Matter, Space, Energy & Time

[repoman]

Was the Big Bang a violation of Conservation of Energy?

 

[bilby]

Was the Big Bang a violation of Conservation of Energy?

There is as yet insufficient data for a meaningful answer.

 

[skepticalbip]

Was the Big Bang a violation of Conservation of Energy?

It depends on what model you are using. Krauss says no, that the total energy of the universe is zero and has always been zero.

 

[bilby]

Was the Big Bang a violation of Conservation of Energy?

It depends on what model you are using. Krauss says no, that the total energy of the universe is zero and has always been zero.

There are lots of models, and little evidence to use to choose between them.

Maybe Kraus is correct.

Maybe the universe has a positive total energy, and always has had, with the singularity marking a sharp decrease in entropy, with no change in total energy.

Maybe the universe has a positive total energy, and that energy came from nothing before the Planck Epoch via some unknown mechanism.

Maybe the universe has a positive total energy, and that energy came from a wider 'multiverse', before the universe became a closed system at the Planck Epoch.

Maybe the universe is not a closed system, and energy leaks in and out from a wider multiverse, with the Big Bang being only the best known of such events.

Maybe something else entirely.

The First Law of Thermodynamics doesn't apply to open systems; It is possible that it also doesn't apply to singularities. But we don't know whether the universe is a closed system; nor what rules apply before the Planck Epoch, so it is all just guesswork. We can rule out a few things that are either internally contradictory, or that imply observable effects (eg on the Cosmic Microwave Background) that are easily large enough to have been detected, but are not. But Sherlock Holmes would be stumped; Once you eliminate the impossible, a stack of things remain, all of which are mutually exclusive, and all highly improbable. One is probably the truth, but we just don't know which - and there may be another idea that nobody has yet had, which will turn out to be the right answer. That's not very likely, but then, nor are any of our other options.

It all seems unlikely, and we have only one instance to study. But science can be confident that the universe exists (as long as we distract the philosophers from weighing in).

 

[skepticalbip]

Was the Big Bang a violation of Conservation of Energy?

It depends on what model you are using. Krauss says no, that the total energy of the universe is zero and has always been zero.

There are lots of models, and little evidence to use to choose between them.

.........snip...........

Indeed. Cosmologists struggle with both answers. A universe with a beginning has a lot of serious problems. An eternal universe has a lot of serious problems.

The only reason that I tend to like Krauss is that he uses a fair amount of humor in his talks which makes them more entertaining.

It all seems unlikely, and we have only one instance to study. But science can be confident that the universe exists (as long as we distract the philosophers from weighing in).

...Amen...

 

[Speakpigeon]

Was the Big Bang a violation of Conservation of Energy?

Derail.

I explicitly asked to abstain from any metaphysics.

Thanks to comply.
EB

 

[Speakpigeon]

Mass does not physically change, relativistic mass is relative to a frame.

That would be an interesting angle to address, I think.

Anyone up for it?
EB

 

[bilby]

Mass does not physically change, relativistic mass is relative to a frame.

That would be an interesting angle to address, I think.

Anyone up for it?
EB

Yeah, sure - Mass DOES physically change relative to the rest frame of the accelerated object.

There are no preferred frames, but that doesn't mean you can just disregard relativistic mass changes by switching to a frame where they are not observed and pretending that they don't exist. Rest mass is unchanged, but that's not mass, which is why it's called 'rest mass' and not just 'mass'.

I guess it's OK for engineers*.










*The oompa-loompas of science

 

[Speakpigeon]

Mass does not physically change, relativistic mass is relative to a frame.

That would be an interesting angle to address, I think.

Anyone up for it?
EB

Yeah, sure - Mass DOES physically change relative to the rest frame of the accelerated object.

There are no preferred frames, but that doesn't mean you can just disregard relativistic mass changes by switching to a frame where they are not observed and pretending that they don't exist. Rest mass is unchanged, but that's not mass, which is why it's called 'rest mass' and not just 'mass'.

If we compare the views from two different reference frames, in motion relatively to each other, at a constant velocity close to the speed of light, and one of them broadly at rest with respect to the entire universe, and the other one associated with an object having a small mass at rest. What are the differences in terms of total mass and total energy of the universe?

I would assume the overall rest masses to be identical. But from the frame broadly at rest, there's just the one small object that's near the speed of light. The energy involved is just the energy required to speed up the small object. No problem.

From the frame associated to the small object, however, it's the rest of the universe which is speeding up and with a velocity close to c. Where could the energy necessary to accelerate the entire universe possibly come from? And if we dismiss that perspective and say there's no energy involved except the one necessary to accelerate the small object, then we also have to dismiss the relativistic mass of the rest of the universe seen as speeding at near the speed of light from the frame of the small object.

This seems to suggest that relativistic mass is more a fiction than a reality.

Or do I have it wrong?
EB

 

[skepticalbip]

Give an equation which shows matter and energy are somehow interchanfeable.

.

E=M c^2
M=E/c^2

In these equations E is energy and M is mass.

Those equations certainly have proven to be damned accurate in all instances where they have been employed.

Mass and energy have different dimensions, you can not equate E to M in the equation. In atomic physics you can substitute E/c^2 for M, that does not mean M=E, there is the C^2 term.

We assign different dimensions because it is convenient for our measurement techniques. If we assume the inflationary model is a fair description of reality then the early universe was nothing but energy. There was no matter in the universe until it inflated enough to cool to a point that allowed matter to precipitate from the energy. This means that matter is just a specific form of energy, not something different from energy. Because of the form, we find it more convenient in our daily lives to measure the mass of solid matter in kilograms rather than electron volts or any other dimension normally used to measure energy. However, in some scientific applications such as at CERN or Los Alamos kilograms would be an extremely cumbersome dimension to use so more applicable dimensions are used. There are lots of forms of energy and we assign different dimensions to the different forms that make it more convenient for our measurement and calculations, not because they are not all energy just energy in different forms.

 

[steve_bank]

skeptical BP

Now you are drifting into philosophy and metaphyics. The SI units as they are evolved over centuries as experiemnt and observation evolved. They were not proactively designed. SI is based on basic definitions that are easy to set up anywhere in the world, except the kilogram. I did read there is work being done on comming up with an alternative mass reference.

Something called pure energy has no meaning in the definition of energy as the capacity to do work. Energy has no independent existence, as in the rope and weight example I posted. When you lift a weight, where is the energy?

Whatever cosmology you like you are faced with causality, what led to initial conditions for the BB for example. It is all speculation and conjecture, albet based in logic and science we can demonstrate.

Uniform energy would be equilibrium and no means to do work. One way put was to introduce the idea of random quatum fluctuations to start the ball rolling. Nothing wrong with that, it is scientific invention. Hit a raod block and figure out a way around it. Dark Matter for example.

Electron volts is energy. Energy and mass are not equal. In E=MC^2 energy is proportional to mass. In SI everything flows from meter, iilogram, and seconds. The MKS system,/ Another is CGS, centimeter,gram,second.

I worked in a number of areas including optics, solid state optical sensors, video, heat trasfer, fluid mechanics. I am well aware of physics units. In a photodetector when the EV of a photon matches the semicnductor's bangap voltage in EV apbsorption occurs and ekectrons are freed.

 

[bilby]

Something called pure energy has no meaning in the definition of energy as the capacity to do work.

That's simply false.

Energy has no independent existence, as in the rope and weight example I posted. When you lift a weight, where is the energy?

It's everywhere. The entire system can reasonably be considered as an interplay of energy in various forms. According to quantum field theory, all there is is energy - matter is just areas of field energy maxima.

A photon has no mass; It is pure energy, with the amount of energy determining its frequency. A proton has mass, but that mass is a representation of the energies of the various quantum fields (divided by c²).

Your engineering approximations work well enough for many purposes, but it is a mistake to believe that they are an accurate description of reality. Quantum Field Theory is the best approximation we have to date, and all other theories are approximations of it (or approximations of those approximations, etc).

 

[steve_bank]

Mass does not physically change, relativistic mass is relative to a frame.

That would be an interesting angle to address, I think.

Anyone up for it?
EB

Yeah, sure - Mass DOES physically change relative to the rest frame of the accelerated object.

There are no preferred frames, but that doesn't mean you can just disregard relativistic mass changes by switching to a frame where they are not observed and pretending that they don't exist. Rest mass is unchanged, but that's not mass, which is why it's called 'rest mass' and not just 'mass'.

I guess it's OK for engineers*.










*The oompa-loompas of science

It is not fair to glue your wicket.

Regardless of your inertial frame a kilogram and second and meter will appear the same in the frames. It is a consequence of C being constant across inertial frames. Two ships at rest, one leaves at 1g, the other accellerates to 0.5c then drops to 1g acceleration. If you lifted 1kg on each ship woold it feel any different?

- - - Updated - - -

Something called pure energy has no meaning in the definition of energy as the capacity to do work.

That's simply false.

Energy has no independent existence, as in the rope and weight example I posted. When you lift a weight, where is the energy?

It's everywhere. The entire system can reasonably be considered as an interplay of energy in various forms. According to quantum field theory, all there is is energy - matter is just areas of field energy maxima.

A photon has no mass; It is pure energy, with the amount of energy determining its frequency. A proton has mass, but that mass is a representation of the energies of the various quantum fields (divided by c²).

Your engineering approximations work well enough for many purposes, but it is a mistake to believe that they are an accurate description of reality. Quantum Field Theory is the best approximation we have to date, and all other theories are approximations of it (or approximations of those approximations, etc).

What is it like out there in metaphysical orbit? Energy is everywhere, like The Force?

Same question to you, when you pick up a weight where and what is the energy? Figure that out and all will be clear.

Energy in science and engineering are both about work, force times distance. Moving an electron in a wire is an energy work relationship. Deflecting a photon is energy work. Everything in scirnce and engineering reduce to SI units,. The equating of heat, work, and energy in SI comes from the 19th century and was fiundation to science and engineering. Look at the paddle wheel experiment links and then debuk it.

Some say it is pure energy, but a photon can do work, that is the test for energy. I disdgree with photons being pure energy. Massless or not in theory it exists and interacts with matter. I went through this one before.

"A photon (mass = 1.67x10^-27 kg) has a kinetic energy of 1.00MeV. If its momentum is measured with an uncertainty of 1.00%, whatis the minimum uncertainty in its postion? ( h= 6.63e-34J-s, 1eV=1.6e-19 J)"

Pure energy implies some kind of existence independent of any physical existence. Photons are matter.

As to engineering approximations, engineering and sceince both use SI, so I have no idea what you mean. Science or engineering work, energy, and heat are in Joules.

 

[steve_bank]

Something called pure energy has no meaning in the definition of energy as the capacity to do work.

That's simply false.

Energy has no independent existence, as in the rope and weight example I posted. When you lift a weight, where is the energy?

It's everywhere. The entire system can reasonably be considered as an interplay of energy in various forms. According to quantum field theory, all there is is energy - matter is just areas of field energy maxima.

A photon has no mass; It is pure energy, with the amount of energy determining its frequency. A proton has mass, but that mass is a representation of the energies of the various quantum fields (divided by c²).

Your engineering approximations work well enough for many purposes, but it is a mistake to believe that they are an accurate description of reality. Quantum Field Theory is the best approximation we have to date, and all other theories are approximations of it (or approximations of those approximations, etc).

You are talking in vague generalities about things you likely have scanned on the net. When energy is redefined from being abile to do work, let me know. If it is scince, energy is objectively defined in SI, there is no other.

Answer the weight lifting question and we can make progress. Knowlede is useless if you can not apply to a simple example.

 

[bilby]

That's simply false.

It's everywhere. The entire system can reasonably be considered as an interplay of energy in various forms. According to quantum field theory, all there is is energy - matter is just areas of field energy maxima.

A photon has no mass; It is pure energy, with the amount of energy determining its frequency. A proton has mass, but that mass is a representation of the energies of the various quantum fields (divided by c²).

Your engineering approximations work well enough for many purposes, but it is a mistake to believe that they are an accurate description of reality. Quantum Field Theory is the best approximation we have to date, and all other theories are approximations of it (or approximations of those approximations, etc).

You are talking in vague generalities about things you likely have scanned on the net.

LOL. Your inability to grasp my point doesn't render it vague; And you are totally unqualified to determine the source or depth of my knowledge - not everyone is as poorly informed as you are, and projecting your failings onto others is just pathetic.

When energy is redefined from being abile to do work, let me know. If it is scince, energy is objectively defined in SI, there is no other.

Answer the weight lifting question and we can make progress. Knowlede is useless if you can not apply to a simple example.

Your worship of units of measure and of definitions doesn't make those things fundamental. They are the tools, not the materials.

Your position isn't wrong, as such; It's just very limited and hidebound. Which is fine for engineering, but no use at all in science.

 

[Derec]

Any physics calculations of these events must balance the energy-mass before and after the event.

That's how existence of the  neutrino was inferred two decades before it was observed (due to its low rate of interactions with matter).

 

[Random Person]

LOL. Your inability to grasp my point doesn't render it vague; And you are totally unqualified to determine the source or depth of my knowledge - not everyone is as poorly informed as you are, and projecting your failings onto others is just pathetic.

When energy is redefined from being abile to do work, let me know. If it is scince, energy is objectively defined in SI, there is no other.

Answer the weight lifting question and we can make progress. Knowlede is useless if you can not apply to a simple example.

Your worship of units of measure and of definitions doesn't make those things fundamental. They are the tools, not the materials.

Your position isn't wrong, as such; It's just very limited and hidebound. Which is fine for engineering, but no use at all in science.

Wow, that's some impressive arrogance. You sound like a Priest offering intercession for your god, science.

 

[bilby]

Any physics calculations of these events must balance the energy-mass before and after the event.

That's how existence of the  neutrino was inferred two decades before it was observed (due to its low rate of interactions with matter).

I thought that was spin conservation rather than mass/energy. In a beta decay, a neutron (spin 1/2) produces a proton and an electron (both also spin half); To balance spin for this event, an electron anti-neutrino with spin minus 1/2 was postulated. Neutrinos are rather like a Sarah Huckabee-Sanders press conference - just spin, with no substance.