Re: Me and David C. Ullrich


Elmo wrote:
> On this forum I have argued the question, "Two coins were flipped and
> at least one is a head. What are the chances that there are two heads?"
>
> Many mathematicians get it confused with "The probability for two
> heads, given at least one head?"
>
> I say that "given at least one head", and told, "at least one head"
> mean two different things.

Really?

>
> Dr. Ullrich has stated in this forum, that the two mean the same thing.
> If for no other reason than that he said so. Also because everyone
> assumes them to be the same. (everyone does not, I don't)

Well, mathematics is not a democracy. But it isn't a
parlimentary system either. There are no minority opinions
allowed, only Truth. And if you think your opinion is Truth,
then you have two choices:

- prove you are right

or

- prove the majority is wrong

>
> I had occasion to visit Oklahoma State University. I found Dr. Ullrich
> in the Student Center. He said I was not welcome there. He refused to
> discuss the question with me there, as he has refused to discuss it
> here.

Here's a probability problem for you: what do you think the
odds are, given this stalking incident and the evidence in these
sci.math postings, that a judge would sign a restraining order
against you if Dr. Ullrich requested it?

>
> The probability for two tails, given at least one tail is one third.
> That is defined mathematically and is not arguable.

Then why are you arguing?

>
> What it means to say, "at least one is a tail" is defined in the world
> domain and means what it says. As the math domain is a subset of the
> world domain, it is not possible to re-define, inside the math domain,
> what "at least one is" means in the outside world.

Huh?

>
> An example:
>
> Suppose that a computer program randomizes the coins, or dice, or puppy
> dogs. Then shows us to colors. Suppose that we see a red and an orange.
>
> We can make the statement"there are two colors and at least one is red"
> or we can make the statement "there are two colors and at least one is
> orange." The red statement tells nothing of orange, and the orange
> statement tells nothing of red.

Ok.

>
> The statements "at least one is red" and "at least one is orange"

Wait a minute. That's TWO statements.

> demonstrate what it means to say "at least one is".

You're trying to put ten pounds of *** into a five pound bag.

>
> Now make the statement, "There are two colors, given at least one red."
> Does that mean the same thing as "There are two coins, given at least
> one head"? If it does, then the probability for two reds is 1/3. To
> mean the same thing as "given at least one", the 'red' statement must
> convey some knowledge of 'orange' and the 'orange' statement must
> convey some knowledge of 'red'.

The statement "given at least one" does NOT specify WHICH one
is heads. If the two coins were a dime and a nickel, then
"given the nickel is heads" DOES convey information about the
dime and would make your reasoning correct. But it doesn't say
that, "given at least one" leaves the issue of WHICH coin is
heads unspecified and your reasoning does not apply in that case.

>
> Dr. Ullrich seems to be somewhat of a fakir. He plays a lot of
> bachgammon.
> He argues a lot in this forum.
> He does not seem to publish.
> He draws a paycheck at OSU, I guess, wonder if he has tenure?
>
> When you accept that "given at least one" and told, "at least one" are
> different;

False premise.

> then it's easy to get from:
>
> P(hh|at least one h) = 1/3 to
> P(hh|told "at least one h) = 1/2.

It matters not if your logical inferrences are valid, the false
premise renders your conclusion meaningless.

>
> Eldon Moritz
> elmoritz@xxxxxxxxx

.

Quantcast