View of the side of the ATLAS experiment during construction in Nov. 2006
ATLAS Experiment © 2016 CERN

by Tomo Lazovich
figures by Alexandra Was

When you picture a science experiment, you probably imagine someone wearing a white coat, hunched over a lab bench, looking through a microscope, or mixing something in a beaker. While this is not an inaccurate picture in many fields, it misses an important dimension of the modern scientific process: collaboration.

In his speech at the banquet for his second Nobel Prize in 1972, John Bardeen, one of the fathers of the transistor and the theory of superconductivity, explained, “Science is a collaborative effort. The combined results of several people working together is often much more effective than could be that of an individual scientist working alone.” Scientists’ ability to collaborate has grown exponentially as both communication and travel across the globe have become easier in the last century. At the same time, scientists are tackling problems of ever-increasing complexity, collecting mounds of data and pushing our reach to smaller and larger energies and distances.

The two trends are not merely a happy coincidence. Large, international conglomerations of scientists, or so-called “big science” collaborations, have emerged as the preferred way to tackle science’s biggest questions. These entities, comprised of hundreds or thousands of scientists from scores of countries, are achieving discoveries at an impressive rate. Their success has also raised questions that challenge the traditional picture of the scientific process, staring a brilliant individual making the breakthrough of a lifetime by virtue of his or her genius alone. Let’s take a closer look at these big science collaborations and find out how they work and what makes them so effective.

Successful collaborations

If you have followed science news in the past decade, you have likely seen many examples of the success of big science. The Human Genome Project (HGP), an ambitious effort to map the entirety of human DNA lasting from 1990-2003, was the world’s largest collaborative biological project. In addition to advancing our scientific knowledge, the technologies for sequencing and understanding genes that were developed during the course of this project spawned entirely new areas of research in both academia and industry.

A 2011 assessment of the economic impact of the HGP stated that in the year 2010 alone, human genome sequencing projects generated 310,000 new jobs and $20 billion of personal income for Americans. Another well-known international endeavor, the International Space Station (ISS), is an example of an experiment pushing the physical boundaries of humanity. Research conducted at the ISS has ranged from the physical effects of microgravity to detailed studies of earth science, and the experiment has produced over 1200 publications as of December 2015. Scientists at the Large Hadron Collider (LHC), a proton collider which has set the record for the highest energy proton collisions ever recorded, announced the discovery of the long-sought Higgs Boson in July of 2012. These experiments all benefit from two key factors: the number of scientists working on them and the international diversity of those scientists.

The number of scientists and budgets of the Human Genome Project and the Large Hadron collider.
The number of scientists and budgets of the Human Genome Project and the Large Hadron collider.

International diversity is the key to success

The level of international collaboration in science has increased rapidly in the past decade. A recent report from the National Science Foundation showed that the percentage of publications with authors from multiple nations increased from 13.2% to 19.2% between 2000 and 2013. In the same time frame, the average number of authors on scientific publications has increased from approximately 4 authors to an estimated 5.4 authors per paper. Studies have also shown that international diversity leads to more successful papers. After analyzing papers from eight different fields published between 1996 and 2012, a team of researchers from the University of Chicago and University of Florida published findings that suggested that papers with more countries in their affiliations performed better in both number of citations and journal placement. Big science builds on the success of international collaborations and takes them to the next level.

Case study: the Large Hadron Collider

One of the most successful big science collaborations of the past decade is the Large Hadron Collider and its associated experiments. The LHC collides proton beams at record energies, and when these protons collide they produce sprays of particles that need to be analyzed. There are four associated experiments – A Toroidal LHC ApparatuS (ATLAS), the Compact Muon Solenoid (CMS), A Large Ion Collider experiment (ALICE), and the Large Hadron Collider beauty experiment (LHCb). The ATLAS and CMS detectors are general purpose, dedicated to measuring whatever they can from the collisions, while the ALICE and LHCb experiments are tailored for specific measurements (as their names suggest).

These experiments are examples of science on a truly global scale. Dedicated to studying the smallest units of matter that make up everything around us, these initiatives boast scientists from over 70 different countries and budgets in the billions of dollars. The ATLAS and CMS experiments also list over 3000 scientists each on their papers, giving them the unique distinction of having the largest author lists of all recent publications. To illustrate why a large collaboration can be so important to getting good science done, let’s focus in on a particular example – the discovery and subsequent measurement of the Higgs boson by ATLAS[1].

Before we get to its discovery, we need to discuss what the Higgs boson is and why it is important. In the 1960s, theoretical physicists developed a framework called the Standard Model (SM), which explained the fundamental particles that make up all matter and the forces that govern how those particles interact with each other. Over the next 50 years, this theory was one of the most rigorously tested in all of physics, with numerous experiments testing its predictions. At the same time that the SM was being developed, Peter Higgs and others formulated a mechanism by which some of the force-carrying particles in the SM could have mass while others didn’t – a fact that was absolutely essential for the success of this theory. This mechanism predicted that there should be an additional particle produced, and this particle was named the Higgs boson. Even though the SM was extremely successful and most of its predictions had been experimentally validated in the subsequent 50 years, the Higgs boson had yet to be discovered. Without it, we could not be sure whether our understanding of the fundamental laws of nature was correct or incomplete. It took a herculean effort at the LHC to make that discovery happen.

ATLAS was an ideal experiment for the discovery of the Higgs, but it also could not have been successful without the large 3000-scientist collaboration mentioned previously. The reasons for its success are the same reasons it required so many scientists – the modularity and complexity of the detector and the amount of data that it took.

The ATLAS detector is incredibly large—as tall as an eight-story building and as heavy as 3500 cars. It is constructed out of sub-components, each dedicated to measuring a different type of particle. The only way such a complex machine could be constructed is in parts and pieces, the same way you built your Lego masterpieces out of individual bricks as a child.

This aspect was actually incredibly important for the discovery of the Higgs. The Higgs boson is short-lived, which means we can’t observe it directly. Instead, when it gets produced in proton-proton collisions, it decays very quickly into different constituents, and we measure the end products of that decay chain in ATLAS. This decay is probabilistic, meaning that one time a Higgs is produced you might measure two photons in your detector, and another time you might get two W bosons (the particle responsible for radioactive decay), which then decay into electrons or muons and neutrinos.

This means that in order to detect a Higgs, ATLAS needed do have many sub-components dedicated to measuring different types of particles. Each one of these sub-detectors has a team of hundreds of scientists dedicated to making sure their component runs smoothly and that the data coming from it makes sense. In this way, the expertise on each component is distributed and no one person has to know everything about this truly complex machine.

View of the side of the ATLAS experiment during construction in Nov. 2006 ATLAS Experiment © 2016 CERN
View of the side of the ATLAS experiment during construction in Nov. 2006
ATLAS Experiment © 2016 CERN

The Higgs boson is also produced at a very low rate, (one in about 10 billion proton collisions produces a Higgs). Therefore, the experiment must record many, many collisions before being able to observe the Higgs boson enough times to confirm its discovery. Scientists on ATLAS sifted through mounds of data in search of the Higgs. The experiment generates 3.2 petabytes of data (approximately 6400 of the typical 500-gigabyte laptop hard drives) each year. ATLAS uses a distributed computing model where labs from around the world pool their computing resources together for data processing. Like with the different sub-detectors, different teams also are experts at analyzing different types of data. This not only helps to distribute the work, but also allows for the results to be derived independently and without bias.

While we’ve only talked about the ATLAS here, which on its own required thousands of scientists to discover the Higgs boson, the particle was also observed in the CMS, which required thousands more scientists to ensure that it was running smoothly and to analyze the data it produced. Importantly, this effort required thousands of scientists from around the world and could not have been accomplished by a single lab or research group.

To infinity and beyond

The success of big collaborations in scientific research has motivated a push for more endeavors of the same type. Now, international collaborations are being formed to address everything from the search for the elusive dark matter to a better understanding of the human body. The U.S. should continue investing in these crucial alliances, both so that our scientists have the opportunity to bring their expertise to the world’s biggest problems and so that we do not miss out on discoveries to come.

[1] CMS and ATLAS jointly announced the discovery of the Higgs boson on July 4, 2012, but we focus on the ATLAS result for concreteness.

Dr. Tomo Lazovich received his Ph.D. from Harvard in May 2016. His thesis research focused on the discovery and measurement of the Higgs boson at the Large Hadron Collider with the ATLAS detector.

This article is part of our Special Edition: Dear Madam/Mister President.

For more information:

Save

Save

Save

Save

Save

Leave a Reply

Your email address will not be published. Required fields are marked *