Anyone here any good at math?

[Guest]

What's the stats on this...

I haven't been caching lately work has been too hectic but I get a day off for good behaviour today and well decide to just hoon off through the Connodale national park, but it gets weirder then that I was stopping to take happy snaps and scoping out possible locations to plant caches, but I wasn't really in the mood to be looking for caches.

However I had a compelling feeling to take some vid snaps of my journey and well I kinda snapped some guy on a motorbike, who after I passed a tad under 2mins later I got to the first fire someone had lit, most likely the guy on the bike who heard me coming and nicked off before being caught.

All said and done there was actually 3 fires in total lit today in different places I went past, all seemed to start by the side the road and I saw some volunteer fire fighters who said there has been about 20 or so this year, so I'm sure whoever has been doing it is gonna be hung drawn and quartered if they ever catch up with him.

Approx location of first fire

Oh forgot to mention the funniest bit, rang 000, which weirdly enough I had coverage at the first location but not very far either side.... "What town or city?" "Dunno, I'm in a national park in the middle of no where", "So what's the closest town", "No idea"... "What state", "Brisbane is the closet city", "What state is Brisbane in?" (Having an aussie accent and not knowing what state Brisbane was in was a bit berwildering)

Needless to say this went on for a bit...

I gave them lat/lon in decimal minutes, which was yet another mistake since they couldn't figure out if 46.659 meant 659 seconds or what.

So, the leason I learnt today is the 000 ones don't know sqaut about positioning beyond cross streets

[ArgusTuft]

1. "Anyone here any good at maths?" - Probably!. Maths is easy. All you have to remember is: 1 + 1 = 2 (except for really large values of 1)

All said and done there was actually 3 fires in total lit today in different places I went past, all seemed to start by the side the road and I saw some volunteer fire fighters who said there has been about 20 or so this year, so I'm sure whoever has been doing it is gonna be hung drawn and quartered if they ever catch up with him.

Approx location of first fire

2. Whilst living in Qld, I was a member of our local Rural Firebrigade (Laidley). At this time of year, we could expect anything up to a dozen roadside fires in the first weekend of summer. These fire were started by some fool on a motorbike who would leave Ipswich on the Warrego Highway to Toowoomba, turn left at Plainlands, continue through Laidley then turn left again and return to Ipswich via the Rosewood Laidley Road. He would stop every 10 clicks or so and throw lit matches into the bush. Part of the equipment we had on our truck was an old broom handle. When asked why we had such a non-technical item on board, I (as the Equipment Officer) would reply that it was an easy way to tell how much water we had in the tank (just by dipping the tank with the stick). We also had an unofficial alternate use for the stick. If we ever caught the fool who kept lighting the fires, the stick would be inserted into his fundamental orifice and then used to beat out the fire. Unfortunately,(during my time in Qld), the fool wasn't caught and I don't know how efficient this method of firefighting would be!

[Guest]

1. "Anyone here any good at maths?" - Probably!. Maths is easy. All you have to remember is: 1 + 1 = 2 (except for really large values of 1)

I'm still trying to figure out the odds of all this, of me being there yesterday, and recording his image at all, has to come close to winning lotto I'm guessing

Unfortunately,(during my time in Qld), the fool wasn't caught and I don't know how efficient this method of firefighting would be!

I doubt efficiency would be the point to be honest

[Dik:]

There are 60 seconds in a minute, just like time, so 46.659 minutes is 46 minutes, 60*0.659 = 39.54 seconds.
</P>

You're not the only one who has trouble with this concept: 20 Second Cache (shamless plug for a much misunderstood and mostly ignored cache)

[Guest]

You're not the only one who has trouble with this concep

I understood completely, I even asked them if they had a calculator handy and to multiply it out by 60 and that would give them seconds.

I should have said to just paste the co-ords into google maps...

[rhinogeo]

... I was stopping to take happy snaps and scoping out possible locations to plant caches, but I wasn't really in the mood to be looking for caches.

However I had a compelling feeling to take some vid snaps of my journey .....

You had time to take photos, video and scope out locations but no time or inclination to actually find any caches

I think you need to reassess your priorities ... stop posting to the forums and get out there and find some caches

[SamCarter]

Pr(anyone here being good at maths) = 1

Pr(event in original description not well defined) = 1

Pr(photographing a pyromaniac on a motor bike) = very very small

Pr(some other combination of rare events) = very very small

However,

Number of combinations of rare events that you encounter during a day = very large

So, Pr(having a seemingly remarkable combination of events happening to you on any given day) = 0.5

(well, maybe not 0.5 exactly, but certainly quite high ... and so the chances of experiencing so-called "coincidences" is quite high)

Read "Innumeracy" by John Allen Paulos.

[rhinogeo]

Pr(anyone here being good at maths) = 1

Pr(event in original description not well defined) = 1

Pr(photographing a pyromaniac on a motor bike) = very very small

Pr(some other combination of rare events) = very very small

However,

Number of combinations of rare events that you encounter during a day = very large

So, Pr(having a seemingly remarkable combination of events happening to you on any given day) = 0.5

(well, maybe not 0.5 exactly, but certainly quite high ... and so the chances of experiencing so-called "coincidences" is quite high)

Read "Innumeracy" by John Allen Paulos.

Good reference SamCarter

A bit of googling reveals (for an easy copy & paste) the classic example of the probability that In a group of 23 people, at least two have the same birthday with the probability higher than 1/2

This could be reformulated the following way. There is a bag of 365 different items. We pick an item at random. Note which one it was and return it back into the bag. The question: how many items should we pick so that with a probability higher than 1/2 we would have picked the same item twice. The items in the bag are assumed to be thoroughly mixed before every trial. Is it not surprising that all it takes is 23 items?

To prove our assertion let us start with just two people. What is the probability p2 that two random persons have the same birthday? It's easier to answer a related question. What is the probability q2 that two random persons have different birthdays? Obviously, p2 + q2 = 1. Thus answering one question we automatically get an answer to another.

Thus we have a person with a birthday which falls onto one of the 365 days and ask what is the probability that another person has a different birthday. Since any day out of 365 but the birthday of the first person would make a different birthday, q2 = 364/365.

Consider now three people. What is the probability q3 that no two of them have the same birthday? Obviously p3 + q3 = 1, where p3 is the probability that at least two of the group have the same birthday. As before, take one fellow and his birthday. The second has now 364 days to choose from and, if the third was born on any of the remaining 363 days they would form a no-overlapping-birthday group. Thus q3 = 364/365 * 363/365.

Proceeding in this fashion we'll get q4 = 364/365 * 363/365 * 362/365, and so on. Since every fraction in these products is less than 1, the sequence q2, q3, q4, ... is decreasing. Therefore, the sequence p2, p3, p4, ... is increasing. Now, perhaps, it would be less surprising to learn that p23 > 1/2. Recollect that

q23 = 364/365 * 363/365 * ... * 343/365

[SamCarter]

Ah, yes, Rhinogeo: the birthday problem. I've done that quite a few times with various groups.

On one bizarre occasion, someone else was conducting it and I had left the room, and for once, in a group of about 30 or so, there wasn't a match. A friend of mine, with whom I had taught maths for a couple of years, came out and told me that no "twins" had been found. I wondered if it might have made a difference if I had been in the room, so at that point we asked each other when our birthdays are ... to discover that we matched! (see: Pr(coincidence) = quite high!!!)

Second story: Did it with a group of 40 and didn't get a match (there's a 90% chance of a match happening with this many).

Third story: Did it with a group of 100 teenagers as a "getting to know you" warm-up activity and had "triplets" and "quadruplets" as well as quite a few twins.

Ahhh, probability is such fun.

Back on topic: Pyromaniacs are not.

[Guest]

Actually it's more bizare than I posted, I was stuck on almost the exact spot of the fires in march, but there was no phone reception where the spot I got stuck was, and it was only because I was irked about not knowing where on a map I got stuck was what led me to being there yesterday.

In fact I had an attempt another day to find the same spot but was coming from the other way, but didn't find it, this was back in August or something, so any who, the odds of me being in that exact spot at that exact time, and video recording when I usually never really do is on par with lotto as best as I can guess.

[Guest]

You had time to take photos, video and scope out locations but no time or inclination to actually find any caches

I've been a shutter bug a lot longer than a cacher, I even did some pro wedding stuff a while back, I have NO idea what the hell I was thinking getting into that game, way way way too much stress

[zactyl]

Was the footage of the motorcyclist any use for indentification?

[Richary]

Yes I hope you handed a copy of the video to the police. Valuable evidence if they do catch the fool down the track even if the number plate isn't clear. They can show your video and point to him lighting other fires.

As for punishment, if I was in the local fire brigage I would just tie the bastard to a tree, and then set up the containment line 100m further back.

[Guest]

Yes I hope you handed a copy of the video to the police. Valuable evidence if they do catch the fool down the track even if the number plate isn't clear. They can show your video and point to him lighting other fires.

Tried to, but I was jumping the gun for them, since I'm classified as a witness, not the land owner/manager they have to wait for a suitable complaint to be filed before I can give them anything. They're used to chasing witnesses up, not the other way round

The video was only happy snaps on a mobile phone, 15fps @ 240x120 res, however there is 5 frames which the person can clearly be seen, he was coming toward me, not away so no number plate but you can make out the riding gear a bit, I'm gonna wait and see what the cops do before posting it publically.

The other thing is, it gives a time frame from when I saw him till when I came across the fire, about 1min 50sec, and I also noticed his bike had what looked like camping gear, not what most off roaders usually have so all this could be some what helpful, if not helpful in and of itself in catching them, just waiting to hear back from the cops.

I gave both 000 and the local copshop my details.

[roundcircle]

Just because you saw this guy and a fire does not mean he lit it.

He might think the same of you.

It certainly sounds like you have been in the area enough. You were the one that rang 000, which is often the case with fire bugs. And you went past 3 places during the day where there were fires. Sounds like there is a stronger case against you than him.

Before you get all excited, I very much doubt that you lit them. But you can see the logic here, and some folks shoot first and think later.

I think you need to be very careful about making public accusations when you really don't know all the facts.