The Pursuit of Speed

Recent human history has, as Jeremy Clarkson constantly loves to point out, been dominated by the pursuit of speed. Everywhere we look, we see people hurrying hither and thither, sprinting down escalators, transmitting data at next to lightspeed via their phones and computers, and screaming down the motorway at over a hundred kilometres an hour (or nearly 100mph if you’re the kind of person who habitually uses the fast lane of British motorways). Never is this more apparent than when you consider our pursuit of a new maximum, top speed, something that has, over the centuries, got ever higher and faster. Even in today’s world, where we prize speed of information over speed of movement, this quest goes on, as evidenced by the team behind the ‘Bloodhound’ SSC, tipped to break the world land speed record. So, I thought I might take this opportunity to consider the history of our quest for speed, and see how it has developed over time.

(I will ignore all unmanned human exploits for now, just so I don’t get tangled up in arguments concerning why a satellite may be considered versus something out of the Large Hadron Collider)

Way back when we humans first evolved into the upright, bipedal creatures we are now, we were a fairly primitive race and our top speed was limited by how fast we could run.  Usain Bolt can, with the aid of modern shoes, running tracks and a hundred thousand people screaming his name, max out at around 13 metres per second. We will therefore presume that a fast human in prehistoric times, running on bare feet, hard ground, and the motivation of being chased by a lion, might hit 11m/s, or 43.2 kilometres per hour. Thus our top speed remained for many thousands of years, until, around 6000 years ago, humankind discovered how to domesticate animals, and more specifically horses, in the Eurasian Steppe. This sent our maximum speed soaring to 70km/h or more, a speed that was for the first time sustainable over long distances, especially on the steppe where horses where rarely asked to tow or carry much. Thus things remained for another goodly length of time- in fact, many leading doctors were of the opinion that travelling any faster would be impossible to do without asphyxiating. However, come the industrial revolution, things started to change, and records began tumbling again. The train was invented in the 1800s and quickly transformed from a slow, lumbering beast into a fast, sleek machine capable of hitherto unimaginable speed. In 1848, the Iron Horse took the land speed record away from its flesh and blood cousin, when a train in Boston finally broke the magical 60mph (ie a mile a minute) barrier to send the record shooting up to 96.6 km/h. Records continued to tumble for the next half-century, breaking the 100 mph barrier by 1904, but by then there was a new challenger on the paddock- the car. Whilst early wheel-driven speed records had barely dipped over 35mph, after the turn of the century they really started to pick up the pace. By 1906, they too had broken the 100mph mark, hitting 205km/h in a steam-powered vehicle that laid the locomotives’ claims to speed dominance firmly to bed. However, this was destined to be the car’s only ever outright speed record, and the last one to be set on the ground- by 1924 they had got up to 234km/h, a record that stands to this day as the fastest ever recorded on a public road, but the First World War had by this time been and gone, bringing with it a huge advancement in aircraft technology. In 1920, the record was officially broken in the first post-war attempt, a French pilot clocking 275km/h, and after that there was no stopping it. Records were being broken left, right and centre throughout both the Roaring Twenties and the Great Depression, right up until the breakout of another war in 1939. As during WWI, all records ceased to be officiated for the war’s duration, but, just as the First World War allowed the plane to take over from the car as the top dog in terms of pure speed, so the Second marked the passing of the propellor-driven plane and the coming of the jet & rocket engine. Jet aircraft broke man’s top speed record just 5 times after the war, holding the crown for a total of less than two years, before they gave it up for good and let rockets lead the way.

The passage of records for rocket-propelled craft is hard to track, but Chuck Yeager in 1947 became the first man ever to break the sound barrier in controlled, level flight (plunging screaming to one’s death in a deathly fireball apparently doesn’t count for record purposes), thanks not only to his Bell X-1’s rocket engine but also the realisation that breaking the sound barrier would not tear the wings of so long as they were slanted back at an angle (hence why all jet fighters adopt this design today). By 1953, Yeager was at it again, reaching Mach 2.44 (2608km/h) in the X-1’s cousing, the X-1A. The process, however, nearly killed him when he tilted the craft to try and lose height and prepare to land, at which point a hitherto undiscovered phenomenon known as ‘inertia coupling’ sent the craft spinning wildly out of control and putting Yeager through 8G’s of force before he was able to regain control. The X-1’s successor, the X-2, was even more dangerous- despite pushing the record up to first 3050km/h  one craft exploded and killed its pilot in 1953, before a world record-breaking flight reaching Mach 3.2 (3370 km/h), ended in tragedy when a banking turn at over Mach 3 sent it into another inertia coupling spin that resulted, after an emergency ejection that either crippled or killed him, in the death of pilot Milburn G. Apt. All high-speed research aircraft programs were suspended for another three years, until experiments began with the Bell X-15, the latest and most experimental of these craft. It broke the record 5 times between 1961 and 67, routinely flying above 6000km/h, before another fatal crash, this time concerning pilot Major Michael J Adams in a hypersonic spin, put paid to the program again, and the X-15’s all-time record of 7273km/h remains the fastest for a manned aircraft. But it still doesn’t take the overall title, because during the late 60s the US had another thing on its mind- space.

Astonishingly, manned spacecraft have broken humanity’s top speed record only once, when the Apollo 10 crew achieved the fastest speed to date ever achieved by human beings relative to Earth. It is true that their May 1969 flight did totally smash it, reaching 39 896km/h on their return to earth, but all subsequent space flights, mainly due to having larger modules with greater air resistance, have yet to top this speed. Whether we ever will or not, especially given today’s focus on unmanned probes and the like, is unknown. But people, some brutal abuse of physics is your friend today. Plot all of these records on a graph and add a trendline (OK you might have to get rid of the horse/running ones and fiddle with some numbers), and you have a simple equation for the speed record against time. This can tell us a number of things, but one is of particular interest- that, statistically, we will have a man travelling at the speed of light in 2177. Star Trek fans, get started on that warp drive…