Author Archives: billycromb

Particle Accelerators are Really Expensive

Plasma inside of a Plasma Lamp, from Wikimedia Commons

Plasma inside of a Plasma Lamp, from Wikimedia Commons

Particle accelerators like the Large Hadron Collider (LHC) or the TRIUMF facility here at UBC are massive projects. The LHC cost roughly 7.5 Billion Euros to build, and has a circumference of 27 kilometers. These facilities allow scientists to perform all kinds of experiments about fundamental physics, but they take years and incredible amounts of money to construct. Ars Technica reported on an experiment at SLAC National Accellerator Laboratory at Stanford that could help reduce the cost of these projects by helping to accelerate particles faster in a shorter distance. All current particle accelerators work by using electromagnets to give energy to a stream of particles. Different designs arrange them in different ways, but the basic design involves a electromagnets arranged around a cavity which the particles pass through. Because the various particles that are accelerated are charged, they can be manipulated by electromagnets. Speeding them up is really not all that different from spinning up an electric motor or any other electromechanical device. The most powerful particle accelerators are large circular tunnels which pass the beam through the same cavities multiple times. The bigger the tunnels can be, the more speed can be added to the particles, which is a big part of why they’re so expensive. Building a 27 kilometer tunnel is expensive in and of itself, and the cost only grows when that tunnel needs to be built with incredibly precise dimensions. With science funding flagging in most developed countries, these costs might make it difficult for researchers to get the kind of investment they need to keep making progress on fundamental physics research using particle accelarators. What the SLAC group proposes is instead to use a field of plasma to transfer energy to particles. A state of plasma occurs when atoms are stripped of their electrons, leaving electrons and positively charged atoms floating freely around each other. The SLAC group found that when a group of electrons was passed through plasma, a “wake” (not unlike the wake of a ship on the ocean) followed them, pulling more electrons with them. These wake electrons were accelerated to nearly the speed of light, drawing energy from the surrounding plasma. This technique is far less straightforward than accelerating particles with electromagnets, but it is also far more efficient, so it could allow us to build more powerful particle accelerators without requiring as much space or money. There is still a great deal of research to be done on the dynamics of plasma, but this is a promising discovery.

Detect Cosmic Rays With Your Phone

Ars Technica reported last week on a paper by a group of researchers at the University of California which proposes using a large number of smartphones to monitor cosmic rays striking the earth’s atmosphere.

An illustration of showers of high-energy photons dispersed by cosmic rays striking the atmosphere. NASA, 2006,

An illustration of showers of high-energy photons dispersed by cosmic rays striking the atmosphere. NASA, 2006, via wikimedia commons

Earth’s atmosphere protects us from cosmic rays. When cosmic rays hit the atmosphere, they create showers of high-energy photons, which is the only way of detecting them from the earth. They’re quite difficult to detect and study, however, since these photons are scattered over a large area.

A large number of detectors spread across a large area can be used to calculate more detailed information about a cosmic ray based on the time and location of detection, to calculate precisely where and when a cosmic ray struck the atmosphere. This study proposes to use idle smartphones as detectors.

The researchers found that the camera in a Samsung Galaxy S3, a popular smartphone, was able to distinguish high-energy photons. It’s fairly reasonable to assume that most other smartphone cameras also has this capability, as they use similar technology in their cameras.

The researchers developed an app which would allow smartphones to run a background process while the phone is charging that would capture video and send the relevant video along with time stamps and location information to a server, which would then process the data from many such smartphones for

This is a really interesting use of idle computing resources that’s not entirely dissimilar from other academic uses of idle computing resources, but it uses some of the capabilities that are ubiquitous on modern smartphones: GPS to detect location, and high-quality digital cameras.

If the researchers can get enough people to run the app, and secure funding for the computing power required to process the data, they’ll be able to gather a great deal of information about cosmic rays, including how frequently they strike, where and when, and with how much energy. While the project may face some challenges in adoption it is a clever and low-cost solution to a research problem.

Research into Medical History sheds light on Issues of Racism in Science

I was fascinated by this interview in The Atlantic with Lundy Braun, a researcher in Africana studies and pathology and labortatory medicine, about her new book, Breathing Race Into the Machine: the Surprising Career of the Spirometer from Plantation to Genetics. It’s notable both for being good science coverage in a national magazine, but also because it highlights an issue of racism in science. The story raises interesting questions that could propably be applied to other areas of science.

Braun discusses the history of the measurement of lung capacity, which dates back to antebellum slavery in the United States and had its beginnings as a sort of pseudo-scientific justification for the notion that different races were not physically equal. Slave-owners at the time looked to variety of sciences now mostly seen as pseudo-science to try to find some sort of scientific proof of racial superiority.

The earliest study was performed by a slave-owner near the height of the slavery debate in the United States, and found that those classified as blacks or “mullatoes” had a lower lung capacity. These findings were confirmed by a large study performed by the union army during civil war. By the 1920s, the notion that black people just naturally had a lower lung capacity was medical conventional wisdom, despite some, more limited, evidence to the contrary (based on more qualitative study).

If black people do indeed have lower lung capacities, it could be due not to some sort of inherent racial difference but to different environmental or developmental factors. Black people in the United States experience poverty at much higher rates than white people and tend to live closer to a variety of environmental risk.

Today, spirometers still feature “race correction,” and read differently for patients who are determined by their doctor to be black (Braun also found that this classification was done inconsistently). Braun maintains that there have been no studies of sufficient sample size exploring other possible reasons for lower lung capacity in some black populations and that there is little justification for race correction.

The implications of this race correction are unclear. In the epilogue of her book Braun discusses how some doctors don’t rely on spirometer readings at all, and others only “eyeball it” (that is to say, the doctors guess what race someone is). Not all were even aware that race correction occured.

While the importance of this particular medical device may not be clear, the story has broader implications for science as a whole. The foundations of a lot of modern science were generated by a society that was deeply invested in justifying profound inequalities and it seems that in this case that over a hundred years of the scientific process working has failed to correct a mistake that’s based in that sort of justifying myth.


A modern Spirometer, a device for measuring lung capacity. From Wikimedia Commons: AdvancedMedicalEngineering