You may remember the furor that was ignited during the build-up to the commissioning of the Large Hadron Collider (LHC) in 2008 when a few under-qualified soothsayers predicted imminent doom and gloom at the hands of high-energy particle collisions inside the powerful accelerator. Fortunately for life on Earth, their predictions of bizarre chain reactions and deadly micro-black holes were based on hype, and a huge misunderstanding of probability, than scientific reality.
But that’s not to say that the hypothetical risks associated with high-energy physics have not been evaluated by scientists. And now, the vanishingly low risk of death-by-strangelets resurfaced not ahead of the opening of a next-generation particle accelerator, but for a particle collider that has been in operation since 2000.
The Relativistic Heavy Ion Collider (RHIC) is found at the Brookhaven National Laboratory (BNL) in Long Island, New York, and is the second most powerful particle collider on the planet (second only to the LHC). Since its original conception and through 14 years of amazing scientific discovery, the RHIC has surpassed all expectations and is now operating at “luminosities” far beyond what its original design permitted.
In particle accelerator jargon, the luminosity of an accelerated beam of particles around the ring of particle accelerators like the RHIC corresponds to how focused the beam is. The more focused the beam, the greater the chance of particle-on-particle collisions. Counter-intuitively, in the case of the RHIC’s recent upgrades, the particle accelerator requires less energy for its experiments. This may sound great for power conservation, but it has fostered some concern.
In an op-ed written for the International Business Times, Eric E. Johnson, Associate Professor of Law at the University of North Dakota, and Michael Baram, Professor Emeritus at Boston University Law School, advocate a new risk assessment before the RHIC is switched back online for its 14th run. Brookhaven engineers have already begun pumping cryogenic liquid helium into the RHIC’s 1,740 superconducting magnets, cooling them to near absolute zero (0 Kelvin or -273 degrees Celsius) in preparation for 22 weeks of collisions that will explore a state of matter not seen in the Universe since the Big Bang, 13.75 billion years ago.
Previous studies of the primordial quark-gluon plasmas have given us a very privileged window into the state of matter just after the Universe went from nothing to something. The laboratory observations of quark-gluon plasmas are fleeting events (remember, physicists aren’t trying to recreate the Big Bang, they’re recreating the conditions, of matter that existed just after the Big Bang) that occur when relativistic particles smash into each other, creating a “perfect” liquid plasma at a temperature of 4 trillion degrees Celsius — 250,000 times hotter than the sun’s core.
“(The) 22-week gold-gold run will include 3 weeks at low energy to complete beam energy scan, 15 weeks at high energy for detailed studies of plasma, plus time for cool down and warm up of magnets,” said Berndt Mueller, Brookhaven’s Associate Laboratory Director for Nuclear and Particle Physics.
The boosted luminosity of the particle beams and the lower energy collisions will optimize the production of quark-gluon plasma — an obvious boon for physics. But this is exactly what concerns law experts Johnson and Baram.
“Critics have called for serious attention to the possibility that the collider might generate a subatomic object called a ‘strangelet,’ which could, if certain assumptions are correct, start a chain reaction converting everything into ‘strange matter,’” they write. “The process would, according to Sir Martin Rees, Astronomer Royal of the United Kingdom, leave the planet ‘an inert hyperdense sphere about one hundred meters across.’”
An inert hyperdense sphere. That doesn’t sound good. Doomsday never sounds good.
A strangelet is the speculative boogieman of particle physics. They are hypothetical post-collision particles that condense from the primordial matter to form an up, down and a strange quark which combine to make a strangelet. Although they have yet to be detected from any particle collision experiment, the risk posed by the potential existence of strangelets, argue Johnson and Baram, should be investigated. One theory suggests that should stranglets be created, a chain reaction with ordinary matter could rampage around the planet, reducing Earth to a hyperdense sphere.
According to the original RHIC risk assessment in 1999, scientists stated: “Elementary theoretical considerations suggest that the most dangerous type of collision is that at considerably lower energy than RHIC.” Originally, the RHIC was designed to operate at energies of 100 GeV. But now physicists are becoming more interested in lower-energy collisions in exactly the range where the original risk assessment said was “most dangerous.” The three weeks of lower energy collisions between gold ions will occur at 7.3 GeV.
The RHIC upgrade comes at a time when a new spending bill was signed into law by President Barack Obama, establishing a commission that will evaluate the cost-effectiveness of the Department of Energy’s national laboratories, including Brookhaven. In their op-ed, Johnson and Baram say that this would be the perfect time for the commission to not only look into budgetary concerns, they should “take a sober look” at the RHIC’s potential of “destroying the whole planet.”
Of course, the op-ed sounds alarming, especially as this isn’t some conspiracy theory being bandied around by a self-proclaimed “expert.” However, we are talking about the very, very, very low probability of strangelets being generated in the RHIC, particles that are purely hypothetical in nature. And the hypothesis that a chain reaction could be sparked by said hypothetical particles, again, is hypothetical. So any risk analysis into the planet-killing potential of the RHIC would need to weigh the probability of doomsday against that of awesome scientific discovery, the latter of which is an inevitable outcome of experiments at the RHIC.
Risk assessments are all well and good, but the “doomsday risk potential” of any particle accelerator is infinitesimally small, compared to the high-energy particles that are being naturally flung around the Universe and colliding with our planet every second. Our planet is bathed in high energy particles across the whole spectrum of energies; of the billions of years our planet has been in existence, if the strangelet chain reaction is real, we shouldn’t be here.
But critics — particularly those who are not experts in the field of high-energy physics — will always have the loudest voice because no matter how tiny the hypothetical risk, they will argue that if the consequence is the end of the world, that’s a real risk that we cannot ignore.
Unfortunately, over-hyping the perceived risk of disaster can also cause unnecessary worry and may, ultimately, stymie scientific breakthroughs in high-energy physics.