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Is this physically possible

EvilYeti: Stick your nose a few inches from your monitor and look again.
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Ahh, you are referring to the pixels on the screen, not the concept of a circle. How clever.
 
xouper said:
Ahh, you are referring to the pixels on the screen, not the concept of a circle. How clever.
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Here we call that anal/pedantic :p
 
INRM,

I don't think that question has an answer. It would depend on the hypothetical laws of nature that apply to this hypothetical universe or entity. If you are asking whether the premise that some hypothetical thing has always existed necessarily implies that it must always exist, then I would say the answer is no.
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So an object that never was created yet existed, could not cease to exist?[
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Who knows? Either possibility is logically possible. As for physically, that is simply not known. It somewhat depends on what you mean by "created". For example, when somebody "creates" a house, he is simply constructing it from components which already exist. Likewise, I know of no way to make those components cease to exist. I only know how to transform them into other stuff.

At the quantum level, matter/energy pops in and out of existence all the time. I don't know that you could really call this process "creation" or "destruction", though, since it is essentially random fluctuations in a field.

To put it another way, I think your entire question is making some very basic assumptions about the nature of reality that, while it may be counter-intuitive, are fundamentally flawed. In the context of Quantum Mechanics and Cosmology, I don't think the questions really make any sense. And as I said before, if you move out of the context of the real world, and into some hypothetical world where things are different, then the questions are too vague, because I don't know anything about this hypothetical world.

Dr. Stupid
 
Interesting Ian said:


If we subsisted in a Universe which had always existed, then an infinite time would need to elapse before we get to where we are now. An infinite period of time cannot elapse. Therefore we can't have a Universe which has always existed.
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Interesting, Ian.

But must it be true that if the Universe had always existed that we must have existed right along with it? After all, God could have deposited us anywhere along this infinite span of time, five minutes or five thousand years ago.

And I suppose that while a circle has a finite diameter you could trace its length for as long as you want, provided you don't stop when you reach your starting point.

All this while conceding that it is actually valid to conclude anything about the natural world based on the properties of Infinity as we conceive it.
 
Originally posted by Interesting Ian

If we subsisted in a Universe which had always existed, then an infinite time would need to elapse before we get to where we are now. An infinite period of time cannot elapse. Therefore we can't have a Universe which has always existed.
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If you pick some starting time and some ending time, the interval between them is not infinite; and this is true regardless of which two times you pick. I assume you meant something like this when you said "an infinite period of time cannot elapse." But saying that the universe has always existed is not claiming that some starting point existed since which an infinite period of time has elapsed. It is simply claiming that each day had a day preceding it, which doesn't seem especially counterintuitive.
If the Universe had already existed for an infinite period of time, then the probability of anything happening now would be one over infinity, which equates to a zero probability. But things are happening now. Therefore the Universe cannot be infinitely old.
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Zero probability is not the same as impossibility.

Would you use the same reasoning to argue that all physical variables must be quantized rather than continuous, since if they were continuous, the probability would be zero that your height is whatever it is, or that your weight is whatever it is, or that the temperature in your backyard yesterday at noon was whatever it was? (By "continuous" I mean "able to take any of the infinite number of values in some range"; by "quantized" I mean "able to take any of only a finite number of values".)
 
Originally posted by PixyMisa

Indeed, we may have lived out the exact same lives in the distant past, except that the PostScript Language Reference Manual was orange rather than red.
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Well, if that were the only difference, I'd still have bought a copy a few years ago for 50 cents at a library book sale, and this little program I wrote would still work. (Send it to your nearest PostScript printer, but be prepared to wait a few minutes for it to print.)
Code: 
%!PS-Adobe-1.0

/c1 3 sqrt 3 div def
/c2 c1 2 mul def

% x y L n gasket -
% (x, y) is center, L is half-width at half-height, n is recursion depth
/gasket
{
	8 dict begin
	/n exch def
	/L exch def
	/y exch def
	/x exch def

	/c1L c1 L mul def
	/c2L c2 L mul def

	x L sub  y c1L add  moveto
	x L add  y c1L add  lineto
	x        y c2L sub  lineto
	closepath
	stroke

	n 1 gt
	{
		/n1 n 1 sub def
		/L2 L 2 div def

		x        y c2L add  L2  n1  gasket
		x L sub  y c1L sub  L2  n1  gasket
		x L add  y c1L sub  L2  n1  gasket
	} if

	end
} def

% a sc -
% scale by a in both x and y; adjust line width so it is effectively not scaled
/sc { dup dup scale currentlinewidth exch div setlinewidth } def

1 setlinejoin
1 setlinecap

72 sc
.2 setlinewidth
4.25 4 translate
1.9 sc

% recursion depth
% adding 1 slows things down by a factor of 2.75 or 3 or so
/n 10 def

currentlinewidth 2 n exp div setlinewidth

0 0 1 n gasket

showpage
 
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