Slashdot Mirror
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.
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
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.
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"?
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.
"Everything should be made as simple as possible, but not simpler." -- Albert 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
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.
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.
Outsource it to Carl Sagan:
https://www.youtube.com/watch?...
My Other Computer Is A Data General Nova III.
"If you can't explain it simply, you don't understand it well enough.""
-- Albert Einstein
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?...
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.
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
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!