The translation of my book ‘Quantum Physics, Information and Consciousness’ is a long term project. However, the preview version – epub format – is free downloadable. You’ll find the first four and the last chapter fully translated and all the other chapters have a summary at the end. Click here for more information.
This kind of quotes do keep popping up in reports about quantum phenomena: “Depending on the way in which it is measured, the quantum object manifests itself as a particle or as a wave.” No, no, and again no, that is not the true image of quantum reality in my opinion. In fact it is severely misleading en confusing.
Such statements create the impression of an object that deliberately adapts to the measurement methods used and then decides whether it shows itself as a wave or as a particle. No wonder many people decide that the quantum world is utterly weird and incomprehensible and stop thinking about it.
This false image, this misunderstanding, has its origins in the image of the world that we received from our earliest memories on. An image of a world existing independently of us and in which we fulfill merely the role of spectator, an accidental bystander who might as well not have been there. We are used to imagining something, every physical thing, as something that simply IS and has always been there. We tend to stick to that way of looking at reality even when, depending on the way we look at it, its properties suddenly appear completely different and extremely ambiguous, like the quantum object mentioned above.
It is rather unusual to think that things are there BECAUSE we perceive them, that they did not exist before our observation and are no longer there after our observation. If we would opt for that way of thought, things would attain properties that we usually attribute to dreams and thoughts and not to ‘real’ things. This way of thinking about reality is not in keeping with the common perception of the permanence of our world. Yet the quantum world teaches us that our idea of an objective permanent world is most likely false.
Looking at the double slit experiment
The double slit experiment is a crucial experiment in quantum physics able to provide a lot of insight. So let’s take a look at it
When we fire a large number of particles, photons, electrons or even large molecules, through a double slit, an interference pattern will be created on the screen after the slits. We see a pattern of light and dark bands. That pattern also arises when we fire particle by particle. Even after a long period of firing single particles, certain areas on the screen appear to be hardly hit, which are the light bands in the picture above.
Such an interference pattern is the result of wave behavior. It occurs because waves reinforce or extinguish each other in certain places depending on their synchronous concurrent or opposite motion, respectively. Watch this YouTube video for a very enlightening demonstration of double slit interference.
There is a mathematical relationship between the spacing of the bands of the interference pattern, the spacing between the slits, the distance from the slits to the screen, and the wavelength, but we don’t need to go into that to understand the meaning of this experiment.
Such an interference pattern of dark and light bands only arises when the originating waves have the same frequency and wavelength. It happens when two wave sources vibrate synchronously. The two slits here function as wave sources vibrating in phase. The rather amazing conclusion drawn from this interference pattern is: “Every particle exhibited wave behavior and must therefore also have been a wave.” This also applies to electrons and even to large molecules of more than 800 atoms.
Catching the particle in the slit
When we adjust the experiment in a way so we can determine for each particle which slit it has gone through, the interference pattern disappears and we get a pattern that you can interpret as two single slit patterns that are projected over each other and therefore are actually indistinguishable from a single slit pattern. Each of the two slits now produces a single slit pattern, which is a single light spot with the highest intensity in the center, in much the same location on the screen.
The correct conclusion is that the waves passing through the slits no longer interfere with each other. The relationship between these two waves running from the slits, which let them extinguish or strengthen each other in fixed predictable places, has disappeared. The often drawn conclusion is that we now see particle behavior instead of wave behavior, which actually makes no sense. A single slit pattern is still for 100% the result of wave behavior, only we no longer observe interference such as occurs with two synchronous wave sources. It seems more like as if every wave, connected to each particle, is now originating from only one of the slits and no longer from both. And that’s exactly what’s going on here.
How we see the world as a collection of things
“.. we can determine for each particle which slit it went through …“. Notice how this sentence is formulated. The implicit assumption here is that there is a particle that travels along a path and that shoots through one of the slits. That is an image that stems from the way we got to know the world around us from childhood. And apparently we find it extremely difficult to let that premise go. Ask yourself: Did the fired bullet travel every part of the path to the target? Or didn’t it?
The simple hypothesis: observation manifests the particle
Now, if only for a moment, try to let go of that premise, set it aside. Imagine now that, there is no particle traveling a path, there only is a wave. A wave that appears to be particularly intimately connected to our perception of the particle. (I will postpone here the effort of trying to understand how this connection works.) A wave that will end when we make an observation. An observation thus means that we seem to manifest the particle at that time and in that location. Immediately after our observation has been made, the particle is no longer there, but the wave is there again starting from where we last observed the particle. Now look again, assuming this hypothesis is right, at the version of that double slit experiment where we could determine which slit the particle passed through. Are we now perhaps able to understand this enigmatic disappearing act of the interference bands somewhat better?
Therefore, try to follow the following five logical steps:
- According to this hypothesis, it is the observation, in this case through which slit the particle passed, that made the particle to appear in one of the slits.
- Its appearance in the slit implicitly means the end of the wave.
- Only at the moment the observation information tells you, the particle manifested and existed in the slit.
- Immediately afterwards there is no particle and a new wave leaves the slit eventually ending up on the screen behind the slit.
- Since the particle did not appear in both slits – at least let’s assume that there is no magical particle multiplying – we now have only one single wave source.
- So there is indeed a wave – between the double slit and the screen – but now there is no more interference, because you need two synchronous vibrating wave sources for it to observe.
This hypothesis – observation manifests the particle – gives thus a complete and logical explanation of the disappearance of the interference when we observe the particle at the slit.
Two time-consecutive manifestations of the particle in a single experiment
Where the wave hits the screen, we do observe a bright little spot. In principle, that is also an observation. So when we set up the measurement in such a way that we can observe in which slit the particle appeared, we create a measurement setup with two consecutive locations for observations – and thus, manifestations. One in the slit and the other on the screen behind the slits. That dual observation is the crucial aspect in an experiment where we do observe the particle at the slit.
So it is confusing to say that the observed object behaves like a wave or a particle depending on the way of observing. In both setups, it is consistently true that there is a wave that results in the manifestation of a particle through an observation. In the setup where we look in which slit the particle appeared, we simply make two consecutive observations, whereby a wave manifests itself twice as a particle. The measurement directly influences the measured object and doing two consecutive measurements at two locations within the setup therefore logically should arrive at a result different from a single measurement done only at the screen. As if you gave during billiards the already rolling ball an extra kick and then got surprised that it influenced the outcome. We really don’t have to assume an intelligent ball for that.
Not a particle and wave at the same time, it’s a probability wave
If we look at it that way, then there is no longer a particle that adapts magically in terms of properties to our way of measuring. The whole process is clear and extremely predictable. As long as we don’t measure the object we want to measure it is a wave. As soon as we measure where and when the object was , we will find the object to have been there. The measurement and manifestation of the object thus become identical! This is a very important and deep conclusion.
Now the question of what that wave is and what it consists of becomes an important one. The answer to that question was first proposed by the physicist Max Born in the early 20th century. In his proposal, the quantum wave is a wave that, when interpreted correctly, gives you the probability per location and time, where and when, to find the object during a measurement. Thus, the quantum wave gives us a prediction of reality but not an exact one. It is a statistical prediction, just like when rolling a dice, the probability of exactly getting a six coming up is 1/6 and that the average outcome of a roll is 3.5. Incidentally, Max Born still assumed that the particle was somehow ‘guided’ by the wave which means that the particle traveled a path, albeit unpredictable. That interpretation was later abandoned by most physicists.
Quantum mechanics is statistics
Statistics is the way in which quantum mechanics accurately predicts the results of experiments. With the enormous numbers of particles that play a role in objects larger than a few micrometres, the outcome of a physical event can be predicted with great precision. Just as the average outcome of a hundred billion throws with an ideal die will be exactly 3.5 with a deviation that we will find only after the 8th decimal place. Many quantum physicists do accept the idea that the particle only manifests itself during measurement, but they disagree about how the measurement achieves this, given the large number of different interpretations. Most interpretations attempt to save the objective permanence of the world but until now these fail to do so convincingly. That there is not a winner since more than 100 years could be an indication of wrong underlying and deeply hidden assumptions. In technical applications, quantum physicists simply use the statistical calculation methods – shut up and calculate – and leave the interpretation to the disputing theorists.
The simplest explanation is usually the best
As I wrote at the beginning, assuming that the ‘thing’ aspect of reality only appears because we are looking and that it does not exist physically when we are not observing, means that the reality we perceive has the same quality as thoughts and dreams. If that is the assumption that provides us with the simplest unambiguous explanation of the double slit experiment, the idea that observing manifests reality might now have become not as strange as it probably sounded to you at first. Applying this hypothesis we are able to visualize every part in the double slit experiment without having to try to imagine something that is simultaneously a particle and a wave, which is impossible. This could mean that our belief that the world is permanently out there, regardless of our presence in it, is a very persistent misunderstanding. That is anyhow my deeply felt opinion. The world is there because we create it when observing it. This also applies to something dramatically destructive like the Covid-19 virus in the end. Such a message should raise of course a number of rather hard questions. For some answers on these have a look at another page on this website.
It turns out to be interesting to compare Aristotle’s ideas about time with my insights about time and quantum physics. There are striking similarities.
A quote from Physics, book 4.11:
But neither does time exist without change; for when the state of our own minds does not change at all, or we have not noticed its changing, we do not realize that time has elapsed, any more than those who are fabled to sleep among the heroes in Sardinia do when they are awakened; for they connect the earlier ‘now’ with the later and make them one, cutting out the interval because of their failure to notice it.
So, just as, if the ‘now’ were not different but one and the same, there would not have been time, so too when its difference escapes our notice the interval does not seem to be time. If, then, the non-realization of the existence of time happens to us when we do not distinguish any change, but the soul seems to stay in one indivisible state, and when we perceive and distinguish we say time has elapsed, evidently time is not independent of movement and change. It is evident, then, that time is neither movement nor independent of movement.
Aristotle says here that time does not exist without change being perceived by our [consciousness]. If no change is experienced, then we also won’t experience time. So time is not the same as change or movement, but it is not independent of it.
Now we perceive movement and time together: for even when it is dark and we are not being affected through the body, if any movement takes place in the mind we at once suppose that some time also has elapsed; and not only that but also, when some time is thought to have passed, some movement also along with it seems to have taken place. Hence time is either movement or something that belongs to movement. Since then it is not movement, it must be the other.
If we observe a ‘before’ and an ‘after’, which is observing a change, then there is time. But time is not equal to change. Time results from the comparison between two now moments. We define the sequence of nows ourselves by assigning it an ‘before and’ after ‘.
When, therefore, we perceive the ‘now’ one, and neither as before and after in a motion nor as an identity but in relation to a ‘before’ and an ‘after’, no time is thought to have elapsed, because there has been no motion either. On the other hand, when we do perceive a ‘before’ and an ‘after’, then we say that there is time. For time is just this-number of motion in respect of ‘before’ and ‘after’.
The ‘now’ itself does not change, but the moments recorded in every ‘now’ do.
The delayed quantum eraser
This vision of Aristotle on time reminds strongly of the conclusions about time that can be drawn from studying the results of delayed choice quantum eraser experiments. In a simple double-slit experiment, observable interference will always occur behind the double-slit. A pattern of dark and light bands. It invariably shows up whether photons, electrons, atoms or even larger molecules are sent through a double slit.
In the delayed choice experiments, in principle, photons are sent through a double slit, and simultaneously information is collected about which slit the photon has passed. The measured information about the passed slit is randomly either recorded or irrevocably destroyed in order to determine the effect of available information about the passed slit on the interference pattern. The experimental results are in line with the predictions of quantum mechanics but nevertheless very intriguing.
- If information is available about through which slit the photon has passed, the result of the experiment is affected in such a way (no interference) that the conclusion has to be that the photon state wave must already have collapsed in the slit manifesting a physical photon there.
- The experiment is set up in such a way that the moment in time when that information is measured and recorded follows in time sequence after the photon appeared (manifested) in the slit.
At first glance, this looks like an effect back into the past, retrocausality. However, this doesn’t mean that we can change the past. Once measured, the past is irrevocably fixed. But as soon as we involve the active observer, retrocausality is no longer needed as an explanation. The observer will by his conscious observation only fix the order of events at that moment . It is then not the instrumental detection of the slit passage that exerts an effect on the interference behavior of the photon. History – the sequence of now moments – is fixed by the observer’s attention. That’s time.
In short, quantum physics seems to confirm Aristotle’s ideas about time. Now we can see an important difference between experienced time and clock time. The latter was introduced by Newton in the 16th century as the only model of time of importance in physics. With that the observer was sidelined and was no longer an important player in the physical universe. But quantum physics seems to restore experienced time as something that also plays a role in physics. The conscious observer acting as an information processor becomes thus an active participant in the universe again.
In addition to quantum physics, I also have of course other interests and fascinations. And sometimes some other than a quantum physics subject is so impressive and important that I want to say something about it on this website, even though it’s not about quantum physics.
It’s about the SAFIRE project. The acronym means: Stellar Athmospheric Function in Regulation Experiment. It was started by a group of plasma physicists, astrophysicists and electrical engineers who wanted to test an idea differing from mainstream physics about the forces that play an important role within our solar system and also in interstellar space. This group is called out by RationalWiki as a bunch of garden-variety physicists or pseudo-physicists. Well, they have answered the challenge and started the SAFIRE project. They have implemented their model of how they think the sun works in a laboratory container, a three-year project, to see if their model can be falsified.
Their result is truly amazing. View the film they produced, read their 72 page report and think for yourself. Either they are completely fraudulent, or they have discovered something particularly important (and that option is my firm impression) that can have enormous implications for:
- Our knowledge about the real processes that take place in a star, especially in our own nearby sun.
- Insights about the origin of the elements heavier than hydrogen and helium.
- Free energy production: a revolutionary way in which energy can be generated. It seems nuclear fusion is happening, because heavy elements appear to be produced, without any adverse side effects and without the need for an incredibly expensive and complex fusion reactor, which has to enclose the hot plasma in extremely strong magnetic fields.
- Safe processing of radioactive waste.
Energy by transmutation of light elements
If this is true, then this is incredibly good news, especially in the context of our current problems with regard to our global energy needs.
Confirmation by replication
When watching the film and reading their report, I am reminded of the facilities that are available on the most universities, to replicate this and to test it. It is not beyond the capabilities of an academic technician with adequate resources. Physics students, accept the challenge.
To keep up to date with the subjects on my website I have to read quite a bit. And a lot of highly interesting material on quantum physics is being written and published. But occasionally I come across something that impresses me particularly and seems worth of special attention. Especially when it considerably broadens or clarifies my view on quantum physics and its interpretations. Therefore highly recommended stuff for visitors of my website. So, I’ll discuss two books here. The first one I want to discuss is: “Beyond Weird – Why Everything You Thought About Quantum Physics is .. different” by Philip Ball.
I am grateful to the student who put this book in my hands. Philip Ball is a science journalist who has been writing about this topic in Nature for many years. You don’t need to be able to solve exotic Schrödinger equations to follow his fascinating and utterly clear explanation of the quantum world and the riddles it presents. Also, he clears some misunderstandings up about this subject. Such as the word quantum, which is actually not the fundamental thing in quantum physics but rather an emerging phenomenon. The state wave is not quantized but fundamentally very continuous. He desctibes how quantum physics in its character and history deviates from all previous physical theories. It is a theory that is not built by extrapolation on the older theories. You can’t imagine what happens in the quantum world as you can do with, for example, gravity, electric currents, gas molecules, etc. The mathematical basis of quantum physics, quantum mechanics was not created by starting from fundamental principles but was the result of particularly happy intuitions that worked well but whose creators could not fundamentally explain what they were based on. Examples are: The matrix mechanics of Heisenberg, the Schrödinger equation, the idea of Born that the state function gives you the probability of finding the particle at a certain place when measured. It was all inspired intuitive guesswork that laid the foundation for an incredibly successful theory we still don’t really understand how and why it works. Ball makes presents a good case for the idea that quantum mechanics seems to be about information. It is a pity, in my opinion, that he ultimately appears to adhere to the decoherence hypothesis. That is the point in his book where the critical reader will notice that what was until then comparably good to follow step by step suddenly loses its strict consistency and that from there one has to do with imperfect metaphors. His account remains interesting but isn’t that convincing anymore. Despite that, the book is highly recommended for anyone who wants to understand more about the quantum world and especially about quantum computers.
The Quantum Handshake
A completely different type of book is “The Quantum Handshake – Entanglement, Nonlocality and Transactions” by John Cramer. His interpretation of quantum physics seems, in my opinion incorrectly, not to be placed on the long list of serious quantum interpretations. Not a big group of supporters. In any case, I had never heard of his interpretation until it was brought forward by someone at a presentation about consilience I attended a short time ago. The subject made me curious because the state wave seems to stretch out backward and forward in time as I see it. Cramers’ hypothesis is that the state wave can also travel back in time, creating a kind of ‘handshake’ between the primary departing state wave and the secondary backwards in time reflected state wave. The reflected state wave traveling back in time arrives at the source thus exactly at the time of departure of the primary wave. This handshake between both waves effects the transfer of energy without the need for the so-called quantum collapse. The measurement problem where the continuous state wave instantaneously changes into an energy-matter transfer would then be explained as the result of a energy transfer by the handshaking state waves. However, in order to finally be able to complete that energy-matter transfer from source to measurement device, Cramer has to assume that the state wave is “somewhat” material-physical. This ephemeral quality of the state wave is considered as a severe weakness in his interpretation. Nevertheless the book provides worthwhile reading for those who want to delve into the various interpretations of quantum physics, also and especially because of Cramer’s discussion of a large number of experiments with amazing implications such as, for example, quantum erasers and delayed choice experiments where retro causality appears to occur. His idea of a state wave that is traveling back in time – which is not forbidden in the formulations of quantum mechanics – remains a fascinating possibility.
I’m very proud of this success. Within one year 500 copies of “Kwantumfysica, informatie en bewustzijn” sold through the regular bookshops in The Netherlands. Copies sold through my own network of friends, acquaintances en students following my lectures are not counted here. The work was certainly not in vain.
In the meantime I am steadily working on the English version to which a new chapter on consilience is being added. This is going to be the introduction to that chapter:
“In science and history, consilience (also convergence of evidence or concordance of evidence) is the principle that evidence from independent, unrelated sources can “converge” on strong conclusions. That is, when multiple sources of evidence are in agreement, the conclusion can be very strong even when none of the individual sources of evidence is significantly so on its own. Most established scientific knowledge is supported by a convergence of evidence: if not, the evidence is comparatively weak, and there will not likely be a strong scientific consensus. “
In this book, starting with the scientific revolutions of de 17th century and, following the threads of its developing history until today, we have arrived at a perhaps baffling and remarkable result, hard science – physics – today is not in conflict with the idea of the existence of an of the body independent consciousness, also called the survival hypothesis. On the contrary, it supports it.
However, should this idea only surface after studying quantum physics and nowhere else in the science domain, this support would be as whacky as a table supported by only one leg. Therefore, the question is, is survival supported by published scientific research in other domains? Indeed, it is. Some of this research was already mentioned in preceding chapters. It is time now to pay a little bit more attention to all published and reviewed evidential material concerning consciousness being independent of the material body.
Einstein had major objections to the implications of quantum physics. In the so-called EPR thought experiment, he spoke of a “Spukhafte Fernwirkung.” I had to think about that when I added the page, “Detection by ‘spooky’ photon“, to the website.
From Wikipedia: Vlatko Vedral is a Serbian-born (and naturalised British citizen) physicist and Professor of Physics at the University of Oxford and CQT (Centre for Quantum Technologies) at the National University of Singapore and a Fellow of Wolfson College. He is known for his research on the theory of Entanglement and Quantum Information Theory. As of 2017 he has published over 280 research papers in quantum mechanics and quantum information and was awarded the Royal Society Wolfson Research Merit Award in 2007. He has held a Lectureship and Readership at Imperial College, a Professorship at Leeds and visiting professorships in Vienna, Singapore (NUS) and at Perimeter Institute in Canada. As of 2017, there were over 18,000 citations to Vlatko Vedral’s research papers. He is the author of several books, including Decoding Reality.
Watch this movie “Living in a quantum world” from Vlatko Vedral on YouTube: https://youtu.be/vaUfZak8Ug4. At the end of his presentation a question from the audience about time and quantum physics is asked (at about 1: 10) and in his answer he describes the behavior of a super-accurate clock and what happens to the last digits when you lift that clock half a meter in the gravitational field. And then he wonders what it means when you imagine that clock to be in a quantum superposition at the two different heights in the gravitational field. A superposition of two different timelines. Fascinating.
By the way, the first part of his presentation – about 45 minutes – is actually a very compact version of my quantum physics book. Everything is presented in an almost blazing speed: interference, the Mach-Zehnder interferometer, Schrödinger’s cat, the Copenhagen interpretation against the multiverse interpretation, delayed choice experiments, interference with very large molecules shot through double slits, the orientation of our robin on the earth’s magnetic field in its annual migration, the 100% efficiency of chlorophyll. Highly recommended.
Quanta Magazine, a web service which often brings interesting articles, published shortly an interesting article where relativity, quantum physics and black holes played an important role. However, in reading it I did hit upon a very common misconception, about which I like to comment here.
Quote from: Einstein, Symmetry and the Future of Physics | Quanta Magazine“Solar energy arrives on Earth and becomes mass in the form of green leaves, creating food we can eat and use as fuel for thought. “
The misconception is that mass and energy are different things and that energy is somehow mysteriously converted into mass and vice versa. However, that’s not the message of E=mc2. Energy and mass are, in the opinion of almost all physicists, more like the two sides of the same coin. They are identical. This can be understood by considering what happens when an object is accelerated up to the speed of light.
According to the special relativity, all the energy that you spend into that acceleration is converted into inertial mass. It will cost you more and more energy to keep accelerating it. That is why we can never reach the speed of light itself in this way, the inertial mass would become infinite. This effect has been convincingly demonstrated when accelerating protons in the Large Hadron Collider at CERN. The faster they go, the more mass they get and the stronger the magnetic fields must be to keep them neatly in their circulair loop.
In general relativity, the central basic assumption is that inertial mass and heavy mass are identical or that the acceleration force due to gravity is identical to the acceleration force that you encounter in, for example, a merry-go-round. The implication therefore is that inertial mass, heavy mass and energy are really all the same fundamental thing. This means for instance that a charged battery must also be slightly heavier than when discharged. However, the energy released by nuclear fusion is often explained in popular terms as follows:
“The mass of the two fused atomic nuclei is smaller than that of the original fused nuclei together. That mass deficit has become energy and that mass is gone.“
Thus it seems as if mass alone is not conserved, mass plus energy should be the conserved property. However, Wikipedia says otherwise: “Mass and energy can be seen as two names (and two measurement units) for the same underlying, conserved physical quantity. Thus, the laws of conservation of energy and conservation of (total) mass are equivalent and both hold true”.
Ponder this. The fused atomic nucleus has received an enormous amount of kinetic energy during the fusion, and that is speed. That kinetic energy is exactly having the same mass as the ‘disappeared’ mass. So, that mass has not disappeared at all. Due to the speed with which the fused core now moves, which means kinetic energy, it also has more mass. That is the message of special relativity. If you could have this fusion taking place in a thermally completely sealed box balanced on a pair of scales, you would find zero difference in weight – and therefore in mass.
Another but related topic. That every observer always observes the same speed of light is a physical observation but goes against our so-called common sense which tells us how adding up speeds normally works. Elsewhere on this website I say something about that in ‘What is light‘.
In the world of physics, we can see a beginning inclination to research the connection between the consciousness of the observer and the observed. Research has already shown that the human senses work and perceive at the quantum level. Not only the eye which after adaptation appears to be able to observe a single photon, but all our senses seem to function at quantum level and even beyond. Our ears are energywise extremely sensitive organs. Read the article by William C. Bushell Ph.D. and Maureen Seaberg at https://www.scienceandnonduality.com/ (SAND).
“In science and history, consilience refers to the principle that evidence from independent, unrelated sources can “converge” on strong conclusions. That is, when multiple sources of evidence are in agreement, the conclusion can be very strong even when none of the individual sources of evidence is significantly so on its own”. Wikipedia
The 38th Society for Scientific Exploration (SSE) conference was held from June 5-8 in Broomfield Colorado. The theme was “consilience” whereby evidence from diverse and independent sources can be used as valid support for scientific theories. For example, on the one hand in quantum physics a conscious observer seems to be needed to trigger the so-called quantum collapse, on the other hand in current medical science applying advanced life-saving interventions the growing numbers of validated near-death experiences can no longer be ignored. So, in both very different domains, the idea of non-matter-dependent consciousness is confirmed.
Within three days 34 presentations of approx. 20 minutes were held, whether or not supported with PowerPoint slides, offering also the opportunity for three to five questioners after every presentation, and 17 poster presentations set up in the hall in front of the conference hall, for which one and a half hours had been set aside on day 2. Personally, I thought that part was the most accessible because you could come quickly in direct contact with the poster’s creator.
To be honest, in my opinion there were some poster presentations actually deserving a full presentation and vice versa there were presentations that could have been better scheduled as poster presentations.
To download a more extensive report click here.