Switch off at the socket?
 

"Bill R" wrote in message
...
I cannot get my head around the concept of power factor and, as there
seems to be no answer for the large discrepancy in the reading between the
two meters the whole thing seems to be a bit of a fudge. Anyway, assuming
all this to be true how does my consumer meter know how much electricity
is being effectively used.

I can't explain the readings on the devices you mentioned. They sound like
nonsense to me.

You probably read this WIKI page on meters:
http://en.wikipedia.org/wiki/Electricity_meter
-"The induction type meter has separate coils for voltage and current"-
So does that mean the readings are different when the voltage and current
are out of phase?
The meter is varying the reading according to the users power factor?

On the WIKI Power Factor page it says:
-"The significance of power factor lies in the fact that utility companies
supply customers with volt-amperes, but bill them for watts.-"

So now I'm confused!

But ok, here's my recollection of college explanation of Power factor:

With AC the voltage and current are normally in phase, that is, as the
voltage rises the current rises at the same time.
If you drew a graph of voltage and current the two sinewaves would be
superimposed on each other. However this is only the case for a purely
resistive load. For inductive or capacitive loads the voltage and current
are pulled out of phase. The degree to which they are pulled out of phase
is the power factor and is measured as a number between 0 and 1.

Inductive loads such as motors:
When the voltage and current of each cycle starts to rise the inductance of
the windings opposes the change and generates a back emf that impedes the
current flow. The current cannot flow until the voltage has overcome the
back emf. The current is said to lag the voltage, or put the other way
around, the voltage leads the current.

Capacitive loads:
As the voltage and current of each cycle begins to rise the current rushes
in but the voltage cannot not rise immediately because the current has first
to fill or charge the capacitor. The current is said to lead the voltage.

Don't suppose that helps much.

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 recall being told that if industrial loads were all electric motors the
power company would need to have four power stations instead of the one they
would need if the loads were only resistive. For this reason power
companies charged more for users with low power factors. Industrial users
with lots of motors had capacitor rooms to try to correct for the inductance
of the motors and bring the PF closer to 1 and thereby to reduce their bill.

Bringing this back to the previous post, if the concept of power factor
really does effectively reduce the actual amount of power used why are we
being urged to replace tungsten bulbs in favour of the new bulbs. The
difference in wattage may be far greater overstated than the actual
difference.

As the old tungston light bulbs are more or less purely resistive so have a
PF of 1 any other type of bulb is going to be worse. I thought I heard the
new type light bulbs are slightly capacitive?

Really I think you have had the 'bamboozle them with tech speak' treatment.

Roger R

Switch off at the socket?
 

Norman Wells coughed up some electrons that declared:


Then you have completely misuderstood relativity.

I'm still waiting for you to refute the Wikipedia article I cited...

Switch off at the socket?
 

"Kennedy McEwen" wrote in message
...


However, any small country could, with the right technology, investment
and political will (which is the most likely barrier in the UK), punch
well above its weight with carbon capture. Indeed, with the appropriate
carbon trading agreements in place, it could be as profitable a business
as any currently vomiting CO2 across the planet.

However it would be far more sensible to do it in a country that had vast
amounts of "free" solar energy, like in the Sahara, the CO2 could be stored
in the oilfields where the oil has come from.
Or maybe it could be used to grow algae and then be dumped in an oceanic
trench to make some coal/oil for use in a few million years.

Switch off at the socket?
 

"Kennedy McEwen" wrote in message
...
In article , Norman Wells
writes

Atmospheric extraction is totally unfeasible. Have you _any_ idea how big
the atmosphere is, and how small in comparison any man-made extractor
would be?

Yes, at surface density, it is equivalent to a uniform layer a little less
than 5 miles thick over the surface of the globe, some 200million square
miles, making the atmosphere approximately 1billion cubic miles at surface
density.

How many would we need do you think?

That depends on how fast you think we need to do it. The argument,
whether you believe it or not, is that we have managed to cause the
problem simply by a few hundred large CO2 producers over a couple of
hundred years. So a similar number of capture units should be capable of
sweeping it all up in a similar time, probably faster.

At a few hundred feet per minute a single atmospheric extraction unit with
a scrubber area of only 1 square mile, would take around 20,000 to remove
all CO2 from the atmosphere, so a distributed system of 50 such systems
around the planet would clear the problem in less time that it took to
create it in the first place - and we don't WANT to get rid of all of the
CO2 or we'd be in for a very cold future.

Wouldn't it be good for the equatorial countries?
They could extract lots of CO2 and cool down to a nice climate and leave us
to freeze.

And wouldn't it be better to use trees as we always have?

No, because trees rely on natural air movement to access the atmosphere,
not forced air movement. And they tend to decay or be burned, releasing
their captured CO2 in the timescale.

Not if you dump them in an ocean trench.

Switch off at the socket?
 

"Norman Wells" wrote in message
...


How much energy do you think that will involve? How will these
'scrubbers' work exactly, and how will they be powered? To extract
anything that constitutes just 0.04% of the atmosphere by passing it _all_
through scrubbers, at speeds sufficient to suck in all the atmosphere of
the planet rather than wait for it to come to you, seems enormously
wasteful.


It is, but unlike other green technologies it might extract significantly
more carbon than it uses.
It is nowhere near as wasteful as wind turbines, solar PV, etc.

Switch off at the socket?
 

Yes, we should all pay full attention to a fictional work whose main
premise is that a nuclear meltdown in the USA would burrow its way through
the earth all the way to China, shouldn't we?

You daft pillock! That wasn't the main theme at all! The "China Syndrome"
was a casual term used in the US nuclear industry at that time to refer to a
meltdown, and the film makers just used it in the title because it sounds
catchy.

Have you seen the film? It raised some VERY important issues about how the
drive for private profit can compromise safety. That's all.

SteveT

Switch off at the socket?
 

"Zero Tolerance" wrote in message
...

"It's not worth taking any action, ever, because China cancels it all
out, always" is, if you will forgive me saying so, not the freshest of
arguments.

Indeed not, but it is an important and valid argument. The UK acting alone,
without China, America, India and Russia, will make no difference to global
warming, but will damage itself economically.

Only if ALL the big players join in can we make a difference. That is where
we must put our efforts.

That is a simple, incontrovertible fact, and to ignore it leads to bad
policy decisions.

SteveT

Switch off at the socket?
 

"Norman Wells" wrote in message
...

sigh

Education today.

Norman, you are making yourself look a prat. You need to do a little
reading about mass-energy equivalence. Then you will understand.

Do you accept that an object increases in mass as it approaches light speed?
If so, everything else follows.

SteveT

Switch off at the socket?
 

"Norman Wells" wrote in message
...
: Steve Terry wrote:
: "J G Miller" wrote in message
: ...
:
: The important thing is the French have run their Nuclear
power
: industry on military lines, if something needs fixing it's
done.
:
: The EU now want it privatised, which is worrying as Three
mile island
: was run that way.
:
: Remember the theme of the movie the China Syndrome was it
costs
: money to do things properly, so under a privatised regime
it's
: tempting to cut corners.
:
: Yes, we should all pay full attention to a fictional work whose
main premise
: is that a nuclear meltdown in the USA would burrow its way
through the earth
: all the way to China, shouldn't we? Particularly since any
knowledge at all
: of gravity renders that impossible, and any knowledge of
geography means it
: should have been called The Indian Ocean Syndrome.
:

OTOH we SHOULD all take notice of the core (no pun intended)
issues that caused the two worst nuclear accidents thus far,
cutting costs...
--
Regards, Jerry.

Switch off at the socket?
 

Jerry wrote:
"Norman Wells" wrote in message
...
Steve Terry wrote:
"J G Miller" wrote in message
...

The important thing is the French have run their Nuclear power
industry on military lines, if something needs fixing it's done.

The EU now want it privatised, which is worrying as Three mile
island was run that way.

Remember the theme of the movie the China Syndrome was it costs
money to do things properly, so under a privatised regime it's
tempting to cut corners.

Yes, we should all pay full attention to a fictional work whose main
premise is that a nuclear meltdown in the USA would burrow its way
through the earth all the way to China, shouldn't we? Particularly
since any knowledge at all of gravity renders that impossible, and
any knowledge of geography means it should have been called The
Indian Ocean Syndrome.


OTOH we SHOULD all take notice of the core (no pun intended)
issues that caused the two worst nuclear accidents thus far,
cutting costs...

Everything we do is subject to cost constraints. What matters is
cost-effectiveness and cost-benefit.

There has never been an industry yet without accidents.

Switch off at the socket?
 

"Ron Lowe" wrote in message
...

isn't it 2.7 absolute or summat?


Better pack a fleece, then.

And a head-torch, it might be dark.

No point, there won't be any usable energy left to make heat for the fleece
to keep in or operate the torch.

Switch off at the socket?
 

Sofa - Spud wrote:
alexander.keys1 wrote:
There have been a lot of comments recently about the waste of energy
due to appliances being left on standby, and various gizmo's that are
on offer to turn them off automatically, or otherwise purporting to
save energy. What everybody seems to be forgetting is that an energy-
saving device comes with most UK socket outlets, it's called a
'switch', and when put into the 'off' position, power cosumption is
zero! None of my appliances, including computers, digital TV
receivers, etc. have come to harm through this practice, I always
switch off at the wall, back in the day when there were fewer
appliances this was standard procedure to avoid fire risk.

From years of having old TV that buzz and smell we always switch off at
the plug when we go to bed, same for the PC, various chargers etc as
well. It's a habit from years ago and the old fire safety films.
Shutting the doors to the lounge , hall etc as well.

Milton Jones: "At the end of the day, my dad goes round switching everything
off and pulling out all the plugs. Very safety conscious. Quite why he got
the sack from air traffic control...".

Switch off at the socket?
 

Steve Thackery wrote:
Yes, we should all pay full attention to a fictional work whose main
premise is that a nuclear meltdown in the USA would burrow its way
through the earth all the way to China, shouldn't we?

You daft pillock! That wasn't the main theme at all! The "China
Syndrome" was a casual term used in the US nuclear industry at that
time to refer to a meltdown

Got any proof of that?

, and the film makers just used it in the
title because it sounds catchy.

Alarmist more like.

Have you seen the film? It raised some VERY important issues about
how the drive for private profit can compromise safety. That's all.

It certainly illustrates how the producers' drive for profit can make the
title of a film blatantly compromise the truth.

As regards the plot, though, it's fiction.

Switch off at the socket?
 

On Fri, 18 Sep 2009 09:57:17 +0100, "Roger R"
wrote:


"Bill R" wrote in message
...
I cannot get my head around the concept of power factor and, as there
seems to be no answer for the large discrepancy in the reading between the
two meters the whole thing seems to be a bit of a fudge. Anyway, assuming
all this to be true how does my consumer meter know how much electricity
is being effectively used.

I can't explain the readings on the devices you mentioned. They sound like
nonsense to me.

You probably read this WIKI page on meters:
http://en.wikipedia.org/wiki/Electricity_meter
-"The induction type meter has separate coils for voltage and current"-
So does that mean the readings are different when the voltage and current
are out of phase?
The meter is varying the reading according to the users power factor?

On the WIKI Power Factor page it says:
-"The significance of power factor lies in the fact that utility companies
supply customers with volt-amperes, but bill them for watts.-"

So now I'm confused!

But ok, here's my recollection of college explanation of Power factor:

With AC the voltage and current are normally in phase, that is, as the
voltage rises the current rises at the same time.
If you drew a graph of voltage and current the two sinewaves would be
superimposed on each other. However this is only the case for a purely
resistive load. For inductive or capacitive loads the voltage and current
are pulled out of phase. The degree to which they are pulled out of phase
is the power factor and is measured as a number between 0 and 1.

Inductive loads such as motors:
When the voltage and current of each cycle starts to rise the inductance of
the windings opposes the change and generates a back emf that impedes the
current flow. The current cannot flow until the voltage has overcome the
back emf. The current is said to lag the voltage, or put the other way
around, the voltage leads the current.

Capacitive loads:
As the voltage and current of each cycle begins to rise the current rushes
in but the voltage cannot not rise immediately because the current has first
to fill or charge the capacitor. The current is said to lead the voltage.

Don't suppose that helps much.

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.

I recall being told that if industrial loads were all electric motors the
power company would need to have four power stations instead of the one they
would need if the loads were only resistive. For this reason power
companies charged more for users with low power factors. Industrial users
with lots of motors had capacitor rooms to try to correct for the inductance
of the motors and bring the PF closer to 1 and thereby to reduce their bill.

AFAIK industries are charged for VA not W, so PF does not affect their
bill. IOW they can't save money by reducing their PF.

Bringing this back to the previous post, if the concept of power factor
really does effectively reduce the actual amount of power used why are we
being urged to replace tungsten bulbs in favour of the new bulbs. The
difference in wattage may be far greater overstated than the actual
difference.

As the old tungston light bulbs are more or less purely resistive so have a
PF of 1 any other type of bulb is going to be worse. I thought I heard the
new type light bulbs are slightly capacitive?

Really I think you have had the 'bamboozle them with tech speak' treatment.
--
(\__/) M.
(='.'=) Due to the amount of spam posted via googlegroups and
(")_(") their inaction to the problem. I am blocking most articles
posted from there. If you wish your postings to be seen by
everyone you will need use a different method of posting.
[Reply-to address valid until it is spammed.]

Switch off at the socket?
 

"Tim S" wrote in message
...

Do you have a degree in physics then?

I have one from imperial college.


Have a look at this:

http://en.wikipedia.org/wiki/Mass%E2...gy_equivalence

Specifically:

"In relativity, removing energy is removing mass, and the formula m = E/c2
tells you how much mass is lost when energy is removed. In a chemical or
nuclear reaction, the mass of the atoms that come out is less than the
mass
of the atoms that go in, and the difference in mass shows up as heat and
light with the same relativistic mass.

It may well be true of a nuclear reaction, however you haven't posted
anything convincing about chemical reactions or explained where the energy
is converted to mass when you lift a weight up and increase its potential
energy, or even wind a clock spring up. It does not require an increase in
mass to store energy.

In this case, the E in the formula
is the energy released and removed, and the mass m is how much the mass
goes down. In the same way, when any kind of energy is added, the increase
in the mass is equal to the added energy divided by c2. For example, when
water is heated in a microwave oven, the oven adds about 1.11×10?17 kg of
mass for every joule of heat added to the water."

However a nuclear reaction creates energy from mass it doesn't just store
energy like a rechargeable battery or the dinorwig hydro plant.

If you feel that's wrong, you should probably go and correct it...

It would take a life time to correct Wiki and then someone comes along and
cocks it up again.

Switch off at the socket?
 

Steve Thackery wrote:
"Norman Wells" wrote in message
...

sigh

Education today.

Norman, you are making yourself look a prat. You need to do a little
reading about mass-energy equivalence. Then you will understand.

Energy and mass are _not_ freely interconvertible. You require absolutely
extreme conditions for it to happen. On earth, you will only find it
happening in nuclear reactions.

Do you accept that an object increases in mass as it approaches light
speed?

Yes.

If so, everything else follows.

No it doesn't.

Switch off at the socket?
 

"The Natural Philosopher" wrote in message
...
dennis@home 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.

Switch off at the socket?
 

"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.

Switch off at the socket?
 

dennis@home coughed up some electrons that declared:



"Tim S" wrote in message
...

Do you have a degree in physics then?

I have one from imperial college.

That's better than me (York) but I did work at Imperial for some years in
the Dept of Computing, so next door to your old bit. When were you there?


Have a look at this:

http://en.wikipedia.org/wiki/Mass%E2...gy_equivalence

Specifically:

"In relativity, removing energy is removing mass, and the formula m =
E/c2 tells you how much mass is lost when energy is removed. In a
chemical or nuclear reaction, the mass of the atoms that come out is less
than the mass
of the atoms that go in, and the difference in mass shows up as heat and
light with the same relativistic mass.

It may well be true of a nuclear reaction, however you haven't posted
anything convincing about chemical reactions or explained where the energy
is converted to mass when you lift a weight up and increase its potential
energy, or even wind a clock spring up. It does not require an increase in
mass to store energy.

My teaching was that the energy/mass equivalence theory was fundamental - it
required no explicit mechanism. It's an effect more than a "requirement".

But it is consistent with the theory that observed mass increases with
relative speed.

In this case, the E in the formula
is the energy released and removed, and the mass m is how much the mass
goes down. In the same way, when any kind of energy is added, the
increase in the mass is equal to the added energy divided by c2. For
example, when water is heated in a microwave oven, the oven adds about
1.11×10?17 kg of mass for every joule of heat added to the water."

However a nuclear reaction creates energy from mass it doesn't just store
energy like a rechargeable battery or the dinorwig hydro plant.

Hypothetically, you *could* use a nuclear reaction to store energy if you
could use energy to reverse a "traditional" exothermic reaction. Small
matter of engineering though... But it would be little different
conceptually from electrolysing water to H2 + O2, then running that back
through a fuel cell.

If you feel that's wrong, you should probably go and correct it...

It would take a life time to correct Wiki and then someone comes along and
cocks it up again.

Seems to work well enough for most Wikis - vandalism is trivially undone.
Don't be shy - have a go.

Switch off at the socket?
 

"The Natural Philosopher" wrote in message
...

E=mC^2. its there., If its wrong, you are right, if its right, you are
wrong.

I would love to see you apply that to quantum mechanics. ;-)

Switch off at the socket?
 

Norman Wells coughed up some electrons that declared:

Steve Thackery wrote:
"Norman Wells" wrote in message
...

sigh

Education today.

Norman, you are making yourself look a prat. You need to do a little
reading about mass-energy equivalence. Then you will understand.

Energy and mass are _not_ freely interconvertible. You require absolutely
extreme conditions for it to happen. On earth, you will only find it
happening in nuclear reactions.

Do you accept that an object increases in mass as it approaches light
speed?

Yes.

Looks like a perfect demonstration of mass/energy equivalence to me. Kinetic
energy, which is itself a relative phenonemum appears to manifest as
increased mass. Where's the problem?


If so, everything else follows.

No it doesn't.

Switch off at the socket?
 

"Enzo Matrix" wrote in message
...
Bill Wright wrote:
"The Natural Philosopher" wrote in message
...
Adrian wrote:
English is the de facto international language.

One thinmg taht did come over

That sounds more like Esperanto!

Mi esporas ke kiam vi venos la vetero estos milda.

"We [at Google Translate] are not yet able to translate from Esperanto into
English."

They recognised the language, though.

--
Max Demian

Switch off at the socket?
 

dennis@home coughed up some electrons that declared:



"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.

Yes, we know that.

But that doesn't negate the fact that photons possess momentum, and thus
mass.

Switch off at the socket?
 

"The Natural Philosopher" wrote in message
...

I suppose what Einstein is really saying is that a things apparent mass
changes depending on the speed of it *relative to the observer*. There is
no such thing as absolute mass, there is only rest mass.. and of course
since a photon ALWAYS travels at the speed of light, it aint a photon if
it stops and gives up its energy to something else..

However the speed of photons does change so they don't always travel at the
"speed of light" as used in e=mc2.

Switch off at the socket?
 

"Tim S" wrote in message
...

Einstein's own book is surpisingly readable. Feynman wrote some pretty
good
stuff too and a really fun book is "Mr Tompkins in Wonderland" which is a
fictional (but scientifically valid) look at how the world would be if the
speed of light were 30mph.

Dark, very dark.
Of course the real question would be, "what is 30 mph?".

Switch off at the socket?
 

"dennis@home" wrote in message
...
"The Natural Philosopher" wrote in message
...
dennis@home wrote:

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.

How big is "much less than a microgram?"

(I seem to have started something here.)

--
Max Demian

Switch off at the socket?
 

dennis@home coughed up some electrons that declared:



"Tim S" wrote in message
...

Einstein's own book is surpisingly readable. Feynman wrote some pretty
good
stuff too and a really fun book is "Mr Tompkins in Wonderland" which is a
fictional (but scientifically valid) look at how the world would be if
the speed of light were 30mph.

Dark, very dark.
Of course the real question would be, "what is 30 mph?".

What?

Switch off at the socket?
 

Max Demian coughed up some electrons that declared:

"dennis@home" wrote in message
...
"The Natural Philosopher" wrote in message
...
dennis@home wrote:

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.

How big is "much less than a microgram?"

(I seem to have started something here.)


I stated 2.88nanograms for a 60Ah lead acid car battery. Be hard to measure
mass to 1 part per billion.

Switch off at the socket?
 

Interesting discussion. Here's some food for thought:

If a sealed container does *not* allow particles to pass its walls but
*does* allow loss of energy via exchange of thermal radiation with its
outer environment, then a chemical reaction within that container could
increase the temperature within that container, and as it returns to its
original temperature it would lose energy and hence mass due to the
relativistic effect of slowing down the vibration (speed) of particles
within that container.

What about a battery? It's a matter of definitions as to what you
consider an ideal battery to be. You *could* argue that an *ideal* battery
is sealed to prevent whole atoms from passing through its walls but is
allowed to exchange energy with its environment via more than one method.

Switch off at the socket?
 

"Steve Terry" wrote in message
...

Whereas the Russian way is, what corners?

Chernobyl had an excellent post meltdown safety system, that worked.
The core melted through the reactor and felt into the offices and storerooms
below where it was spread out so much fission stopped.
I doubt is the PWRs would do that. ;-)

Switch off at the socket?
 

Norman Wells wrote:
The Natural Philosopher wrote:
Norman Wells wrote:

Because relativity says its so. ANY release of energy is accompanied
by a loss of mass.

Its vanishingly small for typical mechanical and chemical energy,
but its there just the same.

If it isn't, relativity is falsified, and there is a huge hue and
cry out for an alternative.

Then you have completely misuderstood relativity. Energy and mass
are interconvertible but only under specific circumstances you will
not find on earth outside nuclear reactions. If release of energy
is accompanied by a reduction in mass then what you've got is
nuclear fission. If you haven't got nuclear fission then you don't
get reduction of mass.

Oh dear me no.

You do. Its just almost unmeasurable, due to the fact that C squared
is a frigging big number.

Outside of nuclear reactions, all you have is energy conservation and
mass conservation, and they are entirely separate. One form of
energy can be converted into another, but not into mass, and mass
can never be converted into energy.


Oh yes it can, it is and it does, BUT the changes are virtually
undetectable.

sigh

Education today.

...seems to have passed you by..

Switch off at the socket?
 

Norman Wells wrote:
Steve Thackery wrote:
"Norman Wells" wrote in message
...

sigh

Education today.

Norman, you are making yourself look a prat. You need to do a little
reading about mass-energy equivalence. Then you will understand.

Energy and mass are _not_ freely interconvertible. You require
absolutely extreme conditions for it to happen. On earth, you will only
find it happening in nuclear reactions.

Do you accept that an object increases in mass as it approaches light
speed?

Yes.

If so, everything else follows.

No it doesn't.
faulty firmware Norman. Get your brain upgraded.

Switch off at the socket?
 

Dave Farrance wrote:
Interesting discussion. Here's some food for thought:

If a sealed container does *not* allow particles to pass its walls but
*does* allow loss of energy via exchange of thermal radiation with its
outer environment,

radioatin is 'particles' they are called 'photons'

then a chemical reaction within that container could
increase the temperature within that container, and as it returns to its
original temperature it would lose energy and hence mass due to the
relativistic effect of slowing down the vibration (speed) of particles
within that container.

What about a battery? It's a matter of definitions as to what you
consider an ideal battery to be. You *could* argue that an *ideal* battery
is sealed to prevent whole atoms from passing through its walls but is
allowed to exchange energy with its environment via more than one method.

Switch off at the socket?
 

dennis@home wrote:


"Tim S" wrote in message
...

Do you have a degree in physics then?

I have one from imperial college.


Have a look at this:

http://en.wikipedia.org/wiki/Mass%E2...gy_equivalence

Specifically:

"In relativity, removing energy is removing mass, and the formula m =
E/c2
tells you how much mass is lost when energy is removed. In a chemical or
nuclear reaction, the mass of the atoms that come out is less than the
mass
of the atoms that go in, and the difference in mass shows up as heat and
light with the same relativistic mass.

It may well be true of a nuclear reaction, however you haven't posted
anything convincing about chemical reactions or explained where the
energy is converted to mass when you lift a weight up and increase its
potential energy, or even wind a clock spring up. It does not require an
increase in mass to store energy.

It does.
Its very very small though.
For all but nuclear reactions.

In this case, the E in the formula
is the energy released and removed, and the mass m is how much the mass
goes down. In the same way, when any kind of energy is added, the
increase
in the mass is equal to the added energy divided by c2. For example, when
water is heated in a microwave oven, the oven adds about 1.11×10?17 kg of
mass for every joule of heat added to the water."

However a nuclear reaction creates energy from mass it doesn't just
store energy like a rechargeable battery or the dinorwig hydro plant.


The basic principles are identical. Chemical reactions affect the
eolectrn patterns in the atoms. So do nuclear. The only difference is
that nuclear reactions also affect the nucleus, which being a lot bigger
and heavier so to speak, is a lot more noticeable.

If you feel that's wrong, you should probably go and correct it...

It would take a life time to correct Wiki and then someone comes along
and cocks it up again.

Switch off at the socket?
 

dennis@home wrote:


"The Natural Philosopher" wrote in message
...
dennis@home 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?

Switch off at the socket?
 

dennis@home 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.

Switch off at the socket?
 

The Natural Philosopher wrote:
dennis@home 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.

Switch off at the socket?
 

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

Switch off at the socket?
 

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.

Switch off at the socket?
 

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.