CERN versus Marsby Roberto Battiston
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| After World War 2 the HEP scientific community, rather than politicians or business leaders, has always led the scientific decision process. The pressure of the business sector, indeed, has never been major justification for the large HEP projects. |
When comparing the two scientific communities, space science and HEP, it is important to compare the historical backgrounds. The HEP community developed largely after the end of the World War 2, on the wave of the extraordinary results obtained by the Manhattan Project, obviously a highly political enterprise. However, the study of elementary particles started half a century earlier with the first studies on the subatomic structure and on the natural radioactivity. HEP studies were justified primarily by scientific curiosity and during the last hundred years the most significant results have been consistently awarded with Nobel Prizes.
Scientists have developed the instrumentation needed to perform their experiments themselves, initially as single individuals or extremely small groups, and eventually in groups including thousands of scientists. The capability to keep under direct control the construction effort of very large accelerators or extremely complex detectors is still today an essential aspect of the HEP community. After World War 2 the HEP scientific community, rather than politicians or business leaders, has always led the scientific decision process. The pressure of the business sector, indeed, has never been major justification for the large HEP projects.
Since its origin, the history of HEP is one of fierce scientific competition but, at the same time, also one of outstanding, strong international exchange and collaboration. National pride did play a role, but when the national politics took over the decision-making process from the international scientific community, the results were of limited success if not just doomed to failure, as in the case of the Superconducting Super Collider in US.
Space science is a younger community, born half a century ago at the time of the space race and the launch the first satellites by the Soviet Union and the US. Science was never the primary goal during the space race: political considerations were the driving force behind the race; science got on board but was not the main justification. It was in this context that the various space agencies were born as direct expressions of the national governing bodies.
As time passed, the space programs largely diversified to cover distinct areas, in particular human spaceflight, robotic planetary exploration, and observation of the universe. The role of science did increase with time, and significant fractions of space budgets were used to develop increasingly sophisticated missions to explore the cosmos—the Hubble Space Telescope being probably the most famous one.
At the root of these space programs, however, we find the agencies more than the scientific communities. Odd as it might seem, the space science community is less used to truly international collaboration than the HEP community. Nowadays a growing number of space programs are indeed performed within the framework of interagency agreements, the most extraordinary example being the ISS. However, even the ISS is just another example of a politically motivated space initiative. The various science communities still operate with a degree of international collaboration that is significantly lower than within HEP. Unavoidably, this situation makes it difficult for global scientific programs to gather a worldwide coherent scientific consensus.
| The HEP community follows a path to discovery that is much more defined than in case of space research. The development of larger and larger accelerators is motivated by our understanding of what has been found (or not found) by previous machines. |
Another interesting comparison is about the scientific goals of the two communities. It is true that both scientific communities are pursuing scientific goals that are extremely fascinating although challenging. HEP is aiming to understand the building blocks and the laws of nature, while the space science community is addressing extraordinarily interesting topics like the search for life on other planets, the origin of space and time, and the study of the most violent phenomena in the universe. It is also advocating grand ideas like the colonization of Moon and Mars as the next step for our civilization. These are wonderful ideas, but each of them has the potential to absorb most of the space budgets during the next 10 or 20 years.
From this point of view it appears that the HEP community follows a path to discovery that is much more defined than in case of space research. The development of larger and larger accelerators is motivated by our understanding of what has been found (or not found) by previous machines. The largest one, the Large Hadron Collider (LHC) at CERN, has been built specifically to detect a key missing particle, the so-called Higgs Boson, within the Standard Model of particles and fields. This is a model tested painstakingly by the HEP community during the last 30 years or more: it includes a few dozen of elementary particles and antiparticles, grouped in three families, and predicts the existence of the not-yet-discovered particle that would be responsible for the mechanism that would provide mass to all others. The HEP community agreed that the construction of the LHC (as it was, of course, for the SSC) was the correct step to address this basic question, and since the 1980s all efforts went rather coherently in that direction.
In the case of space science, the various science communities deal with significantly different research topics and with limited coordination among different agencies and countries. It is indeed impossible to compare one or more additional rover mission to Mars to a post-HST telescope mission or to the establishment of a base on the Moon or to a human trip to Mars. The word “space” does not help here in defining a unifying direction: it looks more like a container for several competing ambitious goals and dreams. This diversification of the goals is one of the reasons that make it difficult for the space community to get the necessary consensus for a specific global program. As a consequence, mainly to satisfy the requests of the various space communities, agencies proceed in various directions, at the same time and with limited resources.
One should also keep in mind the scale of the budgets involved in the projects developed by the two communities. There is a difference of about one order of magnitude between space and HEP projects. For example the largest space laboratory ever built, the ISS, costs about US$100 billion, while the largest HEP laboratory, the LHC, costs nearly 20 times less, including the various large experimental apparatus built to exploit the machine, salaries, and so on. One must admit that dealing with the extremely large amount of resources of major space projects like the ISS, and with the corresponding industrial and political constraints, would have been very challenging even for the well-organized HEP global community.
| There is a difference of about one order of magnitude between space and HEP projects. For example the largest space laboratory ever built, the ISS, costs about US$100 billion, while the largest HEP laboratory, the LHC, costs nearly 20 times less. |
Will it be possible to improve the present situation? Can an international collaboration of scientists lead the initiative for the next large space program? It might be, but will not be easy. Because of the large amount of resources needed, strategic decisions about long-term space programs unavoidably call for significant political initiative, often within only one agency or country. For example, all the large US programs like Apollo, the ISS, and, more recently, the Vision for Space Exploration, were based on political considerations, often implemented unilaterally; the same is true for the programs of emerging countries like India and, most notably, China. There is, however, a increased tendency towards international or even global collaboration among scientific communities involved on the design and construction of large science programs. Some recent examples are the Laser Interferometer Space Antenna (LISA) program on fundamental science, the James Webb Space Telescope, and the Alpha Magnetic Spectrometer (AMS) experiment on the ISS, the last one built by an HEP-style international collaboration involving 600 scientists from 60 institutes located in 16 countries.
A similar discussion could be done comparing large space programs to the programs of the astronomical community gathered around European Southern Observatory (ESO), a strongly motivated, international scientific community, which has been capable during the last 40 years to build amazingly large telescopes in the most remote areas of the world. The latest very ambitious program to build an Extremely Large Telescope (ELT), at the cost of at least one billion euros, is under way.
In conclusion, the answer to the question raised by Stratford seems to be: the success of CERN is due to the existence of a large scientific community with a strong international base. To the extent that space science can get a similar base of support, it might then be more successful in getting political attention and in starting the next big space program.