Re: What would the end velocity be if...?

In rec.arts.sf.science finite guy <adamlewis@[EMAIL PROTECTED]
> wrote:
> On Feb 22, 9:26?am, Erik Max Francis <m...@[EMAIL PROTECTED]
> wrote:
>> finite guy wrote:
>> > Where is the 'boundary' between Newton and Einstein?
>> > What percentage of light 'speed'?
>>
>> It depends on what accuracy level you're going for. ?A good rule of
>> thumb is that 10% c is the point at which relativistic effects start to
>> creep into the third significant figure.
> 
> There are too many 'rules of thumb' used for such precise
> calculations...
> Shall we 'square' the thumb also? Or mutilple it by a finger?

If you don't like rules of thumb then *you* need to be more precise. 
Decide how accurate you want to be. This will then tell you where the 
boundary lies.

For example, if I'm only interested in being within 10% of the true 
answer, then I can use pure Newtonian dynamics up to, I believe, 80% or so

of light speed. But if I'm building a GPS system and need ten or so 
decimal places of accuracy, I need to start thinking about relativity even

though my satellites are only doing a few miles per second.

-- 
Michael Ash
Rogue Amoeba Software