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Jul 07 2013

Sunday school for atheists: the rockets’ red glare

 

As a kid who loved fireworks I looked forward to this time of year for months. Neighbors used to come from all around to watch my fireworks shows. This year pyrotechnic displays are not limited to the US, they’re lighting up the skies in Egypt , too. The awe inspiring glare of rockets and star-shells don’t just signify independence, they harken back to antiquity, signifying ancient celebrations and, today, act as a potent reminder of the most ambitious and iconic projects ever undertaken by our young species. I speak here of rockets.

The pillars of flame lofting vehicles to the skies may appear at first glance to be the most complex and advanced technological creations ever dreamed up by human kind. But they are the first machines driven by means other than human and animal muscles ever created. What’s more, those mere curiosities led to directly to the engines that now fuel every facet of our modern civilization. And to think it all started with mystics and apprentices over a millennia ago in the Middle East and Asia, who could never not have imagined they were embarking on the first small step in a journey that would lead to the bloodiest wars on record, and the greatest modern marvels of peace and prosperity the world has ever witnessed.

Alchemists working quietly before the dawn of the first millennia weren’t known for their openness. Many were working on turning base metals into gold or creating potions conferring immortality. Many were just as concerned with fleecing the nobility as they were in developing new chemistry and devices, and they kept their methods secret. But around 1000 AD, tales of a wondrous new substance began to make their way across the early trade routes from an exotic place called China via the trade routes stretching through the Middle East to Europe. The mysterious new substance was called blackpowder.

 

Rocket

The simple balloon rocket, the force blowing out the back is not balanced, pushing the balloon forward

It was the first practical explosive, used for toys to be sure, small rockets chief among them. But it didn’t take the powers-that-be long to realize that if the new powder could be ignited in a rigid metal tube of some kind, it might blast a projectile farther than the catapults of the day—with devastating results. Fill the projectile with more of the magic substance and it might detonate high over the field of battle, killing the enemy on an industrial scale!

 

Cannon

Powder replaces air, the rocket is fixed and unmovable, the projectile mores instead and the simple rocket becomes a cannon

It sounds easy in principle, but a new and entirely new field of metallurgy had to be born to create specialized metal tubes that could withstand the firing stress, some of which no doubt failed with catastrophic results along the way.

After decades of work the first practical cannon was born. It took more decades and a great deal of work before a reliable, relatively cheap smaller version was slowly perfected that could be held in one hand and blast smaller holes in individual combatants. It is no coincidence that this invention marked the beginning of the end of the era of swords, battle axes, and exquisite suits of armor that had dominated battlefields for millennia.

Thankfully, progress didn’t stop there.Medieval weapons developers realized early on that if blackpowder could shove a big iron ball out of a tube over and over again, perhaps the cannon could be adapted to do the same for some of sort metal block that would move to and fro. Which would be great because it could attached to a mechanical wheels and gears that might perform all manner of menial tasks heretofore relegated to slaves and animals, or the occasional well-positioned waterfall.

 

 

Steam Engine

Steam replaces powder, a piston replaces the projectile, the cannon becomes an engine

 

This took centuries to work out, and even a gunpowder-powered engine was tried. But it soon became clear that steam was the ideal propellant of choice, culminating in James Watts’ improved design in the late 18th century. Watts’ inovastions was among the first practical, affordable steam engine. This new emphasis on engines explains why those early eggheads who fiddled around with various designs and quantified the lucrative science behind them, became known as engineers.

After another more trial and error, a variation of the reciprocating steam engine was developed that could use refined petroleum to heat and expand the air instead of steam. An even more advanced version was created using the heat produced by steam or refined aerosols that turned a fan, an idea no doubt taken from the windmills that had dotted farms far and wide all over the world for centuries. But there was more in store for the ancestors of cannon and blackpowder!

An engine uses an input of heat to create an output of mechanical out. Would it be possible to to reverse the process, put work in and pump out heat? It could! It was a little trickier and less intuitive than cannons or steams engines. In fact, a whole new science had to be refined: thermodynamics, the study of heat and work and those properties of substance that relate to heat and work.

 

Heat Pump

         Refrigerant replaces steam, the piston becomes a compressor, the engin becomes s heat pump

After more trial and error—and advances in chemistry creating a new class of substances based on chloro-fluorocarbons ideal for transferring heat out of a system operating more or less at room temperature — the first mass-produced heat pumps hit the market and soon popped up in virtually every corner of America. Today we know heat pumps by the more familiar name of refrigerators and air conditioners. And I believe I speak for everyone who has read this far on a blazing hot July weekend, thank whatever god[s] you believe in for ice cream and air conditioning!

It’s interesting to note, our entire civilization is utterly dependent on just a handful of developments arising directly and indirectly from black-powder and weapons research: the reciprocating engine, the turbines at the heart of power plants and high performance aircraft, the electrical power those devices make possible, and the refrigeration critical to everything from food distribution to the precise temperature control needed in the heart of nuclear power plants and habs offering sanctuary in the unforgiving harsh mistress of space. Not too bad for ancient inventors who came up with a curiosity called blackpowder.

Which brings us back to the old blackpowder rockets those early pioneers put together, the ones that kicked this essay off. While cannons and engines and heat pumps were being developed, another group of hobbyists, some of them dreamers extraordinaire, kept fiddling with rockets. As chemistry grew from an art into a science, propellants were greatly improved. Soon small quantities of new elements added to the propellant imbued them with brilliant colors. If you love the beautiful fireworks of today, thank the periodic table of elements: thanks strontium for brilliant reds, cesium for deep blues, barium for green and potassium for that eye grabbing violet tinge of deep blue.

Fireworks as they came to be called evolved. From small rockets flown just for show to increasingly complex devices that soared out of sight on a petite pillars of fire and smoke. As performance increased, some designers dared to dream of rockets that would one break the surly bonds of earth back when such thoughts could get one committed to a mental hospital. Robert Goddard and Konstantin Eduardovich Tsiolkovsky were two of the most important such visionaries, they are considered the founding fathers of modern rocketry and space travel respectively. Both men inspired thousands of budding aerospace hobbyists. Many, like their mentors and heroes, were subject to merciless ridicule.

History has proven those dreamers almost prescient, the naysayers wrong in about as big a way possible. If only that could have lived long enough to see the gifts their often thankless work bestowed on millions of people world-wide:

The ancient alchemists would be awestruck to know just how far, how breathtakingly fast, their crude creations were improved and harnessed to take us where no man has gone before. Thanks to them and the generation of engineers who followed, we are now equipped to take on the greatest challenge our species will ever face. Another age of exploration awaits us, with hundreds of new islands awaiting our machines and footprints in this solar system alone. A billion new worlds scattered across a virtually infinite and exquisite ocean of space beyond, a cosmos so vast it will keep us and our descendants occupied essentially, forever.

That’s a tall order for a clever primate that descended from the trees in the blink of an eye, who mastered simple stone tools and fire only recently on cosmic time scales, who still harbor shreds of our shared evolutionary legacy for tribal behavior. But with all our flaws, with all the tragic setbacks of the past visible in 20/20 hindsight, and no doubt many more pitfalls lurking unseen in our collective future, torn forever between the demons of our worst nightmares and the better angels of our nature, I believe we will prove against all odds and naysayers that, once again, we are up to it.

4 comments

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  1. 1
    Randomfactor

    You have a duplicated paragraph, right below the refrigerator diagram. Thanks for this, by the way.

  2. 2
    Stephen "DarkSyde" Andrew

    Thanks for the copy editing Random. I believe I now owe you the usual Internet rate of $0.00 for your effort? :)

  3. 3
    Trebuchet

    I find I must point out that catapults continued to be used on the battlefield for a couple of hundred years after the initial introduction of gunpowder. Technology takes time, as one thing builds on another. Great post, however.

    Now I need to get back to work on my new catapult design!

  4. 4
    lpetrich

    Sorry to be a wet blanket, but humanity has used some non-human and non-animal power for centuries: water and wind power. Water mills have been around for at least 2 millennia, and wind has been used to propel boats/ships for even longer. Simple steam engines have also been around for 2 millennia, though it was only in the last few centuries that steam engines became practical mechanical-energy sources.

    But you are essentially correct about fireworks being an ancestor of guns and rockets.

    I like especially how Konstantin Tsiolkovsky worked out that one needs rockets to travel away from the Earth. He worked out a lot of the theory, including proposing multistage rockets and liquid-fuel rockets.

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