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 DeviantArt.com 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.
