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Blog-a-Day #14 -- Thank-You, Mr. Niven



Extraterrestrial sunsets await us if we can only get to them. In our stories we can, of course. We can take the slow route—centuries at least—via ion drives or light sails. Or, we can get there in decades perhaps, using L-4 drives or fusion drives fed by magnetic ramscoops. And once there, build a teleportation portal to make the next trip instantaneous. But, what if we want to fly around from star to star and not die of boredom, or old age, enroute? A warp drive would work, but that’s been done to death. These are our stories, after all. We want a unique idea, or at least one obscure enough that we can breathe new life into it.

I have one of those. The idea is inspired by—“borrowed from” might be a better way of putting it—a bunch of classic science fiction stories from the pen of Larry Niven. I’ve mentioned Mr. Niven before. I read many, perhaps all, of his Known Space stories when I was young and they made quite an impression on me. He coined the term “Balonium”, which I have used in these articles, for that piece of baloney that moves the story along. The amount of Balonium in speculative fiction helps categorize it, I think. None or a very small amount is hard science fiction. A little more makes soft SF. Add more, ala Frank Herbert, and you get science fantasy, and pouring in the whole bucket gives you pure fantasy.

So what is it? I call it the Bose-Einstein Condensate Quantum Tunneling Hyperdrive, otherwise known as the BEC-QT drive, or just “Cutie” for short. The inspiration is Mr. Niven’s Quantum Hyperdrive. I don’t know if he had any idea of how it might work, or if the two words just sounded good together, but I’ve ruminated on that name and its operation for forty years or so. When in “hyperspace”, no light can get into the spaceship from normal space, resulting in an effect he calls the Blind Spot, so navigation is done by detecting the gravity wells of stars and nebulae you pass.

As you might guess from the name, it is based on quantum tunneling via probability fields. The mechanism of transport is simple. The ship’s drive generates a quantum probability field bubble around the ship. This field effectively turns the bubble into a single particle like an electron, proton, or neutron, cutting the ship off from our normal universe. So far, so good, but to move, the drive must reshape the probability field, extruding a node of it out in front of the ship. That means there is a non-zero probability that the ship and its drive will tunnel forward into this node. When it does, the field and its extruded node move with the drive, meaning it can now tunnel forward again and again and again. The starship is tunneling its way through “hyperspace”.

Cool, right? But there are questions we should be asking. First, is: how fast is this tunneling process? The next is: how do we control the speed? And finally, how do we navigate if we can’t see or interact with normal space? Let’s deal with each of these.

The time it takes an electron to tunnel from one location, or bound state, through a barrier to another has actually been measured (Google “how fast is quantum tunneling”) to be no more than the time it takes to move the same distance at the speed of light, meaning that tunneling itself is instantaneous! Sounds good, but this measured result says that tunneling isn’t any faster than the speed of light. OK, flying at the speed of light is good, but not good enough for our purposes.

Buried at the end of the Forbes article which is the first hit of your Google search, is an explanation of why tunneling is limited to light speed. That explanation uses a normal bell curve to represent the probability field of a tunneling particle. The diagram shows that the leading edge of the probability field crosses the barrier instantaneously, but the remainder of the field travels at the speed of light. Therein lies the solution to our problem because our probability field isn’t shaped like a bell curve. It has a pseudopod-like extrusion at the front. That extrusion “pulls” along the rest of the field and the starship inside it, but how fast? The time it takes the whole ship to move from its initial position to the center of the extrusion should equal the time it takes the center of the extrusion to reach its leading edge at the speed of light.

Picture a probability field shaped like a maraca, one of those musical shakers, with the starship at the end of the handle. The center of the head of the shaker will tunnel the distance to the top of the head at c. If the handle is the same length as the diameter of the shaker head, the entire maraca will travel at 3c, or three times the speed of light because the distance from the end of the handle to the center of the extrusion is three times the distance from the center of the extrusion to the leading edge. If the handle’s length is twice the diameter, the speed with be 5c, and so on.

That answers the second question we should be asking. By varying the size and shape of the probability extrusion, we can control our speed. A probability field whose extrusion is wide and flat greatly increases the ratio between the leading edge distance to the center of the extrusion and the distance from there to the starship, getting us to many times c. For a ship that is, say forty meters long with an extrusion two meters across extended out nine meters in front of the ship, the speed will be 50c! That’s about a month to get to Alpha Centauri, our closest stellar neighbor. Flattening the extrusion head to one meter more than doubles the speed to 100c. Two weeks to the stars.

What about navigation? Good question, because the wider we make the extrusion, and it would have to be very wide if it’s only one meter thick, the more likely it is that we will tunnel sideways as well as forward. So, every so often we need to take a peek into normal space to see where we are. If we do this continuously, flipping the drive on and off quickly, we can watch the stars moving like watching a movie.

Turning the ship into a single particle inside its probability bubble also protects it from the hail of interstellar radiation. But, how do we generate this bubble, let alone shape it as we need to? To start, let’s discuss Bose-Einstein Condensates (BECs). Satyendra Nath Bose and Albert Einstein published a series of papers in which they predicted a new state of matter that occurs at extremely low temperatures close to absolute zero. The first real BEC was produced in 1995. Under appropriate conditions, atoms thus cooled condense into a state where all atoms fall into the same quantum state. From a quantum mechanical perspective this collection of atoms becomes a single particle. When the atoms condense, a single probability field representing the entire condensate appears. Making a probability field on microscopic scales doesn’t help us much, though. We need to expand that field by many orders of magnitude and shape it appropriately. Enter our Balonium.

Classically, atoms consist of negatively-charged electrons, positively-charged protons, and neutral neutrons. The number of protons, or “atomic number” determines what element the atom is. Hydrogen has one proton, Helium has two, and so on. Under normal conditions, the number of electrons and protons are equal, but the number of neutrons can vary from a base number that is stable. Isotopes of an element have additional neutrons above the stable number. In general, the more neutrons an atom has, the more unstable, or radioactive, it is. Elements with high atomic numbers, starting with Polonium at atomic number eighty-four, are radioactive with no stable isotopes. Or, at least that was thought to be true.

There is a theory that says there are “islands of stability” at very high atomic weights (the sum of protons and neutrons). Isotopes in these islands may be quite stable and have very strange properties. Islands of stability are purely theoretical since we have no means of producing elements with the necessary numbers of protons and neutrons. But, a purely theoretical element with very strange properties sounds like Balonium to me.

So, let’s take big, fat, stable atoms with lots of protons and neutrons, and make a BEC out of them. BECs themselves have very strange properties. Multiply that by the strange properties of Balonium and who knows what you may get. Perhaps you’ll get a state of matter that, when compressed by strong magnetic fields reacts by expanding its probability field. The harder you squeeze, the bigger it gets, and if you use an L-4 drive to accelerate the BEC and its field, maybe you can get a kind of maraca shape—and the Cutie is born.

I hope this has been as much fun for you as it has been for me. The topics I’ve outlined in the last fourteen articles have been floating around in my head for many years. It’s very refreshing to finally have them written down, regardless of whether they are particularly coherent or not. Writing them over the course of the last couple of weeks has inspired me to update, organize, and maybe expand them at some point into book form.

This is blog number fourteen, though, leaving one more piece to go. That one will be different. It’ll be a short story built on a foundation of screamers, L-4 drives, ramscoops, and Cuties, but those technologies serve only as the background for a story about love, loss, betrayal, and come-uppance.

Rob Johnson

May 29, 2020

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