interesting concept

[Jazza]

[ QUOTE ]
At first glance, my opinion is that it's bull because the temporal element to population changes things.

[/ QUOTE ]

IMO the temproal element to population is irrelevent

[gasgod]

It is unwarranted because there is no way to choose a number randomly unless you know the range.

Suppose I asked you to choose a number at random. How would you go about doing that? Unless I specified the range (R), you have no way of insuring that the number you pick is both within the specified range, and randomly chosen. Your method, to be random in the mathematical sense, must give every number in the range an equal probability (1/R) of being chosen. If you don't know R, then your method cannot be random.

GG

[Jazza]

i still don't follow, i don't see why we have to know the range

[ QUOTE ]
Suppose I asked you to choose a number at random. How would you go about doing that?

[/ QUOTE ]

i agree i cannot choose a random number without knowing the range, but again i still don't see how this is relevent

[WhiteWolf]

I'm not a probablitity expert, but it seems the problem with the argument rests in the assumption that your birth number is "random," when it is really not (the chance that you have birth number 1 trillion is exactly 0), but the Bayesian calcuation used to show it's conclusion depends on your birth number being truly random.....

[Jazza]

IMO you could use this argument to say cards are not random, once you are dealt 72, the odds you have pocket aces is exactly 0

[gasgod]

[ QUOTE ]
i still don't follow, i don't see why we have to know the range

[ QUOTE ]
Suppose I asked you to choose a number at random. How would you go about doing that?

[/ QUOTE ]

i agree i cannot choose a random number without knowing the range, but again i still don't see how this is relevent

[/ QUOTE ]

The assertion that my "number" is random (in the mathematical sense) is equivalent to saying that the probability of picking my number at random is 1/R (where R is the range)

Let me attack this from a different perspective. Is the nine of diamonds a random card? You might say it's random in the sense that it's pretty ordinary, but once you specify a card, it makes no sense to say it is random. It's the nine of diamonds. (Which, BTW, is known as "the curse of Scotland")

You can say, however, that the method by which you chose that card is a random process. Poker sites do this routinely. They don't back up this claim by selecting a card and then saying "See, it's random." No card is random once it has been selected. Instead, they describe the process of picking a random card, and show that the process itself is random.

With the doomsday paradox, it is not legitimate to say that your number is random. Just because it isn't special doesn't make it random. Only the process of choosing it can be described as random, and you agree that it is impossible to choose a number at random unless you know the range.

GG

[gasgod]

[ QUOTE ]
IMO you could use this argument to say cards are not random, once you are dealt 72, the odds you have pocket aces is exactly 0

[/ QUOTE ]

Exactly true! No card is random. The process of selecting cards can be a random process, however.

GG

[Jazza]

everything you say makes sense to me, except this:

[ QUOTE ]
it is not legitimate to say that your number is random

[/ QUOTE ]

IMO it is a perfectly reasonable assumption

using your card analougy, all I am assuming is that the 9 [img]/images/graemlins/diamond.gif[/img] that you recieved was from a shuffled deck that you do not know the size of, this deck may contain 11's 12's 13's etc but all you know is you have recieved the 9 [img]/images/graemlins/diamond.gif[/img] after some one shuffled the deck and dealt you the first card

[gasgod]

The point is that the nine of diamonds is not a "random card" because there is no such thing. But it is a randomly selected card.

Similarly, your birth number is not a random number, because there is no such thing. However, there are randomly selected numbers. Can your birth number be a randomly selected number? Quite obviously not. If the method used to come up with that number is non-random, then the Doomsday paradox is resolved.

GG

[Jazza]

okay i think i follow now

what i meant the whole time was randomly selected number, not random number, my apologies for the confusion

[ QUOTE ]
Can your birth number be a randomly selected number? Quite obviously not

[/ QUOTE ]

not obvious to me

and btw, as far as i can see this is not a paradox