B What does a line in space look like?

[Kiki]

If a line in space has no thickness, how can I distinguish the line from its surroundings when I look at the line such that I can't see its length? After all, in three dimensional space, you can look at a line from different angles.

 

[jedishrfu]

A geometric line is a one dimensional mathematical object. It's an abstract idea. It's not a physical object that you might see, touch or run into. The same goes for a point or a plane.

https://en.m.wikipedia.org/wiki/Line_(geometry)

 

[Kiki]

A geometric line is a one dimensional mathematical object. It's an abstract idea. It's not a physical object that you might see, touch or run into. The same goes for a point or a plane.

https://en.m.wikipedia.org/wiki/Line_(geometry)

Thanks.

Then why do we describe physical objects with coordinates (i.e. points)?

 

[Drakkith]

Thanks.

Then why do we describe physical objects with coordinates (i.e. points)?

Basically because it is an extremely good way of describing objects and the positions of objects that let's us make useful, accurate predictions.

 

[Delta2]

The fact that you can't distinguish the line when looking at some specific angle (this happens in computer graphics, some objects become invisible when the view camera is at some angles/distances) , doesn't tell us much about how useful lines or points are for describing physical objects. In other words, so what if you can't distinguish the line, it is still useful for the reason @Drakkith says.

 

[fresh_42]

A geometric line is a one dimensional mathematical object. It's an abstract idea. It's not a physical object that you might see, touch or run into.

For heaven's sake, don't tell the string theorists.