Comments about the Comment in Nature: Good data are not enough.

Following is a discussion about this "Comment" in Nature Vol 539 3 November 2016, by Avi Loeb.
In the last paragraph I explain my own opinion.

Introduction

The Comment in Nature is "Good data are not enough" starts with the following header:
A vibrant scientific culture encourages many interpretations of evidence, argues Avi Loeb
I think the word missing is "should". For the rest I fully agree with him.
At the same time every one in science should be very clear if he or she has any doubt and to be supportive towards doubt by anyone else.
During my study I used the standard physics book written in the Netherlands in 1958 by roughly 10 professors. In this book many experiments are discussed. I call this book the laboratory cookbook, because all the evidence could be demonstrated handson in a laboratory, Today this has very much changed.
At page 24 we read:
To truly move forward, free thought must be encouraged outside the mainsteam.
I agree. You have to be carefull and have an open mind.

Blinkered View

Such projects have a narrow aim - pinning down the parameters of one theoretical model.
I agree that such an approach could be dangerous.
Next we read.
The model comprises an expanding Universe composed of dark matter, dark energy and normal matter, which initial conditions dictated by an early phase of rapid expansion called cosmic inflation.
For specific comments read this: Friedmann's Equation & The path of a light ray Almost all what you read about CMBR, related to the Friedmann Equation, does not show any doubt.
The acceleration of the expanding Universe is no issue.
In the next paragraph we read:
In such a culture, the current model can never be ruled out, even through everyone knows that the major constituents( dark matter, dark energy and inflation) are not understood at a fundamental level.
See specic Reflection 1
Instead observers should presents results in a theory-neutral way.
I think the problem is not in the observers, except the observers should make all raw observations availble. At least what you need is a clear distinction between raw observations, how they are performed and calculations.
One specific point is how do you calculate the speed of light and to what extend is the speed of light (which is a parameter of a physical process) constant.
Next:
Observations should not converge on one model but aim to find anomalies that carry clues about the nature of dark matter, dark energy or initial conditions of the Universe.
That is totally true. For example the concept of dark energy should be critically reviewed starting from a definition what energy is and how it is measured.
Further observations should be motivated testing unconventional interpretations of those anomalies. (such as exotic forms of dark matter or modified theories of gravity.)
The problem with dark matter in the first place is: how sure are we that galaxy rotation curves can not be explained by baryonic matter in the form of small objects. Remember: the planets in our solar system can not be visible observed from large distance and as such fall in the cathegory of darkmatter.

Blinded by beauty

Similarly, modern cosmology is augmented by unsubstantiated, mathematically sophisticated ideas - of the multiverse, anthropic reasoning and string theory.
The biggest problem with multiverse is that it considers that there are more universes without a clear definition of what one universe is. A different problem is that the universe is much larger than what is visible of the universe. What is also true is that what we observe is the situation in the past and worse is to define the concept "visible universe".
The CMBR also gives us a information about something in the Universe a long time ago. The fact is to what extend you can link that information to specific physical conditions in the present.
The multiverse idea postulates the existence of numerous other regions of space-time etc.
Already a question mark can be placed after the concept space-time. Is space-time something that exists? or is this a mathematical construct?
The anthropic argument is then often applied. It holds that our region has the parameters it does (including those of dark energy and darkmatter) because other, more likely values would not have allowed life to develop near a star like the Sun in a galaxy such as the Milky Way.
In Wikipedia we can read: https://en.wikipedia.org/wiki/Dark_matter:
"The standard model of cosmology indicates that the total mass–energy of the universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy."
This reflects the mainstream opinion (Whatever it means) and describes the state of the Universe
The problem with the anthropic argument is: what extra understanding does it bring.
IMO, it is easy possible that there are different forms of life around stars near other galaxies than around our Sun. Most probably they are more primitive. That is because we went also trough such a phase. The issue is what does that say about the laws of physics? IMO nothing in general. Most probably the same atoms and molecules exist overthere (except they will have different names) If there are humans like us, we should critically compare the laws we both have. My prediction is that we have to correct certain laws because their laws, assuming the subject and conditions are the same, are more accurate.
This means that terrestrial life might be premature and not the most likely form of life even in our own Universe.
There does not exist an "our own Universe".
The most likely form of life in outer space is a more primitive form compared to our own.
The anthropic argument, etc, suppresses much-needed efforts to understand dark energy through an alternative theory that unifies quantum mechanics and gravity.
IMO dark energy is only important to explain one aspect of the total evolution of the universe i.e. its expansion. Quantum mechanics in some sense already includes gravity (gravitons). Qm describes the smallests building blocks of matter (particles and radiation) and how they interact (Freedmann diagram).
For example, information contained in, say, an encyclopedia is lost if it is swallowed by a Black Hole that ultimately evaporates into heat known as Hawking radiation.
And what is so special with this? This is the same in the evolution of any reaction: A + B = C + D.
The whole issue what exactly is Hawking radiation compared to electromagnetic radiation and gravity radiation.
This contradicts a basic premise of quantum mechanics that information is preserved and is known as the information paradox.
What exactly is information and what means preserved. IMO when you define both exactly there is no paradox.
When two objects collide the shape of the original two objects is not maintained and is lost. That is always the case. so what is the paradox?
in addition, currently viable models of cosmic inflation require fine-tuning of the conditions of the Universe before and during inflation.
This objection is correct. See also Reflection 1, second paragraph.
Words like fine-tuning should not be used in scientific context. Fine-tuning is something humans do.
Cosmic inflation is a physical, chemical process. It is in the details that are the problems.
The reason why cosmic inflation was invented, is because the universe at large is considered homogeneous. The problem is when we observe the universe most of what we observe is in the past. Of the present we almost see nothing, it is out of vision. When we look carefully in the past at far distance "shortly" after the BB, the galaxies should look less developped. The same with the individual stars. Our sun is 4.5 billion years old. 1 billion year after the BB, specific stars like our sun, should look much younger.
The model has difficulties accounting for the luminous gas and stars that we can see in galaxies, while leaving invisble what we can easily calculate (dark matter and dark energy)
Dark energy is not an issue in galaxies. Dark energy is an issue for the universe at large.
The issue is that dark matter is difficult to calculate. What "easily" can be calculated is the amount of missing matter. The difficulty is, to explain what missing matter is. How much is baryonic versus non-baryonic. An additional difficulty is why do elliptical galaxies have no missing matter issue. The same why is there no missing matter in the bulge of a spiral galaxy and why is there no missing matter in our solar system.

Alternative paths

The LIGO discovery of black hole mergers should encourage a 'template-free' search for new sources of gravitational waves that were never imagined.
This search should start from the concept that what LIGO discovered was not the merging of 2 BH's 1.3 billion years ago.
Maybe this merging involved more objects.
Indeed a habitable planet was recently discovered around the nearest star to our Sun, Proxima Centauri, which could be probed with a future spacecraft. http://breakthroughinitiatives.org/Concept/3
This type of research is interesting, but it is not basic.
A healthy dialoque between different points of view should be fostered through multidisciplinary conferences that discuss conceptual issues not just experimental results and phenomenology.
I fully agree
There are many issues


Reflection 1

The central part of the evolution are physical processes and chemical reactions. It is these that we try to understand. Many of these processes and reactions are the same and we call the descriptions laws. Within the same processes and reactions there are also differences. Those differences we call the parameters and by performing experiments we try to understand how these parameters influence these processes. One strategy is to define a model expressed in mathematical equations.
This seems simple but the current reality is different. One major issue is the human point of view in science. In general there should be any. The evolution of the universe in general evolves completely independent without any human intervention. When you study the behaviour of our planets or the stars or the galaxies it does almost not matter that a star emits light.
For Newton's Law it is very important the objects we study and the trajectories these objects follow over a certain range of time. Using these trajectories we can calculate the masses of the objects selected and predict their future. The objects considered are an very important parameter to predict the future. In fact when you want to do it accurately you should include all what has mass (and gas clouds i.e. baryonic matter) inside our solar system. It does not matter if it is visble or invisible.
The problem is we do not know how much invisible baryonic matter there is in our solar system, our galaxy or total Universe. As such a solution when something does not add up to introduce non-baryonic matter is too simple. Such a solution should be considered from all different angles. How does it come that there is no non-baryonic matter within our solar system? Going a step further: around any star? Inside a Black Hole?. Those questions should be raised and answered.
The same type of questions are there also around the inflation model. The inflation model is nothing more than a short period that the size of the Universe rapidly expanded. The problem is if you want to understand this you must know what means size and what means expanded. If that is not clear than how can you understand the inflation model, the description of which should include the processes and reactions involved and how this all started and why it stopped.

All of this science is very much different than the laboratory science I studied at school, mentioned in the beginning.


Reflection 2

The most important aspect of science is the understanding of the processes in general and the chemical reactions in particular that take place during the evolution of the universe from start to finsh.
One important aspect of this evolution is that it has nothing to do with humans. In fact we have to take an open mind: what we assume to be a vacuum (is empty) in our laboratories, may be is not something that exists in outer space. There is always something: radiation. We should in fact perform science with our eyes closed. We should consider BH's, suns, planets and planetoide as objects. These objects "see" each other by means of gravity (graviton) and the speed of communication between these objects is the speed of gravity.

A different aspect is that science is not mathematics.

A whole different aspect should be that all what we study should be physical and testable concepts.
A specific example in Special Relativity is length contraction. Is this physical or mathematical.
A more tricky example is: Does space-time exist or is it more a mathematical construct.


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Created: 8 November 2016

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