Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] Inertia frame of reference



Absolutely no claim of being the BEST definition - but an oldie and goodie is one that is at rest (or moving at constant velocity) wrt the 'fixed' stars.
Of course we know that there ARE no 'fixed' stars - but hey - it gives a starting point to argue from.

Denker's 'unrestrained' free-fall frame is the modern choice of General Relativists.
You might not want to say that this would be a frame that is 'accelerated' by the force of gravity - since general relativity sez that there IS no 'force of gravity'.

You may not be quite ready to teach intro physics from a General Relativity POV. At least I HOPE you're not ;-)

Use what works for you - and the smart kids will figure it out without suffering from too much lasting damage.

On Jul 28, 2009, at Jul 28(Tue) 9:11 , carmelo@pacific.net.sg wrote:

Hi everyone,

Does anyone know which is the best definition on inertia frame of reference?

Ohanian defines "inertial reference frame" as a frame in which Newton’s
laws of motion are valid to a first approximation.
Ludwig Lange argued that any three material points simultaneously
projected from a single point, and moving freely in noncoplanar
directions, constitute an inertial system.
In John Denker's website, he suggests "a freely-falling frame". (It
seems to suggest accelerated frame of reference.)