
Your donations keep RPGWatch running!
Things you don't need to know…
October 1st, 2016, 19:02
If you ask Siri to divide by zero, this is what she would say (though I've heard she doesn't do it anymore.)
loading…
+1: 
October 1st, 2016, 20:24
Originally Posted by EyeTHEN I WON'T ASK YOU, OK?
As you all know the beard is back  pity if you ask me.
Eh… Sorry about that.
Nevertheless, the history of the beard is quite interesting:Interesting. Mine is a combination of the Egyptian and the Greek style.
Beards, Past and Present.
The "Piccadilly Weepers", or "Mutton chops", are awful to see but best to kiss if you ask me, no distracting crumbs or tickling hairs.
My favourite: "La mouche"/"A la royale", because somehow I always assume the man wearing it is wellmannered.
Most fascinating: Mesopotamian beard style.
pibbur who still won't ask the eye who doesn't look like an eye anything. Even kisses. Or hugs. The wife's coming home today after spending two days in Copenhagen visiting graveyards.
Last edited by pibbur who; October 2nd, 2016 at 01:55.
Guest
October 1st, 2016, 20:56
Originally Posted by pibbur whoGraveyards? O dear, what on earth is she up to?
The wife's coming home to day after spending two days in Copenhagen visiting graveyards.
Edit: changed the avatar. Eyish enough for you?

1. It's not what you say  it is the way you say it.
Lovely 2 minute video: 'Change your words, change your world'
2. Getting a YouTube video loaded and other BB codes, see this post
1. It's not what you say  it is the way you say it.
Lovely 2 minute video: 'Change your words, change your world'
2. Getting a YouTube video loaded and other BB codes, see this post
+1: 
October 1st, 2016, 21:07
She's working at the graveyard authority (don't know if that's the right word) here in Bergen. Administration, not digging.
pibbur who likes the new avatar of the eye, but who admits she can choose any avatar she wants to.
pibbur who likes the new avatar of the eye, but who admits she can choose any avatar she wants to.
Last edited by pibbur who; October 2nd, 2016 at 01:54.
Guest
+1: 
October 2nd, 2016, 13:23
[QUOTE=Ripper;1061415063]If you ask Siri to divide by zero, this is what she would say (though I've heard she doesn't do it anymore.)
…
Funny. Unlike google whic does nothing if you ask it to calculate 0/0 (or 7/0, any number/0).
But what is 0/0? 1? Zero? Infinity. Informally, we can say that the answer is all of them. Well, actually we can't say that something is infinity, but 0/0 would match any number we chose. So it's undeterminate.
There is an excellent numberphile video here. covering x/0, 0/0 and also 0^0 and why you can't say that something like x/0 is infinity.
Then we have this one, among other things covering why it's make sense to define 0!=1.
Than we have pathetic things like this, where some amateur tries to prove that you can devide by zero, despite what mathematicians say.
Among the things he does wrong is to assume that you can devide by zero, and use that to prove that you can do it. And that he uses infinity as a regular number.
pibbur who plans to study a lot more mathematics when he retires. Why? Because it's fun!!!
…
Funny. Unlike google whic does nothing if you ask it to calculate 0/0 (or 7/0, any number/0).
But what is 0/0? 1? Zero? Infinity. Informally, we can say that the answer is all of them. Well, actually we can't say that something is infinity, but 0/0 would match any number we chose. So it's undeterminate.
There is an excellent numberphile video here. covering x/0, 0/0 and also 0^0 and why you can't say that something like x/0 is infinity.
loading…
Then we have this one, among other things covering why it's make sense to define 0!=1.
loading…
Than we have pathetic things like this, where some amateur tries to prove that you can devide by zero, despite what mathematicians say.
loading…
Among the things he does wrong is to assume that you can devide by zero, and use that to prove that you can do it. And that he uses infinity as a regular number.
pibbur who plans to study a lot more mathematics when he retires. Why? Because it's fun!!!
Last edited by pibbur who; October 2nd, 2016 at 13:44.
Guest
October 2nd, 2016, 14:03
Guest
October 2nd, 2016, 14:19
Yes, the other day someone asked what the Watch was worth, and I attempted to show that its value is undetermined, since the answer must be x divided by the membership price (zero). The Watch seemed unmoved by my theorem.
October 2nd, 2016, 14:41
Case (1)
Let be x <> 0
Lets assume a definite number y exist, that
x/0 = y
then y*0 must be x.
But y*0 is always 0. x = y*0 = 0.
A contradiction to our precondition x <> 0.
Case (2)
Let be x = 0
Lets assume a definite number y exist, that
x/0 = 0/0 = y
Then y*0 = 0.
But this is true fo every y.
A contradiction to our precondition that y is a definite number.
Ergo:
y= x/0 is not defined
Let be x <> 0
Lets assume a definite number y exist, that
x/0 = y
then y*0 must be x.
But y*0 is always 0. x = y*0 = 0.
A contradiction to our precondition x <> 0.
Case (2)
Let be x = 0
Lets assume a definite number y exist, that
x/0 = 0/0 = y
Then y*0 = 0.
But this is true fo every y.
A contradiction to our precondition that y is a definite number.
Ergo:
y= x/0 is not defined
+1: 
October 2nd, 2016, 15:54
And for the question whether x/0 is infinity or not:
We cold use limits and demonstrate that y/x>infinity as x>0. But this assumes that x >0. Because if x<0 we get y/x> infinty as x>0. Therefore we cannot say that y/0 is infinity, instead x/y approaches (we can make x/y as large as we want) + or  inifnity depending on whether x> or x<0.
pibbur who has an upper limit to the number of quarks and electrons in his body.
We cold use limits and demonstrate that y/x>infinity as x>0. But this assumes that x >0. Because if x<0 we get y/x> infinty as x>0. Therefore we cannot say that y/0 is infinity, instead x/y approaches (we can make x/y as large as we want) + or  inifnity depending on whether x> or x<0.
pibbur who has an upper limit to the number of quarks and electrons in his body.
Last edited by pibbur who; October 2nd, 2016 at 17:24.
Guest
October 2nd, 2016, 15:58
Now for a quick question: Why do we define 1 as not prime? It surely isn't divisible by any integer value other than itself.
pibbur who knows the answer (and he's not talking about 42).
pibbur who knows the answer (and he's not talking about 42).
Last edited by pibbur who; October 2nd, 2016 at 16:25.
Guest
October 2nd, 2016, 16:19
Originally Posted by RipperNitpicking: x/0 is undefined, not undetermined. There is a subtle difference between those two terms.
Yes, the other day someone asked what the Watch was worth, and I attempted to show that its value is undetermined, since the answer must be x divided by the membership price (zero). The Watch seemed unmoved by my theorem.
Assume 1/0=y exists. Then we have 1=0*y. There is no value of y that multiplied by 0 equals 1. Therefore x/0 is undefined.
On the other hand, using a similar argument for 0/0=y. Then as HiddenX pointed out 0=0*y, which holds for any value of y. So 0/0 is undetermined.
pibbur who thinks he's both defined and determined.
Guest
+1: 
October 2nd, 2016, 16:27
Infinity is a fairly troublesome concept in itself, and is also not welldefined, as it means slightly different things in different cases. Some infinities can be shown to be larger than others, for example.
A number of philosophers and mathematicians are not happy about this sort of thing, but most people just shut up and calculate.
A number of philosophers and mathematicians are not happy about this sort of thing, but most people just shut up and calculate.
+1: 
October 2nd, 2016, 16:37
Originally Posted by RipperYep, there is the question of whether an infinite set is countable or not. In a countable set, every element can be associated with one integer. The set of integers is of course countable. So is the set of all even numbers. Or numbers divisible by 7. And the set of rational numbers (fractions). All of these are of the same cardinality (one way of saying that their "equally large").
Infinity is a fairly troublesome concept in itself, and is also not welldefined, as it means slightly different things in different cases. Some infinities can be shown to be larger than others, for example.
But the set of real numbers (pi, e,square root of 2…) can be shown to be not countable and therefore of a higher cardinality.
But it is to some degree a question of how we define things.
A number of philosophers and mathematicians are not happy about this sort of thing, but most people just shut up and calculate.Interesting.
pibbur who insists that the set P={pibbur} is countable. He will however not be held accountable for what he writes.
PS.
For those confused by number sets, here are the important sets, each of them includes the above mentioned sets.
N is the set of natural numbers, integers > 0.
Z is the set of postive and negative integers and 0. The set includes N
Q is the set of rational numbers, positve or negative fractions. The set includes Z
R is the set of real numbers, whch includes the rational numbers and numbers like pi, e and so on. Every number that can be represented on a number line belongs to R. Other numbers do not belong to R, those belong to the next set, the complec numbers.
C is the complex numbes, of the form a+b*i, where a and b are real numbers and i (for imaginary number) is the square root of 1. i is not a real number, since no real number satisfies x^2=1. C contains R, we get R by setting b=0.
DS.
Edit: Corrected a nasty typo. Complex numbers are of the form a+b*i, not a=b*i, which doesn't make sense. *shivers*
Last edited by pibbur who; October 2nd, 2016 at 21:34.
Guest
+1: 
October 3rd, 2016, 18:00
Originally Posted by pibbur whoWell, nobody came up with an answer, so here it is.
Now for a quick question: Why do we define 1 as not prime? It surely isn't divisible by any integer value other than itself.
pibbur who knows the answer (and he's not talking about 42).
We could (and we did for a long time) consider 1 a prime. But if we do, we're making things a bit more complicated than necessary.
One example, the fundamental theorem of arithmetic which says: Every integer >1 is either a prime, or a unique product of primes. As the name suggests, this is a very important theorem in mathematics.
We have for instance 42=7*3*2. No other product of primes give this number (sorting the factors differently doesn't count). Now, if 1 is prime we would also get:
42=7*3*2*1
42=7*3*2*1*1
and so on. This invalidates the uniqueness part of the theorem.
We could solve this by reformulating the theorem: Every integer >1 is either a prime, or a unique product of primes larger than 1. But there are many other theorems where we would have to do the same. So, the most practical solution is to exclude 1 from the set of primes. After all 1 is a very special number with fundamental properties not shared by primes >=2.
Among those we have:
 a*1=a, which actually is one of the fundamental axioms (multiplicative identity axiom) defining the set of integers (and the rational, the real and the complex).
 a*b=1, which is one of the axioms defining the rational numbers (the reals and complex as well), the existence of the multiplicative inverse.
Now for another question about primes. 2,3,5,7,11,13,17,19,23,29,31,37 are all primes, they come up quite often in the example (the primes in integers< 40). Now, is there a sequence of 1 000 000 consecutive numbers where none of them is a prime? If so, how to prove it?
pibbur who doesn't think "which number has the unique prime product 2*3*7?" is the question.
Last edited by pibbur who; October 3rd, 2016 at 19:17.
Guest
October 3rd, 2016, 18:51
1000000!+2 … 1000000!+1000000
gives you 10000001 numbers that are not prime.
by definition n! is divisible by all numbers from 1…n
and
n!+2 is divisible by 2
n!+3 is divisible by 3
…
n!+n is divisible by n
gives you 10000001 numbers that are not prime.
by definition n! is divisible by all numbers from 1…n
and
n!+2 is divisible by 2
n!+3 is divisible by 3
…
n!+n is divisible by n
+1: 
October 3rd, 2016, 18:54
Exactly! (not the faculty)
This also means that there is an infinite sequence of consecutive numbers where none is prime. And of course, being countable, this sequence is just as large as all the integers.
pibbur who, being divisible by for instance b (giving piur), is not prime, although being the only one, is the prime of pibburs.
This also means that there is an infinite sequence of consecutive numbers where none is prime. And of course, being countable, this sequence is just as large as all the integers.
pibbur who, being divisible by for instance b (giving piur), is not prime, although being the only one, is the prime of pibburs.
Last edited by pibbur who; October 3rd, 2016 at 19:19.
Guest
October 3rd, 2016, 19:19
Originally Posted by pibbur whoUnless both a and b are 1.
Observe that 2) does not hold for integers.

In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move. Douglas Adams
There are no facts, only interpretations. Nietzsche
Some cause happiness wherever they go; others whenever they go. Oscar Wilde
In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move. Douglas Adams
There are no facts, only interpretations. Nietzsche
Some cause happiness wherever they go; others whenever they go. Oscar Wilde
October 3rd, 2016, 19:29
Gah! Go away with your maths.
I know the rule of three …
I know the rule of three …

ESOplaying machine
Semper HiFi!
Motto of the 54th Groove Bde.
ESOplaying machine
Semper HiFi!
Motto of the 54th Groove Bde.
Thread Tools  Search this Thread 


All times are GMT +2. The time now is 09:13.