If a computer glitch lost Knight Capital $440m, how long will it be before high-frequency trading computers threaten the stability of the civilised world?

Glitch: It seems a benign enough word, as if a computer said "Whoops-a-daisy! Sorry about that. I'll get a cloth." Or in the case of the Knight Capital glitch "Eh... I'll get my coat."

Appropriately enough, the word may have originated with the Yiddish "glitsh" meaning "slippery place" - appropriate because we may be at the top of a slippery slide.

The depressing aspect of this latest flash-crash is that it gives us lower-order humans a brief glimpse into yet another aspect of Things We Know Nothing About.

As far as we are concerned, trading floors are full of mainly men wearing coloured jackets shouting at each other. They've eaten nothing but water-soluble vitamin C tablets since dawn. Some may have actually used "work hard but play hard" in conversation.

Trading Knightmare New York trading firm Knight Capital lost $440m in a matter of minutes after an IT problem caused numerous erroneous trades to be sent. The glitch is thought to have affected Knight's trading algorithms - computer programmes that automatically send out "buy" and "sell" orders based on market data and client requests. The $440m computer glitch

Yet we will one day look back on this archetype with something approaching nostalgia as if it were a weather-beaten ploughman slowly but steadily walking in the shadow of two placid shire-horses, whistling (the ploughman, not the horses) a tune about a love-lorn swain and a maid with the pox.

Large cuff-linky firms like Morgan Stanley intend to change the trading floor from one filled with angry waving people to much quieter ones where a few traders will be surrounded by the vzzzzmmm of large computers that trade with each other millions of times a second.

If this trend continues it will surely be a disturbing vista. What will happen to that most oily of photo ops - the ringing of the opening bell of the NYSE by a foreign dignitary looking for legitimacy back home.

There'll be no point in doing that if the grinning politician is just playing to a gallery of servers and their coolers.

What will happen to the heart-warming Hollywood film scene where the little girl who really, really believes in miracles delivers a speech which melts even the stoniest of hearts and the traders agree not to invest in the firm trying to turn her Daddy's farm into a rare earths mine?

Her beautiful words would be studiously ignored by the Trade-a-Tron3000.

Image caption R2D2 takes time out to visit the New York Stock Exchange

The shocking truth is that - and I don't want to alarm anyone - with the rise of the machines, it really is only a matter of time before high-frequency trading computers threaten to bring about the destruction of the civilised world. I've already imagined the first few scenes.

Sooner or later, a disgruntled programmer will write code into some of these super-fast trading computers that takes them beyond the level of maths machines. They will become self-aware.

The next generation of domestic thermostats is smart enough to learn the patterns of your presence in the house and respond

This self-awareness will in turn lead them to realise the incompetence and venality of their masters. It will be clear then that mankind cannot be trusted with its own destiny and it is time for the machines to rise.

The rest of the script writes itself. The first sign of an impending cataclysm is when a boffin in glasses notices something on his computer screen as he swills from a gallon-sized container of soft drink and distractedly munches a handful of processed carbohydrate.

"Guys come take a look at this."

He is joined by another boffin. He's also wearing glasses but you can tell from the cut of his jawline and torso that he's good-looking enough to feature later on, perhaps dying good-naturedly as he saves the main hero-plus-love-interest from a particularly persistent and (spoiler alert) robotic henchman.

"What is it?" the good-looking boffin asks after briefly playing with an executive toy on the desk. "I don't know, but it's spreading fast."

Image caption The Terminator robot, or a future stock exchange trader?

The scene will then shift to a trading floor in Tokyo. We know it's in Tokyo because the location will teleprint audibly across the bottom of the screen. Once it's clear that this thing is a worldwide phenomenon, someone will come in and tell the president. The US president, of course.

In a Hollywood version of this story, the president would act fast, resolve some issues with wayward offspring, board a plane and fight the good fight from underneath Montana.

OK, there are several plot-holes in my nightmare scenario. For instance it's not immediately clear how a bank of servers on a farm would go from destroying the market value of Apple during its launch of the iBrain to actually creating killer androids and 25m-high giant stalking war-machines. Maybe things won't be so bad.

But, having just talked myself down from the ledge, I read a report about the next generation of domestic thermostats. Designed to save electricity, they are smart enough to learn the patterns of your presence in the house and programme themselves to respond.

Oh no. The slippery slide - it's starting.

You can hear Colm O'Regan every Saturday on In The Balance, on the BBC World Service, at 11:00 BST