Why is it impossible to draw a perfect circle even with a laser, why is it an idea?

Answer 1

The perfect circle is only a mathematical construct. It can never be achieved with a mechanical device no matter how small, or how curvered it is.

Answer 2

The reason that there is no such thing as a perfect circle is this:
1) Pi is a non-repeating, non-terminating number so you have to round it no matter what. Where you round it will determine how accurate the ratio between the circumference and the diameter is. That is part of the definition of a circle.

2) Even if you drew one by accident you wouldn't be able to measure it accurately enough to know for certain that you had one, for the same reason.

There is always a measure of uncertainty with circles. It is a function of the nature of the circle and what number you use for Pi.

Answer 3

It all is about relative tolerances.

A laser can draw a perfect circle within a incredibly tight tolerance of .0001 of an inch or more, However if it cant draw a perfect circle then it can draw any other shape either.

Answer 4

Imagine a point. Not a pencil dot, a mathematical point.

Now imagine that you want to get a closer view of the point. You zoom in, but all you see still is a point. You zoom in more, but all you see is a point. You can repeat this process forever, but you never will see it as anything more than a point.
The same is true of a line, or the edge of a plane.

So, when anything--anything--constructs a circle, it has a "width" to it that causes it to be imperfect.

Answer 5

Think about what is actually required to be perfectly accurate. Even the laser beam, at the level of the atom, would not make a straight line, rather, it would appear to be wiggly and smeared.

Answer 6

Widen the beam and dont move the laser.