Genius by Stephen Hawking

HAWKING

ONCE WE KNOW THE SIZE OF THE EARTH AND THE MOON, IT'S POSSIBLE FOR MY VOLUNTEERS TO TAKE THE NEXT STEP AND FIND OUT HOW FAR APART THEY ARE. BUT FIRST, A GUESS. I THINK IT'S CLOSER. I THINK IT'S ABOUT THERE.

CAT

THAT IS WHAT I WAS GONNA DO. I WAS GONNA PUT THEM CLOSE, I THINK.

JIM

CLOSER THAN FURTHER. I THINK THAT IT'S A BIT FURTHER AWAY. WOW, THAT FAR? GOING BIG.

JOY

I PUT THIS AS MY GUESS. OK.

HAWKING

SO, HOW CAN WE FIND OUT FOR SURE? THIS EVENING, THERE IS A FULL MOON. THAT IS THE FINAL CLUE THEY NEED, TO THINK LIKE ARISTARCHUS.

CAT

MAYBE WE TAKE THE EARTH AND PUT THE MOON IN FRONT OF IT, UNTIL WE COVER UP THE MOON. SAME SIZE? SAME SIZE. OK. TAKE IT TILL WE LOSE SIGHT OF THE MOON.

HAWKING

CAT HAS THE ANSWER.

CAT

I'M LOOKING AT THE REAL MOON IN THE SKY AND THE LITTLE MOON THAT WE HAVE AND I'M THINKING, "WELL, THEY'RE THE SAME." SO, MAYBE WE NEED TO BLOCK OUT THE REAL MOON IN THE SKY. CLOSER. CLOSER. A LITTLE-- A LITTLE CLOSER. ALL RIGHT. I SAY THAT'S IT.

JIM

IS THAT IT? YEAH. SO, YOU WERE RIGHT. THE MOON IS PRETTY FAR FROM THE EARTH. YEAH, A LOT FARTHER THAN WE THOUGHT.

HAWKING

WHEN THE SCALE MOON IS JUST THE RIGHT DISTANCE AWAY, IT WILL COVER THE REAL MOON PERFECTLY. THAT'S HOW YOU FIND THE DISTANCE. IN THE DESERT, THE SCALE MODELS OF THE MOON AND EARTH ARE 6 FEET APART. UP IN THE SKY, THE REAL MOON IS ABOUT 240,000 MILES AWAY.

CAT

IT WORKED. I'M NOT A SCIENTIST, AND TO BE ABLE TO JUST DO THAT OFF A WHIM AND IT JUST CAME TO ME, THAT WAS--THAT WAS INCREDIBLE.