There's an interesting conversation on Energy Conservation going on under my post about how The Universe can't `Just Exist'. I wrote a reply in that thread which I've decided to turn into a main post.
Saving Energy Conservation:
What would Physicists do if an Experiment showed that Energy Conservation is False?
Just because current experiments seem to show that energy is conserved, doesn't mean a future experiment might not violate energy conservation.
However, what this would actually look like in practice, would be a complicated dialectic involving both experiment and theory.
So suppose for example we do an experiment and it looks like under such-and-such conditions, a box of electrons seemed to get new kinetic energy seemingly coming out of nowhere. Then I think scientists would probably go through something like the following stages (not entirely unlike the silly pop-psych notion of "Stages of Grief")
1. The first thing physicists would do is suspect that there is some sort of experimental measurment error. In other words, reject the experimental result on the basis of well-established theory, and try to look for a reason why the mistake was made. Either because of a measurement error, or because of leakage from some established type of energy (like thermal leakage or external electric fields or something).
[This is like the "Denial" stage of grief, but unlike when somebody dies, most of the time when a scientific experiment discovers something really weird, denial is the right first reaction! Maybe there might be a bit of "Anger" too if the experimentalists are crackpots or making a slipshod mistake, and refuse to accept correction.]
2. If scientists conclude the effect is real, then they would try to find a new physical theory which explains the effect. Most conservatively, by adding a new type of particle or interaction. Importantly, we would normally try to redefine energy in such a way that it is still conserved in the new theory, even if we have to add a new term to the formula for energy.
[I guess this is the "Bargaining" stage of grief, but again if this is successful there is no need to go onto the next stages...]
3. If, after repeated efforts, it appears that there is NO reasonable or natural way to modify our physics theories (and associated definitions) in such a way that there is a conserved energy, then this would rise to the level of a crisis in physics ["Depression"], and people would start looking for more radical solutions to the problem.
4. But if it was discovered that there ARE simple ways to explain the data, by using theoretical models which DON'T have any interesting or useful concept of energy conservation; then (and only then) would we conclude that Energy Conservation is false. ["Acceptance"]
In other words, the first instinct of physicists would be to try to save the paradigm of the theory of Energy Conservation, and there are lots of different ways that this can be done—including questioning the experiment, postulating new physics, and subtle redefinitions of what we mean by "energy". This might lead one to think that physicists have an absolute a priori commitment to energy conservation. But I don't think that's true. I think the paradigm of Energy Conservation is like a piece of toffee, where you can stretch it a lot, but if you stretch it too much it will break. In other words, there exists the potential for future experiments to drive sufficiently radical changes of our theories, that the concept of energy is no longer applicable (except in whatever approximations are needed for the old paradigm to hold).
As I said before, one can certainly write down differential equations which do not satisfy a conservation law, for any quantity that resembles an energy. (A simple example would be if the laws of Nature turn out to be explicitly time dependent. In that case Noether's proof of energy conservation would not apply, and energy could be created or destroyed!
[As I mentioned previously, to some extent energy conservation is already problematic already in general relativistic cosmology, as I've discussed before here and here.]
Nice post! I’m neither a physicist, nor a philosopher, nor a historian of science, but the following ran through my mind as I read it.
The 19th-century belief in the luminferous ether and the Michelson-Morley experiment seem like an example of the stages you’ve described. First the experimental data itself was questioned (“perhaps Michelson and Morley measured at a time when the Earth’s velocity relative to the ether happened to be 0”); but repetitions of the experiment at other times of year made that highly unlikely. Then new theories like “frame dragging” were proposed to preserve belief in the ether, but they seemed a bit contrived, and perhaps inconsistent with other results. Something of a “crisis” ensued, but at last the theory of special relativity came along and, rather than clinging to belief in the ether, simply rejected it and reworked the rest of physics accordingly.
When thinking about all this, I have in mind Quine’s image at the end of “Two Dogmas”: our knowledge and beliefs are like a force field whose boundary conditions are experience. Propositions on or near the boundary can be confirmed or infirmed more or less immediately by experience; propositions in the interior are more resilient. And whatever ultimately happens at the boundary, you can hold on to or give up on any proposition by suitable adjustments in the rest of the system. (You might however twist yourself into a pretzel in doing so.) If this view is right, then it’s never really the case that an experiment falsifies a proposition; but an experiment can lead you to reject a proposition, because clinging to it would disturb other parts of your system more severely than you’re willing to tolerate.
Now conservation of energy must lie rather deep in the interior of our field of beliefs—not as deep as belief in modus ponens or the belief that one has conscious experiences, but probably deeper than Gauss’s law, and that the speed of light in a vacuum is independent of reference frame, and deeper than 19th-century physicists’ belief in the ether. Maybe it’s around the same depth as the second law of thermodynamics. It would therefore take quite an experiment to make belief in it too “costly” to cling to—but the possiblity, as you say, cannot be ruled out! This also means conservation of energy is a nice example of a proposition that lithely slips past the analytic/synthetic distinction and verificationism, since it’s neither a mere definition, nor a mere empirical fact.
‘A simple example would be if the laws of Nature turn out to be explicitly time dependent.”
I never considered that laws of Nature might be time dependent; are you saying that, if so, gravity would weaken, or even cease?
Physicists claim 95 percent of the mass in the universe is invisible dark matter.
This is how much they are willing to stretch the toffee.
Belfast,
Since we're talking about a hypothetical new laws of physics, I suppose in principle you could pick whichever "constant" you like to vary, as long as it doesn't vary so fast that it contradicts the experimental bounds (which are very stringent in some cases).
That being said, it makes the most sense to think about time dependence of "dimensionless" constants which are defined without any units (like meters or seconds or grams), since a change in a constant with units can be compensated for by changing your system of units. (For example, if you have two constants with the same units, e.g. masses of elementary particles, then the ratio between them is dimensionless.) So it doesn't make a whole lot of sense to talk about Newton's constant varying unless you make it clear what else you are holding fixed.
Mactoul,
Point taken. However, it's only about 25% of the mass of the universe that comes from dark matter. The other 70% or so appears to be a nonzero energy density in empty space.
One reason why scientists take the concept of dark matter seriously is that there seem to be multiple independent lines of evidence pointing to it which all seem compatible. Alternative models, such as modifying the laws of gravity, don't seem to be able to explain things like the Bullet Cluster. Here, two galaxy clusters collided with each other leading to both of them slowing down, while the dark matter seems to have kept travelling into the empty space on either side, and was detected using gravitational lensing. This is an example of dark matter behaving like an independent "kind of stuff" with inertial properties, rather than like a modification of the gravitational force law.
As for energy density of empty space, it's the simplest possible way to modify Einstein's equations of General Relativity, so until there's good evidence it's something more complicated than that, I'm going to stick with that.
Ned,
Thanks for your comment, and welcome to my blog. I'm not a big fan of Positivism, but I assume proponents of the Verification Principle thought it was fine to have propositions that combine definitions and empirical facts, as long as it is possible to conceptually decompose the proposition into the two aspects.
In fact, ALL sentences about empirical facts presuppose some definitions, so this linguistic point is not unique to Energy Conservation. Any time I have a concept X and then encounter a new and somewhat X-like situation, I have to decide whether the situation is close enough to my previous examples of X that it is worth calling it by the name "X", or whether a new name is justified.
Hallo Aron,
Indeed a nice post from you! But also a nice comment from Belfast!
Belfast's comment and question is somewhat analogous to my assumption of being not worth it to write down physical differential equations, which describe how elephants come into existence out of nothing. Sure, if that would happen in our universe, then we should consider those physical differential equations as possible explanations for that phenomenon.
I also like to add the problem of empirical induction stating, that there is no rational basis or fundament to assume, that Nature behaves consistently. Sure, you or somebody else would suggest God for that rational fundament, but I see no rational reason for that. I'm a naturalist, if Nature doesn't present God to be the case, then I have no good reasons to assume, that God should be the case.
Hallo Mactoul,
Actually physicists claim, that roughly 68% of the universe is dark energy and about 27%, is dark matter, because of observations and empirical data in combination with our current understanding of physics.
For more of that please consider the following source:
https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy
Further I wouldn't refer to this as "This is how much they are willing to stretch the toffee.", but I would rather refer to this as the process from Aron's post, how physicists make knowledge claims about Nature. Sure, you want to rather refer to Nature as God's Creation, but again I as a naturalist am comfortable with the assumption of Nature's consistency and with waiting for God's presentation by Nature/God's Creation. Also I'm quite confident with the postulation of energy conservation, till Nature presents it to be not the case anymore. In my opinion this is the correct application of Occam's razor.
You see, we are able now to find the neutrinos thanks to the postulations of neutrinos by Wolfgang Pauli in 1930, by James Chadwick in 1932 and by Enrica Fermi's theory of beta decay with the necessary inclusions of energy, momentum, and angular momentum (spin) conservation in 1934 (basically the second scenario from Aron's post).
Just for completion the first direct measurement and observation occurred in the now known as Cowan–Reines neutrino experiment done by Clyde L. Cowan and Frederick Reines in 1956.
So please present an observation or explanation in order for me as a naturalist to consider third and fourth scenarios for doubting energy conservation!
Best regards,
Zsolt
Aron: sure, anything that neatly decomposes into definitions on the one hand and empirical propositions on the other is no problem for positivism. But to be clear, my doubt is that one can neatly decompose conservation of energy in that way.
I think that abandoning Noether’s first and second theorems of invariance amounts to the disruption of General Relativity since it amounts to breaking any link between GR and the stuff before 1918 (Newton ) .These theorems act as a skeleton . Respectfully .
Pablo,
Noether's theorem is a theorem, so it applies whenever its assumptions hold.
This includes applications to General Relativity, but might not apply to some future generalization (since we are discussing hypothetical new physics). As long as GR still holds approximately in some limit, this would not "break any link" with previous physics.
Mactoul,
Just because physical models are not the same as reality, does not mean that there are no realities corresponding to the things in the models. Do you really think that neutrinos aren't real just because they happen not to be capable of being directly detected by human senses? Why can't there be invisible substances?
Aron,
Neutrinos are a part of physical models. Whether they really exist, how would we know.
A neutrino is something that is entirely specified by its properties as tabulated in the physics. It has no unspecified attributes.
But things we directly perceive, such as chairs, air or lightening have attributes beyond those specified in physical models of these things.
We can't doubt that the chair exists since it presents itself to our senses and to doubt our senses per se would make any further proceeding nonsense. So, the chair is prior to inferences and reasoning.
But a neutrino is a conclusion of long series of inferences starting from direct perceptions of pointer readings, for instance. And the inference is not fully determined in the sense that the same perception (or pointer reading) may give rise to quite a different physical model and different posited entities.
In short, there might be other physical theories that may explain the same result without positing neutrino.
Nothing rules out such a scenario. So, the existence of neutrino is provisional to the acceptance of some physical theory .
Hallo Mactoul,
It appears to me, that you have a double-standard.
You suggested, that a chair's existence couldn't be doubted, because we are capable of directly perceiving it and otherwise it wouldn't be sensical. A considered chair is prior to inferences and reasoning.
Yet you simultaneously suggested, that the existence of neutrino is provisional to the acceptance of some physical theory, because other physical theories may explain the same result without postulating neutrinos.
Why do you think, that a considered chair is prior to inferences and reasoning, but a neutrino is not?
I think, that a considered neutrino might be as prior to inferences and reasoning as a considered chair could be.
Also why do you think, that a neutrino is not prior to inferences and reasoning, but a considered chair is?
If other physical theories may explain the same result without postulating neutrinos, then also there might be physical theories, that may explain the same results of perceiving objects, without postulating chairs.
Best regards,
Zsolt
[I edited the last sentence for clarity, based mostly on a correction sent by Zsolt--AW]
Zsolt,
There is no double standard. There are objects directly perceived and there are entities we posit to help understand behavior of these objects. The posited entities may well exist (in some sense and in some space) but that there is a categorical difference between the two seems pretty obvious.
Physical theories are like a map and nobody would confuse a map with the territory that the map depicts.
I recommend the epilogue of CS Lewis' book The Discarded Image for this and further discussion on curious position of quantum mechanics and relativity.
Aron,
A neutrino does not merely "happen not to be capable of being directly detected by human senses". What about others--in fact, all entities posited in physics are incapable of direct perception. Indeed, that's why they are posited. If they were directly perceived, they wouldn't need to be posited.
Physics is the endeavor to explain the visible by the invisible. To explain the direct by the posited. So, the claim is that the posited entities are a different category from the non-posited. And many questions that are meaningful of one category aren't meaningful in the second category.
Hallo Mactoul,
I still think, that you have a double-standard regarding perception, observation, measurement and postulation or explanation of all those things.
According to you (or CS Lewis), how does the perception of a chair and observation of a chair through your eyes differ to a measurement of the image of a chair taken with a camera?
The one and only necessary entity for every measurement of an image taken with a camera is light or in other words electromagnetic waves, which are postulated and explained by Maxwell's equations.
So for the "physical perception of a chair" and observation of a chair via measurement of images the one and only necessary entity is light and not the solid existence of the chair in prior.
If there is no difference between the observation of a chair taken with your eyes or a camera, then likewise to the "physical perception" also the one and only necessary entity is light for your perception of a chair through your eyes. So how do you define or explain that light other than with physics? Or how do you exactly define your perception of a chair other than physically?
In my opinion every perception is a physical perception. Again I'm a naturalist, but I'm open to other rational ideas. If you think, that there is or that you have a better perception of a chair than a physical one, then I like to know that.
I'm as confident in other measurement/perceiving devices as I'm confident in my own body as a measurement/perceiving device. Likewise I'm confident in the observations and measurements of neutrinos. Further I'm as confident in the postulation and explanation of the existence of neutrinos as I'm confident in the postulation and explanation of light or the solid existence of chairs, unless an observation and measurement come along and contradict those postulations and explanations.
Again it appears to me, that you accept very easily the general perception of the existence of a chair but not likewise the perception of the existence of a neutrino. So either you have a better perception of the existence of all objects or you have a double-standard.
Best regards,
Zsolt
PS:
"Physical theories are like a map and nobody would confuse a map with the territory that the map depicts."
I also think, that physical theories are like maps. Further in my opinion physical theories/maps can make testable propositions referring to the physical/natural world. You have confidence in those or not. But how do you accept one over another one rationally? How are you confident in the existence of a chair but not in the existence of neutrinos?
A blind person certainly can't see the image of a chair taken by a camera.
But why couldn't that person hear or feel that image and understand the existence of the image and the existence of that particular chair?
"How are you confident in the existence of a chair but not in the existence of neutrinos?"
Existence of a chair does not depend upon any scientific theory. It is prior to science. Rather it is input to science. Its properties, mass, color, its electric, thermal properties are explained in science in terms of posited entities like electron, proton etc.
Existence of an electron depends upon the currently accepted scientific theory. If you would recall the history of electrons, the electron was posited to help explain electric phenomena in cathode ray tubes. Now suppose, tomorrow electron is further explained in terms of strings. Then the electron will not be fundamental. It may even lose its place in physical theory.
Hallo Mactoul,
I still don't quite understand, how you exactly differentiate the perception and idea of the existence of a chair and a neutrino or an electron.
According to you why are "chair" and "particle" not interchangeable?
To put it in your words:
According to you why is this not considerable:
Existence of a "electron, proton etc" does not depend upon any scientific theory. It is prior to science. Rather it is input to science. Its properties, mass, color, its electric, thermal properties are explained in science in terms of posited entities such as mass, energy, color etc.
Existence of a "chair" depends upon the currently accepted scientific theory. If you would recall the history of chairs, the chair was posited to help explain chair phenomena in nature. Now suppose, tomorrow "chair" is further explained in terms of strings. Then the "chair" will not be fundamental. It may even lose its place in physical/natural theory.
So how is our perception of a chair better than our perception of particles?
I don't see good rational reasons for having a better perception for chairs than particles.
Best regards,
Zsolt
This argument is starting to remind me of the Medieval dispute between Nominalists and Realists (neither name meaning at all what a modern would think).
Seriously, guys, surely it's clear that we have more direct perception of chairs than we have of electrons, and equally that we have direct perception of phenomena to which we give the name electrons. I don't see where we are getting by insisting that our experience of chairs and electrons are exactly the same, or that they are totally different. Surely some things about them are the same--we have actual physical perceptions of reality that we are taught to call "chair" and we have actual physical perceptions of reality that we are taught to call "electrons" (for instance lightning, or plugging things in and seeing sparks, or using a battery etc). Equally some things about them are different--the chairs are easily manipulated and shown to others, and electrical phenomena are difficult enough that it took us a long time to assign the name "electron" to part of it.
I think it's pretty funny that you picked a "chair" as the representative "real" object when us linguists love to use "chair" as example of a word which is actually hard to define (consider the beanbag chair). In any case, I think there is a real confusion here between the physical reality and the words we use to describe that reality, which I suppose in their way constitute a folk theory of "physics".
I almost said "inarguable" instead of "clear" above, but if this blog teaches us anything it's that everything is arguable.
Nobody perceives electrons. I suppose it is a measure of success of physics that we feel electrons to be as familiar as chairs. But electrons are nothing like familiar things. Strictly speaking, an electron is a quantized excitation of a wave function. It is an entity in physics and physics alone.
Hallo Mactoul,
I still dislike your formulation of sentences and your use of the word "physics".
Physics is all about making statements and descriptions about nature, that is all around us.
So your sentence "It (electron) is an entity in physics and physics alone." is not very sensical in that regard for me, because if electron is an entity in physics, then it is an entity in nature, that is all around us just like the entity chair is.
As for electrons being not familiar things, well you could try to stick your fingers in an electrical socket or you could try to go to the biggest high point in a thunderstorm and catch a lightning in order to “familiarize” yourself with “the physical entity” electron. But I wouldn’t recommend it to do so, because according to experience too much electrical current on direct contact could severely damage or even kill you. But I would recommend you to buy an oscilloscope or an old picture tube television. It’s a much safer way to familiarize yourself with “the physical entity” electron. As for catching lightning in a thunderstorm everybody knows how it was done by Benjamin Franklin. It was done with a kite.
Best regards,
Zsolt
Physics= a field of scientific enquiry.
Not a synonym for Nature.
Electrons were posited to help explain electric phenomena.
How do you know that electric current is due to motion of particles each having a charge of 1.6e-19 coulomb and mass 9.1e-27 g and spin 1/2h ?
Hallo Mactoul,
Yes,
Physics=a field of scientific enquiry about Nature
Not a synonym for Nature.
BUT every statement and proposition made by physics is a specific statement and proposition about Nature.
That's the whole purpose doing physics: Making and validating statements and propositions about Nature.
Yes, electrons were posited to help explain electric phenomena. That's called a postulation - making a statement and a proposition about Nature.
C, mass of 
kg and spin of 
?
How do we know, that electric current is due to motion of particles each having a charge of
Well, we know all these things through validation of the postulation by simply looking at Nature via experiments, measurements and observations:
- electric current is due to motion of charged particles
That’s the definition of an electric current. An electrical current is a unified motion or flow of charged particles like ions or electrons.
“[In metals] the outer shells of their atoms are bound rather loosely, and often let one of their electrons go free. Thus the interior of a metal is filled up with a large number of unattached electrons that travel aimlessly around like a crowd of displaced persons. When a metal wire is subjected to electric force applied on its opposite ends, these free electrons rush in the direction of the force, thus forming what we call an electric current.” from ‘One, Two, Three…Infinity’ (1947) by George Gamow.
We know all these things because of a lot of cumulative testing - looking at Nature very carefully.
- charge
C of an electron
Robert A. Millikan and Harvey Fletcher measured it first in his oil drop experiment in 1909 - looking at
Nature very carefully.
- mass
kg of an electron
Arthur Schuster measured the mass-to-charge radio first in 1890 by measuring the deflection of cathode rays due to a known magnetic field in a cathode ray tube.
Seven years later in 1897 J.J. Thomson showed that cathode rays consist of streams of particles, to be now called electrons, and made more precise measurements of their mass-to-charge ratio again using a cathode ray tube - looking at Nature very carefully.
In combination with the results of the oil drop experiment by Robert A. Millikan and Harvey Fletcher the mass of an electron can be determined and calculated.
- spin
of an electron
- looking at Nature very carefully.
After the experiment’s conception by Otto Stern in 1921, the now called Stern-Gerlach-experiment was first successfully conducted by Walther Gerlach in early 1922.
In the original experiment, silver atoms were sent through a spatially varying magnetic field, which deflected them before they struck a detector screen, such as a glass slide. Particles with non-zero magnetic moment are deflected, due to the magnetic field gradient, from a straight path. The screen reveals discrete points of accumulation, rather than a continuous distribution, owing to their quantized spin.
So the spatial orientation of angular momentum is quantized and hence, an atomic-scale system was shown to have intrinsically quantum properties.
This experiment can also be done with electrones (cathode rays) in order to show the quantized spin to be
Mathematics is an abstract discipline in science. Pure Mathematics has not much to do with Nature.
But you can’t say the same for physics. Physics has very much to do with Nature.
So please, Mactoul, don’t conflict the two disciplines of science with each other. There is a fine distinction between those two disciplines.
Further just stating, that you are only capable of "looking at chairs" but not capable of "looking at electrons", is not quite rational or convincing to state. Your "looking method at Nature" might be not sophisticated enough.
Best regards,
Zsolt
You invoke "looking at Nature carefully "
Actually the scientist looks at pointer reading. And then he makes series of inferences --for some reason you omit this part. Science isn't just looking, observing or measuring -- it is making inferences.
So electron is only arrived at at conclusion of series of inferences
You may put it that the election is perceived intellectually.
Sure, okay, so the electron is only arrived at a conclusion of inferences (it's called reverse engineering, sure thing).
We may put it that the electron is perceived intellectually.
If so, then how is the chair not perceived intellectually? How is the postulation of the chair not reverse engineered likewise to the postulation of the electron?
Why would you postulate something that could be seen and felt directly?
It can't be all postulates. At one point you need to connect with the physical reality.
For instance, the pointer reading or the oscilloscope trace can't be postulated. They are input to the series of inferences.
So, doing science consists of observing and then making inferences based upon what was observed.
Observation is eyes prior to thinking.
Making inferences is pure thought.
Correspondingly, we have objects seen with the eyes and objects posited in thoughts aka physical theory.
I am sorry to belabor this point -- that some things are prior to inferences-- because in my experience a great deal of confusion exists by ignoring this point.
People talk easily of multiverses and what happened billions of years ago and what will happen trillion years after but are in doubt regarding the reality right before them. Bertand Russell begins his Problems in philosophy by saying that table is mostly empty space.
Hallo Mactoul,
It can't be all postulates. At one point you need to connect with the physical reality.
For instance, the pointer reading or the oscilloscope trace can't be postulated. They are input to the series of inferences.
Again, postulation's purpose is to make an accurate statement and proposition about Nature. How much connection do you want to have between a postulate and physical reality?
Yes, postulations can be inputs to the series of inferences, that can be validated or tested, measured and observed. But also postulations can be the conclusions of series of inferences or of other measurements and observations (aka reverse engineering).
You have a very twisted understanding about experiments or “pointers”.
So, doing science consists of observing and then making inferences based upon what was observed.
Observation is eyes prior to thinking.
Making inferences is pure thought.
Correspondingly, we have objects seen with the eyes and objects posited in thoughts aka physical theory.
I don’t understand a sentence from this section. Would you be so kind and please elaborate on this section much more in detail? Do you mean with the word “objects” chairs or electrons? What’s the exact difference between them? How are your senses better than the senses of any measurement devices?
Are you trying to say again, that chairs are prior to thoughts/theories? If so, then why can’t electrons be prior to thoughts/theories, which then could be validated via experiments and measurement devices with better senses than your senses? Why and How?
I am sorry to belabor the point -- that some things are prior to inferences-- because in my experience a great deal of confusion exists by ignoring this point.
You don’t need to be sorry. But I would be thankful, if you could give a proper elaboration on “that some things are prior to inferences”. How are your senses better than any other measurement device’s senses? How do you then exactly determine that chairs are prior to inferences but particles such as electrons are not? How did you eliminate the possibility of electrones being prior to inferences?
It appears to me, that you made that elimination only on the fact, that your senses are not capable of registering electrones. It’s not rational and not sensical to do so only on that fact, because there could exist measurement devices with better senses than yours, that are capable of registering electrones.
People talk easily of multiverses and what happened billions of years ago and what will happen trillion years after but are in doubt regarding the reality right before them. Bertand Russell begins his Problems in philosophy by saying that table is mostly empty space.
Sure, one can make a lot of guesses about multiverses just like about some things, which are prior to inferences. But regardless of that, the now called Geiger–Marsden experiment performed between 1908 and 1913 by Hans Geiger and Ernest Marsden under the direction of Ernest Rutherford certainly implies, that the table is mostly empty space.
For myself I wouldn’t call that a problem. But anybody to think, that they are capable of only relying on their own senses to acknowledge their surroundings and Nature itself and ignore any results of any other measurement devices or observations, I would call that notion of thoughts a problem.
Best regards,
Zsolt
Measuring devices typically produce a number. And there is a gap between this number, such as electric current and electron. This gap is bridged by physical theory.
But objects such as chairs have no such gap and thus require no theory. In this way they are prior to theory.
By the way, the measuring devices are utterly different from our senses. There is a difference in kind such that it doesn't make sense to day if one is better than the other.
Hallo Mactoul,
Measuring devices typically produce a number. And there is a gap between this number, such as electric current and electron. This gap is bridged by physical theory.
But objects such as chairs have no such gap and thus require no theory. In this way they are prior to theory.
A photo-camera measures images in the form of light. Similarly our human eyes measure images in the form of light and further our human eyes have a lot of similar components to photo-cameras or photo-cameras have a lot of similar components to our human eyes. Again how does it differ to measure the image of a chair by a photo-camera or your eyes? Why is there a “gap” between the measurements done by a photo-camera - given the idea of a chair by Nature and the actual chair prior to the measurements, that has to be bridged by physical theory, yet by measurements done with your eyes - similarly given the idea of a chair by Nature and the actual chair prior to measurements there are no such “gap” to be bridged by physical theory?
Oscilloscopes or cathode-ray tubes are measurement devices for cathode-rays/electrons similarly to photo-cameras being a measurement device for light-rays/photons. If the cathode-ray tube functions properly, then electrons are detected on the electron-sensitive screen of the measurement device similarly to if a photo-camera functions properly, then photons are detected on the photo-sensitive screen of the photo-camera also similarly to if your eyes functions properly, then photons are detected in your photo-sensitive photoreceptor cells in your eyes on your retina.
If there is no “gap” to be bridged between the measurement of chairs done by your eyes (or in that regard other measurements done by your other senses) and the actuality of chairs, so that chairs are prior to all measurements/inferences, then why is impossible for electrons to be similarly prior to all measurements/inferences?
Again, please don’t confuse the two disciplines of science mathematics and physics with each other.
By the way, the measuring devices are utterly different from our senses. There is a difference in kind such that it doesn't make sense to day if one is better than the other.
I hope, that I could explain in my previous sections, why and how this conception is clearly not the case.
Best regards,
Zsolt
Output of measurement is a number by definition of what measurement is.
Your first sentence, therefore, needs to be reworded to make sense.
But we both are concerned about the input right now or we are concerned about what is prior to input, not the output.
So why are chairs prior to any input and output?
Can electrons be prior to any input and output just like chairs?
If no, then why not?
You, Mactoul, are still not answering my questions.
By the way, I agree with you, Mactoul, that the output of a measurment is a number by definition. But in a broughter sense it doesn't have to be that and further I'm not concerned about the output of a measurment.
And if you really want to have the completed version of my first sentence in that regard, here it is:
A photo-camera measures images in the form of light, that can be associated with numbers.
Here is an entertaining video about how an image is put in to numbers by Matt Parker:
Stand-up comedy routine about Spreadsheets: https://www.youtube.com/watch?v=UBX2QQHlQ_I
Just think about it.
Thank you.
And are our sensations are associated with numbers? They happen to have essentially non-numerical quality.
Which is a categorical difference from instruments that measure and give a number.
Hallo Mactoul,
Again, Mactoul, you are not answering my core questions.
How and why are chairs prior to any measurements and observations?
Can electrons be prior to any measurements and observations like chairs can?
If not, why not?
You don't seem to understand the implications of creating images via spreadsheets for example done by Matt Parker or by any digital display for that matter and how images are similarly captured/measured/observed by human eyes and photo-cameras and what's the difference between Input and Output for measurements/observations.
I guess, that's your double-standard then. You accept, whatever your brain is producing as an Output of "measurements"/observations for chairs. But you can't similarly accept the Output of other measurements/observations, because of "your dislikement of numbers"?
Seriously what a joke?
Do you accept then photos as an Output of chairs produced by photo-cameras?
I can't understand through this conversation with you, Maftoul, how or why you would accept photographs or you would not accept photographs as Outputs of chairs produced by photo-cameras.
Again, if you don't accept photographs as Outputs of chairs produced by photo-cameras, then why and how are you capable of accepting whatever your brain/mind is producing as an Output?
I want answers to my questions!!! Not just "because measurements are numbers and I personally dislike numbers".
Best regards,
Zsolt
"How and why are chairs prior to any measurements and observations?"
My core point was chairs are prior to chains of inferences.
These chains of inferences (aka physical theory) are required to establish electrons, protons, neutrinos et al from measurements.
Measurements themselves involve macroscopic objects. They don't need to be posited but microscopic objects of physical theory need to be posited.
Haollo Mactoul,
You still state and give as a response to my questions, that microscopic objects need to be posited and macroscopic objects like chairs don't need to be posited by physical theory.
We had this already. It's called reverse engineering.
This response doesn't clearly answer my questions.
My questions are:
On what basis did YOU decide, that macroscopic objects like chairs don't need to be posited by physical theories?
AND
Could microscopic objects be posited like macroscopic objects such as chairs posited without any necessary physical theories?
If chairs don't need any physics, then why couldn't electrones also not need any physics?
On what basis did you decide THAT?
Do you decide that with only your senses?
Do you trust your eyes more than photo-cameras?
What is your justification for that?
Is your justification for that only your own senses?
You are still not answering my core questions.
Best regards,
Zsolt
Zsolt,
You are welcome to continue this argument with Mactoul here. But can we keep it classy and not throw random sexual references into a discussion about philosophy of science? I don't want the search bots to get confused about what kind of site this is.
Anyway, I removed two comments by you. If you want a more risqué discussion of energy conservation, you are welcome to start your own blog...
Thanks,
The Moderator.
Hallo Aron,
Thank you for your allowance of the argumentation here.
Yeah, I did the google search and citation of that research on second thought on my previous post.
At least based on that, my previous post was justified.
Again, thank you for your allowance and understanding and I apologise for that.
Best regards,
Zsolt
Regarding the merits of the conversation, I agree mainly with Zsolt.
Of course it is true, that chairs are known to exist even prior to doing any kind of formal or mathematical physics.
But that doesn't mean that chairs are known apart from any kind of measurement process, i.e. without any mediating factors or mental deductions. We do not directly perceive the essence of the chair. Instead, light has to bounce of the chair and reach our eyes and brain, before we can become aware of the chair. It is also possible to be wrong about the existence of a chair, for example in the case of an optical illusion. These illusions prove the existence of a sort of informal, unconsicous ability to posit objects, which is by no means infallible (in individual instances).
On the other hand, it is also possible for a human being to see the tracks of individual charged particles (including electrons) in a cloud chamber. Please watch the following video. Each condensation track that appears is due to an ionizing particle following that track.
This observation of particles is somewhat indirect, in the sense that we are observing the condensation rather than the particle itself. But I see no meaningful way in which this "indirectness" is more severe than the usual indirectness, that is always involved when you observe things through light bouncing off of them (or sound waves, odors, etc.). True, you cannot usually see the path of an electron outside of a cloud chamber. But you also cannot see a chair in a perfectly dark room. The circumstances have to be right to observe different objects. Although the circumstances required to observe elementary particles are considerably more esoteric than the circumstances to see chairs, I see no fundamental epistemological difference between the two cases. (But I do think there is a fundamental difference between both of these cases, and when we observe our own consciousness.)
(Incidentally this video also disproves the statement that all scientific measurements are numbers. Staring at a cloud chamber is not a number. There are various numbers that could be extracted from this data; for example if you film it and then measure the lengths and curvature of tracks. This can in turn be used to extract information about masses and charges, and related to the mathematics of QFT. Nevertheless, the data in this video is not most immediately presented to us in the form of a number, and there are some things that are learned from it even before calculating such numbers.)
While scientific reasoning involves some new tools and features not present in everyday experience, quite a lot of science is in fact continuous with everyday notions of observation, and can be understood as a refinement of common sense notions of looking at reality. There is no sharp dividing line between scientific observation, and "regular" observation.
(This does not necessarily imply that physics is methodologically capable of discovering all true features of the world. Rather it means that some amount of physics is implicitly there in our everyday interactions with material systems.)
Zsolt,
Please don't worry about it. I felt the need to draw a line, in order to avoid setting a possible bad precedent for the tone of future discourse here. But I don't blame you for not knowing exactly where that line would be, nor do I blame you for finding the joke amusing. Just don't do it again.
Aron,
This discussion is hampered by deep disagreement on very meaning of the word. I should have thought that measurement admits of a simple meaning--to measure something is to quantify, attach a number.
But it seems that all kinds of things may be called measurement.
In my opinion, cloud chamber produces phenomena which admits of measurement. For example, length and relative angle of tracks etc. The tracks themselves are not measurement. And what they may be tracks of, is a question of theory and nowise observed--directly or indirectly.
For a physicist to cast doubt on general reliability of sensation, as you come close to doing, is to saw the branch one is sitting on. Sensation is the only point where physical theory meets reality. If sensation is to be generally doubted, one is left merely with pleasing theories.
I reiterate the only point of physics to to explain the unposited with the posited. The whole history of physics, from epicycles onwards, is the history of this endeavor. Thus, there are and must be two different fundamental categories of objects--the unposited and the posited.
Any attempt of see or feel the posited entities must draw upon theory and upon the unposited for the sensation.
"Staring at a cloud chamber is not a number"
One may stare at a cloud chamber for ever but unless one measures something, it is not going to lead to electron or muon etc.
Zsolt,
"Do you trust your eyes more than photo-cameras?"
It is an irrelevant comparison nowise suggested by any of my remarks. Eyes are not competing with cameras. Even with all the cameras in the world, you will need to use your eye.
I think it is the use of the word "posit" that is creating confusion. When you ask
"On what basis did YOU decide, that macroscopic objects like chairs don't need to be posited by physical theories?"
Webster 1913 dictionary defines "posit" as
-To assume as real or conceded;
A macro object that is right before your eyes is real, without any qualification. Unless you take it as real, you can't even begin to behave in a sane manner, much less do physics. So, there is no sense in positing macro objects.
Macroscopic objects or just plain objects don't need to be posited. They are before you
Hallo Mactoul,
Finally some response from you, that comes closer to my core questions. Thank you for that.
So my first question is partially answered. According to you macro objects are real without any qualifications. On what basis, do you know that?
Could be on the same basis in similar fashion to be assumed, that micro objects are real? If not, then why not?
Note, that I'm not questioning you to doubt your senses. But I'm questioning your doubt in other measurements and observations.
Some extra for you to think about: If you listen to radio, then do you listen to sound or light?
Best regards,
Zsolt
Mactoul,
Perhaps I should have use the word "observation" rather than measurement. The fact remains that not all scientific observations take the form of numbers. (And it is certainly possible to distinguish between e.g. alpha particles and electrons in a cloud chamber, simply by looking at the trails without making any numerically precise measurements.)
I think you are equivocating here on the words "general reliability". What I claimed, is that sensation* is not infallibly reliable. In other words it does not lead us to the truth 100% of the time.
This is very different from saying that sensation is 0% reliable, i.e. that it has no correlation with truth. That would indeed be insane. But of course I never said or implied any such thing.
If our conclusions drawn from sensations are reliable say 99% of the time, but we can sometimes be tricked by optical illusions and the like, that in no way makes science impossible! (Indeed, one important part of scientific measurement is identifying the limitations of ordinary human perception, so that we can do better.)
Your belief that sensation gives us immediate access to the macroscopic properties of physical objects, seems to be inconsistent with the existence of optical illusions. For example, if I place a pencil partially into water, then it will appear to be bent. This is an illusion caused by refraction of light.
Do you believe that such pencils really are bent? Do you believe that objects which are farther away really are smaller? That there is actually a chair in the youtube video I linked to? Unless you are willing to say these things, then you also do not believe in the total reliability of sensation.
*really this should be our immediate deductions from sensation, because two people could have the same sensation but draw different conclusions from it, e.g. if one person is taking into account an illusion, while the other is not.
I have not much experience with html tags and attributes.
With this post and link in text I like to give a refrence to, what I meant with the similarities between photo-cameras and human eyes.
I hope, that it worked.
Judgement that the pencil is red or black does not normally involve an excursion in physics.
But judgement that the tracks are alpha particle or beta particle does involve physics. Thus, this judgement is not an observation but an inference.
Aron
The term "general reliability" naturally allows for occasional optical illusion and such like. But the success of physics itself attests for the reliability of senses otherwise the physicists could not be sure of the pointer readings.
My point is that we make an unqualified, though occasionally mistaken, judgment of the existence of external objects. This judgment is prior to series of inferences that are involved in physical theory and indeed it is the basis for all series of inferences.
Judgment of existence of things like electrons is qualified: the judgment lies at the end of long series of inferences and thus depends upon the correctness of inferences. Also, the physical theory is not fully determined by observations. Gravitation is both force at a distance and local curvature of space. All physical theories are provisional in nature. Hence the entities that are posited in various theories are provisional to a degree as well.
Zsolt,
"macro objects are real without any qualifications. On what basis, do you know that?"
It would be insane to think otherwise.
Hallo Macoul,
If it would be insane to think (and you think that based on what Inputs? Senses again?), that macro objects are not real, then in similar fashion it could be assumed, that it would be insane to think (on no particular Inputs, I guess), that micro objects are not real.
If you think, that this is not the case, then why is this according to you not the case?
Let's try this with different words:
According to you, Mactoul, the assumption/postulation of macro objects doesn't require any justifications.
According to you the assumption/postulation of micro objects require a lot of justifications and inferences done by physics, therefore it is easily doubtable.
Let's assume or let me assume, that the assumption/postulation of micro objects is done in a similar fashion as the assumption/postulation of macro objects.
Is my previous assumption rational according to you? If it is not rational according to you, then how and why is it not rational according to you?
Hopefully you give me an understandable response without any "senses" and "numbers".
Best regards,
Zsolt
Zsolt,
The key point that I am apparently unable to get through to you is
"Macro objects don't need to be postulated or assumed". They convey their reality to us without our having to think. Postulation/assumption is an act of thought.
Consider that pointer readings are macroscopic. What does it mean to postulate a pointer reading? How can physics work with postulated pointer readings?
Hallo Mactoul,
I understand your key point and my key point is, that your proposition is a double-standard between human senses and other measurements/observations.
Macro objects convey their reality to us through our senses. Based on that we justify our assumption/postulation of macro objects.
If macro objects convey their reality without our having to think, then why couldn't micro objects also convey their reality without our having to think?
As you see, I follow your key points. But I also follow them further - looking at their implications.
This is basically the same core question from my previous post, that you still are not capable of addressing it appropriately.
Again, it's called reverse engineering. I don't have a double-standard as you have, so I trust those "pointers" as much as I trust my senses. My senses are leading to macro objects and some "pointers" are leading to micro objects. Simple as that.
Best regards,
Zsolt
PS: Sorry for my last post and my repost.
I'm still figuring out, how to use html tags appropriatly.
I hope, that it worked this time.
[No problem, I've deleted the duplicate comment. I haven't been able to figure out a good way to give people the ability to edit their comments, but I am happy to do it for others upon request---AW]
Zsolt,
I see you have managed to omit the key word "inferences" yet again
Clearly, I have failed to convey my argument. Further discussion will be fruitless.
Well, Mactoul, I also think, that in foreseeable future our discussion will not reach any significantly good number on a scale from 0 to 10, where 0 means, that we don't understand each other, and 10 means, that we completely understand each other and we are in agreement.
Again I apologize for taking our discussion once below 0 in a negative range.
Best regards,
Zsolt
Aron,
reverting to the original topic of energy conservation, I have a doubt regarding your point 4.
"4. But if it was discovered that there ARE simple ways to explain the data, by using theoretical models which DON'T have any interesting or useful concept of energy conservation; then (and only then) would we conclude that Energy Conservation is false".
You may be able to conceive of theoretical possibilities here but I can't imagine a situation where we find electrons accelerating for no apparent reasons and the physicists just saying that it just shows energy conservation isn't experimentally true.
My understanding is that experiments don't and can't measure energy directly. The expressions for energy are derived from assuming conservation of energy. Thus, it is impossible to experimentally invalidate energy conservation.
In other words, to do physics is to assume conserved quantity (or quantities) and we can call this quantity to be energy.
I am aware that violation of time-symmetry yields energy non-conservation. My masters thesis was the topic of particle creation in evolving spacetime, something I now find unscientific.
For instance, while you would probably rule out Hoyle steady-state universe on grounds of experimentally false, I would argue on the more fundamental basis of being unscientific in assuming particle creation (and even worse-- particle sink at large distances).
If there is a redshift due to the expansion of space, can't we say that this is a decrease in energy in each one of this photons, and therefore the universe is losing energy?
flavio,
I think that's too hasty. First one needs to inquire as to whether or not there is energy stored in the expansion rate of the universe. If there is, then it is logically possible that the energy is simply being transmitted from the photons to space itself.
Note that, for this viewpoint to work, it would need to be the case that photons act gravitationally on spacetime in a different way from slow & massive "dust", which does NOT redshift as the universe expands but only thins out. This is indeed the case! Photons have pressure as well as energy density, and pressure also causes gravitational attraction.
However, as I've mentioned before it is no straightforward way to define an interesting conserved energy in cosmological settings...
Mactoul,
-I agree with your first sentence.
-There is a lot of truth in your 2nd sentence, but I don't think it gives a complete account of what we mean by energy. For example, electric charge is not conserved, but it isn't considered acceptable to rename this "energy" in order to save energy conservation. In order to reasonably be called "energy", a conserved quantity has to have at least some relationship to what we meant previously by the word "energy". In particular one requires it to have a close relationship to time translation symmetry...
-Your 3rd sentence does not follow from your 2nd sentence.
Suppose we come up with a new model M of physics which is based on experiment. (Of course no experiment can ever completely determine which model M we use and we need other criteria as well such as simplicity, but let's suppose that all rival models to M are a lot more complicated and arbitrary.) And suppose further that in this model M the old formula of energy E is not conserved.
Then I grant you that physicists will try to look for a new quantity E' which is conserved in M, for example by adding some additional term to E. And that having found such an E', they will probably call it "energy".
However, logically it could also happen that in this new model M, there is NO reasonable quantity E' that is conserved. (Or at least, no quantity with a reasonable algebraic expression in terms of physical quantities... I'm not counting mathematical constants like "pi" or something horribly gerrymandered and arbitrary.) Within such a model M it would be reasonable to say that energy is not conserved, meaning that there is no reasonable extension of the concept that is conserved.