part0065

Man’s ability to live, thrive, and survive has always been to some extent dependent upon his ability to move himself, and his supplies, around in a reasonably effective and reliable way. Up to about 5000 BC the only way to move relatively heavy items was to pass them over wooden rollers – in the way that it is supposed the ancient Britons moved the twenty-odd-ton stones that were needed to construct Stonehenge. Then, the invention of bronze chisels enabled wood to be formed with sufficient accuracy for reliable axle-wheel assemblies to be constructed – providing something of a revolution in the speed with which heavy goods could be transported (the wheel is often described as the greatest invention of all time but this accolade could be more accurately attributed to the axle).

The next dramatic increase in speed of transport did not occur until the nineteenth century, with the invention of the steam locomotive and railways. The twentieth century then saw the greatest increase in speed of travel that mankind has ever experienced, (which might never be exceeded) – specifically a 200-fold increase from a 100 mph train to a moon rocket travelling at over 20,000 mph. Will we see any further substantial increases in the future? The answer to this is surely yes, but whether they will occur in our lifetimes, or that of our children, is a different matter. When travelling on the surface of the Earth, one problem that high speed travel has to contend with is that of air resistance, which creates a drag force, the size of which is proportional to the square of the speed and to the cross-sectional area of the moving object. Consequently, travel at very high speeds means a very high drag, necessitating a great power or expenditure of energy (this explains why most cars can accelerate to 100 mph quite easily, but a very powerful engine is required to exceed speeds of, say 200 mph). One way around this in the future would be to build long airtight tubes which would have all of the air pumped out. Inclusion in the walls of the tube of devices similar to the mass accelerators described earlier, would then enable very high-speeds to be attained – perhaps of the order of tens of thousands of mph for transporting goods. The maximum speeds for humans would depend upon the g forces that passengers could endure in the periods when they would be accelerating up to, and down from, the high speed. Of course, building the tubes over long distances, and installing/operating the mass accelerators, may well turn out to be very laborious and expensive (but then, when jet engines were first invented most people thought they would be too expensive to run for human transport purposes – which, of course, proved to be very far from the truth). Although constructing a junction for these tubes (analogous to a junction on a railway line), would appear to be a task of prodigious complexity, it may be that no junctions would be required – particularly if these high speed transports were primarily employed for very popular routes for which high volumes of traffic would be expected. One can, for example, imagine such a tube being constructed between Southampton in England and New York. In fact, two tubes would be required – one for travel in each direction, and they could be suspended a relatively short distance below the ocean’s surface – say 200 feet. This would allow them to be missed by any ships passing overhead while being sufficiently close to the surface to allow reasonably easy maintenance as well as avoiding all the demanding and expensive physical strength that would be required if the tubes were experiencing higher pressures at greater depths. The route would be fixed without requiring junctions, since once coming up onto land they would enter termini that could employ railway hubs (or perhaps other tube hubs in the USA), for onward travel to the traveller’s exact destination. I must say I like the idea – I should seek a patent for it (but this has probably already been filed).

These types of transportation systems do not require great scientific breakthroughs – they could be developed using modest developments of the technologies available to us today. It may be that they would be expensive to build, but once operational they could offer transport speeds that up to now have only been dreamed of, as well as affordable operating costs and on-going substantial environmental benefits. But what about high-speed travel in the air? It is, of course, easy to imagine aircraft that could travel at significantly higher speeds than current airliners. In fact, for many years we had one regularly operating between London and New York – the previously mentioned Concorde, which could comfortably cruise at Mach 2. Since it travelled faster than the rotation of the Earth, it famously enabled passengers to disembark in New York before they set off from London (at least according to the local times). I know I have already included images of this stunning aeroplane, but I had to do so again because it is so beautiful.

Yes, Concorde was certainly a great engineering achievement – perhaps the most beautiful commercial airliner ever built – but efficient it was not. Its Rolls Royce Olympus engines may have been the epitome of reliability, but they could not be described as frugal. Concorde, alas, is no longer flying, and in recent years there has been a move away from speed towards saving money, so that nearly all of today’s airliners employ turbofan engines which (for reasons we will not go into here) are much more efficient than turbojets such as the Olympus, with the disadvantage being that they operate best for aircraft that are traveling at a maximum speed of around 0.8 Mach.

It would, however, surely be possible to design aircraft that could travel at speeds well in excess of that of sound while still performing with reasonable efficiency – perhaps by flying very high in the atmosphere while employing the ‘Ram Jet’ principle. Such supersonic ram jets, or scramjets, have been the subject of theoretical and practical studies where their potential to travel at up to Mach 6 has been explored; but up to now little has emerged in terms of developments that indicate capabilities for commercial air travel. Perhaps the technology is considered too expensive or risky, or maybe the major carriers feel that the average customer can be kept happy with extended/premium services to cover the extra time that is needed to make a journey at a lower speed. No doubt their business cases and projections show that a far greater profit can be made by providing increased service instead of increased speed.

Another travel environment to be considered is the vacuum of space. The main problem encountered with space travel is that in order to get thrust to move forwards, we need to push backwards on something; or to put it another way, we have to obey Newton’s third law, which states: 'every action has an equal and opposite reaction'. In space, it’s clear that there is precious little to push against (just the occasional hydrogen atom) – which is why the only types of drive that have been employed, in practice, in space are rockets – here the thing we push back against is the gas escaping from the back of the rocket.

There are other types of drives that have been experimented with, such as ion drive, where a gas is ionised and then accelerated in an electric field before exiting at the back of the drive, providing thrust. Plasma drive is similar but involves a plasma which is accelerated via an electric current. Another type of drive that could theoretically accelerate (very small) spacecraft to high speeds is laser drive, where a high-power laser (usually on the ground) is used to aim a laser beam at a craft, to which momentum is transferred, thereby accelerating it (the effect being enhanced through use of a laser-pushed ‘lightsail’). Although these methods are perfectly reasonable from the physics point of view, the magnitude of the forces that they have been shown to be capable of providing, at least up to now, are far too small to accelerate spacecraft containing humans up to usefully high speeds in reasonable time periods (of course, that is not to say they will not undergo further development in the future and become practical methods of propulsion).

There are, by the way, one or two other species of spacecraft thrusters that seem implausible but have generated a good deal of interest in certain sections of the media. One such device is the EMDrive , or radio frequency resonant cavity thruster . It is claimed that it generates thrust by reflecting microwaves internally in the device. Unfortunately, in doing this it would be in violation of the law of conservation of momentum and Newton’s third law. Also, it seems that there has not been independent verifiable evidence from tests that it can generate thrust forces any greater than those attributable to experimental error. However, if at any time such forces are demonstrated in the verified tests, I will be all ears…

So, what does this leave us with? Yes, the good old rocket engine. Old is certainly the operative adjective – the Chinese were launching crude rockets over 1000 years ago. Rocket engines, although cumbersome and occasionally unreliable, are perfectly capable of providing thrust for rockets aimed at exploring our solar system – as all the robotic probes launched in recent decades have illustrated. The problem arises when much higher speeds are required to enable interstellar travel within liveable time periods (i.e. perhaps years rather than millennia). To state it simply, if a rocket is to contain enough fuel for the motor to burn long enough for it to reach very high speeds, it would be too heavy to actually launch! But I did say I was going to address the developments of the far future and, as mentioned, the rocket is an invention that is a thousand years old. So, let’s dispense with it and let our imaginations roam more freely. If we were to ignore the constraints of current technologies for the time being, what might we imagine transport mechanisms of the far future would be able to do and how could they work? And why did I just ask myself a question that is just about impossible to answer?

When thinking of the farther future, for me Star Trek often comes to mind. What an original show and one that, for once, envisioned the future as an exciting place where you would want to live, full of all sorts of fantastic possibilities; rather than some kind of grim, fashionable, dystopian nightmare. One of these fantastic possibilities is, of course, the transporter mechanism; but is it really a possibility? In my view, it is one of the least believable ‘gadgets’ that appear in the show, perhaps partially because one finds it difficult not to think of it as slightly too convenient – a simple business of stopping the camera briefly so that the actors can walk off set, then start it again so that they seem to disappear. Use an optical printer to combine this with a glittery effect (film of someone shining a light through a cascade of glitter) and, hey presto, the guys have beamed out! Suppose they have beamed down to a planet – the next scene can show them in a glittery re-appearance on the planet surface (AKA Desilu Studio 3 on the Paramount Lot, Culver City, LA). Having said that, my God, I love those old Star Trek special effects; of an era perhaps, a bit cheesy no doubt, but great! But in any case, the simple expedient of stopping the camera for an apparent ‘beam down’ is so much more convenient and cheaper than all of the optical effects that would be needed to show Kirk and the boys getting into, say, a shuttlecraft and gliding all the way down to the planet surface.

But what does the transporter actually, or should I say allegedly, involve? Dr (Bones) McCoy, used to say in a depreciative tone of voice, that he did not wish to have his ‘atoms spread across the galaxy’ or something similar. But the only thing that is moving in the case of the transporter is information. The process essentially involves three stages, the first being to break the human body down one atom at a time.

The next two stages involve transmitting the associated information and then re-assembling the body an atom at a time in a different location. Such matter transmission is not instantaneous, it takes a certain amount of time – for example, the transmission would be done using electromagnetic waves that travel at the speed of light. Transmitting a single atom would not take long, but when we consider that there are of the order of 1027 atoms in a human body, calculations show that transmitting a single whole body would be expected to take millions of years! It is interesting to note that Gene Roddenberry and his writers were well informed as to the scientific aspects of Star Trek ; it may be that between the making of the original Series and Star Trek: The Next Generation (STNG) they became aware of the long time we would expect a transporter to take to transmit a whole human. Consequently, in STNG the transporter mechanism is described as a system that transmits a very large number of channels of information in parallel (in fact millions or more). If enough of such parallel channels were employed, then it could be imagined that the time needed for transmission of a man could become more manageable in magnitude.

I mentioned accuracy and this is an important point; in order to transmit and replicate a given atom of the body, the device would need to accurately record its original state. The Heisenberg Uncertainty Principle states that there is a fundamental limitation to the accuracy with which this can be done. It is important to note that this limitation arises from fundamental quantum physics rather than being due to limits in the resolution/quality of our instrumentation – there is a limit, even in theory, to the accuracy with which the measurements of the atom could be taken (interestingly, Einstein did not believe this; he famously said “God does not play dice with the Universe” and thought that the fundamental error in possible measurement specified by the Heisenberg Uncertainty Principle was due to our incomplete understanding of the physics factors involved – but most modern physicists consider that Einstein was wrong about this). So, if there are fundamental limits to how accurately we can record and so re-create a human, what implications would this have on the quality of the copy?

And this discussion does not even address more metaphysical aspects – for example, what you might call the soul of a person. And, as others have pointed out, there is also the alarming possibility of the transporter being used to create multiple versions of the same person. In fact, I seem to remember this happened to Jim Kirk on more than one occasion – usually featuring a good Kirk and a bad Kirk which, in the episode ‘The Enemy Within’, were actually supposed to have emerged from the transporter at slightly different times during a storm. You might consider this a slightly weak plot, but at least this episode provided some good opportunities to display a good selection of Shatnerisms in the acting – or should I say over-acting (good stuff I say; over-acting may not be to everyone’s taste, but I feel it is suited to a sci-fi TV series such as Star Trek and that it keeps the entertainment level up). Anyway, all things considered, perhaps Bones was right.

Maybe, after all, a matter transmitter or transporter mechanism is a little too fantastic for "suspension of disbelief" (as Coleridge termed it in 1817).

The series was set on a Moon base in 1999, but unfortunately featured the slightly ridiculous plot line that an explosion in a dumpsite for nuclear waste created an explosion sufficient to blast the Moon out of its orbit and off into interstellar space. Apparently, the main actor, Martin Landau, was annoyed by the viewers refusing to suspend disbelief sufficiently to accept this outlandish plot concept. In other ways, Space 1999 was not that bad a TV series, but the performances of the lead actors, Martin Landau and Barbara Bain, are likely to forever remind us about how bad things can get for a TV series when the main characters are just not interesting and don’t have engaging interactions or a decent rapport (or even arguments … or anything!)

Coming back down to Earth, or getting our feet on the ground (if you will forgive the puns), how might we use control of gravity to provide a means of transport? One way was imagined by H. G. Wells in his engaging novel The First Men in the Moon . This was originally serialised in The Strand magazine (as nearly everything I mention, bar Star Trek , seems to have been), from December 1900 to August 1901. The book tells the story of a journey to the Moon undertaken by the two protagonists: a businessman narrator, Mr Bedford; and an eccentric scientist, Mr Cavor. These characters discover that the Moon is inhabited by a sophisticated extra-terrestrial civilisation of insect-like creatures that they call ‘Selenites’. Good grief! I know that Wells was quite a knowledgeable scientist and can only imagine that he somehow managed to synthesise lysergic acid diethylamide in 1900 (38 years before Swiss chemist Albert Hofmann was credited with doing so), since I can think of no other explanation for how an author could come up with stuff like that. Whether or not he was into drugs, I do think that Wells was a great author who produced some exceptionally novel novels.

We are told that a novel should be unique but most authors of fiction, even nowadays, seem to frequently produce wordy love stories – modern day versions of Jane Austen’s tales. In contrast, consider The Time Machine – completely unique when it emerged and full of new concepts and far out ideas. The same can be said of his other books like War of the Worlds and also, of course, The First Men in the Moon . In the latter, Bedford befriends Cavor when he learns he is developing a new material, cavorite, which can mask the force of gravity. Bedford sees in the commercial production of cavorite a possible source of "wealth enough to work any sort of social revolution we fancied; we might own and order the whole world" (which is a bit of megalomania that reminds one of the titular character in another of his great works: The Invisible Man ). Cavor comes up with the idea of a spherical spaceship made of "steel, lined with glass", and with sliding "windows or blinds" made of cavorite by which it can be steered, and persuades a reluctant Bedford to undertake a voyage to the Moon. Strong move, no doubt.

There is only one slight problem: such a thing is impossible – or as near to impossible as we can get. The reason for this is that a material such as cavorite would break a fundamental law of physics – the law of conservation of energy. This law states that energy cannot be created or destroyed - it can only be transferred from one type to another. For example, when you start a journey in your car, chemical energy (the petrol in the tank) is converted into heat energy in the engine and the kinetic energy of your car moving along the road. After the journey, some of the chemical energy has been transformed into other forms, (the fuel gauge has gone down a bit), but the overall amount of energy is exactly the same. This law has never been observed to have been broken and is believed to apply throughout the Universe.

This is not to say that gravity control is impossible – just that it would require application of a good deal of energy for it not to break the law of conservation of energy. If a portable/lightweight power source were invented that could be used to power an ‘antigravity’ machine, then it could indeed comprise a convenient means of transport - allowing one to hover in any location and to move freely in any direction. Such a facility would certainly comprise a transport revolution. It must, however, be borne in mind that, of all the forces in nature, gravitation is the least understood in modern science. In physics, fundamental forces are realised through particle exchange, or ‘mediation’. For example, electromagnetism is mediated by the photon, the strong interaction by gluons, and the weak interaction by the W and Z bosons (apparently). Physicists are reasonably sure of this since the behaviour of these forces are in close agreement with modern models of particle physics. In contrast, in the case of gravity, it is hypothesized that forces between masses are mediated by an as yet undiscovered elementary particle, dubbed the ‘graviton’; the behaviour of which is somewhat less understood. According to Wikipedia: “There is no complete quantum field theory of gravitons due to an outstanding mathematical problem with renormalization in general relativity.” And I won’t beg to differ.