How to picture the speed of light for a 2 year old child

(перевод на русский – см. ниже)
The picture:

Imagine the moon.
Light can travel from Earth to the moon in 1 second.
Moon is very far.
If we will travel to the moon by train it would take 1 year. Fast train in 1 year can go to the moon and back (round trip).
A train can go to the moon faster or slower but light cannot travel faster or slower – it’s always 1 second to the moon and one second from the moon back to Earth.

DETAILS:

I assume that the child cannot count. So I use only “1” as a number.
I assume that the child doesn’t know words: “speed” or “constant”.
1 year could be explained as the time from birthday to birthday.

How to start a conversation?

We cannot say to a child:
Sit still. Shut up and listen.
Now I will teach you about the speed of light.

We need to find a way to start a conversation. To make a child to be curious.

So to start a conversation you can ask: do you know what is the fastest thing in the world?

But there’s a better way. If a child was running by – you can notice “wow, that was fast! do you know what is the fastest thing in the world?”

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Evaluation of the simple explanation of the speed of light is 1 billion dollars. The lowest estimation is 1 million dollars.
See details here

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If you want to know how to picture another physics concepts to a 2 year olds please join the FB group.

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Как объяснить скорость света ребенку 2-х лет

Представь себе луну. Луна очень далеко.
Но свет может долететь от Земли до Луны всего за 1 секунду.

Если мы поедем на Луну обычным поездом, то это займет 1 год. Если поезд поедет быстро то за 1 год он может доехать до Луны и вернуться обратно.
Поезд может ехать быстрее или медленнее, но свет не может лететь быстрее или медленнее – до Луны он всегда будет лететь одну секунду и одну секунду он будет лететь обратно от Луны до Земли.