BRAINY QUESTION

[SUBHAJITRAHUL]

SUPPOSE WE DRAW A LINE ON EARTH SURFACE,IT IS CALLED STRAIGHT LINE,,BUT MY QUESTION IS EARTH IS ROUND SO WHEN WE DRAW THE STRAIGHT LINE ,IS THAT LINE CALLED STRAIGHT OR CURVED?
IF CURVED THEN WE HAVE NO CONCEPT OF STRAIGHT LINE,WHY?
AND THE MAIN FACT IS THE NEWTON'S FIRST LAW IS WRONG...??????

[vascop]

Agreed. I like your avatar!

[birdie1971]

SUBHAJITRAHUL - “... My question is earth is round so when we draw the straight line ,is that line called straight or curved? If curved then we have no concept of straight line...”

A line drawn on the earth's curved surface can be said to be straight on plan but curved on cross section. The idea that because the earth is round (or rather, an oblate spheroid) we cannot have a concept of a straight line is simply not true. It certainly in no way invalidates Newton's First Law.

It's all about tangents. Have a look here:
http://en.wikipedia.org/wiki/Tangent

[vascop]

Einstein didn't disprove Newton's law, he just generalised it. All calculations which involve everyday speed values are done with Newton's laws.

[jomifl]

sub.. If you draw a line around a sphere you get a circle. Any part of a circle is a curve, therefore even if the earth's surface was perfectly smooth you couldn't draw a straight line on it. The rest of your question is therefore invalid.

[atalanta]

The shortest distance between two points on the earth's surface is called the Great Circle. This can look really odd, especially when you realise that the shortest route from Los Angeles to Gatwick goes across the Arctic, almost over the North Pole

[SUBHAJITRAHUL]

we have no concept of straightline,,,,think about this then write something,,,,

[TheOtherHalf]

So when my mum sez stand up straight!! I can say " But I am standing up straight "

[vascop]

@sbhajit
//we have no concept of straight line, think about this then write something//
What is your definition of a straight line? You can't say we have no concept of what it is if you haven't defined it. If you can't define it, then this whole conversation is meaningless.

[jomifl]

We must have a concept of a straight line otherwise we wouldn't be discussing it.

[birdie1971]

SUBHAJITRAHUL - “... we have no concept of straightline,,,,think about this then write something...”

You are rather stupidly avoiding responding to other people's posts and simply choosing to believe that your initial question still stands and is valid.

It isn't valid. Accept and acknowledge that you are wrong and move on.

[SUBHAJITRAHUL]

@birdie what is ur concept about straight line?