Archive for category industry

Why don’t I live on the moon?

I’ve just watched a fascinating animation of the international space station being assembled. That got me thinking and next thing I knew I was hammering out a blog post.

The International Space Station, keeping man in orbit since October 2000

When I was young I always wanted to be an astronaut. When I was four I went on holiday to Florida and visited the space centre there, from then on I was hooked. I loved rockets and shuttles to the extent that even now if I see a rocket launch on TV I get glow of pride and awe that our species has managed to do this. In my pre-teen childhood I was quite into all the traditionally geeky space stuff like Star Trek and other shows which now if I ever see annoy the hell out of me for two reasons;

Firstly, any TV show that calls itself “science-fiction” typically takes a white-western conservative culture and bolts on shiny tech.

Secondly, flying off to other planets isn’t a dream that is going to be available to us any time soon.

Every now and then I meet someone who admits that they believe the moon landings were a hoax. My second response to this (my first being to try to beat them to death with their own internal organs) is to ask why they think this way. Aside from flag waving, shadows and reflections the only interesting question that is asked is “why haven’t we been back?” The last Apollo mission was nearly forty years ago and since then there hasn’t been any grandiose feats to rival those missions. We live in a world where technological development appears to progress almost exponentially. Moore’s law is a good example of this (transistor numbers on computer chips double every two years) and we see it in our daily lives. The laptop we bought that was state-of-the-art last week was barely second best when we got it home from the store and by now deserves a dusty shelf in some museum. Now I’m not suggesting that space science has not progressed in the last forty years but it’s important to note that in that time space science has not yet developed to the point where it can give us cheap space travel.

At the time of the space race NASA was costing the US 4% of the federal budget. Out of every dollar the US spent 4 cents went to NASA and with this they got to the moon. This is thing about manned space travel, its hideously expensive, it takes a significant cut of a very rich country’s budget and it gives no profit back. I’m not suggesting that we should only commit to projects that have economic benefit (far from it) but the fact is that any manned space travel project requires a fortune in surplus funds (Note: the US didn’t go to the moon because they had some spare change and a twinkle in their eye, they did it for competition and the potential dangers of having a USSR military dominance in orbit).

Space travel is inspiring, it’s romantic but above all its bloody expensive. But all is not lost to the warcries of “cuts”, “audit” and “profit”. As technologies progress and economies grow we may find ourselves again in the position where we have the capability and the will to strive out into space with manned travel. Mars has always been seen as the next step for human exploration but a Mars mission is a world more difficult than a lunar one. Once a ship leaves the protection of the Earth’s magnetosphere (which the moon is within) the intensity of radiation exposure from the sun massively increases. Even more of a problem is the fuel and engine technology it takes to get there, the probes we send to Mars take years and are only making a one way trip.

Will VASIMR rockets like this take us to Mars and beyond?

All current rockets use chemical fuel as a propellent, but this gives a very limited burn time before the fuel runs out. With an equal fuel:rocket ratio our current technologies can give only a few minutes of thrust (for more info see “specific impulse“). There are other technologies being used, some probes use ion thrusters which can burn for months but they give very very low thrust (0-60 in about four days). However all that may be soon to change, the next generation in rocket technology will soon be launching to the international space station. In 2014 a VASIMR rocket will be attached to the side of the station, this type of rocket promises to give high thrust with very long burn times (hours-days). It does this by heating its fuel until it turns into a superhot plasma that it then shoots out of the back of the engine with a magnetic field. If this engine passes testing and gains investment we could be seeing a wave of VASIMR craft capable of taking us back to the moon and across to Mars in just months of travel time rather than years. In addition to this there have been a sprinkling of other technologies proposed such as a plasma bubble generator that would protect the ship from radiation by making a strong magnetic shield to deflect it, and the always jaw-dropping proposal of building a tower to orbit.

Space science isn’t as attractive as it used to be, the middle generation grew up with the images of moonlandings and shuttle launches. We’ve got budget cuts and Justin Bieber. But this isn’t the end of man’s story in space, our science marches on and when conditions are favourable we’ll be able to invest in technologies that will get us back out there. I’d like to think that this lull we are in is just the first interval in a long epic play…and the second act is starting soon.


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How many men does it take to make a light bulb?

Not just men in fact but women as well. The question has been one that I’ve been throwing back and forth for a while now. I’ve encountered similar questions before all essentially asking “how many people does it take to sustain a technologically developed society?” The question implies a society that we in Britain are used to with as much consumerism, technology, law and light bulbs as we have today. The answer might be a little more than most would guess.

Throughout history we have gone forth and multiplied. Countless times wooden boats have been built carrying less people than the average train on the Tube across waters to new lands where those people have managed to build a society. From that we would think that the answer to “how many people does it take to sustain a technologically developed society?” wouldn’t be that much. Perhaps the citizens of our hypothetical society can each be employed only in jobs that are necessary with no overlap or needless jobs (by needless jobs I refer to multiple companies providing the same service which in our hypothetical society can be cut down). In colonial times they would start essentially from scratch and work their way back up with trade and supply from neighbouring lands boosting the fledgling society. But in trying to answer “how many men…” we need to come to a number of how many people we need to maintain the world we are used to rather than rebuild it.

Pre-1900 most things could be constructed by generalist industries (blacksmiths, carpenters, masons etc). Over the past century however our world has exploded into an ecology of superspecialisms. Whilst early machines could be built or maintained by the typical tinkerer in his workshop the complexity of everyday objects today has pushed the reality of one dedicated jack-of-all-trades up to a large interdependent group of masters in one field.

A few examples; today’s smartphones contain microprocessors built from transistors just tens of nanometres thick, wires etched a few dozen atoms wide, GPS systems, radio transmitters, microscopic pressure sensors underneath a full colour screen all packaged in a palm sized container. In the medical field rather than having the traditional doctor, surgeon, nurse, dentist we have specialists in far narrower fields like cardiologists, radiologists, neurologists, ophthalmologists etcetera etcetera. Examples like this can be seen in all walks of life and in building our hypothetical society we can forget none of them! A temporal lobe neurosurgeon might seem unnecessarily specialised until you get a tumour that needs to be excised. And for each field we must have a sizable portion educating the next generation. Contrary to Heinlein’s popular quote specialisation is not just for insects.

So to address the original question, how many men does it take to make a light bulb? Let’s break it down; a typical incandescent light bulb is made up from a glass bulb containing a tungsten filament surrounded by an inert gas. Sounds simple at first but for all of that we need an industry to mine and refine the materials, transport to take those materials to factories (and consequently an industry to maintain that infrastructure), make the bulbs and ship them out to the people. Apply that to every product we have and how many industries do we need now? Sure there may be no overlap in some areas (we may only need one tungsten mine and one infrastructure maintenance consortium) but the sheer complexity of life in the developed world today is mind boggling.

Adding together the populations of large hives of industry such as NAFTA, the EU and China we come to a number of over two billion. This number can be trimmed to about one billion by taking into consideration the communities that provide little overall input (half of China’s population is solely agrarian for example). If we take one billion people to be the upper bound we can consider removing as much overlap as possible whilst maximising efficiency but I see no reason as to why the lower bound number would not be less than the high tens or low hundreds of millions. So to live in a society capable of providing all the technologies and services we are used to would require a population greater than that of the United Kingdom today.

This realisation has important implications. For those of an ideology that the world would be a better place with less people simply living in one with nature or those who have a special place in their heart for the idea of living on Mars (or any other non-Earth body) the reality is quite different. To maintain a technologically developed society such as ours we are not going to be living in self sufficient pioneering communities, instead we have to be a thriving interdependent hive of industries, experts and above all specialists.

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