Thursday, 17 November 2016

Chapter 3

It was getting close to Easter and Fret was hard at work on the larger portal aimed at the Canary Islands. Luckily lectures were becoming less frequent so there was more time to spend on it. Harry was 'helping' with the building work, each gold-plated cube had to be positioned just right in the array so there was a lot of fine distance and angle measurement with a network of lasers.
It had now dawned on Mum that if she was going to step into this contraption she be a lot happier understanding a little bit about how it worked, so down she came to the cellar to ask
‘So, how does it work then?’
‘Are you serious? You never asked for details before.’
‘Well, I just thought, if I’m going to allow your work to transport me 1000 miles through nothingness, I’m entitled to an explanation, but remember I’m an engineer, not a physicist.’
‘What do you want, pictures?’
‘Don’t get cocky! Engineering is what happens when physics is forced to be useful!’
‘I know, I know. Alright, can we go back to Mach and Einstein?’
‘Yes, I’ve heard of them.’
‘Right, well they considered this train..’

Henry perked up at this. He knew all there was to know about trains.
‘Was it a Crosscountry or a Great Western?’
‘Er.. a Great Western I suppose.’
‘And this train is struck by lightning at both ends.’
Henry was awed by this
‘Is this for real!?’

Harry looked crest-fallen and, afraid he was losing his audience, Fret changed his mind.
‘OK. It’s for real!’
‘I knew it’, said Henry.
‘So. Bang! The train is struck by lightning at both ends and there’s a guy in the middle of the train who sees these two strikes.’
‘Wait a minute,’ said Mum, ‘How does he see the two strikes? Does he have eyes in the back of his head?’

This question completely floored Fret for a while. No one had ever asked that when he’d studied relativistic physics at university. They’d all been too busy writing things down and cramming to have time for anthropogenic questions like that. But, then he rallied, he had been thinking about this for a long time and really felt he should be on the home straight here.
‘OK, but look, that isn’t the point. This is not a question that depends on the particular design of human beings. We imagine there’s an intelligence that can gather information from light completely efficiently, so, yes, he does have eyes in the back of his head.’
‘Like Grandma! She said she had eyes there’ said Henry.
‘Yes, indeed. Can I continue?’
‘Go ahead!’
‘Thank you. If the train has stopped then the guy sees the light from both ends at the same time, so he says “Aha! It’s a simultaneous strike!”

'..but if the train is moving forward then he’ll see the first strike first because he’s moving towards it and the light from the back will have to catch up with him, so then he will say “Oh, it’s not simultaneous”.'

'So Einstein said the times of events that occur are dependent on how you are moving so there’s no one clock in the cosmos ticking time, everyone has their own time and also by extension everyone has their own space too.’
‘So how does that help to delete the space between here and the Canaries then?’
‘Imagine we now have a train going forward at light speed.’

Henry was keeping up
‘You mean, like the USS Enterprise?’
‘Yes, like that. The light from the back of the light speed train would never catch up with the guy in the middle so he’d never see the back lightning and Einstein made a bold assertion that led him to relativity. Everyone subsequently forgot the assertion, even Einstein after a few years, and just kept the maths that came from it, but he said that if you can never in principle see a thing, then it doesn’t exist for you. Actually, Mach first alluded to this...’

Mum began to shake her head now.

‘Look, I’m an engineer, and if you’re trying to tell me that the Moon isn’t there when I can’t see it, you’ve got another thing coming!’
‘No. It’s not whether you’re looking or not. It’s whether you can possibly see it or not. There is a difference. With my loops here, which are actually called metamaterials, what I’m doing is bending all the kinds of radiation coming from this area of space behind them away from us, so we’ll never see that space. That means, from our point of view, that that region of space does not exist, so when we step through the loops we’ll appear to jump across that non-existent space to the space beyond.’
‘A sort of “What you can see is what you get?”’
‘Yes, that’s the idea.’

She raised her hands as if to say ‘that’s enough for now’.
‘OK. You’ve deleted some space. It sounds completely mad, but you did project that fishing rod. The big question is, are you ready to put us through it? It looks a bit bigger, but is it safe?’
‘The main problem is that I can’t put us directly onto the ground, my accuracy in position is only about 100 metres.’
‘That’s good enough.’
‘The trouble is, it might be 100 metres up in the air, or under the ground.’
‘..but you can see through it can’t you? Why not set it up, look through it and fine tune?’
‘I never thought of that.’

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