Sunday, 18 March 2018

The Speed Of Information

Hi Guys,

Bit of a change in topic this time. First up the next book – Fineas and Tusk: The Epic Journey of a Man and His Pig, is with the editor at the moment, but since she's in the process of moving house at the moment, it may be a while before it returns to me. The image above by the way is one that I found on while I was searching covers for the book, and while I can't use it since it doesn't really match the story at all, I loved it so I thought I'd share it. I may contact the artist and get him to paint me something similar.

However, this time I thought I'd return to an old chestnut of mine – Relativity and space opera. We all know the basics, Relativity means that faster than light travel is essentially impossible, so most space opera is impossible. In essence if we want to write space opera grounded in any sort of reality we have to resort to cheats like warp drives and hyperspace. Theoretical speculations and mathematical possibilities but still things not observed. Or else write things like The Expanse and Starhunter – sub-light speed space opera contained within the solar system. Alternatively we risk arousing the wrath of hard science fiction fans and being told we're fantasists. (That may actually be true in my case!)

But as some of you may know, I have never been the most ardent believer in Relativity. Yes I know – it's one of the most tested and validated theories in physics, and even suggesting that it may not be right is like standing on sacred ground for many. But I have never been comfortable with the idea that time is mutable. To me it seems that if time can be slowed by motion or gravity, or even stopped, then it can be reversed and time travel becomes possible – and I really do not accept time travel. To me something either is completely mutable or it isn't at all. And if time is actually mutable as Relativity says, than we live in a universe of time travel paradoxes.

Naturally I don't think my speculations are going to end up on the title pages of any physics text books any time soon! In fact quite likely I may end up labelled as a Luddite! But that's life.

However in keeping with my views, I've often found myself wondering over the years, is there a way to explain the observations of Relativity without actually having to claim that time itself is somehow being bent? And the answer is yes – at least in my view. I'll attempt to explain my answer here. (Physicists avert your gazes now – this may be treason!)

So my theory is a simple one. That what is observed, has nothing to do with time being bent or slowed. It is in fact nothing more than an artifact of what I'll term the speed of information. Time is not in any way affected by motion. Only the information about it is.

Now I should say at the outset that this artifact is real. It must logically exist. So any theory of apparent time dilation must include it. I'm not sure however, if it's included in current relativistic calculations. I thought about contacting NASA and asking but could feel the laughter building!

OK, that said lets consider the old twins paradox which is what essentially buggers up a lot of space opera. Now according to Special Relativity we have one twin on Earth and the other on a rocket ship leaving Earth at the speed of light. The twin on the rocket ship has time slow down or stop for him, so that when he returns to Earth, he finds he is in fact younger than the twin he said goodbye to. And we have evidence that objects travelling away from Earth do in fact appear to be experiencing less time. Sounds like a case closed sort of thing doesn't it?!

But what I would ask you, would we expect to see if Relativity wasn't an issue? If the universe operated purely by Newtonian principles? Would we expect to see the rocket ship leaving us at the speed of light and everything as if it was happening right in front of us?

Actually no. If Relativity was not an issue we would expect to see that rocket ship which is heading away from Earth at the speed of light, seemingly only travelling at half the speed of light. And if there were portholes on that ship, we would expect to see the people on board moving and ageing at half speed. It would look like everything was in slow motion.

This has nothing to do with time dilation. Time is not being slowed in any way. This is purely an artifact of the speed with which the information about that rocket ship's travel comes back to us – at the speed of light.

To explain this, consider that the rocket ship has been travelling at the speed of light for a year. Could we sitting on Earth staring at it with our telescopes, expect to see the rocket ship one light year away? No. We would see it at the six month point in its trip. This is because the light from the rocket ship as it travels takes time to get back to us. So at the one year point in its journey, that light will take a second year to get back to us, meaning that we will observe the rocket ship at its one light year point, after two years.

To extend this point a little, if the ship is travelling to Alpha Centauri, four and a half light years away and is travelling at the speed of light, it will arrive in the system in four and a half years. But we on Earth will observe it arrive nine years after it left, without any time dilation being involved. Naturally this fits perfectly with the fact that everything we see of Alpha Centauri is four and a half years out of date.

Now lets reverse this a little. What does the man on the Rocket ship staring back at Earth see when he's travelling at the speed of light? And the answer assuming that he sees anything at all, is that he would see the Earth as if it was frozen in time. Someone had hit the pause button on the dvd player. This again is simply an artifact of the speed of information. All the light from Earth telling him what's happening there, is travelling with him at exactly the same speed. So the light that left Earth one second after he did, is still one second behind him for the entire journey.

And again to extend this point a little, when he arrives at his destination and stops, four and a half years later, he suddenly sees the Earth start moving again as someone hit play on the machine. But everything he sees is four and a half years out of date. Naturally once more this fits perfectly with the fact that everything seen of Earth from Alpha Centauri is four and a half years old.

Now lets add a third observer. This time the guy at Alpha Centauri watching the rocket ship come to him. What does he see in a universe without time dilation? Oddly, he sees nothing. The rocket ship takes off, but he won't see that until four and a half years later – at exactly the same time as the rocket ship arrives beside him. So he has the unusual experience four and a half years after the rocket ship leaves Earth, of seeing it take off, travel for four and a half years, and arrive all in the same instant. A sort of photonic boom.

So what does all of this mean for us space opera writers? It means at the very least that there is a simple explanation for why we might observe what seems to be time dilation without it actually existing. It also means there might be a very simple reason that we cannot observe anything travelling faster than the speed of light – all the information about that thing travels to us at the speed of light since it's axiomatic that light cannot travel faster than the speed of light.

Most importantly it means that we can write space opera involving faster than light travel without having to invoke the gods of hyperspace and warp drive etc, and still feel good about it! Hard science fiction be damned!!!

Anyway, must dash. I see the men with the white coats walking up the drive and I suspect they have a new jacket for me – one that straps up at the back!

Enjoy your writing.

Cheers, Greg.