I'm sure I wont be the first or the last to point out that you are clearly too young to remember pulse dialing with a rotary input device.
The whole point of 999 was that a nine was the only number you could guarantee to accurately dial blind on a rotary input device with only your sense of touch and a little knowledge about the device itself available to you.
I'm also not too sure why any other number would be preferable. 999 really stands out whereas all the other emergency numbers across the world do not. I'll accept that because I'm a Brit that I have been conditioned to 999 being THE emergency number might bias me somewhat but I think my point still stands: 999 is far more obvious than any other emergency number.
I do a lot of (modern ie VoIP) telephony work and can only think that the 9 for an outside line plus rubbish dial plans and crap hardware and programming meant that 999 might not work for some systems. I've also explored the "not British" criteria for the number ... 8)
Can anyone explain why 999 is not the best emergency number ever chosen?
The problem is the amount of time you spend waiting for the dial to return. At the standard rate of ten pulses per second, you would end up waiting nine pulses three times or (0.9 * 3)s plus the pause (approximately 3 pulses wide) for the dial to return, plus however long it took you to finger and wind the dial three times. Could easily take upward of six seconds.
111 (if it could feasibly be allocated) would be the best three-digit code. You would spend the least amount of time rewinding, fingering, and returning. The minimum time per symbol would be 0.1s for the single pulse, ~0.3 seconds for the pause (that section on the dial between the backstop and the 1 digit hole) and about 0.1-0.2s for the finger and wind (reduced due to Fitts's law, and easier for the blind since it is the first hole from the backstop rather than the second). These factors combined could cut the dial time easily in half.
> Can anyone explain why 999 is not the best emergency number ever chosen?
Numbers with widely separated digits such as 911 in the US or 119 in Japan are less likely to be accidentally dialed than numbers with similar or identical digits such as 999 or 112. As the article notes:
"However, around 35 per cent of calls do not involve actual requests for help, with the majority of these made by children playing with home phones or people accidentally dialling 999 or the European emergency number 112, often from a mobile handset in a pocket or handbag."
Though phones which map the emergency number to speed dial may negate the advantage.
Accidental calls waste time and potentially divert resources from real emergencies.
I work on VoIP systems and 999 is set up on these as a priority dial (built into the system as "emergency number"), giving it's route out to whichever ARS is available. I cannot see this limited by the "9 for an outside line" as it bypasses these constraints, along with having to login to a phone to use 999.
If you look at images of rotary phone dials I think you will see that it is 0 and 1 that can be dialed easily without vision. Only in New Zealand can 9 be dialed so easily (they use a different dial, however unbelievably).
I used to use the bloody things (I'm 47) - I suspect your research is based on pictures and supposition.
At rest the rotary dial was at say null. As soon as you moved it over a number and then released it, that was the number that was dialled. 0 and 1 were first (obvs). When you hit the backstop (a small metal shim) then you had hit nine. It isn't as bad an interface as it might sound. You would get feedback via a series of clicks as the dial returned to null and also via force (springs etc).
There really was a good reason for picking 999 originally and the world has moved on since but I still assert that 999 is a far better number (or nowadays: a symbol) for invoking an emergency call than any other number.
That's a really strange phone you're describing. Did it have a single hole on the dial? Where are you from?
I too used rotary phones - I'm 28 (if it makes a difference) and I grew up in a former Soviet republic. The phone had a dial with 10 holes in it: 1-9 followed by 0 (just like on a modern phone keypad, by the way). You stick your finger in a hole over the digit and rotate clockwise until the the stop. Then, take the finger out and wait for it to rotate back to the original position. Then you dial the next digit.
Just FYI, Hacker News seems to be flagging most of your comments and making them invisible or "dead". I was browsing with showdead on and was able to "vouch" for your comment and raise it from the dead.
I'm not sure what to tell you to do to fix this problem, but I thought you might want to know. I think the site tries to trick you into thinking everyone can see your comments when they're actually made dead. So you might never know.
That's really interesting! With North American rotary phones, you put your finger into the hole that corresponds to the number you want to dial, turn til you hit the backstop then release. There was no null position.
Unless I'm misunderstanding what you are saying, which is entirely possible.
Do you have a picture of this style of rotary phone? I've only ever seen or used the kind ficklepickle described (and that's all I can find pictures of online).
I remember the emergency number being 90000 back when rotary dials were common. It's harder to misdial that 999, because you want as separated numbers as possible, and it's faster to dial because only the first 9 takes time, and then you zip through a bunch of zeroes at the end.
Most rotary phone systems had 1=1 pulse, 2=2 pulses and so on, with 0=10 pulses. In that system, 0 would take even longer to dial than 9. New Zealand apparently went with 1=9 pulses, but still kept 0=10 pulses. Was there somewhere that had 0=1 pulse?
> The Australian letter-to-number mapping was A=1, B=2, F=3, J=4, L=5, M=6, U=7, W=8, X=9, Y=0
wat?
> In the United Kingdom the letter "O" was combined with the digit "0" rather than "6".
nooo...
> In Norway, the North American system with the number '1' corresponding to one pulse was used, except for the capital, Oslo, which used the same "inverse" system as in New Zealand.
holy crap
> the United Kingdom selected 999 due to the ease of converting call office dials to make free calls. "0" for the Operator was already free, and the cam that removed the shunt on the line when the dial was rotated to the "0" position could be altered to include the adjacent digit "9" (and "8" if required) so that calls to "0" and "999" could be made without inserting coins.
And there we have the explanation for GPs assertation that "999" was the best number, it was instead a purely technical limitation in the mechanical construction of pay phones.
I've just read a few other comments here and it seems that I might be a little older than most of the HN commentards, these days.
When I was a lad you put your finger into the bottom left hole of a rotary dial and moved the dial clockwise until it was over the chosen number. You then released your finger and allowed the dial to roll back to null. You then dialled the next number etc
You did not press keys. That is why 999 was chosen. Telephones with rotary dials had obvious clues to where the home "hole" was - where you would dial from - and you would hit the backstop when you hit nine when you rotated the dial.
The whole point of 999 was that a nine was the only number you could guarantee to accurately dial blind on a rotary input device with only your sense of touch and a little knowledge about the device itself available to you.
I'm also not too sure why any other number would be preferable. 999 really stands out whereas all the other emergency numbers across the world do not. I'll accept that because I'm a Brit that I have been conditioned to 999 being THE emergency number might bias me somewhat but I think my point still stands: 999 is far more obvious than any other emergency number.
I do a lot of (modern ie VoIP) telephony work and can only think that the 9 for an outside line plus rubbish dial plans and crap hardware and programming meant that 999 might not work for some systems. I've also explored the "not British" criteria for the number ... 8)
Can anyone explain why 999 is not the best emergency number ever chosen?