8.01x - Module 21.05 - Right Handed Coordinate System

[@bitskit3476]

Here's something that no one ***ever*** seems to explain about this: whether or not a coordinate system is left or right handed has ***nothing*** to do with which axis is pointed up. Make the tripod with your right hand. ***IF*** the x axis is your thumb, your index finger will be y, and your middle finger will be z. ***IF*** the y axis is your thumb, your index finger will be z, and your middle finger will by x. ***IF*** the z axis is your thumb, your index finger will be x, and you middle finger will be y. What is confusing the absolute hell out of you is that mathematicians keep drawing the Z axis as the up axis with x coming out of the screen, and if you set your thumb as x, you physically can't "map" the shape of your hand to what you're seeing without breaking your wrist. So instead, in this particular situation, point your middle finger at yourself and let your thumb be the y axis. Your index finger will be z. Your middle finger will be x.

[@engineerweeky9533]

This is the kind of after hours teaching I need. I always get excited when I see well thought out explanations of concepts from physics on KZbin.

[@lecturesbywalterlewin.they9259]

:)

[@respuestasbiblicas7634]

I love this guy fr

[@raulmg1264]

X x Y= -Z , But if I use the right hand, is the result correct?

[@lecturesbywalterlewin.they9259]

it should be +Z

[@raulmg1264]

For example: X= i, Z=j and Y=k. ixj= k ; jxi=-k jxk= i ; kxj= -i kxi=j ; ixk= -j then we have to: ixk = -j or X x Y = -Z and give a negative and not positive value X x Y = Z Is my interpretation correct?

[@lecturesbywalterlewin.they9259]

this is my last msg. *X cross Y = + Z*

[@PraveenKumar-qr8wx]

Walter Lewin how?

[@coasterstar090]

Use the corkscrew rule and it’s easy to find that x cross y indeed equals positive z, as the professor has stated.

[@peterhoebarth4234]

where is gravity ? This in Video is 3 DoF. Earth is a Sphere ?

[@Bushra-qk1mw]

That was unhelpful

[@bhanukumar5276]

Thanku sir

[@johnrebeiro1066]

Thankyou

[@AliRaza-dl5hh]

GD