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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.
Seconded, you don't need to. Why on earth would you think you do?
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
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).
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?...
They will probably have a very hard time understanding the magnitude of the numbers involved.
So what? You don't have to understand scientific notation to know that you can vaporize Klingons with anti-matter.
When kids ask questions, they just want a quick overview. They aren't expecting you to read them a PhD dissertation. Although that might be effective way to get them to go bother someone else the next time they have a question.
The way I'd explain Relativity to a kid is that people always thought that time and space (distance) were universal constants, and everything could be represented assuming those two were constant. If two people are in the same location observing the same thing, but one person is stationary and the other moving, a light beam will appear to be moving at a different speed to the two people.
Einstein showed that the speed of light is what stays constant. Light appears to move at the same speed to both those people in the above example. Space and time themselves warp to make that possible. In this case, by time appearing to pass more slowly for one person.
If this is a typical 9-year old, he'll think "that's weird," go to sleep, and the next day his mind will be back on TV, video games, and sports. If he's atypical, he's going to spend a long time awake thinking about this and have a bunch more questions for you in the morning. Then you can introduce him to all sorts of fun stuff like light clocks, the twin paradox, (the lack of) simultaneity (I especially like the ladder paradox since it's very intuitive and demonstrates how the loss of simultaneity resolves seeming paradoxes).