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I'm not sure that 95% of the world knows much at all about metallurgy. If you break into the top 5%, there are still over 350 million people who know more than you. That's a hell of a lot of people, probably everyone with an interest in the topic.
Hi;
You probably thought that finding the square root will simplify the expression, but that is only true once you assume that x is positive (which it is).
Hi! (:
Hi;
Won't there be infinitely many solutions to this? Perhaps it should be restricted to integer coefficients or something. Nevertheless, I am unfamiliar with the methods of answering this question.
Hello
x cannot be -2 or 2
Hi Solvitur, welcome back (:
The question of whether the idea of an infinite universe makes sense is discussed by all sorts of thoughtful yet unqualified folk xD It puzzles a lot of people that, for instance, one thing could be twice as large as another, while both are equally insignificant parts of an infinitely large whole. Or, similarly, that one thing is made up of infinitesimal bits, while another seems to be made up of twice as many. It is my equally unqualified understanding that in physics, 10^-100 metres is nonsense; nothing related to length occurs at that scale to distinguish it. If my statement that the infinite divisibility hypothesis is unverifiable is valid, then it is a significant objection, because the scientific method takes experimentally unverifiable claims to be worthless.
If something were essentially determined but not predictable, how would we know? And if we could not know, on what basis could we claim that it was essentially determined?
I used to think, and some philosophers do think, that the idea of an essentially random event is logically incoherent. Your first question is rhetorical unless this can be demonstrated, and I am quite sure it cannot. As to your second question ... I suppose you have given me a very concise explanation xD The quantum theory has led us to disregard our intuitions about causality, and I think rightly so.
Incidentally, Einstein himself claimed that the universe is essentially determined despite quantum theory (which he regarded as provisional); he also admitted that this belief was entirely based on faith.
PS: Regarding your last question, you may find the OP here http://www.mathisfunforum.com/viewtopic.php?id=22752 to be relevant. Basically, there is almost nothing about the world we can be absolutely sure of. If you are doubtful enough, you can virtually always find a way that reality might not at all correspond to what you observe or think.
The scientific method is so successful because it comprises the set of principles (read: assumptions) that best identify consistency in what is observed. That, I think, is the basis of gaining knowledge about the world.
Hello!
x cannot be -3, 3 or 4. One simplification is:
Not really. Although I can see why you'd link it, since the Gettier problem is about how difficult it is to specify the "justified" criterion of knowledge. But it's not the same because most people do not want to define knowledge as certainty; most people are fallibilist. So we aren't specifically discussing the general definition of knowledge at all; unless you want to make knowledge and absolute certainty synonymous.
So does that mean that by tearing a page out, it happens the day after?
I think that is the simplest interpretation, yes (:
There are an infinite number of pages in this book. Every day has a page that represents it. Assume they are in order. It appears, at first, that he will not get to have a birthday very often, since for every birthday page, there are 364.2425 non-birthday pages (if he isn't born on leap day; if he is, then there are 1,505 and 15/97 non-birthday pages for each birthday page!). But nevertheless, he can always flip to the next birthday page and tear that out for tomorrow, so effectively he has more birthdays.
I honestly think that the role of the book and the gods is unimportant. The principle is that he can choose the order of an infinite set, such that only the least common elements appear, and that is somewhat counterintuitive.
Hi everyone
I personally agree with Nehushtan that a priori knowledge is certain - this is actually what I meant to say, but without the terminology (it is not a philosophy forum, after all ). But I think there has to be an important qualification to this: We know that particular theorems follow from particular axioms, and particular implications follow from particular definitions. But we don't know for sure in what sense those axioms or definitions are necessarily true.
It's related to what Calligar is getting at. My response to the argument that 1 + 1 = 4 is that if you don't agree that 1 + 1 = 2, then we aren't talking about the same thing; it is true by definition. But that is almost like saying it is true because we said it must be; in what sense is it certain that 2*1 equals 2, or x * 1 equals x, before we have defined those expressions to have that meaning?
It seems to me that all we know for sure is that, for example, GIVEN that x*1 = x, then 1+1=2. Which is quite restricted. Our certain knowledge is entirely conditional.
I understood that I'm not sure if you can say that 0/0 could be anything, honestly, unless you create a framework for it. But in elementary arithmetic, although no answer is satisfactory, I think some answers make more sense than others.
In particular, if you graph a few functions, you will get answers for what functions approach when various things get arbitrarily close to 0, and they will not be 3.9425. I stated in the thread "What is 0^0?" what these limits are.
For example, you mentioned that the answer to 1/0 could be infinity. But if you graph 1/x, you will find that it could be infinity ... or it could be minus infinity, depending on which direction you approach x=0 from. The same holds true for any nonzero real number in the numerator.
As for 0/0, if you graph x/x, it is always 1. If you graph 0/x, it is always 0 (although x has to be positive). So, the answer to 0/0 could be either 1 or 0, or plus or minus infinity, in a sense. But it doesn't work unless there is one consistent answer.
What kinds of truths, in all seriousness, do you think are absolutely impervious to doubt? Suppose that you are the kind of person who does not believe anything you can find the smallest amount of uncertainty in. You will, of course, reject authority, religion, the methods of most fields of knowledge; in fact virtually anything that is merely said or written down. You will only trust things you see for yourself, for a while.
But then it gets more interesting, if you are a ruthless doubter. You will start to question everything outside yourself; you will lose your belief that certain historical events actually occurred, that there is a Great Wall of China, that the earth is spherical or not the centre or even the entirety of the universe. For that matter, why even believe there is an earth, except for what you are currently looking at; perhaps most of it disappears when you turn your back to it. One day, if you persist, you will even doubt that other people have minds like you do, and you will stop believing that they are alive.
Continue in this manner, and one day the following question will occur to you: How do I know I am not dreaming? How do I know I am not in a simulation or a hallucinatory or drug-induced trance? At which point, your doubting mind will systematically assume that everything you experience is totally unreliable.
The question is, what is left? When Descartes tried this thought experiment in the 17th century, he concluded that he knows only that he is having experiences, and therefore that he exists. He did not even believe that mathematical knowledge (1+1=2) or tautological knowledge (all bachelors are unmarried) were absolutely reliable, since he thought we may just be perpetually confused.
For my part, I think certainty is in all of those or nothing. If we can't even lay down definitions with a certain meaning, i.e. we can't ensure that our language correlates at all to our thoughts, then how can anyone say they know for sure that they exist, given that they may not even know what, if anything, the word "exist" refers to? It seems more likely to me that the logical consequences of our definitions in maths, logic and linguistics provide certainty; namely, it is certain that those definitions imply those consequences.
Hello,
I am not totally sure of the interpretation, but I have assumed that you are after a single a-value that gives two x-values where one is double the other.
Yes! It is a neat implication, one of many when working with 0. Your thinking is that the solution to 0/0 is v in v*0=0; but then v=0/0 can be literally anything. One of the fundamental issues with dividing by zero is that if you allow it, then just as you get 1*0=0, 3.9425*0=0, you also get 1 = 3.9425
Personally, I think rather than saying that x/0 is equal to some undefined variable v, it is best to say that it is a question that does not make sense. When you think about 20 divided by 5, you are thinking about how many times you subtract 5 from 20 to get 0. So how many times do you subtract 0 from 1 to get 0? Well, you never will. How many times do you subtract 0 from 0 to get 0? As many as you like. They are really nonsense questions from that perspective.
Hi;
Oh, you just average them (:
Hello;
Hi!
My answer agrees with yours bobbym, even though it is a strange result for this kind of problem P:
Hello Calligar,
I think the best way to help is to restate the entire paradox in a clearer way.
A man is made immortal; he will live forever. However, he only has divine powers on his birthday. Nevertheless, he has the ability to choose which order the days of his life will take place.
The paradox is that he can prioritise his birthdays such that he experiences many more birthdays than non-birthdays, forever. (As mentioned later, he can even choose to delay having a non-birthday indefinitely.)
The book is just symbolic. The idea is that tearing a page out represents choosing that day next.
Hopefully that's a little more understandable, but if not, let me know what is unclear (:
It's really the principle that is a little paradoxical. It's like if you were told to name every number, in any order, and for every prime number you name you get $100 and every other number you lose $1,000, you will never go broke because you will only name prime numbers (even though there seem to be so few prime numbers by comparison).
Hello!
Hello;
Hello!
Hey bobbym,
It's a good approximation. For example, for this problem, the error is only about 560mL, or about 725 milliseconds worth of water.
But for some reason, I just don't like using approximations when an exact answer is within reach xS
It's actually quite enlightening to graph the various functions and see why it's so ambiguous what happens at 0.
For 0^0, if you graph:
x^x you get 1,
x^0 you get 1, and
0^x you get 0.
For 0/0, if you graph:
x/x you get 1, and
0/x you get 0.
For ordinary division by 0, if you graph y/x you get plus or minus infinity. Plus the implication that if, for instance 1/0 = 2/0, then 1 = 2
Hi bobbym
I noticed that you used the same formula, but taking pi to be 22/7
Happy New Year!