Randam Chaos

[homedeeth]

i was walking to the shops the other day through my estate. It was pretty much quiet with no cars on the road. I turned the corner and 50 yards up the road a car reversed out of it's drive, another car came up and stopped for it, a cyclist had to stop because of the cars and then another car came from another direction and had to stop. I stopped aswell. I thought this was very odd and random because it was so quiet before and then suddenly there was a situation involving 3 cars, me and a bike. I called it a Randam Chaos Theory and wondered if there was such a theory out there!

[heathfield]

That's the universe for you. It's always busy, busy, busy.

Some time ago there was a long discussion (I forget which magazine or newspaper) on the chances of the following...

A cyclist or walker is proceeding along an otherwise empty road. Two vehicles approach from opposite directions. The two vehicles pass each other at exacty the spot where the cyclist or walker happens to be. You wouldn't believe the number of people who said it had happened to them - far more than by random chance, it would seem.

It's just the universe playing around with us. Best ignore it !! ;-)

[jake-the-peg]

This could be considered under something called queue theory.

If you know what the average traffic rate is and you block the road for a set time you can calculate how long you expect the queue to grow.

You can apply this to things from call volumes into call centres to lane closures on motorways. If you have 200 lines and a call takes 5 minutes you can calculate the probability of not getting through.If you close a lane on the M1 you can use the formulae to calculate how long you expect the queue to be.

A lot of this was worked out first by a guy called Erlang http://en.wikipedia.org/wiki/Agner_Krarup_Erla ng and some of the equations and units are named after him.

[factor-fiction]

"The two vehicles pass each other at exacty the spot where the cyclist or walker happens to be."
Sounds like quite an unlikely event depending on 3 things coinciding until you realise that if two cars were driving in opposite directions they have to cross somewhere so all we are looking at is the chance that you are at the same point at the same time. And in reality on any quiet road there are likely to be several walkers and several cars, so there are several chances of it happening every day ona ny road. And there are lots of quiet roads we walk down. And of course I might remember the coincidence of 2 cars passing me at the same time but I'll probably instantly forget all those times individual cars passed me or pairs of cars passed each other 200 yards away.

[joggerjayne]

Randomness and coincidence ...

If you Google the Birthday Paradox, you will find that, at a party of 57 people, the chance that you did NOT share a birthday with another guest is only 1% !!!

(because it would require each guests birthday to fall on an "available" date and, as you work up from 1 to 57, the ratio of "available dates" to "used dates" falls dramatically).

So when you find that you share a birthday with another guest to whom you are chatting, it is not a "coincidence" ... it is the statistical norm.

[factor-fiction]

Joggejayne- the 1% figure is the probability that that there are no shared birthdays in a room of 57 people- that is there's a 99% chance that two people somewhere in teh room will share a birthday.

But if one person goes into room of 57 people the chances that someone has the same birthday as him is 57 in 365 ( or about 15%), so the chances are that no-one will share his birthday

[fo3nix]

Perhaps you're in the Truman show?