Workshop 2: Richard Haley, ‘Experimenting with Extreme Cold’

Richard Haley (Physics, Lancaster University) started by thanking the organizers for a chance to talk to a totally different community, emphasizing the experimentality and importance of this interdisciplinary workshop. Furthermore, he invited the participants of the workshop to visit and explore his lab. Haley opened his presentation by explaining that the pursuit of extreme cold is a never-ending quest towards the “infinity” of the absolute zero of temperature at a very chilly -273.15 degrees Centigrade. He argued that the historical development of low temperature physics is a long story of cooling things down to see how they behave, with the hope that new physical discoveries will be made, and recognised. When the experimenters get lucky, Haley pointed out, these new discovered behaviours can be further exploited to create new technologies and tools to cool lower, and the cycle continues.

Richard Haley continued in illuminating that the element helium plays a pivotal role in this conquest. Initially discovered as a mystery spectral line in the sun (“Helios”), it was later isolated as a rare gas on earth, and first liquefied just over 100 years ago, at 4 degrees above absolute zero. Haley illustrated how when this liquid was cooled further by forced evaporation of the liquid itself, a miraculous discovery was made. Rather than solidifying, a completely new state of matter appeared in the apparatus. Haley explained that the helium had undergone a phase transition from a regular liquid into one that flows without any friction, later named a “superfluid”. He emphasized that helium is the only substance for which this happens.

Haley proceeded in explaining that helium has an even more rare, lighter isotope, labeled helium-3, that becomes liquid at even lower temperatures than regular helium. It was discovered that mixtures of the two isotopes had new properties that neither had separately, and that these properties could be exploited to create a new tool for cooling further: the dilution refrigerator. These machines then spurred a race to ever lower temperatures, and the search for superfluidity in helium-3 began. It was finally found at a thousandth of a degree above absolute zero.

Richard Haley concomitantly stated that at Lancaster University research of his team takes 3 broad strands: they continue to develop cooling technology, now achieving temperatures around a few millionths of a degree; they investigate the quite exotic behaviour of superfluid helium-3 itself; and they use the superfluid as a system in which we can perform experiments that simulate sometimes far removed physical phenomena. Haley argued that these analogue experiments include studies of turbulent flow, one of the last great problems facing classical physics, and of phase transitions that bear remarkable similarities to those that are thought to have taken place in the early Universe shortly after the Big Bang.

DISCUSSION

Discussion following Richard Haley’s presentation focused around five main themes: a problematic of a specific laboratory conditions, experimentation and historical remembrance,  creation of a gap between the experimentators and theoreticians, layering and experimentality itself.

Firstly, the experiments described by Haley were considered through the lens of a metaphor of a Russian doll. Here, the experiments’ requirement for specific laboratory conditions was emphasized. Debate considered the extreme cold experiments as a process of creating Russian doll spectres where laboratory itself is a part of it (and with an additional layer combined of experimentators). Here, some questions were posed about: what is going on in 6 months of research, moment of inspiration to come up with a solution or a big discovery and non-idiomatic characteristics of the experiment. Further, a dialectic of hope was considered in the scientific context: when the experiment wasn’t suppose to do what it did – hoping against hopeless – and when the experimenter is trained to look for the unexpected – hoping for the unexpected. It was concluded in agreement that this constant search describes something profoundly cosmological.

Secondly, Haley was questioned whether he imagines being remembered historically while conducting his experiments. Here, a reference was made to  Helmholtz - as Haley’s contemporary - in terms of an awareness of relativity of knowledge. Haley responded explaining the fragility and uncertainty accompanying such discoveries and as an example, he described another group of researchers who probably made discovery before his team but did not notice it because they were using a different equipment (a digital recorder).

Thirdly, slight worry was voiced for the discipline regarding the developing divide between theoretical and experimental sides. Here, in was pointed out that the experimentation taking place at a  very refined and advanced level makes it difficult for the experimentators to communicate with the theoreticians. Further, the extreme specialisation required in order to work in such a specific field was emphasised, consequently illuminating the fact that theory seemed to explain it all in the past but then we discovered that there are many experiments that haven’t been conducted and many unanswered questions that were not even posed. It was concluded that it is vital that experiments attract the theorists back so that productivity and knowledge can be increased.

Next, the way one can map onto the cooling universe and historical time was discussed. It was noticed that Haley is able to both create the low temperatures and to investigate them, because of the layering of different experiments. Here, references were made to art history in terms of the historical development of cultural forms – similar kind of historical analysis can be done of the way cultural artefacts are layered. Further, it was argued that with a piece of music composed and recorded at the particular time, in order to understand it, one has to insert it in a particular sequence: just as in a Russian doll. Concomitantly, it was emphasised that the experiments described by Haley also allow to ‘build upwards’ through very refined pieces of machinery and subsequent control which gives them superiority over a Russian doll metaphor. Finally, it was pointed out that the experiments that Richard Haley and his research group are conducting now, could not have been done before. 

Finally, it was stated that there is a sense in which the described experiment is an assemblage of different concepts of experimentality themselves, including the recurring theme of the improvisation in the workshop. References were made to the very precise experimentation and accompanying it issues of collaboration/interaction with theoretical physicists – some of them participate and some of them reject it so it doesn’t interfere with their pure theories – just as discussed in terms of recording the improvised music. It was agreed that all of these are in a way kinds and modes of experimentality. Finally, it was questioned whether experiment in itself is a fraud as its is very difficult to recreate it following descriptions from journal articles or research papers  due to the lack of details (and as the access to the log books is usually restricted).