Take the Einstein Challenge

So you think you are as clever as me?

Einstein started thinking... What would it be like to catch up with a beam of

light?

Question 1

HOW FAST DOES LIGHT TRAVEL IN EMPTY SPACE

(in a “vacuum”)? A. 300000 km per second B. It varies C. 300 km per second

Answer 1: A

Speed of light is 300000 km per second

That’s…

7 times around the world in one second !

Question 2

Imagine you’ve decided to find out what it is like to catch up with a beam of light. You build a super rocket with limitless fuel.

You are in deepest outer space so there is nothing to bump into, and you have all the time you could possibly need.

You start the engines…you go faster and faster.

WOULD YOU BE ABLE TO CATCH UP WITH AND OVERTAKE A BEAM OF LIGHT?

Options

A. Engines create a pushing force causing you to speed up. It’s only a matter of time before the rocket will reach 300000 km per second.

B. No, it is just impossible for anything to travel faster than the speed of light

C. It could if it wasn’t for friction. As your rocket goes faster and faster friction gets greater and greater creating a breaking effect that cancels out the engine thrust.

Answer 2: B

Einstein realised that nothing could travel faster than the speed of light.

As you will discover amazing things happen to a rocket (or any material object) that tries to get close to the speed of light.

What happens? Well first a little detour…

Question 3

Einstein is famous for the equation:

E=mc²

What does each letter stand for?

Options

A: E= energy m=mass

c= speed of light

B: E= energy m=mass

c= current

C: E= electric charge m=mass c= speed of sound

Answer 3: A

This equation doesn’t look special but if you understand it, it tell us

something…

AMAZING!

Our common sense tell us that everything we encounter can be

divided into TWO groups…

EnergyOR

Like heat and light, movement…..

The stuff that makes things happen

Like you, the table, the earth…..

The stuff that things are made of

Matter

What E=mc2 is telling us is that …

ENERGY CAN SOMETIMES TURN INTO…

energ

y

What is telling us is that …

ENERGY CAN SOMETIMES TURN INTO MATTER …

energ

y

Matter is the stuff that you and I are made of

…and the other way around.MATTER CAN SOMETIMES CHANGE INTO …

…and the other way around.MATTER CAN SOMETIMES CHANGE INTO

PURE ENERGY

energy

Sounds like magic ????

Question 4

Back to our rocket….what happens to the rocket to make it impossible to catch up with light?

Guess which answer Einstein would give….

Options

As the rocket goes faster and faster… A: The rocket loses mass (could say it

gets “lighter”) and therefore loses energy and can’t speed up

B: The rocket’s mass is unchanged C: The rocket gains mass (could say

it gets “heavier”) so it becomes increasingly harder to speed it up.

Answer 4: C Einstein worked

out that as material starts to move it gains more mass (in simple terms…it gets “heavier”)

The faster you move the greater the gain in mass

Every part of your rocket (including you if you are on it) gains more and more mass as you go faster and faster

….Why is it so hard to get a large truck moving by pushing it?

…..because it’s got lots of mass The more mass an object has the more

energy it takes to speed it up.

Why does an increase in mass stop you catching up with light???

Einstein worked out…

In attempting to reach the speed of light your mass will become… INFINITE

All the energy of in the universe would not be enough to speed up an object to catch up with light, never mind overtake it.

Imagine you are standing on earth watching someone move past you in their space rocket.

They are travelling at a steady speed…about 120000km per second (nearly half the speed of light).

Einstein reasoned that you would notice something else strange happening to the rocket……What is it?

Question 5

Options

A: The space rocket and everything in it would appear to shrink in the direction it was travelling in.

B: The space rocket and everything in it would appear to expand in the direction it was travelling in.

C: The space rocket would appear to expand in all directions

Answer 5: A

The rocket would appear to

From where you are standing…

Answer 5: A

The rocket would appear to

From where you are standing…

Strangely…

The person in the spaceship cannot see the shrinking. Everything looks normal to them.

Everything they measure with a ruler appears to be the same length as before….

Question 6

Why would their ruler not show up the change?

A: Rulers are no use in space B: The ruler is not accurate enough to

measure any change C: The ruler shrinks too and so

measurements look the same

Answer 6: C

The ruler shrinks too

The super brainy part is… Einstein realised that it’s

not just the rocket, ruler etc. that shrinks…..

You are seeing SPACE ITSELF SHRINKING!!!

That’s hard to get your head around ….unless of course you are Einstein!

E =mc2

Question 7

If Einstein is right then every time we move (according to measurements taken by someone watching us) we gain mass and shrink.

How come none of us have never noticed?A: People are too busy to notice.B: At everyday speeds the gain in mass and

shrinking is so small we cannot measure itC: Because Einstein was obviously wrong

Answer 7: B

You have to achieve colossal speeds (close to the speed of light) for these effects to become measurable.

NOW FOR ANOTHER MIND BOGGLING QUESTION….

QUESTION 8

IS TIME TRAVEL POSSIBLE?

You ask such tricky

questions !!!!

Options:

A: Yes you can travel backwards and forwards in time.

B: You can only travel forward in time, not back.

C: No

Guess what I think…

Answer 8: B Surely time is……

well……time! You can’t change it. It must be the same everywhere????

Einstein reasoned that TIME DOES CHANGE depending on

How you are moving and Where you are in the universe

Question 9 Let’s go back to watching our spaceship from

earth… So far we have seen it gain in mass and shrink…

Einstein says there is something else you will see…….something to do with TIME….

What is it…?

Options

A: Everything inside the rocket appears to happen in slow motion…..time slows down!

B: Everything appears to be speeded up…..time speeds up!

C: Everything happening in the rocket appears to be going backwards…..time is in reverse.

Answer 9: A

The passenger on the rocket is completely unaware of time slowing down…

…..Their brain processes have slowed down too!

Travelling at steady high speeds is one thing but if you really want to mess with time you

need to know more….

First a definition: (to a physicist)

“ACCELERATION” means….Speeding up/ slowing down/ changing direction.

If you really want to travel in time Einstein would suggest that you go on a journey that involves colossal rates of acceleration!

Imagine if…

You had a twin.

…you go on a white knuckle ride on your space rocket (lots of accelerating) for a number of years, whilst your twin stays behind…

EINSTEIN CLAIMS THAT WHEN YOU GET BACK….

You would not have aged as much as your twin…

Back from your trip! The twin who stayed at home!

Question 10

Einstein says that when you accelerate time slows down.

On your recent space rocket ride…. in which direction have you travelled in time?

A: Forward in timeB: Backwards in timeC: You haven’t travelled in time at all

it’s just an illusion.

Answer 10: A

You have travelled into your twins

future!…but Einstein realised that there was

more to time travel than hair raising spaceship rides….

Question 11

Something else can slow down time. What is it ?

A: Electricity

B: Magnetism

C: Gravity

Answer 11: C

The strength of gravity on the earths surface slows down our clocks by about 1 second every century.

Scientists have put clocks on high flying planes (high up gravity is weaker) and they come back having gained a tiny bit of a “tick”

Gravity

For serious time travel you need

“BIG” GRAVITY! The more mass something

has the bigger it’s gravitational pull…

You need something like a BLACK HOLE !!! The gravity monsters of the universe

So now you know why Einstein is a GENIUS

Sitting at his desk he carried out

“thought experiments”

That led him to conclude that…

That Space and Time are not as simple as our everyday experience

suggests!

“Spacetime”

(as Einstein called it) can

It’s not science fiction but real physics!

&

Congratulations on completing the Einstein Challenge

Time for one last challenge ?

Anyone who has never made a

mistake has never tried anything

new!

Try a bit of “free thinking”We’ve been watching our friend moving past us

in a space rocket at nearly half the speed of light….

We understand that we will see:Their MASS increaseTheir LENGTH shrinkTheir TIME slow down

The question is……

When your friend looks out of her window at you…

HOW DO YOU LOOK TO HER? Will she see any difference in your MASS, LENGTH and TIME?

What do you think?