Parallel Universes: Part One

Parallel universes, or alternative universes or mirror universes have had a long run of popularity in science fiction and science fantasy, in both print and visual formats. One need only look at an “Alice in Wonderland” or look no further than the “Star Trek” universe (our Universe in less than obvious disguise) to view the near endless plot variations that such parallel / alternative / mirror universes provide our heroes and heroines. Do they actually exist and do they explain anything?

There are apparently two theoretical counterparts in our real world, or in our physics. Firstly, there’s the idea that from the beginning, there’s an infinite number of parallel universes where all things that can happen, do happen. Our Universe is just one of that infinite set. In five of those universes, you 1) flip a coin – in one, it’s a heads you flip; in another, tails; in the third, the coin stands on edge! Or, in a fourth universe you decide not to flip a coin at all, or in universe #5 you decide to flip something else instead.

The other theoretical set of parallel universes is a set that ever increases, staring with just one. Universes split whenever an either/or choice is forced upon it, such that all results that can happen, happen. In this (our) Universe you decide not to flip a coin – but that decision results in a division, the universe splits and in that split, in the new universe, you do flip a coin. In that universe it comes up heads. But, that universe then splits into two and yet another universe where your flip has tails comes up. There’s also another universe where the coin lands on edge! There’s also a universe that originally splits off where you decide to flip something other than a coin. This is known as the ‘Many Worlds Interpretation’ theory, (which resulted out of a need to explain certain quantum phenomena). With every passing second, more and more universes branch off (actually trillions per second).

I’ve never been a fan of the Many Worlds Interpretation of all things quantum. That is, the universe keeps splitting each time it comes to a fork in the road. The question of where all the matter/energy comes from – created out of nothing apparently – I’ve yet to see addressed in the texts. But, many top notch scientists adopt it – perhaps as the least of all the evils certain quantum phenomena dish up. As to where they fit, all those extra universes, that’s not as much of a problem. A motel with an infinite number of rooms never has to put out a ‘no vacancy’ sign – if you get the analogy. Oh, the Many Worlds Interpretation also means that there’s no such thing as free will. You may think you have free will in deciding to wear your red dress instead of your green dress, but in the Many Worlds Interpretation, you do both – so no free will.

However, I myself go for the Copenhagen Interpretation* – when you come to a fork in the road, one and only one choice is made – the other possible choice(s) are never realized and ultimately never have any reality. But, if you start out from scratch with an infinite number of universes, or at least a vast number, then the issue of ‘where’ all the universes are is irrelevant, and the creation of all the stuff that makes them up is equally irrelevant. In the beginning, it was so!

You can have an infinite number of universes in an infinite amount of space. An analogy – there are an infinite number of whole numbers like 1, 2, 3, 4, 5, 6, etc. There’s also an infinite number of even numbers such as 2, 4, 6, 8, 10, 12, etc. Ditto an infinite number of odd numbers. Yet the infinite set of even numbers, plus the infinite number of odd numbers, equals the infinite set of whole numbers. Infinity + infinity = infinity! Or, if you like, think of your house (volume) with just one molecule (universe) in it. You’d agree there’s room for one hell of a lot more molecules (universes). If your house had infinite volume, then…

I had always assumed, and followed the assumptions of others infinitely more brilliant than I, that such theoretical constructions, such parallel / alternative / mirror universes, was forever beyond our actual reach – works of fiction aside of course. We could construct them as an intellectual exercise, but could never verify and understand the actual existence of these mental or thought experiments. That’s because these universes, if they exist, would not be part of our space-time continuum and thusly we could never interact with them.

But what if that assumption is wrong? What if parallel / alternative / mirror universes not only exist, but can and do interact with ours, and thereby give some additional credence to the adventures of our “Alice in Wonderland” and “Star Trek” characters, not to mention the reputations of those physicists who propose infinite universes or Many Worlds Interpretation theories. 

Micro & Macro Mysteries: Well, those assumptions just might now be put to the test. I’d love to be able to say I thought of this idea, even independently, it’s just that brilliant. Alas, I didn’t, and I’m kicking myself because it’s just so simple and elegant.  The credit for this goes to physicist David Deutsch, and for a fuller and better outline of his proposals, see his book cited below**. 

The basics are as follows and deals with the paradoxical and famous ‘double slit’ experiment with light – an experiment with photons.

If you shine a light (millions of photons worth) at a slit, you’ll get a blob of light on the surface behind the slit. No problems – the photon ‘bullets’ go through the slit and impact on the surface behind.

Now you shine the light (millions of photons) at two slits. Contrary to expectation, you don’t get two blobs of light – one opposite each slit – but a classic wave interference pattern of alternating light and dark areas on the surface behind. So photons aren’t ‘bullets’; light must be a wave.

Thus is demonstrated the classic wave-particle duality or paradox of light. Is light a continuous wave, or is it a collection of individual ‘bullet’ particles?

Instead of firing millions of photons at these slits at a go, redo the experiment by firing off photons one at a time – say one per hour. That can actually be done. If you fire the one per hour photons at a single slit, the picture that emerges over time is your blob of light behind the slit. Photons are behaving as ‘bullet’ particles as before.

Now, fire the photons – one per hour – at the two slits. Clearly, you’d expect two blobs of light to ultimately form on the (say photographically sensitive) surface that is behind each slit. Sometimes the single photon would go through one slit; sometimes the other. Alas, you still get a wave-like interference pattern! How can this be? What’s interfering in real time with the actual photons that you’re shooting off?

The only object capable of interfering with photons, to cause wave-like interference, an alternating light-dark pattern, is other photons. But there are no other photons in the vicinity if they are shot out at one per hour and your photon source is the only photon source!

The inescapable conclusion is that there must be other photons around that can’t be detected (seen). Call these photons virtual photons, or shadow photons or ghost photons. Where do they come from? The answer is from our parallel / alternative / mirror universes. There is therefore a form of weak interaction between universes.

To be continued...