For some reason, there have been a number of articles on the web recently on the realism of fictional space wars. Some of the points in fiction are obviously wrong, thus space vehicles travelling in a straight line do not need to have motor firing, and using wings to bank and turn is, well, just plain wrong because wings do not do anything in a vacuum. On the other hand, the purpose is to be entertaining, and in a film, being technically correct my merely leave the average viewer wondering. But what about in fiction? Technical explanations may turn off many readers, while correct physics without an explanation may just seem to be incomprehensible.
I had this problem in my ebook, Scaevola’s Triumph, which is now available from Amazon. This concludes a trilogy and the basic plot is that the planet Ulse is losing a space war and faces extermination. However, the future has engineered a small party of Romans to be abducted by aliens so that Scaevola could save Ulse by turning around the war. It may not seem realistic that an ancient Roman could change anything, and that is what the Ulsians believe too, nevertheless he can, and can you see why?
The purpose of the first two books was to show how science works, and what it is like to make a discovery, so it was important to try to get the science right in this book, particularly with the battles. So, what would a space war look like? If you are writing a story where you need a space war, you have to take some liberties, if for no other reason than to keep the story interesting. The first point is that distances would be very great, and would extend over light centuries. This had the problem for my civilization in that if an invasion force could travel near the speed of light, and they deployed enough military force, the invasion could proceed at near the speed of light, and hence the civilization would lose most of its dominions in that direction before they even knew there was a war. Actually, this problem first occurred with Alexander, who moved about as fast as a messenger sometimes.
What scientific issues arise in a battle? One issue is relative velocity. If two vessels are going in opposite directions, the time they have together is trivial. In one battle in my book, it took hours to approach, and a few seconds in a battle zone. Since such short contact time is undesirable, ships attacking others in my wars usually spend much of their time slowing down. Even then they might pass through the enemy, and then take at least half an hour to turn around and come back. Looping around the back of a planet is a good way to turn.
What about weapons? My view is that lasers are useless because if you depend on them, the enemy merely has to get bright and shiny, and reflect the energy. One solution is to fire otherwise undefined constrained bursts of mass/energy approaching light speed. They are difficult to avoid because the energy arrives almost as soon as the light signature of the firing. Some people have suggested that small pieces of matter are all that is needed. Chaff hitting your ship fast enough will do extreme damage. However, if ships are capable of travelling at velocities approaching light speed, they must have some means of dealing with bits of rock, etc, so that will not work. (The fact you do not know how they could do it is beside the point; we do not know how to approach light speed either, but if we did, we must have the other.) I have also seen criticisms of “fireballs”. Strictly speaking, fire cannot occur, but if you see fire merely as a plasma, then there is no reason why jets of metal vapour in a plasma could be realistic. Of course, in science fiction you can be inventive. The weapon I “invented” is one that within a locked zone the weapon exerts a field that changes the value of Planck’s action constant on a given vector direction. All nuclear structure on that axis disintegrates. Defend against that! (I know – a variable constant is uncouth, but then the question arises as to why it is constant. We don’t know that there are no circumstances when it could not have another value, do we? And this is fiction.)
Science fiction also has the “cloaking device”. In my space war, that is there – all electromagnetic radiation that strikes the vessel is absorbed and re-emitted on the other side, on the same vector. (Really, more a chameleon device.) Now, supposing there were an enemy using such a technology, how do you defend against that enemy, which means, how do you locate him? There is a way of seeing ships using such technology. Can you work it out?
Yes, it is all fiction, and I am sure that there are a number of faults there too, but the question then is, is it entertaining, and does it encourage anyone to think? If so to either, then it was worth writing it.