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Does the number π really exist? watch

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1. (Original post by justanotherposter)
That was a typo I mean to put 2 radius (aka the diameter,) I'll edit that now. I'm assuming that's what you meant, if not please give an example of when the ratio of the diameter to the circumference is not pi. I'm a second year undergraduate in maths whilst you seem to believe the only numbers that exist are rational numbers please don't try to act like you know more on the subject than the numerous people who have already explained why you are wrong. There are two possibilities here, either you are a troll (in which case well done you've actually succeeded in trolling unlike most idiots who try to troll badly on this site.) Or you genuinely believe pi isn't a number because you can't write it down in decimal points in which case you need to at the very least revise GCSE maths before making ridiculous claims. There are an infinite amount of numbers that cannot be written down as a decimal, what makes pi so special to you?
No. I'm not a troll. I made this thread cause I dreamed about Pi. Kinda weird, really.

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2. (Original post by Liamnut)

They

Don't

Actually

Exist
English language actually doesn't exist? So you didn't make this reply in English? What did you use to communicate with me?

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3. (Original post by Smaug123)
Please tell me exactly how to construct one of you before you assert that you are "good enough" as a being.
I didn't say " I'm good enough as a being."

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4. (Original post by majmuh24)
Pi is formally defined as the ratio of a circle's diameter to it's circumference, so I think you're the one who needs to brush up on his maths skills.

Pi does in fact exist, but your concept of numbers "existing" seems to be a check that they have a finite representation in base 10, which is not true for pi. It is however, representable on a number line, but it's exact value is unknown as it cannot be represented as a ratio of two numbers which is why it has it's own symbol.

If you are working in base pi however, the value of pi is 10
Just typo. Anyone can make a mistake, sometimes. And you have just brushed up his Math skills...hehe..

Pi is really representable on a number line? According to my Math dic, a line is a geometrical figure that has length but no width. So in the real world, a number line actually exists? I can't find any line that has no width. Can you? Pi, in fact, does exist in the real world? Don't you think Pi and its value are just some of our imaginations used to understand reality of physical world?

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5. (Original post by skunkboy)
Just typo. Anyone can make a mistake, sometimes. And you have just brushed up his Math skills...hehe..

Pi is really representable on a number line? According to my Math dic, a line is a geometrical figure that has length but no width. So in the real world, a number line actually exists? I can't find any line that has no width. Can you? Pi, in fact, does exist in the real world? Don't you think Pi and its value are just some of our imaginations used to understand reality of physical world?

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Can you please say what exactly you mean by exists.
6. (Original post by skunkboy)
I didn't say " I'm good enough as a being."
You didn't - I misphrased, I didn't mean "good" as in "morally good" but "good" as in "sufficient". (I realise it reads differently, coming back to it a week later.)
You said it was "not good enough" to prove the existence of something, if you don't know its value. You assume your own existence, but you don't know how to make one of you, and that's not good enough (by your reasoning).

By the same logic, by the way, you can easily assert that 1 (as a real number, not an integer) doesn't exist. The Dedekind cut of "those rationals which are less than 1" produces a real number 1, but you can't draw it. I know its exact value, but it's meaningless - for any scale, for any line I draw, the line will not have length one according to that scale.
7. (Original post by rock_climber86)
it's a man made number that is defined as being the ratio between the ratio of the circumference of a circle to it's diameter. Of course it exists. It's just a stupid number that no human could ever write the whole value of because it's irrational

I hate irrational numbers
Yeah, true. Pi and its value do exist in your mind while you're thinking about them.

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8. It = Pi which can also mean pie which means Pi can =

9. (Original post by konvictz0007)
yes the exact value of Pi, is Pi, the real number constant.

You do not understand what you mean by exact value, have you ever thought about how you count and why there are 10 digits rather than say 8 or 16? There is binary ternary, denary hex etc. It just so happens that Pi is a rather long expansion, infact infinite, under denary. You see it is a limitation of our numbering system is why you cannot understand why Pi exists.

Im not from Korea, not sure why that is important.

This is the problem when people talk about numbers without doing any sort of degree in mathematics. To really understand Pi, you need to understand Real numbers, which are constructed with different methods such as Dedekind or Cauchy sequences, things which you clearly do not understand, and therefore will not be able to understand Pi.

The square root of 2 can be constructed, and does exist, clearly, yet just like Pi it is irrational, i.e. has a non repeating infinite decimal expansion.

This discussion is beyond your level of understanding. Go away.
Go away? Where to? Your country? Now I don't believe you're not from North Korea!

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10. (Original post by james22)
This question is pointless without first defining what you mean by "exists". I assumed you meant that a number exists if it is a real number, which pi certainly is.
It means to happen or to be real.

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11. (Original post by skunkboy)
It means to happen or to be real.

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Well pi is certainly a real number.
12. (Original post by skunkboy)
Yeah, true. Pi and its value do exist in your mind while you're thinking about them.

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Mathematical constants are interesting, but if you want something truly mind boggiling look up 'dimensionless physical constants' these are quantities that have relevance in the physical world (like the speed of light) but have no units associated with them (unlike the speed of light), that means there is something fundamentally special about them and how our universe behaves.

One example is the fine structure constant which is about 1/137.
13. I like to think of π as a property of algorithms which produce sequences.

So the the algorithm which produces the sequence:

(4, 4-4/3, 4-4/3+3/5, 4-4/3+4/5-4/7,...)

Has the property called π-ness. It is an "algorithm of the π type".

Used in a sentence we could say: "After a finite number of steps an algorithm of the π-type produces only fractions between 3 and 22/7."

But that's just me. Maybe I'm weird.
14. (Original post by Implication)
http://en.wikipedia.org/wiki/Proof_t..._is_irrational

We aren't just assuming it's irrational because we can't find prove it's rational; it was actually proven to be irrational several centuries ago.
Hahahahaha...thanks for the link. I thought you were such an intelligent guy. I was completely wrong! You couldn't prove it, but those people could.

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15. (Original post by skunkboy)
Hahahahaha...thanks for the link. I thought you were such an intelligent guy. I was completely wrong! You couldn't prove it, but those people could.

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You're just rude. And stupid. The proofs of Pi's irrationality really aren't hard. It's just that the irrationality of pi was known well before all our births, so of course we wouldn't be the ones to prove it.
16. (Original post by Implication)
(a) Why on Earth did you reply to that? I posted that last week and we've been having a civil discussion since then.

(b) What are you talking about? That's precisely my point. You were arguing that questions x and y weren't silly because they hadn't been deleted; my point was that they wouldn't be deleted even if they were silly questions. I explicitly made the point that this was an "amateur" board so I don't really know what your point is.
(c) why on earth did you ask that question?
(d) Hahahahaha.... you are a student or not? You know full well... hehe...

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17. (Original post by D4rr3n)
It is an irrational number.
..that doesn't exist in the real world.

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18. (Original post by skunkboy)
..that doesn't exist in the real world.

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As someone has already been said, under what definition of 'exist'? In the sense you can't count out an irrational number of something, no, but I don't see why that should be the definition of existence. Arguably, lengths of physical objects can be irrational if you were to measure them to infinite accuracy, down to the molecular level. In manufacturing materials aren't cut to 100% accuracy, but adhere to something like of manufacturing specifications (depending on what has cut it). So, for example, the diagonal length of the monitor you're posting onto TSR from may supposed to be 14, 17, 19, etc. inches, but in reality it's not going to be exactly that many inches, it could easily be an irrational length.
19. (Original post by KeepYourChinUp)
This thread is just getting ridiculous now. At first your ignorance was funny but now it's just annoying. Judging by your posts I'd say you were about 15 years old with no experience of mathematics or philosophy. You strike me as one of those people who reads about philosophy online and then thinks of a ridiculous question to ask and calls it philosophy.

There's like 2 people in this entire thread who think your question is somewhat valid... I think you need to go back to the drawing board, "Plato"
I'm supposed to say good bye now? No. You should say that if you think it's annoying or boring. Cause I made this thread, you didn't. And I didn't force you to reply,right? I am not a dictator.

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20. (Original post by james22)
Can you please say what exactly you mean by exists.
I didn't tell you the meaning of exist? Sorry. It means to be real or to happen. Am I clear?

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