From: bavafa@netcom.com (Hooshyar Naraghi)
Subject: Re: Physics-1A Question
Organization: physics
Distribution: world 
Date: Fri, 2 Oct 1992 07:49:29 GMT

In article <BvFp4C.5A1@news.udel.edu> keivan@brahms.udel.edu (Keivan Esfarjani) writes:
>In article <1992Oct1.001904.1354@netcom.com> bavafa@netcom.com (Hooshyar Naraghi) writes:
>>In article <BvDtuo.LqM@news.udel.edu> keivan@brahms.udel.edu (Keivan 
>>Esfarjani) writes:
>>
>Hi HooshAyr khAn!

Hi ostAd Keivan,

>>elaborate a little further:  we cannot define temperature without the
>>presence of matter perhaps because it is a property of the matter.  Now,
>>can we say matter exists because it has temperature?  In other words for
>>matter to exist, does it require to possess a property, among many other
>>properties, such as temperature?
>
>No, all these concepts of temperature electric and magnetic field
>etc... are there because matter was there. Physicists made or DEFINED
>those concepts in order to CHARACTERIZE matter. This is the language 
>physicists use to communicate, make theories, predict and measure.

'kheyli khoob!'  So it seems matter was just there.  Simply because we
defined bunch of properties to characterize it or its behaviour does not
prove the existence of matter.  Am I right in this statement?

>>Or, is it the other way, that is matter exists as it is and it just happens 
>>that we humans have learned - through experiments - that it has certain
>>properties.  In this case, we cannot construct the phrase 'look, I am
>>telling you matter exists and the reason is it has properties that _I_
>>can detect and even measure.'
>
>You are right, we can't!

Another OK from me is in order.

>As I said, temperature is defined for a
>MATERIAL system. For example, for a system of fixed total energy E
>and fixed number of particles N, the temperature of the system is
>defined so to satisfy :
>1/T = (partial S)/(partial E)
>where S(E,N) is the entropy of the system of N particles of total
>energy E. This is kind of abstract and defined for a microscopic
>system, but you can later SHOW (or prove) that this quantity T is
>the same as our tangible intuitive temperature : when it's 100 C 
>water boils. Let me emphasize on the fact that heat, energy and
>temperature are 3 different things. Heat and energy and k*T have all
>the same units of Joules, but they represent 3 different quantities.
>(in the above k=1.3*10^-23 J/K is the Boltzman constant)

I always guessed all those pages that I skipped meant something. :-)  Thanks
for the explanation, Keivan.

>>>A real challenge now for everybody:
>>>The other day my friend was telling me that his professor had told him
>>>that warm water freezes faster than cold water!!!!
>>
>>By faster shall we assume he meant less time?
>>
>>I only remember from Thermo in college that warm water would take more
>>heat to solidify, right?  But, I have no idea of the time dependency of
>>either experiments.  Could this have to do with the rate of heat supplied to
>>the process, or power as dQ/dt?
>>                         |
>>                         |------> I know, it's delta but I have none!
>>
>Well, the rate depends on the heat conductivity of water, and indeed
>you are right, the above is the way to proceed ie:calculate the dQ/dt
>for warm and cold water. However I don't know how the heat coductivity
>changes with the temperature, I would assume it's almost the same for both.

Not bad, I was almost right in one thing!

>So, are you going to make your final statement?
>We are waiting!

Do I really have to?  I have no position or statement at this time!  But if
any, I would say the statement is 'the human's ability to measure certain
properties of the matter cannot necesarrily be taken as the _proof_ that
matter exists.'  What do you say?

Let me conclude by asking 'how do we KNOW for sure that matter exists?'

>Regards,
>K1

Same regards,
Hooshyar F. Naraghi
bavafa@netcom.com
(415) 322-8056