Science a GoGo's Home Page Forums General Discussion Physics Forum Mass & Velocity

I don't think you are getting picky there Paul. In fact, I think you have made an important point.

What we are looking at here is the gravitational field.

Is that field everywhere in space and time?

Is the average energy of that field zero or non-zero?

Can we identify waves in that field?

lets leave time out of this , OK.

I'm going to guess that everywhere inside the universe there is
a gravity field.

unless the field has been blocked through some device.



there is no energy in a gravity field in my opinion.



we can identify the magnatude of a gravity field.

I don't think there are waves in a gravity field
gravity permeates all that is.

it's there everywhere.

I think I see where your going with this and that is that
we call it a field ( thus it must have waves )
like a magnetic field.

I only call it a gravity "field" for lack of better terminology.

I was moving more towards the question as to whether, if you measure a field as zero at any point in space, how could you say that there was a field there.

maybe its like light , it radiates from its source.

why does gravity bend light?

Okay Paul I need you to define a field, a force and energy in whatever description you can.

There is no right and wrong here I just need to see you definitions so I can work from there.

All logical definitions should be workable to the same conclusions a fact born out by QM. A little secret of QM is that it doesn't have a thing called velocity this is because of the uncertainty principle but you can construct a statistic equivalent to what classic physics calls velocity.

So long as definitions are consistant science and logic should get us to the same place.

Finally we need to clarify the term spacetime which seems to be causing some confusion. I am using spacetime to mean any random section of of the world around us. I am using it to distinguish it from space as in not on earth etc and I notice in your energy type post you sort of wanted to discard some types of energy from discussion by looks based on space?

So to be clear our random section of spacetime can be anywhere and may include matter or not specific types of energy may require matter but we know fields or force or whatever you want to call them transit thru matter like earths magnetic and gravity.

I use the time part because its important and you probably havent thought about this but here goes. Science makes a massive assumption and because you wanted to exclude time so do you. The assumption goes like this any experiment you do today is reproducable tomorrow and the day after that is you are both make a massive assumption that space itself is not changing or changing so slowly that it won't change results.

Under big bang and quite a few cosmic theories space changes over time so the time bit becomes important I think you are having a static consistant universe so the time bit doesn't matter to you but if we stick with spacetime we can even cover stuff that allows the universe to change.

Anyhow long discussion but I need definitions of field, force and energy.

Myself I am going to go the full QM version which initially will look weird, I am not even going to use the classic definition because I think it has issues

Energy = Any quantity (position, velocity, electric field at a given point, volume of a gas, the percentage of an isotope or carbon dioxide in it, and so on) that is evolving in time is evolving because it doesn't commute with spacetime is thus a Hamiltonian – with the operator of energy. So the energy has to depend on a related "complementary" quantity describing very similar things.

Really everything that may change and that may be measured in the world is energy and I shall define as quantum information and for practical purposes quantum information = energy.

A field is created across an area of spacetime when energies between two points in spacetime differ on some quantity.

A force is a generic energy change being exerted onto an object or point in space. Forces can be positive or negative and thus have directionality. Fields are hence always a force.

Those are my definitions.


An interesting aside some of the more astute may have notice I have settled if energy real or not under my definition. Under classic physics none could give me a conclusive argument if energy was real or not. Under the definition of energy I have given above it is impossible for energy to not be real it may have an arbritrary value but it is most definitely real in the same way the US dollar has an arbitrary value but is most definitely real by definition.

However there was penalty for getting energy to be real and that was conservation it cost no energy to stay the same it costs energy to change. Intrinsically this is the same as money if I have 1 dollar it remains 1 dollar until I spend it ... that is a dollars value is conserved. Now the real astute will realise that is not neccessarily true of money if I am trading across currancy and I will leave it to discuss later if such mechanisms are possible with energy since it looks something like currancy under my definition.

Orac

I'll think about all that tomorrow.

I'm watching a movie right now , but I'll get back
to it soon.

meanwhile , would you mind giving a brief definition
of what you think a field is and what you think energy is?



I don't think were going to get anywhere if everything
is
energy.



if everything is energy , then the above say's that everything will cause a field between everything else , because if everything is energy and everything is moving ( and everything is moving ) then everything would have a constantly changing magnitude of energy.

can I ask if any of your definition's are influenced by
any math or theory?

I'm just curious.

I noticed you used "in the world" but we are still talking about space right?

read again what I have written ANYTHING that changes with respect to time is a change in energy.


In your classic world it is an extension of Newtons first law in a different way



So the extension is not just movement it is anything that changes with respect to time.

So for example radioactive decay involves a change of a measurable quantity in time as such it is energy.

So we clear energy isn't everything it's involved in anything that changes a measurable quantity in time.

If you can measure it and it changes from one time to the next time then energy was exchanged.




Not quite because of your problem above anything that exchanges energy will have a field.




This is Quantum Mechanics explained in a really very simply way that you have probably never seen before it is a push to demystify QM and it involves no mathematics or complications.

It sort of a generic education push that is being discussed and sort of as a prelude to where you end up I will proved a link to a movie NASA has done called visual magnetic fields.

http://www.trendhunter.com/trends/magnetic-fields-made-visible-nasas-magnetic-movie




We are talking about any piece of space you randomly pick it could be here on earth or out in space as in between earth and the sun. From a QM perspective there is nothing different between any piece of space just some may have matter and fields in them some may not ... QM care not it will work the same in any situation.

It is unimportant to QM because if you look at the definitions above QM positions itself as the master of the laws it can not hence have laws imposed on it. You should be familar with this problem in your religious context if you have a GOD then he can not be made to obey anyone else. It is important to also point out that QM does not seek to be a GOD in that at it's heart QM is a set of rules but no intelligence behind why those rules exist. We have no idea why such rules would come about and hence it is entirely consistant that perhaps there is a GOD and he made the rules or equally such rules came about by pure chance we have no way to test this.

In the above statement it becomes obvious why QM can violate so many normal classical laws and it also tells you that even inside a black hole or a biggest sun the laws of QM have to still hold or else the whole theory breaks down it would be the religious equivalent of saying GOD stopped working in a black hole or big sun. There are only very very specific ways that QM can be stopped or have what we call boundary conditions imposed but thats a much later discussion.

I will assume I got you through that because it's not complicated with just a couple of simple definitions we have established some interesting facts of the theory

1.) Energy is by definition real.
2.) Time has to exist otherwise there is no energy because if you can't change a quantity between units of time there is no energy.
3.) Between any two units of time the systems energy has to be conserved.

If you want a challenge try proving those 3 things under classic physics.

I guess what was disappointing for me was when I asked questions about energy and time being real not one person on the forum identified that those facts must be true if QM is true.

The fact is if you see an article which makes energy or time abstract and not real you should be able to construct an experiment under QM to falsify the assumption. Energy or time not being real is a direct violation of QM and that is the memo.

Orac, I'm not questioning your line of reasoning, nor the conclusions you reach. However, there seem to be two definitions missing:

1. How do you define reality?
2. How do you define QM?

You say, for example, that energy is real. Unless you have defined reality, you have said no more than that energy appears to be real in what we perceive as reality.

Pe=mgh

two room's side by side.

one room is in total darkness.
the other room is lit up by a light bulb.

a single particle travels from the dark room into the light room.

the particle gains energy ( E radiant ) as it enters into the light

NO energy was EXCHANGED

the light bulb did not require more energy to illuminate the
particle.

if we measure E of the particle we see it has gained energy.

it has heated up.

I think that energy was exchanged when the particle left the dark room and entered the light room. The total energy in the dark room decreased by the energy of the particle, the total energy in the light room is increased by the energy of the particle. That is one energy exchange. Also if the particle absorbs energy from the radiant energy then it starts moving faster so it has absorbed energy from the radiant energy in the room. That is another energy exchange.

Bill Gill

is that a energy exchange or is that simply moving energy
from one room to another?

when the particle left the dark room , what did the particle give
to the room and what did the room give to the particle in exchange?

when the particle entered the light room , what did the particle give
to the room and what did the room give to the particle in exchange?




is that a energy exchange or is that energy absorption?

when the particle absorbed the radiant energy did it absorbe the
radiant energy from the room or from the light bulb?

when the particle absorbed the radiant energy , we could say that
the light bulb gave the particle something , but what did the
particle give the light bulb in exchange?

now I suppose we need to define what exchange means.


if we look at the overall total energy before and after
we see an increase if we make the walls of the light room
made from mirrors.

this way the light is never absorbed until the particle enters
the light room.

An energy exchange happened to the particle when it was struck by the light. This causes the particle to 'speed up', which would be an energy exchange into the lit room as heat.
The room that lost a particle would have lost energy (potential energy maybe?) from the particle leaving. This is also an exchange.

Energy exchange in it's simplest form seems to be a difference in energy from one point of measure to another. It does not necessarily mean a 'trade' as it were, just a difference.

That's how I figured it anyways. "Energy exchange" seems to be a pretty generic term, so it seems to have pretty generic definitions.

They are correct Paul even in your classic world one photon of light or even a molecule changes energy of your boxes.

Specifically in classic physics with a molecule it is known as maxwells demon

http://en.wikipedia.org/wiki/Maxwell's_demon

Science even built an optical version which is exactly what you described Paul

http://www.nature.com/nphoton/journal/v2/n8/fig_tab/nphoton.2008.145_F2.html

And to prove it exchanges energy it can be used to cool
http://iopscience.iop.org/1367-2630/11/6/063044/
http://george.ph.utexas.edu/papers/Maxwelldemon.pdf

I could talk about the quantum version but it would freak you out

However I am not even going to bother arguing any of this because under the definitions I gave you it is implicit.


You may hence argue you don't agree with the definitions but the logic per the definitions I gave is explicit and it also equates precisely to the classic result as per maxwell etc.


For you Neo I already defined energy exchange as any quantity that can be measured quantity and changes with time. If you can measure it and it changes then energy was exchanged and that is the standard QM definition. The definition is clear and there are no ambiguities or tricks.

It's one of the interesting things about QM is people have invariably heard about the weird funky mathematics and weird effects but many don't realise how basic it's framework really is.

I am not going to get involved in the classic physics discussion because it is all over the shop with energy and time you will be arguing till the cows come home and its going to get even more weird with Paul because he has his own funky definitions.

The important thing to learn if nothing else is that so long as QM remains a valid science theory any discussion of time or energy being abstract or fuzzy or not real is rubbish because that is an instant falsification of QM. So if such concepts are proven QM falls it is that simple.

according to the definition's listed below you are the one
with funky definition's not me.

I was critical of your usage of the word "exchange" and in
my world the word "exchange" has the following definitions.








Neo pretty much hit the nail on the head , what your trying
to imply is that the difference is an exchange.



but an exchange is extremely different from a difference.





if QM wants to demystify itself it should not use terminology
that conflicts with known definitions.

I have read a little about what QM says about
energy exchange and from what I have read an energy exchange
is nothing more than a difference in polarity.

I think , I just spent a minute on it.

I agree with Paul - it's misleading when a one-way energy transfer is called an energy exchange. No one appears to have conceded that absurdity.

Perhaps Paul call it difference or change at this layman level it hardly matters and feel free to change it. It matters to you I understand but the problem is we are dealing with many levels of science skill here.

Redewenur I am really surprised you of all people didn't figure why it is called exchange. The stuff is vibrating in a QM oscillation how do you think your going to have a clean one way interaction when was the last time you saw two vibrating objects have a clean one way interaction.

Rede I know you know that even a static empty piece of spacetime vacuum is exchanging energy and now you want to insist on directionalty of an exchange I would like to see that????.

I conceed from Pauls layman level it probably is better to put it as change or difference but at your science level redewenur it is an exchange and there are no one way interactions at the QM level ... there can't be because of what is happening.

Even bringing the problem back to a classic problem try viewing what happens when a fast moving by not spinning basketball runs into a stationary but spinning basketball describe what happens? At some macro level the moving ball made the staionary ball move but you are ignoring the staionary ball imparted spin on the moving ball. Ok this is a classic physics spin problem but it shows the issue.

At your science level Rede it is definitely an exchange and it's important not only that you realise it is but why.



Hence this statement is absurd to me coming from someone of your science knowledge.

Perhaps it is his Redewenur's degree of knowledge that the statement comes from.

have you ever considered that some people just have the ability
to reason beyond what is written?

QM is sort of new , and it seem's as if it changes a lot
as it finds new things , but if QM conflicts with definitions
that are mainstream then perhaps it needs to learn to comply.

Rede knows at least enough QM to grasp string theory so I am not saying something out of place to his level of science.

The definition doesn't conflict with mainstream its just in classic physics you oversimplify everything see this basketball example

What happens when a fast moving by not spinning basketball runs into a stationary but spinning basketball?

Classic physics: Well the stationary basketball was imparted energy and the staionary ball started moving. It's true but it misses part of the story and if you were studying the collision linear velocity exchange its not important and the collision is viewed as one way energy exchange.

QM physics: Well the stationary basketball was imparted energy and the stationary started moving however the staionary ball also imparted spin energy back onto the moving ball.


The problem here is classic phsyics actually thinks that you get real world moving ball and a stationary ball collisions in which one or both arent actually spinning wake up people the classic type collissions would be extremely rare in real life.

Physics and science teaching books are full of these static simplified examples and people therefore think that there are such things as real world one way changes in energy.

The reverse is true most collisions and energy exchanges as described in science books is contrived and your want to change the word exchange for difference enforces and strengthens that contrivance and that is the issue for me.

Anyhow enough said if you want to call it difference or change go ahead but it is really an exchange in most real world interactions and QM does not seek to contrive anything.