Thought experiments

Inside the Atom

A/N my submission for  GE Adventures In Science contest. I've copied the picture it comes into the story.

"What are we doing here?" Elizabeth asked as she scrambled up the path leading to the large hill in front of them."You disappear for three months out of my life with little more than a cryptic text every so often to keep me going. Then you turn up and whisk me out here. I have a life. I have a new job next week in a big financial company in New York. What's up with you Joe?"

"Today I'm going to show you everything" said Joe.

"and the hill is here because?"

"well it's got  the best view. And you know maybe just maybe it's a metaphor" answered Joe.

"Couldn't you have chosen a lower metaphor Joe" said Elizabeth scrambling up the steep slope.

"Your dad is a physicist right?"

"And my mum" said Elizabeth.

"Makes you think that two wrongs can make a right doesn't it?" said Joe even he was starting to get breathless at the pace they were doing. "Anyway I have a story for you."

"OK" said Elizabeth too breathless to get started and argue.

"There was a physicist called David MacKay. He writes this book called sustainability without hot air. In it he says you can never run America by wind Power alone. You know why?"

"No, but I have the uncanny feeling you're going to tell me." said Elizabeth catching up to Joe.

Joe stopped and he held his palms out.

"So this Cambridge Professor David Mackay says if you look at a wind turbine if you put them close together then they begin to interfere with each other" while he did Joe moved his Palms close together to show the wind from one word turbine interrupting another. "too far and your wasting space you could fit more turbines in." said Joe his palms moving out "from this he derives this mathematical law that wind turbines should be at a particular distance apart. This fixes the maximum amount of wind you can get per square mile "

Joe spread his hands out to show and evenly spaced forest of turbines.

"yes and..." said Elizabeth impatiently.

"So McKay says the laws of physics shows there is an optimal density of wind turbines. He also points out that the cost of the wind turbine goes up with the square of a height. Double the height quadruple the price. From this he says the laws of physics tell us we would need to cover millions of square miles of America in wind turbines to make all our electricity. And they would have to be away from cities where we use it. He says, he's sorry, but you can't beat the laws of physics"

"Then he is right" said Elizabeth looking down.

"Your dad also said he would never let an engineer marry his daughter"

"Like he has any say in the matter," said Elizabeth sitting down on the grass "is that why you went off   You were In a huff because my dad is looking down on you?"

They were half way up the hill, even this high up the electric car looked small. They could now see to the fringes of the city beyond.

"and your mum" added Joe.

"Well he's right and she's right you can't break the laws of physics. Or do you mean my mum's Book? She really hates a whole marriage industry she wrote that whole book about it. If her daughter married anyone she look like a complete idiot. I told you I'm not marrying anybody, it's impossible." added Elizabeth.

"When we started at University the guys I was with told me it was impossible to date a girl taller than me. Arn't you glad that I ignored that one." said Joe starting to walk up again.