a thing as "magnetism"; what we see as magnetism is really just the electrostatic force as affected by special relativity (and some quantum mechanics). I would have readily understood why there are no magnetic monopoles, for example. And it would have shown me how every field in physics is related to every other, in fact that there really is only one "physics".
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, really strongly, all the time. You could speed up so much that the back of the car (roller coaster, rocket ship) feels just like the ground. You could even stand up like it was the floor. Einstein is famous for figuring out that if that happens, the back of the car really is just like the ground. People used to think it was just a trick or a coincidence, but it turns out there's no difference, actually. That changed a lot of what people thought about science.
If the kid understands that, give them a good translation of Einstein's book to read.
First play him some insane clown posse and then get a couple of long wires and show him how a magnet works.
Nullius in verba
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
Nullius in verba
I've had my kids watch the TV shows Eureka https://www.youtube.com/watch?... 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 relative to each other. I then give the example of a rocket trying to travel to the nearest star. The star is 4 light years away. The first ship takes 6 years to get there. We build a second ship that goes twice as fast. To the observer on earth the ship takes just over 4 years to get there. The person in the ship though gets there in 3 years according to his watch. However the person in the ship has a meter stick and he measures the distance and discovers it wasn't 4 light years, it was a little less than 3 light years. So his measured speed was still less than the speed of light because relative to him the distance decreased.
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....
HA! I just wasted some of your bandwidth with a frivolous sig!
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 your toes.
Not entirely correct, but then again - the laws of Newton aren't either.
In terms of relativity, the experiment about dropping a ball inside a train (or bus) is quite easy to understand - inside the train the distance the ball falls, is equal to the height of which it is dropped. But for a viewer outside, the apparent distance is longer - the hypotenuse of a triangle. It might even be possible to show using a car.
Oh in that case you should teach who actually came up with e=mc2 first:
https://en.wikipedia.org/wiki/...
An oldy but a goody!
Your child may not get everything right away, but that's probably less important than the examples of thought experiments, and the honest effort to provide some explanation in simple terms. Often when things make an impression that way, children remember and wind up understanding years later.
The Day After Tomorrow - Into Infinity (www.youtube.com/watch?v=xF6YBU0bqR4) is good fun and has good science in it although the end bit is nonsense! Brian Blessed and Nick Tate (Space 1999's Alan Carter) are in it as well.
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 Luftwaffe.
And because people hadn't yet invented hashtags and blue hair dye, people didn't yet organize to realize his achievements were due to his white male privilege.
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.
Vintage computer games and RPG books available. Email me if you're interested.
Yeah, maybe I'm underestimating nine year olds but I'd go for something like:
Einstein is famous because he was bloody intelligent, did a lot of thinking about stuff nobody had thought about before, and shared his thoughts with people. They found this useful, thanked him for it and invited him to lots of parties.
Nine-year-olds can be smarter than you think. Just keep him interested with simple things that are imaginable and relateable, either to the real world or TV/movies. First, light travels with a constant speed. How do we know? When NASA spoke to the men on the moon, it took half a second for the radio waves to get there. When NASA radios satellites around Mars, it can take 5 to 10 minutes. And Voyager 2 is way, way out there. It takes almost a day for a command to get to Voyager just to find out if it's still working (it is).
Einstein's thought-experiment with the train near the speed of light and the two mirrors and the simultaneous lightning strike is a little complicated. Skip that for now. Just tell him the reason Star Trek has warp speed and Star Wars has hyperspace is because we all know, under normal circumstances, you can't go faster than the speed of light.
Next, gravitation. What's cool? Einstein figured out that gravity bends light. How do we know? Mercury. Draw your kid some circles around the sun with Earth and Mercury, tell him that when Mercury gets close to the sun it appears in the wrong place in the sky. Einstein predicted, correctly, that the light from Mercury is bent when it passes close to the sun. When did he prove it? During a solar eclipse, when we could actually see Mercury when it's real close to the sun, Mercury's little dot was right where Einstein said it should be, not where it would be if its light went in a straight line.
If he's impressed and still interested, equivalence. Acceleration, gravity, same. Ever ridden in an elevator, little man? You like roller-coasters, right? Same thing as gravity. If you're riding in a space-ship that's accelerating at 32 ft/s*s, then it feels exactly like standing on the earth. Now, if that space-ship is going really, really fast, like close to the speed of light, and there's a window in the side of the spaceship where light is shining in (draw a picture!), by the time that light hits the opposite side wall of your spaceship, the accelerating spaceship has moved a little out of the way and the light shines a little below the opposite window. Draw a line: light is CURVING because your spaceship is accelerating so fast.
Well, if acceleration and gravity are the same, Einstein figured a whole lot of gravity should make light curve. Then came the solar eclipse, and Mercury was right where Einstein said it should be, it's light curving around the sun. Neat, huh?
If he's still with you, thank your stars you got a bright, imaginative little kid. Move on to Black Holes, gravity so powerful light can't escape. Cooooool. So long as you can keep tying the theories to stuff your kid can relate to, either in the real world or the movies, you got a chance. Run it as far as it's worth, he might catch the bug.
Take it easy, Charlie, I've got an Angle...
If it was possible to explain Einstein's theory of relativity to a nine year old it would mean that Einstein was only as smart as a nine year old, which, obviously is not correct.
That's great news for anyone who does understand relativity because it means that we are all as smart as Einstein! Sadly though it is generally accepted that the 'genius' comes in figuring something out for the first time, not in being able to understand the idea once someone has figured it out. Lots of people understand Newtonian mechanics but I doubt anyone living today is as smart as Newton was.
In fact the reverse is probably true: the easier the idea is to explain the smarter the person who came up with the idea is generally perceived to be. It's a lot more impressive to come up with a new, simple idea in an area that lots of people have thought about before than it is to come up with one in a highly specialized, esoteric area where you may be the first person to ever really think about that thing.
Also, magnets: Show how a magnet can pull something without touching it.
Long live the Speaker Bracelet
Rolo D. Monkey
What is so incredible about Einstein finding is not E=MC2, it's the concept of relativity. It basically say that the truth change depending on the point of observation. So two different person with two different point of view could both be right. A person traveling at the speed of light will experience time diffrently from someone on earth... at the same time. From there, you can teach your kid that if someone disagree with them, they could both be right.
"Failure is not an option, it come bundled with the software"
One of his short novels in the juvenile class. I read this to my then 7 year old daughter. She was tickled pink regarding the concept of time and space and speed. And how one sibling could stay on earth and age while the other one would remain young.
We then watched Interstellar, which was a bit harder to process but showed the similar affect with regards to a black hole.
Obviously this just skims the surface, but it did help her conceptualize the ideas.
I would have just gone with "It's the hair".
Perhaps it's a good thing I don't have kids...
"Grab them by the pussy" -- President of the United States of America
Mass displaces Space. Space (spacetime) curves around that Mass.
That displaced Space creates a vacuum where the Mass actually exists.
That vacuum is Gravity.
Sort-of...
Self-importance and self-indulgence is the root of ALL evil.
Einstein's theory of relativity explained in words of four letters or fewer:
http://www.muppetlabs.com/~bre...
my, your, his/her/its, our, your, their
I'm, you're, he's/she's/it's, we're, you're, they're