I love optical illusions. You know, the type with lots of closely spaced circles that don’t move. You look at it, and it looks like they are rotating (like the famous Enigma painting). They make you feel frustrated that your brain doesn’t have the ability to correctly comprehend the situation and make the correct decisions. Prof Donald Glazer (Prize winner 1960 and inventor of the bubble chamber) showed us many optical illusions of different types, designed to dupe and confuse the brain. His talk was aimed at quantifying the noise that can be generated in the human brain. He mentioned that there is an optimal level of noise that can be added to a circuit which can actually improve the signal. His example made perfect sense. Take a person with diabetes. Diabetics have a tendency to fall over terrible non-healing ulcers which can be very deep). SO this can be visualised by a fairly low signal under the threshold in the brain coming from the feet, therefore the balance cannot be adjusted. Now if you add some ripples in the persons insoles of the shoes, the nerves are continuously stimulated, so the tendency to fall over is drastically reduced. It made sense to the 500+ audience anyway. It works well in studies of the human brain, the idea of “bumping up” the signal by the addition of noise in order to cross a certain threshold. I’m not sure if the people who spend absolute fortunes on super-cooled electrical circuits would agree with him though! He finished by an anecdotal discussion about how marijuana inhibits visual illusory motion.. hardly surprising really......
Something we studied a lot at undergraduate level was the optics of lasers. So it was for this reason that I really enjoyed the lecture by Prof Nicolaas Bloemberg (1981 Prize winner), who gave a historical overview on the development of the laser. His main goal was to bring us right up to date on the development of the atto-second (1×10-18 sec) laser pulse, which has yet to be achieved (currently there are pulses from lasers lasting 1×10-15 sec. The amazing technological development of the laser since its invention by Maiman in the 60’s was documented by each “milestone laser” as he called them, i.e. an increase of the pulsing repetition rate (the gain bandwidth must increase as the pulse gets shorter), or an increase of the power contained in the pulse (higher intensities lead to more non-linearities in the laser). In order to get a sense of scale for the unbelievably unimaginable short length of time a high intensity pulse taking 1×10-18 sec takes, we were asked to consider the alternative time scale of 1×1018 sec (called 1 exa-second by the way). Any idea how long this makes? If you thought it was only a few hundred years in length you’d be fairly mistaken. It actually stretches further back to before the birth of the universe!! The push towards attosecond laser pulses continues.
Another fantastical scale came from Prof Roy Glauber (2005 Prize winner) in a lecture about the “individuality of light quanta”. As an example, there are 1017 quanta in the light flux per second from a laser pointer. Prof. Glauber asked if we could imagine 1 single light quanta, and a analysed the “Gedanken” experiments of Youngs twin slits, and a disassociated diatomic molecule in terms of quantum states. If we get a large diffraction pattern from a regular solid state light source, then what type of pattern would we get from a single light quantum? The answer is “the exact same pattern”, showing that light behaves the same regardless of the amount of quanta present. This is where wave-particle duality comes into effect. In Youngs twin slit experiment, we know that light must share similar properties to particles, although this in no way means that each particle can travel through both slits! According to Prof Glauber, the light quanta are not equally divided in the first place. Also touched on was the sensitivity of the human eye, which is sensitive to 100 light quanta, although only 5-7 of these actually make it to the photoreceptors (the rest are absorbed to create the signal). He went on to talk about entanglement and entangled states, which is a quantum description of how even the quantum states of 2 or more spatially separated particles are linked so much, that you cannot descripe the properties of one without describing the properties of the other.
The great Prof Brian Josephson (1973 Prize winner) of Cambridge, UK held a strangely interesting lecture called “Which way for Physics”. I expected this to be a rather general discussion about what is left for Physics to explore and discover, but I ended up thinking rather critically about this lecture. He began with a discussion about cold fusion, and provided compelling evidence that this was already achieved but “propaganda against cold fusion” shot down the idea. I won’t go on about the cold fusion aspect, just like he didn’t but he gave us a website to pursue the evidence at
http://www.lenr.org/, and after looking at it, there is some very interesting aspects. Many scientists reacted to low-energy nuclear reactions sceptically, due to irreproducibility of results (in normal fusion, temperatures and pressures resembling that found in starts are required). It still remains a highly controversial area
The remainder of his talk centred on self-organisation of the human physiology and a hint at possible explanation for natural selection. Personally I found this part the strangest, and a very unclear explanation as to the actual point. Perhaps I completely missed something by trying to understand his “biology aspect of the Standard Model” but his discussions of fractals (phenomena at many length scales) left me confused. Clear as muddy water as they say. He ended with an interesting statement which led me to at least consider his odd theories “Todays crazy ideas sometimes can be tomorrows greatest insight”. A completely true statement, or a statement of justification, I’ll let you decide. To be fair I heard during the week that the person who pioneered NMR technology when asked “what can it be used for” he answered “damn all”
BY far the most interesting talks to me today were Prof Douglas Osheroff (1996 Prize winner for discovering superfluidy in helium 3, he also served on the Columbia space shuttle disaster investigation panel) and Prof Gerardus t’Hooft (1999 Prize winner with his then supervisor and yesterdays speaker Prof Martinus Veltman). The entire point of Prof Osheroffs talk can be summarised in 1 sentence from the Laureates mouth “Nature doesn’t knock loudly, she whispers softly”. In essence this means looking with a fine tooth comb for the subtleties in your results, and not leave anything to chance. A fine example was the discovery of the microwave cosmic background (spoken about yesterday) where the group in question pointed their dish in a region where there was supposed to be no radiation source. Months were spent trying to remove the noise (they thought) and it wasn’t until someone looking for the radiation perused their data. This related directly to his experiences, making a discovery at 2.45am. His entire talk was a motivational speak for young researchers, and I hope he connected more with the entire audience like he did with me. Echoing his statements on climate change from Tuesday he said “Inventions must find a purpose, but if we find a need then the technology we require might not be obvious”. Classic case of an inverse problem! He also outlined research strategies that can increase the chances of a discovery, and for those interested in more tips to win a Physics prize they are
· Understand what your instrumentation is measuring
· Avoid too many commitments
· Gain perspective
· Failure is an invitation to try something new
· Look at unexplored regions of your work
· Beware of unexplained behaviour, don’t dismiss it
· Use available instrumentation where possible (“don’t re-invent the wheel, borrow it”)
We had the privilege of interviewing Prof Osheroff for Irish radio (see the pic at the bottom) , in which I thought he was somewhat controversial in some areas, especially about the commitments. He mentioned women in science, and the fact that priorities shift when children are involved. I guess he is talking honest here, he seems very down to earth in the interview and humbled about his discovery. A point that hit home was “Advances in science are seldom made by individuals alone” yet we didn’t hear many Laureates thank their co-workers for influence.
A fantastical voyage through the future (with terrible sound effects) was provided by Prof t’Hooft who began by indirectly contradicted Prof Osheroff saying “its fun to re-invent the wheel”. Contradiction between the different personalities seemed to be a common theme of the week. He proposed some big-hitting questions such as “What applications can be gained by knowing what constitutes a quark?”, “can we store information at the molecular level?” and “what can modern science do and what will always remain out of reach?”. He provided some food for thought in predicting the future by mentioning “knowing the laws of Physics, we know what can be done”. Thus stepwise advances of science can be improved upon by visionaries understanding of expert areas. He provided some optimism on the limit of modern technology saying that we are only starting the modern information age, and because of Moores law, we are decades away from the atomic scale limit (if this indeed is the limit). A few moral issues arose as he discussed robotics, and the fact that they are only as intelligent as we make them. “In principle” he continued, “we make machines to dig faster than us, compute faster than us and fly for us. Technically, in certain areas they already are more intelligent than us”. More moral issues arose in genetic manipulation, saying its completely possible to retrieve information from DNA and it is human nature to tamper with it. I wondered if he skipped the social implications on purpose or whether he just isn’t interested in them. Sometimes scientists seem to believe things should be done just because they can. Some more futuristic questions revolved around “when will humans colonise other planets”, “will we outlive our Earth” and “how long can we prolong human life span”. I felt this was all a bit fantastical, but great to hear the futuristic thoughts of this Laureate who was so full of ideas and energy that he ran well over time and was asked twice to finish up. I was getting hungry after all, and this doesn’t compete with colonising Mars.
The talks finish today, and signals the end of the conference program. Friday was a 3 hour boat journey to the Countess’ island of Mainau for a farewell party. A Bavarian evening was on, complete with Lederhosen-clad Bavarian band and traditional food! Few drinks and R&R was had by all.
These are the frequency of a string results.
