gritch said:
... I'm really not good at riddles apparently. I can't figure your's (or even my own out). I will assume your calculations were correct for my riddle but we still have a issue. Logically, the way the problem is stated one one theorize that the hare and tortoise never meet up but physics as well as common sense tells us otherwise.
One can use the concept of the Harmonic Series to prove this but I can't for the life of me find it in my damn Calculus notes.
I'm sorry, I can't find a way to solve your riddle.
Note: Pardon the delay, had to feed myself.
Your riddle was really just a physical example of the halfway paradox (there is a better name but for the life of me I cannot remember it). If I walk from point A to point B, I must at some point reach a half way point, but before I reach the half way point, I must reach the 1/4 point, but before I reach the 1/4 point, I must reach the 1/8 point and so on. By this logic I cannot move because I must always reach a half way point of my intended destination.
Cerdog said:
That's not quite correct. Infinity isn't a number, so it's quite hard to use it in a situation like this, but the size of an infinity depends on the cardinality. For example, the natural numbers (0, 1, 2, ...), the integers (... -2, -1, 0, 1, 2, ...) and the rational numbers (fractions) are all the same "level" of infinity; as weird as it sounds, they are all the same size. On the other hand, the real numbers are larger.
True, infinity is not a number, it is a concept, and this makes it difficult to use mathematically. However this is not impossible. 1 + x > x for all real values of x. You might say infinity is not a real value, therefore the previous equation does not apply, which is somewhat correct. But lets think about that statement, Pi is not a real number. sqrt(2) is not a real number. sqrt(-1) is not a real number. But isn't Pi + 1 > Pi? Isn't sqrt(2) + 1 > sqrt(2)? Isn't sqrt(-1) + 1 > 1?
Consider the example of 0 / 0. It is not a real number and the equation (0 / 0) + 1 > 0 / 0 is debatable at best. However we can think about this in terms of limits and approximate an answer. As I've said previously 0.00000000001 / 0.00000000001 = 1.
Graph y = x / x and check the value at zero, you will get a hole in your graph. But as an old teacher once said to me, this does not mean that the answer does not exist (DNE). It instead means you're going about it the wrong way. y = x / x can be simplified to y = 1, therefore y(0) = 1 as I said above.
If you do the Lim[sub]x->0[/sub](x / x) you will get DNE as an answer. Unsolvable right? Wrong. As I said a couple posts back this is a very easy L'Hopital Rule problem, derive the top and bottom and you get Lim[sub]x->0[/sub](1 / 1) = 1.
Didn't I just prove that 0 / 0 = 1 three different ways? As such, the question of (0 / 0) + 1 > 0 / 0 can be proven by substitution. 1 + 1 > 1, I hope no one doubts that part.
I can't help but feel I'm going off-topic, you said that infinity + 1 = infinity because the infinity overpowers the 1 and can be simplified to infinity = infinity. However, let's look at it on a smaller scale. 0.0000000001 + 1 != 1. The 1 greatly overpowers the decimal, but it still has an effect. 1 + 0.000000001 > 1 no matter how small you make that decimal. In fact, lets make it the SMALLEST decimal, 1 + (1 / inf) > 1. Common sense will tell you that 1 / inf is the smallest positive number, since, isn't 1 divided by ANYTHING a positive number? It's a dammed small number, but a number nonetheless. If I could type this, I would say (1 / inf) equals 0.0(repeating)1. However, no matter how many decimal places you go, if you add 1 to an infinitely small number, you will still get a number greater than one. You can use this same logic to the infinity + 1 = infinity problem. No matter how big infinity is, if you add one to it, it gets bigger.
Infinity + 1
may equal infinity, since infinity + 1 can be simplified to just infinity. But that depends which level of infinity you use, as you said yourself. Infinity is not just a really big number, it also 1 + that number, it is also 2 + that number, it is also 1 million + that number, it is that number to the power of that number. Infinity holds an infinite range of values, none of them equal to one another, but all of them equally reachable.
A final example would be:
(2 * inf) - inf = inf (Because infinity is not being redefined mid-equation)
but
inf + 1 != inf (Because infinity is changing on the left side, but not the right, an algebraic impossibility.)
BehattedWanderer said:
Calculus says that 0[sup]0[/sup] is indeterminate. Officially, 0[sup]x[/sup] is 0 for all x, right? By that logic 0[sup]0[/sup] = 0. But x[sup]0[/sup] = 1 for all x, right? By that logic 0[sup]0[/sup] = 1. There are two rules of mathematics here that are fighting each other. Therefore the answer is considered indeterminate. Although if you take my limit answer, 0.0000000000001[sup]0.00000000000001[/sup] = 1. I have yet to have a mathematician validate this, but I have yet to be proven wrong as well.
BehattedWanderer said:
[Just because you can apply the rules, doesn't mean the rules apply.]
As much as I disapprove of the context of this statement, I like it. I'm going to have to remember that one.