Monday, June 15, 2015
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Lunch and Learn about vein disorders - June 16

English country dancing at Kuhn Barn with live music - June 21

Scottish country dancing moves to auditorium, meets Tuesday evenings through summer

International folk dancing moves to auditorium, meets Thursday evenings through summer

Monday yoga registration due today

NALWO lecture: Beauty of Barns - June 16

Thursday Yoga registration due June 18

art/LArSoft course at Fermilab, free registration - Aug. 3-7

Wilson Hall 2E restrooms and drinking fountains out of order

Wilson Hall air conditioning shut down

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One minute with Alex Drlica-Wagner, postdoctoral fellow

Alex Drlica-Wagner is the Ellie Arroway of dwarf galaxies. A postdoctoral fellow on the Dark Energy Survey, he stands in front of a sticky-covered map of the Milky Way. Photo: Reidar Hahn

How long have you been at Fermilab?
I've been here since September 2013. Before this I was a Stanford graduate student working at SLAC.

What brought you to Fermilab?
I had been working on searches for dark matter through gamma rays. During this time, the Dark Energy Survey was preparing to start, and I saw an opportunity to use DES to search for new dwarf galaxies, which are one of the best targets for dark matter. Coming to Fermilab seemed like an amazing opportunity. It was a natural next step.

What does your typical workday look like?
I work in several different areas of DES. I spend part of my time working on the DES data management, processing and quality. I also work a bit on DES operations, which keeps the survey up and running. Recently, most of my time has been spent analyzing the DES data and searching for new dwarf galaxies.

What would you consider the most exciting part of your job?
The most exciting day was definitely earlier this year when we found the new dwarf galaxy candidates. Discovering things is the most exciting part of the job, but it happens only once in a blue moon.

Going down to the DES site in Chile is really amazing. Being there is a unique experience. You're on the top of a mountain, you're pretty isolated, and depending on what you're doing, sometimes you're working all night and sleeping all day. It's very different from your usual day.

The person who nominated you mentioned that you keep a poster of the Milky Way where you tag dwarf galaxies that have been found with colored stickies. What inspired that?
It's a map of the sky in gamma rays. It was given to me in Rome at a symposium for the gamma ray telescope that I worked on at SLAC. I brought it back and pinned it above my desk while I was a graduate student working on dwarf galaxies.

The objects tagged in red are previously known dwarf galaxies. The green stickies point to interesting gamma-ray sources. I tracked down a new color of sticky — yellow — for the new dwarf galaxies that we found in DES.

What is something people might not know about you?
I play semiprofessional ultimate Frisbee for the Chicago Wildfire.

Diana Kwon

If there's an employee, user or contractor you'd like to see profiled in Fermilab Today, please email

Photos of the Day

Brown fuzzies

Both broad-leaved cattail ... Photo: Leticia Shaddix, PPD
... and Indian hemp dogbane can grow two or three meters tall. Photo: Leticia Shaddix, PPD
Tip of the Week:
Ecology and Environment

Why are there so many species?

A very uncommon resident at Fermilab, this smooth green snake was observed at Fermilab this spring. Photograph and left arm are courtesy of Tristan Schramer, former Fermilab Natural Areas wildlife monitor currently working as a summer student at Roads and Grounds.

There are almost a half million species of vertebrates and flowering plants in the world. Add to that almost a million insect species, and one begins to wonder just where they all are. In fact, the vast majority of species are rare by any measure. A survey of nearly any ecosystem will uncover a few common, dominant species and many, many additional species that are represented by less than 1 percent of the total number of individuals. Considering ecosystems as functional systems, it is reasonable to ask how these rare organisms function.

One approach, of course, would be to deny the assumption that ecological systems are functional at all and that assemblages of living things are in large part random. That would require that natural selection keep "cranking out" new species without any ecological constraints on them, which flies in the face of what we know about how natural selection works.

Biodiversity is a cornerstone of ecology and, more importantly, of conservation ecology. Land managers strive for biodiversity, following the rule that more species are better. But a number of theoretical studies have shown that ecosystems with low diversity are just as stable as highly diverse ones. So what ecological good are uncommon species?

Rare, but special? Some species are known as keystone species because they exert a disproportionate effect on the entire ecosystem. Many predators can be thought of in this way, because they serve to limit the numbers of plant-eaters. At Fermilab a relatively small number of coyotes may have an important role in controlling mice, groundhogs — even geese! Uncommon animals also alter the physical environment, creating new habitats. Again at Fermilab, beavers' engineering and construction of dams and ponds is an example.

Waiting in the wings. The notion that systems with low diversity are stable assumes that ecological conditions are stable as well. Obviously that is not always the case. Natural phenomena such as forest fires, floods and volcanic action have profound effects on previously stable environments. Some species, especially plants, are well known as colonizers. They are able to quickly colonize newly available and often harsh environments to begin rebuilding a new ecosystem. They may have very little function in a stable system and yet be the saviors after ecological trauma.

Strength in numbers. Because all species are constrained by genetics, having a high level of genetic diversity, which requires more species, can exploit the environment in more ways. In the prairie, there are a small number of species that are nitrogen-fixing, while most are not. That allows a more efficient nutrient cycling than a small number of species that all use nutrients in the same way.

From a management perspective, then, one must presume that all species in a system are potentially important. Their value may not be obvious or even evident in the short term, but a number of scenarios suggest great ecological potential.

Rod Walton

In the News

The LHC is the largest machine ever built by humans — here's the plan for an even bigger one

From Business Insider, June 10, 2015

The Large Hadron Collider (LHC) is a giant 17-mile underground loop full of supercooled magnets, thirty-foot particle detectors, and miles of accelerator tubes.

It's the largest machine that humans have ever built.

But there are plans for even larger machines.

One, a whopping 50-mile-long circular particle accelerator with energy collisions nearly 10 times as powerful as the LHC, might be a little too ambitious for the near future. We don't even know how to build magnets capable of accelerating particles to that kind of energy level.

Read more