Switch off at the socket?

[email protected] wrote:


"The Natural Philosopher" wrote in message
...
[email protected] wrote:


"Max Demian" wrote in message
...
"Owain" wrote in message
...

On 16 Sep, 23:42, "Max Demian" wrote:
Energy is neither created nor destroyed
Only according to classical physics.
Except in nuclear power stations and in stars.
And springs and batteries and everything else that stores energy.
(Not that
you can measure the differences in mass.)

Surely if you're storing energy you're not creating or destroying it?

Maybe, but it violates the conservation of mass.

You can store energy without converting it to mass.
Chemical (batteries), and mechanical (springs) methods store energy
without converting it to mass.


Oh, but they DO.

Its a very very very small change though. We calculated the difference
in weight between a discharged and charged lithium batery. Much less
than a microgram IIRC.


Just because you can calculate a mass change using e=mc2 doesn't mean
there is a mass change.
You should be able to measure a change that big BTW.


what.. less than a few parts per billion?

[email protected] wrote:


"The Natural Philosopher" wrote in message
...


A chemical compound does not weigh QUITE the same as its elements
taken separately.

A physicist doesn't confuse mass with weight BTW.

You can see the effect described and IIRC tested in terms of light
pressure on a sail ..photons - things with no rest mass at all, are
emitted by even chemical reactions, and can exert momentum changes on
things.

Light pressure has nowt to do with the mass of photons.
The little paddles driven around when you shine a light on them are not
driven by the momentum of photons at all as anyone with an O'level in
physics should be able to tell you.



I wasn't talking about those devices.

The Natural Philosopher wrote:
[email protected] wrote:


"The Natural Philosopher" wrote in message
...


A chemical compound does not weigh QUITE the same as its elements
taken separately.

A physicist doesn't confuse mass with weight BTW.

You can see the effect described and IIRC tested in terms of light
pressure on a sail ..photons - things with no rest mass at all, are
emitted by even chemical reactions, and can exert momentum changes
on things.

Light pressure has nowt to do with the mass of photons.
The little paddles driven around when you shine a light on them are
not driven by the momentum of photons at all as anyone with an
O'level in physics should be able to tell you.



I wasn't talking about those devices.

No, the question is whether you know what you're talking about at all.

On Sep 18, 8:38*am, "Jerry"
wrote:
"Kennedy McEwen" wrote in message

...
: In article , Bill
Wright
: writes
:
: Of course my grandparents' generation used the word for the
room (or shed)
: with the lavatory in it.
:
: Derr, isn't that the origin of "coming out of the closet", as
in
: "cottaging"?

Err, no, I think you are thinking of "Skeletons (secrets) in the
closet".

AIUI the Homosexuals "came out (into the open)", after the many
years of having to hide their sexual orientation from the law and
society (even post '67 to one degree or other, many still have to
'hide').

Few homosexuals would not want to admit to "cottaging", even
today, as it's still an illegal act...

Martyrs to their cause.

MBQ

On Fri, 18 Sep 2009 10:53:01 +0100, Norman Wells wrote:

You require absolutely extreme conditions for it to happen.

No you do not.

On earth, you will only find it happening in nuclear reactions.

Not true. Just you repeating it ad nauseam does not make it so.

You have been given examples of how it happens outside of nuclear
reactions, and even a link to a government sponsored science site
where it states categorically that a car with increasing velocity,
and thus increasing kinetic energy, increases in mass.

As you continue to make unsubstantiated claims without entering into
reasoned debate, you are appearing more and more like the Alf Garnett
of physics.

On Fri, 18 Sep 2009 10:49:45 +0100, brightside S9 wrote:

Where do you get all this crap from? It sounds to me your physics teacher
(if you ever had one) was a chemist or a biologiost.

That is a unwarranted slur against chemists and biologists.

Norman Wells wrote:
The Natural Philosopher wrote:
[email protected] wrote:


"The Natural Philosopher" wrote in message
...


A chemical compound does not weigh QUITE the same as its elements
taken separately.

A physicist doesn't confuse mass with weight BTW.

You can see the effect described and IIRC tested in terms of light
pressure on a sail ..photons - things with no rest mass at all, are
emitted by even chemical reactions, and can exert momentum changes
on things.

Light pressure has nowt to do with the mass of photons.
The little paddles driven around when you shine a light on them are
not driven by the momentum of photons at all as anyone with an
O'level in physics should be able to tell you.



I wasn't talking about those devices.

No, the question is whether you know what you're talking about at all.
The answer is, I do, and you don't.

J G Miller wrote:
On Fri, 18 Sep 2009 10:49:45 +0100, brightside S9 wrote:

Where do you get all this crap from? It sounds to me your physics teacher
(if you ever had one) was a chemist or a biologiost.

That is a unwarranted slur against chemists and biologists.

Its perfectly obvious whoever 'taught' him, and I use the word
advisedly, thought that Newtonian equations were exact, and relativity
ONLY applied to other stuff like nuclear reactions.

This does not surprise me at all. The standard of science education is
and has been falling for some time, and very few people even now really
understand Newtonian mechanics, let alone relativistic.

There are people out there with science and mathematics qualifications
who don't even understand what a vector is.

Viz a rough precis of a conversation on the net last month

'how much kinetic energy does a car travelling at 70mph have'
'kinetic energy with respect to what? Kineti9c energy is a function of
the vectors sums of *oow* velocities..'
'energy is a scalar, so it doesn't matter'


sigh.

"Mark" wrote in message
...
On the Wiki page you mentioned:
http://en.wikipedia.org/wiki/Power_factor
Note the section headed:
-Importance of power factor in distribution systems-

I often wondered if a domestic user could reduce the power factor of
the supply and hence reduce the bill.


Well I'm wondering if I should have been worrying about that too.
(I assume you mean '...the power factor of his load...' )

What about the inductive loads like the washing machine motor and 'wallwart
transformers'?
Should I be investing in power factor correction?

I don't recall any of those 'energy efficiency labels' on washing machines
quoting a power factor value!

Roger R

On Fri, 18 Sep 2009 12:21:42 +0100, The Natural Philosopher wrote:

'how much kinetic energy does a car travelling at 70mph have' 'kinetic
energy with respect to what? Kineti9c energy is a function of the
vectors sums of *oow* velocities..' 'energy is a scalar, so it doesn't
matter'

And no doubt forgetting that if you know exactly how much energy the car
has, you will not be able to determine exactly where the car is located