Earlier quoted context omitted.
Actually I found that the animation showed a clear example demonstrating that pi is wrong. I don't know about you, but when I looked at it I immediately recognized the blue arrow and the centre of the wheel. That's a radius. There's no easy way to determine that a diameter was in the picture. As it rolls over the circumference, it's the radius line we follow. Therefore, I agree that pi is truly the wrong constant to…
??? What do you think those vertical blue bars were all about? I've read the Tau Manifesto before, and I think it makes some really good points. I'm probably 60-75% in agreement with it. But this animation is fine.
Pi explained
41–46 of 46 posts
Re: Pi explained
#42Earlier quoted context omitted.
See my reply here: http://news.ycombinator.com/item?id=2667461 There is no discrete base unit of space, and on top of that objects do not have determinate sizes.
I thought the Planck length (1.616252×10−35) was the discrete unit of length. Is that not true? http://en.wikipedia.org/wiki/Planck_length
A physical object does not have a sharp edge.
Re: Pi explained
#43Earlier quoted context omitted.
See my reply here: http://news.ycombinator.com/item?id=2667461 There is no discrete base unit of space, and on top of that objects do not have determinate sizes.
Isn't the Planck length a theoretical base unit?
But it doesn't matter, actual physical object do not have definitive sizes.
Re: Pi explained
#44Earlier quoted context omitted.
Actually, no they can't. At a quantum level things do not have definitive sizes. They have sort of "clouds", where the center of the cloud is more likely to be their size, and the edges are less likely - but still possible.
So a string of 24 carbon atoms is not 2 dozen carbon atoms long? Unit=dozen carbon atoms, length=2?
And especially when you attach atoms together the spacing between them varies depending on the strength and type of the bond.
Additionally, molecules are constantly in motion (heat) - one of the motions is changing the size of the spacing between them.
But even if you froze it to absolute zero (which is impossible), it doesn't matter, the size is not determinate, it's only probabilistic.
So a real physical object can never have a fixed size.
Re: Pi explained
#45Earlier quoted context omitted.
> number theory How does number theory relate to this? (I think you just misused the term, and are thinking more about the philosophy of mathematics and not about that specific discipline.)
Number theory relates because his question suggests that a transcendental length might be especially problematic. I don't think it is, because of the hard limits on our ability to measure physical phenomena. So it doesn't matter if we're talking about lengths that are integer, rational, algebraic, transcendental, computable, or otherwise. The end of the string is fuzzy at many different scales, so even defining its l…
That isn't what the field of number theory concerns itself with.
Re: Pi explained
#46Earlier quoted context omitted.
Number theory relates because his question suggests that a transcendental length might be especially problematic. I don't think it is, because of the hard limits on our ability to measure physical phenomena. So it doesn't matter if we're talking about lengths that are integer, rational, algebraic, transcendental, computable, or otherwise. The end of the string is fuzzy at many different scales, so even defining its l…
> Number theory relates because his question suggests that a transcendental length That isn't what the field of number theory concerns itself with.
Recall what I said here: "In the real world, you always run into limits on how finely you can measure things before you run into quandaries about number theory."
In other words, when you measure entities and processes in the real world, it is unlikely that you'll ever have to think about the nature of the continuum, or transcendental numbers, or even for that matter precise integers.
For example, back in the '80s when I was using an Apple II computer to collect measurements from a microwave dish, it was obvious that we should measure amplitudes to four decimal places (or whatever, I forgot), and not concern ourselves with the impossible task of counting a precise integer number of energy quanta at each frequency.
Certainly when you're measuring energies in a particle accelerator you'll have different standards, but you will still always come face to face with the economics of "good enough" and even Heisenberg's hard limits on observability in principle.
So to reiterate: the constraints of the real physical world will always bind you long before you ever have to care about the vagaries of number theory.
Nevertheless, the abstract theory of real numbers is definitely useful even in the physical sciences, because that theory transcends all physical constraints and therefore imposes no a priori limits on observations. So it is not wise to fetter your mathematics with the chains of physical constraints.