Following the recent news of the Virgin Galactic malfunction and crash I thought I’d write something about these type of endeavours. Many have said limiting these projects would hold back science. Virgin Galactic, SpaceX etc, aren’t scientific pursuits however, but merely joyrides for millionaires. I don’t agree with limiting them either; if people with enough cash want to go into space and peer at the earth that’s great and they’ll have an incredible experience, but they’re not pushing back any scientific frontiers.
If I was offered the prospect of going to Mars and being the first person to set foot on the Martian soil I’d gladly take it, even if it might be a one way ticket. My name would go down in history. I wouldn’t be taking a tiny step towards getting humanity to the stars though.
We’ve just about reached the theoretical efficiency limit of jet engines and chemical rocket engines. We could maybe squeeze another 10% out, but that’s it. Rockets are not going to get people into space in the way space travel is often thought of i.e. beyond Mars, the Solar System or even across the galaxy. This might seem obvious, but it could be that no future technology can take us very far from this massive rock we currently reside on.
A corollary to all the amazing scientific discoveries of the past 150 years is that the knowledge we gained has also put a limit on what we can achieve. We know, for instance, all the stable chemical elements and their isotopes. That there’s an element lighter than hydrogen or a stable element with 300 protons is extremely unlikely if all the universe obeys the same laws (there’s no reason to think it doesn’t). This means there’s a limit on the strength, robustness and longevity of anything you can construct. We don’t know what a lot of the universe is made of but it would be a logical leap too far to say that one day we will know what dark matter/energy is… and we can manipulate it, and it can solve a tangible engineering problem we have. The effects of the fundamental physical forces at a macroscopic level are understood for all practical purposes. If one day electromagnetism and gravity are combined in a unified theory this wouldn’t make getting a payload into orbit any easier.
If science is limitless then you are free to believe anything. This type of thinking is more akin to religious faith rather than scientific thought. Whenever there is an insurmountable problem regarding space travel the argument generally goes that ‘we’ll figure it out in the future’ or ‘if we use this unproven (and often impractical theory) we can do this or that’ or ‘if we can travel at 0.1 times the speed of light then…’ (an ambitious premise to build an argument on). This is akin to an ontological argument; that if we can conceive of an idea then it can exist in reality. This is flawed logic. The idea that mankind has a grand destiny in populating the galaxy and beyond is analogous to a theological framework. It’s instinctive to think this way; we like to think there is a point to our existence and are predestined to greatness, set apart somehow from the natural world.
These statements could come across as overly pessimistic and similar to statements made at the end of the 19th century when some thought every useful object had already been invented. Many point to the car and air travel as proof that seemingly impossible things can be done. The car was not a scientific problem however, it was an engineering one. Small explosions producing a force on a piston, changing its momentum and driving an axle wasn’t outside of known physics and chemistry before the first auto-mobile. The engineering problem of making parts small and robust enough was the major hurdle. Likewise with flight, even though the equations were unknown people knew flight was possible just by looking at nature. Humans are incredibly impressed by their own constructions; the pyramids, skyscrapers, computers etc. Termites and ants have been building giant elaborate constructions for millions of years and the brain is much more complex and efficient than any computer. Through the relatively simple trial and error process of evolution nature has accomplished more than we have in many areas. Yet we think we can manipulate gravitons (not even known to exist), fold space or journey through wormholes.
In fiction there’s often the story of bringing a person from the distant past back to life in the present day. It’s true that person would initially be amazed by the modern world. After a few weeks and months what may strike them is how similar life is however. The main changes that have occurred are that we can journey from place to place quicker, we can exchange information almost instantly and we die less from disease. Major steps forward, but in all other aspects life is generally the same. Electric lights, kettles, fridges etc. are wonderful inventions but they all work using the same fundamental forces and heat exchanges as their crude predecessors.
Christopher Nolan’s space epic Interstellar has just been released at the cinema, which portrays a journey to find a new world after the earth has become unable to produce food. I haven’t seen the film so can’t make any judgement on how good or bad it is. There is a slightly worrying political message in the film that if we ruin the earth and its environment it’s not a major problem because we can just move to a new planet. This set-up is a convenience so the film’s protagonists and the audience can journey into space, but if taken totally seriously seems to indicate some curious priorities on behalf of mankind. I’m not sure if the film addresses the problem that scientists and engineers can’t work out how to produce food after an environmental disaster but can construct an Alcubierre drive or similar enabling faster than light travel (speculative, unproven, impractical). It’s a science fiction film so plot devices can be fantastical without being a major problem, but confusing science fiction with reality can be a problem.
There’s an incredible amount of exciting research at the moment in genetics, neuroscience, biochemistry, robotics, cybernetics etc. that are pushing forward our knowledge of the world and ourselves. Research that seeks to make our lives sustainable and the earth environmentally secure seem to have more to offer in the long term.
TL;DR – I’m not advocating limiting science research. I’m saying that what we know of the natural world limits what we can achieve and our flesh and bone bodies limit what we can endure.