Heat, Work, and Energy

[steve_bank]

International System of Units - Wikipedia

en.wikipedia.org

In SI units heat, work, and energy have the same units, the Joule. It is not arbitrary, it reflects experiments in the 19th century like Joule’s paddle wheel experiment that demonstrated the equivalence. In everyday work the equivalence is fundamental mechanical or electrical.

Energy is defined as capacity to do work, and work is Force * Distance, Newtons * Meters. In SI dimensions energy is kg*(m/s)^2. Dimensionaly anything that reduces to that represents energy.

Mechanical kinetic energy = . 5 * kg * (m/s)^2. Energy stored in a capacitor is .5*C*(V^2) where c is farads and V is volts. Dimensionaly reduces to Joules.

From steam table steam has an energy density in Joules/kg which depends on several variables..

So you can say energy is a measure of work.

In a coal fired steam turbine generator the energy in coal is a starting point. Coal goes to heat which goes to heat water which goes to steam which does mechanical work on the turbine. At all points the sum of the forms of energy must equal the starting energy plus losses.

Add to that the Laws Of Thermodynamics and that is thermodynamic in a nutshell. Energy can not be created or destroyed, the form changes. Coal chemical energy to heat to steam to work on the turbine. All in Joules.

Conservation of mass and energy, and entropy.

What is an energy source is more generalized by divergence.

Divergence - Wikipedia

en.wikipedia.org

For a volume
A source has positive divergence.
A passive area has zero divergence,
A sink has negative divergence.

Consider a gasoline powered air compressor connected to a tank by a hose. When air is being compressed the compressor is a source with + divergence and the tank is a sink with negative divergence.

Point the hose at a wheel and open the tank valve and the wheel spins, the tank is a source with + divergence that does work on the wheel.

Put a resistor across a battery. The volume of the battery has + divergence, the volume of resistor has zero divergence, net outflow equals net inflow.

Air is just air, but in the tank it represents energy. In a steam turbine the volume of steam examining tem has a + divergence.

Saying something is energy can be semantics that can lead to debate. Mathematically and scientifically energy is a number that gets plugged into an equation. No different than kilograms or meters.

I go by SI not scifi…...

 

[Jarhyn]

It is different from meters insofar as energy is more "one way" than meters.

I am also curious, a question popped into my head the other day: if motion through time and motion through space happen as components of the same normal vector, would that mean that the SI unit of time should really be... Let's see... How long does it take light to travel 1 meter in a vacuum? It would be that, right? The "light meter", which is a measure of both time AND space.

 

[bilby]

Conservation of mass and energy

Mass and energy are NOT conserved; They can be interchanged with each other, in proportion to c².

Einstein's most famous work is his description of this interrelationship.

Total mass/energy of a closed system is conserved, but neither mass nor energy are conserved in their own right.

if motion through time and motion through space happen as components of the same normal vector, would that mean that the SI unit of time should really be... Let's see... How long does it take light to travel 1 meter in a vacuum? It would be that, right? The "light meter", which is a measure of both time AND space.

The light per meter is a measure of time, in the same way that the light second is a measure of distance (or, if you prefer, a measure of space).

Dimensional analysis is your friend; "light" is c, which has dimension L/T.

(L/T)/L = T
(L/T)*T = L

A light metre would be (L/T)*L or L²/T - it would be measured in SI in square metres per second. I have no idea what it could be used for in any practical sense. It describes the area swept by a one metre long line that is travelling at c.

 

[Jarhyn]

The light per meter is a measure of time

Technically, it would be a measure of both; it's just finding the exact period of time that corresponds to an exact distance, because of "time" is a dimension same as the spatial dimensions, through which things physically travel, it's really just extending the concept of the meter into time as well.

Technically, you can measure passage of time in meters.

 

[steve_bank]

Time is defined as the second. C, seconds, and meters are set so that the SI system is consistent. Important in electromagnetics.


You can look up how the standard meter, second, and kilogram are physically created.

Technically the SI distance is the metre not meter.

It is as simple as that. Starting in the 19th century there ere multiple systems. SI represents an evolution and consolidation.

The MKS miters, kilograms, seconds system.

There were multiple units of energy. Ergs, dynes, centimeters. CGS system.

There were confuting units. There were pounds mass and pounds force.

 

[steve_bank]

It is different from meters insofar as energy is more "one way" than meters.

I am also curious, a question popped into my head the other day: if motion through time and motion through space happen as components of the same normal vector, would that mean that the SI unit of time should really be... Let's see... How long does it take light to travel 1 meter in a vacuum? It would be that, right? The "light meter", which is a measure of both time AND space.

Time and distance are scalars not vectors, they only have magnitude. A vector has magnitude and direction.

Force in Newtons and velocity in m/s are vectors.

 

[Jarhyn]

It is different from meters insofar as energy is more "one way" than meters.

I am also curious, a question popped into my head the other day: if motion through time and motion through space happen as components of the same normal vector, would that mean that the SI unit of time should really be... Let's see... How long does it take light to travel 1 meter in a vacuum? It would be that, right? The "light meter", which is a measure of both time AND space.

Time and distance are scalars not vectors, they only have magnitude. A vector has magnitude and direction.

Force in Newtons and velocity in m/s are vectors.

I really wish you could bring yourself engage with the interesting parts of my posts first rather than the dumb shit that you KNOW is just an issue of vocabulary.

Instead you pick at dumb vocabulary shit as if it matters here whether it's a "scalar" or a "vector";

The maximum speed of the universe is 1. Everything is always traveling at a speed of 1, and sometimes it travels at a speed of 1 through time and sometimes it travels at a speed of 1 through space, but everything is always going at that speed, and sometimes it goes at that speed in the dimensional direction of "the future state" and sometimes it goes at that speed in the dimensional direction of "forward, in the present state".

I used the term "normal vector" because it always ends up being a fraction of a fixed "whole" number in any one dimensional component of the motion of a thing, and the directional motion of a thing is a vector, not a scalar.

My point is that if you're so busy with using SI units, you should be willing to use a more appropriate unit of time than the second, since time IS measurable in meters, without the need for seconds at all, assuming that time is no different structurally than space.

 

[steve_bank]

Thermodynamics 101, conservation of mass and energy.

Imagine a bubble around a gas powered car. As the car moves air comes in, fuel is consumed, heat is generated, and combustion products leave the car. The car has kinetic in Joules .5*m*v^2.

At any time the energy debited form the fuel equals the kinetic energy plus losses plus heat generated. If the car speed is reduced by using disk brakes the change in kinetic energy of car equals the heat generated in the disks. In car racing you can see the brakes glow dung braking.

That is conservation of energy. At any point in tie input energy consumption equals energy leaving the system plus energy in the system. Work, heat, and energy are equivalent.

At any time the mass of gasoline burned plus the air taken in equals the mass of combustion products. That is conservation of mass.

Mass an energy can not be created or destroyed, only forms change. If you get more energy out of a system than what goes in you have made a measurement or calculation error,

Pop quiz for the ‘scientist’.

A hydro turbine generator is putting out 100 megawatts RMS continuous at mains voltage and frequency. The load is resistive, no phase.

The turbine efficiency is 0.9.

The dam is 200 meters high.

How many m^3 of water per second has to enter the turbine to maintain the output?

Estimate has much heat is generated by the system.

Use STP to find the water density.

Energy = Joules. 1 watt = 1J/s.

 

[steve_bank]

Jaryn

I posed on science not philosophy. I did have an energy tread on philosophy.

Meters, kilograms, ad seconds are definitions that are physically created as standards, they are not metaphysical abstractions. There is no debate as to what they are.

An object does not move through time. Seconds measure a rate of change of position in meters.

I have no idea what you mean my moving through time and a normal vector. Normal(90 degrees) to what? Vector cross product, dot product, projection?

Write an equation in seconds and meters.

 

[Jarhyn]

Jaryn

I posed on science not philosophy. I did have an energy tread on philosophy.

Meters, kilograms, ad seconds are definitions that are physically created as standards, they are not metaphysical abstractions. There is no debate as to what they are.

An object does not move through time. Seconds measure a rate of change of position in meters.

I have no idea what you mean my moving through time and a normal vector. Normal(90 degrees) to what? Vector cross product, dot product, projection?

Write an equation in seconds and meters.

Normal as in "measured as a fraction of 1" against a reference.

If time is a dimension the same as space is, then things do move through it, and so movement through time happens along a distance.

A meter should be just as valid a measure of time as conventional distance.

 

[Swammerdami]

On the topic of heat/work/energy perhaps someone can help me intuitively understand  Gibbs free energy ("useful" energy, ΔG).

ΔG = ΔH - TΔS​

or

ΔH = TΔS + ΔG​

Since ΔS ≥ 0, waste heat reduces useful energy gained when potential energy is spent; and reduces new energy stored when useful energy is spent to increase potential. Is this correct so far?
I understand multiplying by T is necessary so all terms have dimension of energy, but what does this imply? That losses to waste heat are usually higher at high temperatures?

I'm hoping one of you can offer insight that helps the equation "click" in my mind.

 

[Bomb#20]

An object does not move through time. Seconds measure a rate of change of position in meters.

I have no idea what you mean my moving through time

Jarhyn is talking about Special Relativity. The speed factor and the time dilation factor add up the same way the components of a vector add up -- you can calculate them using the Pythagorean Theorem. So for example if you're moving at half the speed of light then your clock advances .866 times as fast as a stationary observer's -- .866² + .5² = 1². Calling this "Everything is always traveling at a speed of 1" is a popular way of thinking about it. If this were quantum mechanics instead of relativity we'd call it an "interpretation".

 

[bilby]

The light per meter is a measure of time

Technically, it would be a measure of both; it's just finding the exact period of time that corresponds to an exact distance, because of "time" is a dimension same as the spatial dimensions, through which things physically travel, it's really just extending the concept of the meter into time as well.

Technically, you can measure passage of time in meters.

Literally none of this is true.

Timelike dimensions in relativity have the opposite sign to spacelike dimensions, and this has profound implications in calculating vectors in Minkowski spacetime.

 

[bilby]

My point is that if you're so busy with using SI units, you should be willing to use a more appropriate unit of time than the second, since time IS measurable in meters, without the need for seconds at all, assuming that time is no different structurally than space.

That is a false assumption, as detailed in the links I provided above.

Greg Egan's excellent Sci-Fi novel "The Clockwork Rocket" (part one of the Orthogonal trilogy) imagines a universe in which time operates like a spacial dimension, as you assume here. It's very weird indeed.

 

[steve_bank]

Jaryn

I posed on science not philosophy. I did have an energy tread on philosophy.

Meters, kilograms, ad seconds are definitions that are physically created as standards, they are not metaphysical abstractions. There is no debate as to what they are.

An object does not move through time. Seconds measure a rate of change of position in meters.

I have no idea what you mean my moving through time and a normal vector. Normal(90 degrees) to what? Vector cross product, dot product, projection?

Write an equation in seconds and meters.

Normal as in "measured as a fraction of 1" against a reference.

If time is a dimension the same as space is, then things do move through it, and so movement through time happens along a distance.

A meter should be just as valid a measure of time as conventional distance.

If you say so.

But again, in SI to make it consistent with reality time and C and meters are interrelated, they can not be separated.

velocity = meters/seconds. Given velocity and time meters is derived. Given velocity and m,eters time is derived. Regardless of the relative velocity of an inertial frame within the frame a meter, second, and kilogram appear the same as in any frame. C as measured IAW SI in any frame will be the same. It is what makes it all work.

Pulse a laser trough a block of glass and there is a time delay through the glass. That measured time delay will be the same in any frame.

SI is a system of defined quantities.

I have no interest in trying to unpack odd speculations copied from the net without details.

Post a procedure that supports your idea, same kind of response I'd give to a theist on a pseudo science claim.

 

[Bomb#20]

Thermodynamics 101, conservation of mass and energy.

Imagine a bubble around a gas powered car. As the car moves air comes in, fuel is consumed, heat is generated, and combustion products leave the car. The car has kinetic in Joules .5*m*v^2.

At any time the energy debited form the fuel equals the kinetic energy plus losses plus heat generated. If the car speed is reduced by using disk brakes the change in kinetic energy of car equals the heat generated in the disks. In car racing you can see the brakes glow dung braking.

That is conservation of energy. At any point in tie input energy consumption equals energy leaving the system plus energy in the system. Work, heat, and energy are equivalent.

At any time the mass of gasoline burned plus the air taken in equals the mass of combustion products. That is conservation of mass.

Mass an energy can not be created or destroyed, only forms change. If you get more energy out of a system than what goes in you have made a measurement or calculation error,

You are not describing reality; you're describing a mathematical model. Nature is under no obligation to conform to it. People believe in conservation laws because they do some accounting on the natural phenomena they observe and notice that if they put some of the numbers together with some of the other numbers in a particular way they get a constant. Then somebody observes a phenomenon that violates it, a phenomenon that nobody accurately measured before, and then they check for errors, and if they find none, then some people abandon the mathematical model and look for a better one, and some people keep using the old model anyway even though they know it's wrong because it's still a useful approximation, and some people keep actually believing in the old model because, well, basically, because they're fuddy-duddies.

You are describing nineteenth-century classical physics. People believed in a lot of conservation laws in the nineteenth century, not just conservation of mass and conservation of energy. They believed in conservation of hydrogen, conservation of helium, conservation of lithium, conservation of beryllium, right up through the whole periodic table. They believed in them because nobody had ever seen them violated. Then starting around 1900 we discovered radioactivity, fission and fusion, and all those conservation laws went away, replaced with newer concepts like conservation of baryon number. And conservation of mass and conservation of energy went the same way, ...

Conservation of mass and energy

Mass and energy are NOT conserved; They can be interchanged with each other, in proportion to c².

Einstein's most famous work is his description of this interrelationship.

Total mass/energy of a closed system is conserved, but neither mass nor energy are conserved in their own right.

... replaced by conservation of mass+energy. But that's still just a mathematical model, and nature is still under no obligation to conform to it. Conservation laws didn't stop being invented, believed in, and then abandoned once Einstein had done his thing. We believed in conservation of "parity" until the "weak force" was found to violate it in the 1950s. And we're in the same situation today. About thirty years ago people started observing systems that just keep on gaining astronomical amounts of kinetic energy, but we haven't observed any corresponding loss of other forms of energy or any corresponding loss of mass to balance the "Total mass/energy of a closed system is conserved" accounting books. We're still puzzling over that one. We haven't just abandoned conservation of mass+energy, not because we have any good reason to still believe in it, and not because we're fuddy-duddies, but only because nobody's figured out a new model to replace it with yet. Until then we just make up a label for our ignorance, and take it on faith that the books are all going to balance again when we include "Dark Energy".

 

[steve_bank]

From Laws Of Thermodynamics entropy.

In any physical system there is energy in the system that can not be used to do work in the system

In a capacitor when it is changed there can be energy locked in the dielectric that can not be utilized.

Waste heat can be used to do work in the system, but efficiencies multiply so it can be hard to do useful work with it. Amount of work that can be don e is proportional to a potential energy difference.

If you imagine for any work done here on Earth there is a ds that shows up against a cosmic store of energy, that leads to the idea of a thermal death of the universe. And that seqways into cosmology.

Thermodynamics applies to a system with a finite volume with mass and energy going in, mass and energy in the system, and and mass and energy out.

 

[Bomb#20]

Pulse a laser trough a block of glass and there is a time delay through the glass. That measured time delay will be the same in any frame.

I don't think that's correct. Moving objects get shorter in the direction of travel. The measured time for light to go through the glass will vary from one frame to another depending on the length of the glass in each frame.

 

[steve_bank]

Multiple choice questions.

In terms of thermodynaics

You put 2 liters/second into a pipe and get 4 liters/second out.

Do you
A Assume the excess water is coming from a hole in the space time continuum.
B. Assume God did and make it a holy site to god.
C Assume the excess water is spontaneously coming fro nothing,.
D Assume water is getting into the pipe from somewhere else in the plumbing system.

You put 2 liters/second into a pipe and get 1 liter/second out.

Do you
A Assume it is leaking out through a hole in the space time continuum.
B Assume aliens in orbit are transpiring your water to their ship.
C The water is vanishing into nothing spontaneously.
D Start looking for a leak.

In relativistic and quantum mechanics there is still conservation, in terms of SI units everything has to be accented for.

Someone will always say hat at high percentages of C mass is no longer consented, but that is not exactly true. As you accelerate in a frame to you a second is still a second and a kg a kg. To an observer in another frame your second appears different IAW with time dilation.

In your frame an electric charge appears electrostatic. To a passing frame it is electrodynamic

I an sure someone will dispute me, no working theory can gave something from or to nothing,.

Someone always brings up virtual particles and argue it is something from and to nothing. To me it is a computational method. In digital control systems in order to change from one state to another there can be a mathematical virtual state in software that serves as a transition state.

In antenna design

What is the image theory of antennas?
Image Theory: Radiation From Hertzian Dipole Above Ground ...
In image theory, a radiating antenna (actual source) is placed at some distance h from a perfect conducting plane. An image of this antenna (virtual source) is placed below the conducting plane at the same distance, h, as shown in Figure 2 [3].May 1, 2024

 

[Bomb#20]

Multiple choice questions.

In terms of thermodynaics

You put 2 liters/second into a pipe and get 4 liters/second out.

Do you
A Assume the excess water is coming from a hole in the space time continuum.
B. Assume God did and make it a holy site to god.
C Assume the excess water is spontaneously coming fro nothing,.
D Assume water is getting into the pipe from somewhere else in the plumbing system.

E. I assume there is no excess water. The density of the water goes down in inverse proportion to the volume, which increased because while it was in the pipe the pressure of the water went down or its temperature went up or some combination thereof. PV = nRT.