How could you practicly use this statement?

um…maybe if you were talking to a blind person that had no concept of a circle… but then they would probably not have a concept of a line either perhaps…hmmmm

Personally, i couldn`t find any use instead of teoretical

From wikipedia: In classical geometry, a radius (plural: radii) of a circle or sphere is any line segment from its center to its perimeter.

The concept of a radius doesn’t pertain to a line. What you’re saying is nonsense.

It’s not nonsense at all. If you accept the existence of the concept of “infinity”, then it’s perfectly logical.

Like most imaginary mathemematical constructs, however, it has no practical purpose.

When I go straight to east without changing direction, I end up on same place where i started

Thing is we can only get closer and closer to infinity, but we can`t reach it in physical reality. Still we can get pretty far.

@MrItty
I accept the existence of the concept of infinity. Nope. Still not logical.

You could explain your reasoning instead of just making an assertion.

chamelion, you’re not going straight, and you are changing direction. That’s kinda the point of the world being round.

You’re speaking nonsense. A circle with radius infinity is not a line. A line is a one-dimensional figure that extends in two directions infinitely. A circle is a collection of points equidistant from another point. The radius is the distance from the midpoint to any point on the outside of the circle. Therefore if the radius grows to infinity, so does the collection of points. Therefore a circle with radius infinity is just a really big circle.

And you could explain your lack of understanding rather than just asserting the OP is spouting “nonsense”.

As circles get larger and larger, their radii get longer. That much, I hope, is obvious. Also, as circles get larger and larger, an equivalent distance on the circle is comparatively “flatter”, which is to say that its arc has a smaller degree.

If it was possible to have a circle of infinite radius, which of course, it’s not, that circle would be “flat” – 0° arcs – at all points.

@MrItty
No it wouldn’t. It would approach 0° but never actually get there. ( .000000000001 ≠ 0 )

yeah, that’s exactly correct. Just like you’ll never get to infinity.

If all you people who obviously haven’t taken a college math class before would do a tiny bit of research before responding, you’d look a loot less foolish.

Please, save yourself some embarassment and Google It

If I knew the answer i wouldn`t ask. My point is to hit the limit of distance people could travel as far as possible

Hahahah. From Vinifera’s own resource, Wikipedia:

http://en.wikipedia.org/wiki/Circle
“Thus, if A, B, and C are given distinct points in the plane, then the locus of points P satisfying (1) is called a generalized circle. It may either be a true circle or a line. In this sense a line is generalized circle of infinite radius.”

@MrItty I’m not sure what makes you more qualified than us on this subject, but your high horse is not necessary.

A circle is definitely not a line, despite the fact that it may appear to be one in the infinite case. I know it’s an accepted math fact, but it’s a silly fact that carries no meaning. There is no practical use for this knowledge.

Perchik, the fact that A) I majored in Math in college, and B) I gave the user a correct answer instead of i) giving him an incorrect answer, and ii) insulting him.

All of that combined makes me more qualified than you on this topic. My high horse was in direct response to your high – and wrong – horse.

@MrItty
I have taken a college math class before. You can turn off the pretentious drivel.

A line is a single point extending in one dimension for a set distance. If that distance is infinite, it’s a vector, not a line.

On the contrary, a circle is distinctly in two dimensions.

Sorry for being so ingorant.

Meh whatever I’m done here.

Vinifera, just stop talking. Seriously. Everything you say is making it worse.

A line is not a single point that “extends”. That’s a contradiciton. A line is a series of points that extends infinitely in both directions. A vector, on the other hand, is a series of points that extends infinitely in only one direction, and has an end-point on the other. A line segment is a series of points that has an end point on both ends.

There’s nothing wrong with being ignorant. There is something very wrong with being ignorant, pretending you’re not, and insulting someone who asks a question to remove their own ignorance. You and Perchick both owe the OP an apology.

Sorry for thinking that we were allowed to have a discussion here.

“The concept of a radius doesn’t pertain to a line. What you’re saying is nonsense.”

That’s fostering discussion? Really? Explain to me how, please? For my own benefit.

I was thinking a bit, and it looks like i am trying to find use for sth what cannot be used, but i can get close to it. So it could be just kind of motivational use to increase circle of knowledge we like so much

Wow, there’s a lot of my dick is bigger than yours in this thread.
Play nice, nerdy boys. :)

Its not nonsense. Its is true.

More like my math degree, but yeah… :-P

A line can have a set position in space. If a circle has an infinite radius, then we can define one point on the circle, but we cannot define any other point (at least one reason for which is that if we were to use radians to define a point, we would be doing so in fractions of infinity). Therefore, the line in this case would be one drawn between a point and…an undefined point an infinite distance away? So while the idea seems intuitively correct, it seems dicey to define it as true at the extreme of r=infinity. It seems like all we can say is that the second derivative of the curve (its curvature) approaches 0 as r approaches infinity. But really, all I’ve proven is that infinity confuses the hell out of me.