I forget who, but someone once told me that mafia hit men would sometimes kill their targets by cutting stoves’ gas lines and breaking a light bulb (while the light was off) so that when the mark turned the light on, the spark from the light bulb would ignite the gas and BOOM. They said it was an “old mob trick.”
Has anyone ever heard of this? Is it even possible?
I’ve heard of it in fiction. It won’t do much good unless there’s the proper mixture of gas and oxygen in the area of the light bulb.
And since cooking gas is scented with that gawdawful smell of mercaptan, the mark will smell the leak long before it reaches the concentration needed to go boom.
Am I the only one who saw the title and mentally completed it “…that doctors don’t want you to know about”?
Mythbusters tried to replicate what was essentially the same scenario from one of the Bourne series movies. Simple answer, no, it won’t work.
Longer answer. It will only go boom if you have a critical mix of air and gas, too low or too high a concentration of gas and it won’t explode. And getting the gas to mix with the air usefully is also very hard. Yes, there are very nasty accidents when there have been explosions, but to construct a situation where you can guarantee it is very difficult. Your mobster is not going to manage it except by dumb luck.
Yeah, I didn’t think it would work. As for the smell…you’d be hard pressed to miss that when you get home from a long day of snitching guys out.
This is one of those times we get to use one of my favorite words - stoichiometry. Get too far in either direction from the ideal air to fuel ratio and your would-be boom is just a pffft.
It’s not impossible for the mob goon to set this up but it’s incredible unlikely that the ratio will be just right when the mark gets home. For natural gas (methane), the range is approximately 5-15%.
If the mob hit happened before 1937, it’s quite possible that the gas was not odorized. Odorizing gas in the US wasn’t required until after the New London school explosion.
Very possible a person would walk in the room, turn on the light automatically, and then notice the gas.
Even when I know the power is out, I keep hitting light switches automatically.
Never work. The guy would immediately smell a rat.
The broken light bulb would also need to arc. I’m not sure whether your average light has enough power going through it to accomplish that. Anyone know?
I assume that by ‘break a lightbulb’, they just mean breaking the glass bulb itself, not the filament. My experience has been that bulbs broken in this way burn out quickly, but that they still work briefly - certainly long enough to ignite a flammable gas mixture, if one were present.
The problem with the setup is not the ignition source, but (as other posters have mentioned) the fact the mix of gas and air has to be within fairly narrow parameters to detonate.
When I read it, my thought was “Ancient Chinese Secret…hunh?”
Which shows how old I am.
So does that mean that you could reliably guarantee an explosion by leaving a source of flame and then just releasing gas into the room until the right mixture was reached?
I’m thinking here of a scene of The Bourne Supremacy (movie, not book), where Bourne breaks the gas line and then puts the toaster down with some magazines in it. If those magazines caught fire from the heat of the toaster, and kept burning, would the level of gas in the room reach a critical point and create an explosion?
The variant of that one I heard of was drilling a small hole in the light bulb near the screw part, filling it with the right amount of gasoline - not enough to drown the filament ; then screwing it back in. If all goes to plan, the bulb is supposed to become a grenade when turned on.
I highly doubt it works in practice - at worst the target might get light cuts to the face, as I doubt ~20mL’s worth of gas vapours at atmospheric pressure is enough to accelerate shrapnel all that much. Anybody want to try and Mythbusters it with a dead pig at home, be my guest (endeavour to not be in the same room, though 
).
Possibly, or possibly you’ll just get a gentle flame that burns the gas as quickly as it’s released. I wouldn’t want to count on either answer.
John Gardner used a variation of this in his James Bond novel, No Deals, Mr. Bond. Bond is imprisoned in a cellar. He takes the sole light bulb in the room and carefully twists the glass envelope off, puts gunpowder in the envelope, and replaces it, screwing the doctored bulb back in. When his captors open the door and switch on the light, the momentary spark ignites the gunpowder, producing a makeshift Flash-Bang grenade that disorients them.
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So does that mean that you could reliably guarantee an explosion by leaving a source of flame and then just releasing gas into the room until the right mixture was reached?
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It would just burn locally at the flame. I don’t have the means to test this but I believe I have seen it demonstrated that you could go from zero concentration to the lower explosive limit (approximately 5%) and all that would happen is the flame might get a smidge larger. Keep raising the concentration and the flame continues to burn the gas until you have insufficient oxygen and the flame is snuffed.
In the 1974 version of the movie The Longest Yard, the prisoner “Caretaker,” played by James Hampton, was killed this way. YMMV.
Mickey Spillane used the OP’s device in one of his most famous Mike Hammer books, Kiss Me Deadly, except that he released the gas in a closed room (so the occupants wouldn’t smell it), and somehow rigged a telephone in the room to trigger a spark when the telephone was rung. After he escaped from the house, he went down the road and called that phone. Boom!
It was a very satisfying denouement to the plot, and I’m glad I didn’t know at the time how unlikely it was that it would work.
n.b. the movie of the same name didn’t use this device, instead it blew up the house in an even more unlikely way.
Maybe it would work in a tiny, sealed studio apartment but in a home where the kitchen has numerous entry points the gas would disperse.
Also modern HVAC systems circulate the air anyways.