Hans-G. Hildebrandt:

You are right: "There is never a stupid question, ...". This is not only German; it is a universal dictum. In fact, your question is very profound.

My 'simple' answer is: Yes; "physics is able [in principle] to declare observations (experimental findings, etc. ...) without always bearing theories in mind". However, from time immemorial, our scientific experience has taught us that without some conceptual framework, or without exploring some patterns, or elaborating some relations with other findings, our observations degenerate into a mere 'catalogue' of data.

The point is that the perpetual 'conversation'/'dialogue'/'dialectic' (!) between experiment and theory has proved to be quite fruitful. Without experiment, physics is mere metaphysics or philosophy; without theory, physics is a mere catalogue of data.

Kindest regards.

I don't think so.

Just imagine your mind is wiped clean of all physical theories, and you observe the path of the sun each day. How can you explain this, if you were on your own? Given enough understanding and time and additional observations, you would create a sequence of explanations like "celestial spheres with sun, moon, and stars attached to it", geocentric universe, sun centered solar system, gravitational fields etc. And in each case, wouldn't "explanation" be just another term for "theory"? (Admiitedly, today theories are expected to be quantitative, so "celestial spheres" would be rated not much higher than "Cassiopeia banned to the sky for punishment".) The only difference were that you yourself invented the theories.

From another point of view, Occam's razor (indirectly) demands that you don't construct yet another theory (= explanation) if there is already one explaining the new phenomenon well. So, while you can privately follow your intuition wherever it leads, before publishing an explanation based on something new you have tentatively to apply the not yet refuted theories.

Thanks for your answer, Joerg.

The greatest problem in physics and other sciences is to declare the reality by unreal inventions which are based only on thought processes and ideas.

You told par example the 'celestial spheres' in the medieval astronomy. I call quarks, black holes, dark matter and some others in contemporary physics as pure inventions, as whishful thinking.

A theory is an attempt to declare the reality. The most theories in modern physics are based on its own inventions. The research results are evaluated under the assumption of the rightness of the underlying inventions and not in search for other and real causes. Physics stagnates in circular arguments.

If a theory is obviously speculative or becomes more and more in contradiction with the reality than we have to realise that this theory is wrong!

If I wait until a theory is demonstrably wrong and only then I try to search for a better theory than I'm not a scientist but rather a religious man.

„Es ist klug und weise, an allem zu zweifeln.“ (Volaire)

Hans-G. Hildebrandt I partly agree with your answer, and completely with Voltaire's quote.

There is this anecdote that a visitor of Voltaire was astonished to see the bible on Voltaire's desk, and Voltaire said something like: "You must always have the document of the opposing party at hand."

Your question contains the sequence "without always bear the theories in mind". But you cannot simultaneously doubt a theory and don't think about it.

No-the question doesn't make sense, since the words ``observations'', ``experiments'' don't make sense in the absence of a ``theory''.

Stam Nicolis: We say in German: There is never a stupid question, but many stupid answers.

A theory doesn't make sense in absent of observations, experimental results, experiences etc. It is impossible in exact science to sit on the desk and declare the reality by godly thoughts and mental games. The result of the LHC-experiment at CERN was: Quarks do not exist! Physics can forget all the godly theories in particle physics and the related theories like 'big bang' with its invented quark epoch.

If you are still able to leave the worn tracks of theories than read plaese this paper:Thesis The Reason of a realistic View to Particles and Atomic Nuclei

We should stay on a firm ground and not follow refute theories like devout believers.

Joerg Fricke: One more 'Voltaire': „Es ist gefährlich, in Dingen recht zu haben, in denen die etablierten Autoritäten unrecht haben.“

Joerg Fricke: " Occam's razor (indirectly) demand that you don't construct yet another theory (= explanation) if there is already one explaining the new phenomenon well. "

No, I don't think that Occam's razor gives earlier theories priority. Its rule about "minimising the number of entities" applies within a theory, not between theories. It's supposed to be an attempt at producing a fair and objective way of judging an idea's merit based on logical structure. Saying "we already have theories that are sufficiently good, we don't want another" would introduce a social bias based on arbitrary chronology.

A fractionally better theory would then be rejected in favour of a fractionally worse theory that was already entrenched. The preservation of the status quo would (to some extent) override issues of science or logic.

Human beings already act like this, as a way of minimising the amount of work they have to do, without requiring philosophy, they don't need to be encouraged! :)

In the sense of Occam:

It can be accepted that the world of particles is composed of two elementary particles. It is unimaginable that dozens of particles which are invented on the desk should be necessary to build the world.

I had to learn all the questionable theories too. My immediate reaction was: How can a man of exact science replace the imperfections of his theories by his own inventions?

Savants on the desk like Pauli, Gell Man, Higgs et al were unable to analyse the properties of the particles to recognise their structures. The rocky and steep path of recognition lies ahead and not behind.

Eric Baird I agree with you that Occam's razor hasn't any relation to temporal development nor to different theories.

The background of my thought was that the unification of hitherto separate theories form the "peak moments" of scientific discovery; e. g. the realization that light is an electromagnetic wave. After this discovery, Occam's razor would ban the simultaneous use of two different types of aether, a "luminiferous" aether and an "electromagnetiferous" aether, inside the same theory (if any kind of aether was needed at all).

Now, if electromagnetic theory had the status of 1900, but optical theory didn't exist so far (sighted humans were the result of genetic mutation in 1875 ;-) , and Hans-G. Hildebrandt began to establish optical theory, he could spare himself a lot of elaboration of terms, laws, and corollaries which had to be discarded later on (after unification) if he first tried to explain optical phenomena by applying existing theories, in this case electromagnetism.

So, Occam's razor does not prevent anyone from setting up new theories but in view of its possible consequences later on, it seems wise to have a look at existing theories first. That's what I meant by "indirectly".

Hans-G. Hildebrandt:

You are right: "There is never a stupid question, ...". This is not only German; it is a universal dictum. In fact, your question is very profound.

My 'simple' answer is: Yes; "physics is able [in principle] to declare observations (experimental findings, etc. ...) without always bearing theories in mind". However, from time immemorial, our scientific experience has taught us that without some conceptual framework, or without exploring some patterns, or elaborating some relations with other findings, our observations degenerate into a mere 'catalogue' of data.

The point is that the perpetual 'conversation'/'dialogue'/'dialectic' (!) between experiment and theory has proved to be quite fruitful. Without experiment, physics is mere metaphysics or philosophy; without theory, physics is a mere catalogue of data.

Kindest regards.

Hi Joerg!

Okey-doke!

One of my favourite "alternative history" scenarios is the one produced by Wolfgang Rindler, in which Riemann realises in the 1850s that the reason why his curved-space description of gravity isn't working is that it needs the time dimension to be curved, too.

Article General relativity before special relativity: An unconventio...

In that scenario, we effectively get a general theory of relativity in the 1850s that doesn't reduce to SR (SR having not been thought of yet)

In Rindler's version of the story, SR is then discovered as the flat-spacetime limit. I don;t think that's what would have happened.

The "1850sGR" would use the Newtonian equations for gravity-shifts, which would mean that (unlike GR1916), horizons would be effective horizons rather than event horizons, and would leak radiation. So we'd have classical Hawking radiation being studied around the 1880s/1890s.

A study of the properties of the resulting dynamic metric would give us the field of acoustic metrics in the 1890s instead of the 1990s.

Observed causality would be different to current GR, our ability to observe something would relate to our ability to place a massed sensor at the location, and we'd have a form of observer-dependency, so when QM emerged, some of the the QM wierdnesses would be familiar. We'd see them simply as the result of quantising a relativistic acoustic metric, and we'd probably have had a worked-up theory of quantum gravity by about 1910.

If someone had then suggested special relativity, I think they'd have been laughed at: it wouldn't be compatible with gravitational theory, it wouldn't be compatible with cosmology, a change to the Minkowski metric would break GR and make GR incompatible with QM ... it would break too many powerful things like the principle of equivalence that were already working.

In that hypothetical alternate timeline, SR would still exist as a mathematical solution, but it wouldn't be a physical one: GR based on the NM relationships would be time-asymmetrical (with an "arrow of time") – there'd be an energy-loss and an expansion forwards, and an energy-gain and contraction backwards, multiply those two together and square root, and the resulting time-symmetrical oddity would be special relativity. Maybe somebody would find a use for it, but it might have stayed an obscure piece of group theory mathematics with no obvious purpose.

Besides the 'black hole' above:

Physics has par example present four (to five) cotradictionary theories to declare the atomic nucleus. Atomic nuclei are actual spatial grids of particles. If a nucleus is smashed we can observe this particles and many bigger fragments. If a nucleus decays orderly than we observe more or less stable particles and fragments like electrons, positrons, protons, neutrons and cluster. Has no one of the theorticians ever analysed the facts and instead of this made fancy theories?

Theoretical physics is moving further and further away from reality resp. from the base of all exact science. Its world view exist as a system of theories and not as the sum of sure knowledge.

Joerg Fricke: The problem in science is not to make theories or to

bear the theories in mind. Each theory is only a temporary measure or transitional stage. We have to search for knowledge! Our world resp. the reality is recognisably.

Prophetic powers of great theoreticians are useless. we need sharp analytical mind.

Hans-G. Hildebrandt "The explorers are convinced that they saw a 'Black Hole' because the theorie claims in the centre of every galaxy exists a 'Black Hole'."

Two problems with this statement:

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"A first critical question: Why have they detected the 'Black Hole' in a far galaxy? Wouldn't it be much easier to detect it within a closer galaxy?"

I note that you are not asking a question in search of information: you are asking a "critical question" to try to prove a contrary point, that somehow a huge network of seasoned experts got it wrong and you are right. That's a big distinction and so I am going to answer it in the manner befitting how you asked it.

What matters more than the distance to the BH is the mass of the BH and the angular diameter of its event horizon. You don't seem to acknowledge that the presence of a supermassive BH in M87 has been known for decades, from other observational evidence that yielded its colossal mass estimate - and prior to EHT, constrained its bright emission region to be larger than the effective diffraction limit of EHT. Such calculations showed that M87 was an ideal target for the EHT. This is all well explained in the Akiyama et al paper that you cite in your own manuscript, yet you do not seem to have paid it much attention.

You also cannot imply that they selected the "wrong" galaxy without offering at least 1 specific alternative that, in your view, they should have targeted instead - which nearer galaxy would you have chosen?

With such flawed "critical questions" and incorrect claims, you betray an innocence about the observational work around supermassive BHs. That puts you in a very weak position to be making criticisms about the interpretation of the observations.

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Which takes us to your "Contemplation on a Black Spot" manuscript.

• You've got the lambda/d part right enough, but you misunderstood the references to coherence in interferometric imaging: it is not about the source or its resolution, but rather about synthesizing a single effective larger diameter telescope, despite the baseline gaps, by exact knowledge of the wavefront path differences (and hence phase differences).
• So your conclusion is incorrect: "the received signals from M87* are still coherent. This means that the observed object is smaller than the resolving power of the virtual telescope". (Think about it: a classical single aperture telescope works by definition with coherent wavefronts from every point within the field of view, and yet it has no problem resolving details on say, the Moon or Jupiter).
• You completely overlook a page of the Akiyama et al paper where they explain that they deconvolved the interferometer point-spread function from the Fourier-transformed visibilities...and then reconvolved it with a 20 microarcsec beam. This approach is standard radio astronomy practice. Things are more complex than your thinking, which was informed only by principles of direct optical imaging. (Although super-resolution is well established in optical imaging too!).
• Your dismissal of their ability to resolve the 7.5 microarcsec diameter BH shadow is similarly tainted by not appreciating what was stated plainly by Akiyama et al: it was made possible by using "regularized maximum likelihood and CLEAN reconstructed images". These techniques trade spatial noise correlation and PSF invariance for gains in angular resolution.
• In short, the paucity of references and seizing on one simple idea (then misapplying it) is classic "lone amateur enthusiast tries to beat the professionals" stuff.

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Finally, from your post above:

"We know about wheel galaxies and totally disturbed galaxies like "Zwicky". Compare please a wheel galaxy with an exploded Nova. Take into consideration that in the centre of every galaxy can take place from time to time a much more gigantic explosion than an explosion of a Nova. The gravitational centre is more or less destroyed and the well-ordered spiralc paths of the stars going out of order. All the live on planets within the galaxy is at stake by extreme radiation and particle flows. Such events were happening during the history of Earth once in a while but we can't no longer ask the dinosaurs."

I don't know where you are going with this rambling paragraph or how it relates to the EHT observations of the BH. Please explain?

Ray Butler: Please note that I'm not the author of the manuscript "Contemplation on a Black Spot". The author W. Engelhard is obviously doubtful of the 'observation of a black spot' too.

Theory claims that in the centre of every galaxy exist a 'black hole'. The publishers of the picture claim in the absence of a real declaration they had observed a 'black hole'. But we can't be sure not at all that the theory is right nor a 'black hole' exist at all.

I would point out that there are similarities between well known explosions of stars (novas) and the disputable picture. If I evaluate the Hubble-pictures of galaxies unbiased than I see different stages of development. We can observe well ordered (regular) galaxies and many appearent statically stages which are pointing to gigantic periodically processes within the centre of galaxies. All the processes within galaxies appear statically because of their large extension.

If we consider that all stars of a galaxy move gradual on spiralic paths to the centre than we have to conclude explosions resp. outburst of radiation and material matter from time to time. Galaxies are nothing than the centres of matrerial-energetical cycles within the universe. The universe exists in its known form since eternities and for eternities. It changes itself but remains similar to itself.

Thesis The Deceleration of moved Energy emitting Objects by the Dop...

No, it has become commonplace among scientists that "observations can never be freed of theory.”

Source: Steven Weinberg. “Dreams of a Final Theory”.

Luciano Vanzo: "observations can never be freed of theory.”

Please replace better the term 'theory' in this statement by 'own ideas' or 'whishful thinking'. It is right in every religion and within a science if it is facing new and unexpected facts.

A seriuos scientist has to bear in mind that all the theories are merely temporary solutions and questionable.

Your statement, "All the on planets within the galaxy is at stake by extreme radiation and particle flows" presumes carbon-cycle life. Terrestrial life forms live in a very narrow range of conditions, there is no reason to presume that other types of life do not exist in environments that would never support "conventional" life forms.

As my colleague says, "we don't know anything!"

As they say in the "business" side of showbusiness, "Nobody knows anything!"

Scott Suhr: All the forms of life on Earth have a quite narrow tolerance towards energetical influences. You can be sure that other forms (if they are possible at all) of higher life are also very sensitive against energetical or even particle beams over dozens of years. Insects have a surprising resilience. Maybe a result of a survived number of "galactic bangs"?

The mankind has not a chance to survive such an event, but we have a good chance to survive an impact of an asteroid.

Hans- I do not contest that radiation is a hazard to "Earth" life. Where I disagree with you is there may be forms of life that use radiation to live. . . or are tolerant of it. Maybe they are Pu-based instead of Carbon-based. Our search for life in the Universe is hamstrung if we only look for liquid-water planets.

Every theory is only instrument for description of observable dates obtained during some period of time. Any theory lives during interval of time when it can explain observed dates. If the given theory cannot explain new results it is necessary to find another instrument (main theory for given interval of time) that to explain new results. The main theory in cosmology is General Relativity. But that to explain observable dates it is necessary to solve Einstein equations for concrete model which can explain new results. It is impossible to use during many years Friedman theory of expanding Universe, because all Friedman models consider the time as is Special Relativity, where the time does not depend from gravitational action. That to explain observable red shift it is to solve equations for nul geodesic lines in the space-time where temp of time depends on gravitational fields of cosmic bodies including gravitational field of the Universe. For example, de Sitter model with positive lambda-term explains redshift as the result of changing of frequency of photons.

theoretical physics and experimental physics are two sides of a coin....

It every scientist will explain observable dates by means of different theories then scientists cannot understand those scientists who use own theories. The main theory must be as united language for all scientist. The main theory of cosmology is General Relativity . It must be used for concrete calculations of different models. Really, cosmology is based on the theory of expanding Universe where the temp of the time is the same in all space. Therefore all results are explained only by expansion of the space (its deformation only). But the main force in the Universe is gravitation which is connected immediately with changing temp of the time ()deformation does not connected with gravitational fields of the Universe and its gravitating objects. GR is strongly mathematical theory and it is necessary to calculate different models (for stars, galaxies and the Universe) It is not correct only study old cosmological models: it is necessary to built new models by means of solving of Einstein equations.

Larissa Borissova: " The main theory of cosmology is General Relativity . It must be used for concrete calculations of different models. "

Unfortunately, it seems that general relativity is geometrically incompatible with current cosmology:

Preprint Cosmological redshifts vs. gravitational redshifts

It's all very well having people studying string theory and fiber bundles and all that hyper-advanced stuff, but if nobody in the math community bothers to do basic checks as to whether the foundational geometry of the current theory is consistent, then really, what's the point?

Theories are the intellectual shadowing of the reality.

Knowledge is the safe image of reality.

Only experiments, observations etc. deliver precise results on the reality but never theories. Otherwise we could the world recognise only by thoughts and mental games.

Every theory can be applicable until it explains observed dates. If we cannot explain observed dates in frames of accepted theory we must understand the cause of given situation. If we are sure that new results are right, we''ll think: what is it? Two ways are possible in this situation: 1) construct new theory as generalization of accepted theory; 2) to understand what it means. The spread of the Universe can be explained as: 1) deformation of 3-space (Friedman models); 2) the time flows uniformly de Sitter bubble). The both explanations are possible in frames of GR. Kozyrev dates where he has determined positions of stars, clusters and Andromeda nebula at the moment of observation, are not explicable in frames of GR, because GR prohibits momentary spread of information (energy). Contemporary scientists do not see these results because the contradict GR. The problem arises: how to understand these results? This is just the case when we must decide this problem until in mind.

The theories of relativity, both SR and GR have no basis in objective reality and have no philosophical or scientific validity. These are subjective, abstract. mental and geometrical constructs with false claim of tangible physical, mechanical and metrical attributes. Article The Philosophy of Space-Time: Whence Cometh "Matter" and "Motion"?

The faulty notion that "experimental proof" is the sole criteria of positive knowledge has given the opportunity to modern parasitic monopoly capitalism and their allies - decadent theology. to use these obscure theories as ruling ideas by creating a sense of mystery. awe and reverence about the creators of these mythical theories. They use the lure of fame, fortune and fund to have these theories "proved" with multi-billion dollar mega "scientific" projects and with contrived,deceptive and outright false claims.

But our historical experience shows that the only valid criteria of a theory is its social/historical practice and relevance to new technology. In more than hundred years of their existence; these theories have not led to even a single instance of practice or new technology. Centuries long claim of "experimental proof" can never make a theory valid. As the saying goes, "The proof of a pudding is only in its eating". The theories of classical physics did not need even a single experimental proof! Those theories arose out of practice and experiments are proved millions of times a day through the practice of modern humanity.

" The question whether objective truth can be attributed to human thinking is not a question of theory but is a practical question. Man must prove the truth, i.e., the reality and power, the this-sidedness [Diesseitigkeit] of his thinking, in practice. The dispute over the reality or non-reality of thinking which is isolated from practice is a purely scholastic question". Karl Marx, Theses on Feuerbach.