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# How would you explain Albert Einstein’s theory of relativity to an 11 year old?

Help. Very average 11 year old. And it’s importance to the world today.
Sorry – no apolstrophe after its!
She has to do a project on a famous mathematician – which she’s done. But she nees to explain the relevance to the world.
She shoudl have stuck with Archimedes screw.
This is my child’s homework. Ok. I don’t do physics at all.

• Gretchen says:

0KAY, iM THiRTEEN AND i AM iN ELEVENTH GRADE MATH, SCiENCE,&& LiTERATURE, AND TENTH GRADE LANGUAGE ARTS AND GE0GRAPHY. WHY iN THE W0RLD W0ULD A 4TH GRADER BE LEARNING AB0UT THE THE0RY 0F RELATiVITY?!

• karen l says:

why choose something so complex for an eleven year old?? time enough at high school. why not find out about simple, yet important to the world just the same! the invention of light for example, or the telephone… very easy to find out about and not so taxing on the brain.if somethings too difficult it can cause a great deal of stress… why walk before you can run

• Bobby B says:

Try something more simple first, say the conservation of energy; i.e. that energy can not be destroyed, it merely changes from one form to another.

eg.

Electric Lights, Electrical Energy transforms to Light Energy to Thermal energy (heat).

Relativity merely relates Mass, Energy to a fixed number (i.e. the constant speed of light). This enables scientists to create nuclear power stations potentially the cleanest form of renewable energy on the planet.

• tiger_the_prince says:

use practical analogies…. it is easy. A straight line is the shortest way to go from A to B. What does it mean? what is shorter? if I am facing a wall, the shortest way is to go around it. The shortest way is the one which requires less muscular effort, i.e. less energy. Your kid knows the earth is round, that means the shortest way on earth is a curve, and what we “feel” as a straight line is always a curved one.
Because we live on a sphere, it is obvious that you can have an infinity of parallels going through the same point ( look at the globe, and the longitude meridians ).
And when a car comes toward you, the sound of the motor changes, which is the easiest, the most practical example about relativity.

• bill says:

That is relatively difficult .

• primary_clone says:

First, its great the 11 year old wants to learn science. Ok basically there are two thing which then get split into two again. The first two is basically all physics works in a place where it is inertial. Eg the object is reluctant to move, like when you are in a car and it stops, you go forward, because you want to continue moving forward but the car stops you. The second is everyone no matter where you are measure the speed of light the same 300000000 metres per seconds (really fast, eight zeros). It also the faster anything can move.
The other things are then Time dilation where you get two clocks leave one on earth and but one in a rocket to space bring it back and the rocket one is slower, because it was moving so fast time actually slowed down for it, because time and space are connected.
And also if something moves really fast to you it would seem it’s getting smaller. That’s kinda it but still hard and vague. soz

• Blunt Bloke says:

Thought experiments…..

Imagine light bouncing back and forth between two mirrors. The two mirrors are on a train passing through a station at nearly light speed. If you watch the light (photon) from on the train, it appears to go in a straight line up and down following the same path. From the platform the photon appears to be creating a zig-zag as the train moves along.

with me so far…..?

Clever bit next…..

light travels at only one speed (light speed – its fixed 186,000 miles per second) but the zigs and the zags are different lengths to the straight up and down route of the light.

So what?

To someone looking in at the photon and mirrors from outside the train on the platform, time appears to run slower as the light (traveling a fixed speed) has further to go, so it must get more time.

ANother thing to think about……

If gravity was suddenly switched off, and all the stars and planets didn’t pull towards one another anymore, would it happen instantly, which would require gravity to travel faster than light (but it can’t!).

So, how do we orbit the Sun?

In Einstein’s model of the universe, the Earth travels in a straight line through curved space-time. The curve is determined by the mass of objects nearby (in stellar terms) distorting space-time. Think of the Sun as a bowling ball in the middle of a trampoline and the earth as a marble running across the surface of the trampoline….

It’s big stuff for an 11 yr old!

• Paul says:

And you think he’ll remember it fully? Get him started on something appropriate for his age!!! Honey – what’s your problem? Let the kid grow up with the other kids for goodness sake! Important to the world today? What’s important is to let kids be kids. Your rush-rush attitude will create a lonely psychotic that will love to have guns and bombs someday.. Slow down! Go get a DVD with kid’s stuff on it. Set it up for him and go get yourself an aspirin.

• wimbledon andy says:

Also no “l” in apostraphe…

Explaining relativity to 30 year old is hard enough; the key concept of general relativity is that gravitational effects aren’t forces but manifestations of curvatures in space-time. That’s not exactly intuitive.

Try this :
Light is affected by gravity.
Haven’t you noticed that it’s easier to drop things in the dark?

At least he might remember that, whereas he’s unlikely to remember a precise definition of a Lorentzian Manifold, for example.

As for special relativity (the other half of the theory, developed first) it’s famous for the e+mc2 equation, which means that the potential energy in anything is equal to its mass, times the speed of light, times the speed of light again. That means that even something really small and light contains loads of energy. If you can destroy the matter completely, you get all the energy instead, and that’s how atomic bombs work.

That’s enough for now; there’s some more stuff about properties of the speed of light, but if he wants to know about that then he can surf for it or wait till college.

(Disclaimer; he means he/she throughout and I have no idea how much the average 11-year-old knows about physics)

• John H says:

Don’t you mean E=MC2.

E = Energy
M = Mass
C = Constant (The speed of light)
2 = Squared

In laymans terms is means the Energy possible from any matter (M) is the same as the mass (amount) of the matter multiplied by the speed of light squared.

It is with this equation that a football size amount of hydrogen can produce all the power in an atom bomb.

• marlenne n says:

get him dive!

• papeche says:

if you are riding in a car at 55
and you push your hand forward,
its going at like 2 miles an hour( relative to you),

if someone on the street looked at your hand, its going 57 relative to them

how fast something is going is relative to the perspective of the person watching it.

also it covers the speed of light,
The speed of light is the same to any observer,

now there is an important thing that uses the speed of light
nuclear reactors, and of course bombs

they use math to determine how much energy will be released,
I’m sure you’ve heard it
e=mc^2
energy released=mass times the speed of light squared.

I hope this is helpful

• Manny Calavera says:

I’d go with a car theory. On a car on the highway (at 60 mph) look at the pavement. It goes very fast. However, from your referential (the car) you don’t move (look at the seats for example). So the “motion” depend on your point of vue and what you are looking at. Making everything relative. The seat doesn’t seem to move to you if you’re in the car. However a external person, on the side of the road see this seat moving at a very fast speed

• waspwithstinger says:

How about pollution? Matter cannot be destroyed, only transformed. Fossil fuels are burned and toxic fumes are the result. (along with propulsion)

• Hammer says:

Every action has an equal and opposite reaction:

If I push this car with my finger it rolls across the table faster and further the harder I push……See you try it!!!

I think that, that should do the trick!

The trick will be to relate the information to something that they can relate to.
Let us know how it goes.

• Safety First says:

Pity your poor eleven year old. You could put them off science for ever if you try and force feed them such advanced areas.
Make science fun – have practical experiments with floating, magnetism, simple circuitry etc.

• thomasrobinsonantonio says:

Tempus Fugit.

‘Time, it is relevant’, or so Einstein said,
It came from a notion, somewhere in his head,
But Pad won’t believe it; maybe he’s wise,
He said ‘ Tempus Fugit’, or to you,‘ Time flies’.

Poor Einstein – his theory of relativity,
Was a sign, old Pad said, of naivety,
That theory is one thing that’s not in God’s plan
He’s said to have said, ‘ Time waits for no man’.

If Einstein were right, what would a man do?
But fly back a few years, then forwards a few,
His antics they would be just like a woman,
‘Till no one knew if, he was goin’ or comin’.

‘You would be able to see, if Einstein were right,
Next week’s news headlines, sometime tonight,
And last years potatoes, the ones that you ate,
Would not yet be planted, or gathered as yet’.

‘You could meet your own son when he’s ninety-one,
Then see your own father, when his life begun,
Then kiss your own mother when she was a girl,
Life, if he’s right, would be all in a whirl’.

‘So take my advice’, Old Pad, thinks he’s right,
‘That Einstein was clever, and yes, very bright’,
‘His theories’ says he, ‘they surely won’t last’,
‘What’s done, it is done, and what’s gone, is the past’.

————————

• Marcy C says:

If you did it correctly his head would explode. I’d wait a coupla years