Author: marinscienceseminar

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Bacteria, Botulism, and Beauty

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By Talya Klinger, MSS Intern

The molecular structure of botulinum toxin
What do foodborne illnesses, neck dystonia treatments, and celebrities’ beauty regimens have in common? Clostridium botulinum, baratii, and other species of Clostridium bacteria produce all of the above and more. These seemingly innocuous, rod-shaped bacteria, commonly found in soil and in the intestinal tracts of fish and mammals, produce one of the most deadly biological substances: botulinum toxin, a neurotoxin that intercepts neurotransmitters and paralyzes muscles in the disease known as botulism. Nonetheless, botulinum toxin isn’t all bad: this chemical not only protects the bacteria from intense heat and high acidity, but it makes for an effective treatment for medical conditions as wide-ranging as muscle spasms, chronic migraines, and, yes, wrinkles. 


C. botulinum
Clostridium botulinum and similar bacteria can make their way into the human body in a number of ways. Wounds infected with Clostridium botulinum or spores ingested by infants can lead to the rare but serious disease of botulism, as can accidental overdoses of medicinal or cosmetic botulinum toxin. Botulism is often foodborne, usually contracted by infants from honey or by adults from improperly home-canned foods and unrefrigerated herb-infused oils. Regardless of where any case of botulism comes from, it causes muscle paralysis, which can manifest as blurred vision, dry mouth, and muscle weakness in adults or lethargy and constipation in infants. These are only early warning signs for an illness that, if left untreated, can paralyze a patient’s respiratory muscles to the point of asphyxiation. Although 95-97% of botulism patients receive treatment and survive, they often require months of intensive care and suffer years of muscle weakness, fatigue, and shortness of breath.

So how does the neurotoxin that makes botulism so deadly work? Clostridium bacteria produce several protein compounds with similar structures and molecular weights, consisting of two chains of amino acids—one small and one large. These two amino acid chains are linked together by a covalent bond between two sulfur atoms, one in each chain. The botulinum toxin proteins bind to nerve endings where they join muscles, blocking the neurotransmitter acetylcholine, which ordinarily causes muscle contractions. This blockage is permanent, paralyzing the muscle until a new nerve ending forms a synaptic connection with it. Because the process of forming new neuromuscular junctions takes at least 2 or 3 months, the affected muscle will often atrophy in the meantime, causing the long-term side effects that plague botulism survivors.

Ironically, the very mechanisms that make botulinum toxin so dangerous give it a wide range of beneficial medical applications. When botulinum toxin is administered in small, controlled doses, its muscle-contraction preventing effects make it a viable treatment for neck dystonia, sustained involuntary eyelid closure, chronic migraines, neurogenic bladder dysfunction, and other conditions caused by involuntary muscle movements. In popular culture and tabloid media, Botox’s serious medical applications are often overshadowed by its cosmetic notoriety: smoothing out wrinkles. Cosmetic Botox inhibits the neuromuscular activity that leads to wrinkles, relaxing the surrounding skin. Seeming to reverse one of the telltale signs of aging may have given botulinum toxin its Hollywood appeal, but its wide ranging pharmaceutical uses are what continue to fascinate research scientists.

In a nutshell, the molecule botulinum toxin is a toxic protein made by clostridium botulinum bacteria. In measured amounts, the toxic protein is marketed as Botox for pharmaceutical uses. When uncontrolled doses of the bacteria are ingested, however, Clostridium botulinum can result in deadly cases of muscle paralysis called botulism. 

 If you are intrigued by the terrible beauty of such a versatile molecule as botulinum toxin, come to Marin Science Seminar on September 30th, at Terra Linda High School, 320 Nova Albion Way, in Room 207 from 7:30 to 8:30 pm, when bioanalysis and pharmacology expert Dr. Erik Foehr will discuss his research on botulinum toxin.


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An Interview With Dr. Erik Foehr

By Zack Griggy, MSS Intern, San Marin High School, Novato

          In today’s world, infectious disease remains a deadly concern to humanity. Some of these diseases include anthrax, Venezuelian equine encephalitis, bubonic plague, MERS, Eastern equine encephalitis, and, of course, botulism. Botulism is a disease that can cause paralysis and even death, but what makes botulism so different from the rest of these diseases is that the substance that causes it, botulinum toxin, is widely marketed as a beauty product under the name Botox. Dr. Erik Foehr, an expert in the fields of bioanalysis, immunogenicity risk assessment, and drug development, is currently investigating the toxin and how the body responds to it. Attend his presentation at Terra Linda High School, 320 Nova Albion Way, in Room 207 from 7:30 to 8:30 pm on September 30th.

In order to gain a little more insight before his talk, we interviewed Dr. Foehr about his work and research.

1. What drew you into the fields of pharmacology and bioanalysis?
I have always enjoyed learning about biology and how living things work.  After high school at Drake, I went to UC Davis and studied genetics and biochemistry.  I eventually worked in the biotechnology industry and specialized in pharmacology and bioanalysis.

 2. What have you studied in the past and how did this lead to your study on botulinum toxin?

I studied cell biology and how cells signal and function. I also spent many years studying immunology.  In my current job I study how botulinum toxin works and test if people develop antibodies to the toxin.

 3. How is botulinum toxin used in beauty products? How are dangers minimized by these products?

Its a bit crazy to think something so dangerous can be used as a beauty product (it removes wrinkles).  The trick is to use a tiny amount and inject it at the site of the wrinkle. The toxin inhibits the neuro-muscular activity so that the skin looks “relaxed”. They are finding other more medically relevant uses of the toxin.
 4. What do you enjoy the most about your work? What do you enjoy the least?
I enjoy learning about the huge number of experimental new drugs being developed for unmet medical needs and helping to study them. Sometimes I would like to spend more time “thinking” and less time “doing”.
 5. Do you have any advice for high school students who aspire to be pharmacologists?
Study what interests you and be prepared to be a life-time learner. Science and technology move really fast and you need to adapt and learn on the go. Don’t get replaced by robots!
Join us Wednesday, September 30th, at Terra Linda High School, 320 Nova Albion Way, in Room 207 from 7:30 to 8:30 to hear Dr. Foehr talk about his work and his study on botulinum toxin and other lethal diseases. 
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Chemosynthesis in the Deep Sea

Chemosynthesis In the Deep Sea
by Jane Casto, MSS Intern, Terra Linda High School
     
          The deep sea- where cold, stable pressures and darkness rule. Within that darkness lies life; a broad spectrum of biodiversity. The most fascinating thing about the deep sea, however, lays within what goes against lifeforms on land. 
          On land, plants and animals alike require some form of energy. The same is true in the deep sea, but one thing, particularly about plants, is quite different. Photosynthesis, the process plants use to turn sunlight into usable energy through chlorophyll, is almost always the method that plants use to get said energy. However, in the deep sea, quite a difference can be seen with that process.
          One of the reasons as to why deep sea ecosystems, such as hydrothermal vents, do not use the process of photosynthesis is obvious. Little sunlight reaches that far down into the ocean. With that in mind, however, the question presents itself: how do these ecosystems get their energy?
          Jenna Judge has studied just that. Her research has been following Marine Biology, specifically the deep sea and, our answer, chemosynthesis. Chemosynthesis is the process in which energy is obtained by reactions of inorganic chemicals, occurring within bacteria and other living organisms. 
          “Chemosynthesis also seems to be fueling ecosystems at organic substrates, such as whale falls and wood falls.” Jenna said during her presentation, Patterns of Specialization in the Deep Sea, “We found that rather than sunlight fueling this reaction, it’s reduced molecules such as sulfide, and in other cases, methane, than can fuel these microbial metabolisms.” 
          According to wiseGEEK.org, the process relies on oxidation, or redox reactions. Organisms, namely bacteria and those that belong to the kingdom archea, use chemosynthesis to manufacture food. This food is used as a carbohydrate, made of carbon dioxide and water, rendering it usable for the bacteria just as a carbohydrate would be usable to us. 
          While the deep sea is one of the most extreme examples of chemosynthesis, believe it or not, chemosynthesis is also found on land. The key is that chemosynthesis occurs where sunlight is not present. Therefore it can occur in a variety of places above land, i.e. in soil, in the intestines of mammals, and in petroleum deposits. In fact, some scientists believe that due to the tendency of chemosynthesis to take place in extreme environments, it may feature prominently on other planets depending on weather patterns. 
          The deep sea has many unexplored aspects. It is nice to know that some things are no longer a mystery, and it is also exciting to think about the fact that it is not yet fully explored, leaving room for ventures for years to come.
Wednesday, September 9th, 2015
7:30 – 8:30 pm
Terra Linda High School, San Rafael
Room 207
        
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An Interview with Dr. Jenna Judge, Marine Biologist

by Talya Klinger, MSS Intern

Driftwood is a common sight on beaches, but what happens to driftwood when it sinks to the seafloor? Dr. Jenna Judge, a recent doctoral graduate of UC Berkeley’s Department of Integrative Biology, researches evolution and ecology in deep-sea habitats, such as driftwood, as well as hydrothermal vents and sunken whale bones. Her research shows that these unusual substrates host diverse, lively communities shaped by the wood they inhabit. Attend her research presentation at Terra Linda High School, Room 207, from 7:30-8:30 pm on September 9th.


In Dr. Judge’s words:


1.   Why did you decide to become a marine biologist in the first place?

Well, I grew up in the mountains, but I was always interested in nature and science. I also loved the beach when my family would go on camping trips to the coast. However, I really decided to pursue marine biology in high school after learning about extreme deep-sea environments and the strange animals that live there from my AP Biology teacher. From there, I looked for colleges that offered a marine biology major for undergraduates and went to UC Santa Barbara. My interests in the ocean and the deep sea in particular were reinforced with each class I took and especially the semester abroad I spent in Australia doing a marine biology program. At the time, the obvious next step for me to take was to apply to graduate school to pursue a career as a marine biologist. While this route has served me well, I usually advise college students to take some time after graduation to explore options before jumping into graduate school. It is a big decision, and it’s important to have a strong sense of yourself and what you want to get out of an advanced program before choosing a program and an adviser.

2.  How did you decide to research driftwood?

I ended up studying sunken wood as a habitat for deep-sea animals after learning that the communities on wood are similar to other deep-sea ecosystems I was initially interested in, but had been much less studied. These ecosystems were hydrothermal vents (basically deep-sea volcanoes), cold seeps, and whale falls, which I’ll explain more about in my talk. Due to a series of conversations with scientists at the Monterey Bay Aquarium Research Institute, I was given the opportunity to test whether the kind of wood matters in shaping animal communities by sinking a bunch of wood at about 2 miles deep and waiting 2 years to see what happened. You’ll see what happened during my talk.

3.   How does your work on communities that form around driftwood relate to other ecosystems?

The experiment I did on sunken wood showed that, like forests and other terrestrial (land) ecosystems, the immediate habitat can act as a filter that shapes the community that colonizes that habitat. This means that the ocean isn’t just a big bathtub with a soup of organisms floating or swimming through it, but that even on small scales, the complexity of a habitat can significantly affect who decides to settle down there. I see all ecosystems as a connected web across the Earth, and I am especially interested in links between the land and the ocean, like wood, but also how the increase in artificial materials like plastic is affecting marine ecosystems.

4.  What advice do you have for high school students who aspire to be biologists?

Follow your curiosity! Ask questions and read about what interests you to keep learning and following your interests. Reach out to people who are doing things you find interesting. Scientists are always happy to hear from people who appreciate what they are doing, and it will help you learn more about what it might be like to pursue certain career paths. And once you have some ideas, research colleges that will support that passion and allow you to fully explore and develop your passion. You might find that the best program for you isn’t at the “top” university in the state or the country. For me, I was only looking at CA schools, and I was really excited about marine biology. So, I focused on applying to schools that had specific aquatic or marine biology majors like UCSB and UCSC, but I did not bother applying to UC Berkeley or UCLA even though they rank higher overall. I encourage you to find a good fit for your interests (and of course a good personal fit!) when choosing a college, and if you don’t have a clear idea about what you want to pursue (most people don’t, I was unusually focused), take your time. If you are looking to pursue marine biology in particular, here is a good site that lists all the programs across states: http://marinebio.org/marinebio/careers/us-schools/.

5.  One final question: do you have a favorite driftwood-dwelling creature?

My favorite wood-dwelling creatures would have to be limpets, since they are what led me to studying sunken wood in the first place. Limpets are snails that have no coil in their shell and a particular group of them are specialized to live in a wide range of deep-sea habitats, including hydrothermal vents, cold seeps, whale falls, and sunken wood. They also  live on empty shark egg cases, crab carapaces, worm tubes, squid beaks, algal holdfasts, and likely other organic substrates that sink to the bottom. 

Join us Wednesday, September 9th, 2015, 7:30 – 8:30 pm at Terra Linda HS, 320 Nova Albion, San Rafael – Room 207 – to hear Dr. Judge talk about her work.  Link to Dr. Judge’s Marin Science Seminar profile. 

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All About Lysosomes

by Angel Zhou, Branson School


Lysosomes, discovered and named by Belgian biologist Christian de Duve, who eventually received the Nobel Prize in Medicine in 1974, are membrane-enclosed organelles that function as the digestive system of the cell, both degrading material taken up from outside the cell and digesting obsolete components of the cell itself. The membrane around a lysosome allows the digestive enzymes to work at the pH they require. In their simplest form, lysosomes are visualized as dense spherical vacuoles, but they can display considerable variation in size and shape as a result of differences in the materials that have been taken up for digestion. Lysosomes contain an array of enzymes capable of breaking down biological polymers, including proteins, nucleic acids, carbohydrates, and lipids.


The lysosome’s enzymes are synthesized in the rough endoplasmic reticulum. The enzymes are released from Golgi apparatus in small vesicles which ultimately fuse with acidic vesicles called endosomes, thus becoming full lysosomes. Lysosomes are interlinked with three intracellular processes, namely phagocytosis, endocytosis and autophagy. Extracellular materials such as microorganisms taken up by phagocytosis, macromolecules by endocytosis, and unwanted cell organelles are fused with lysosomes in which they are broken down to their basic molecules.
Synthesis of lysosomal enzymes is controlled by nuclear genes. Mutations in the genes for these enzymes are responsible for more than 30 different human genetic diseases, which are collectively known as lysosomal storage diseases (LSD). The group of genetically inherited disorders are a type of inborn errors of metabolism caused by malfunction of one of the enzymes. The rate of incidence is estimated to be 1 in 5,000 live births. The primary cause is deficiency of an acidic hydrolase, a hydrolase which functions best in acidic environments. The initial effect of such disorders is accumulation of specific macromolecules or monomeric compounds, affecting the brain, viscera, bone and cartilage the most drastically.

To learn more about how lysosomes can communicate with the rest of the cell to act as recycling centers of cellular waste material in good times and about how lysosomes can act as overly-filled, toxic trash cans in bad times, contributing to cell death and the onset of disease, join us this Wednesday, April 7th for this week’s Marin Science Seminar “Let’s Learn About Lysosomes“ with Gouri Yogalingam, Ph.D. of the BioMarin in Room 207 at Terra Linda High School in San Rafael. 


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Interview with Dr. Katie Ferris of UC Berkeley

by Angel Zhou, Branson School

Monkey Flower 

Monkey flowers and mice – two radically different things. Yet, biologists, like Dr. Katie Ferris, are studying how native monkey flowers and mice have adapted to drastically different environments. 
Dr. Ferris currently works with Dr. Michael Nachman at UC Berkeley, using genetic sequencing and samples of monkey flowers and mice to show how organisms are often adapted to their local environment and that these adaptations are genetically based. 
To learn more about Dr. Ferris and her work with Monkey flowers and mice, read the following interview:
1) How did you decide to enter your field of work?
I decided to become a biologist pretty early on in life. When I was little I loved being outside and interacting with the natural world, especially with plants. Because of my attraction to plants I often got in trouble for picking flowers in my mother’s garden. When I was three years old I picked off every single bright green new hosta lily shoot that popped out of the earth. My mother was furious that I had laid waste to her hostas. After she calmed down a little she told me that when I grew up I should be a botanist because then I could pick any plant that I wanted without getting in trouble. The notion stuck and I pursued biology throughout high school and into college. In college I got a job in a lab that studied plant evolutionary genetics and learned a lot of new and exciting things through doing my own research. That experience is how I became interested in my current field of the genetics of adaptation in wild organisms.
2) Describe your typical day at work as a geneticist. What are the best parts of your job? What are the worst parts?
My typical day at work involves several different kinds of activities, which is something I like. Typically I will attend a scientific talk on something related to my interests, do hands-on work with mice (or monkey flowers in my former job), spend an hour or two doing molecular biology in a wet lab and of course spend a little time working on my computer analyzing data or reading scientific papers. The work with animals and in the wet lab usually involved working with undergraduate students who volunteer in the lab in order to participate in research. Some of the best parts of my job are getting to work with students and trying to spread my love of biology and scientific research. I also enjoy the precious and satisfaction of laboratory work and the personalities of the mice. The worst part of my job is when I have to spend a lot of time dissecting dead mice. I did not go into medicine for a reason 🙂
3) How did you decide to study monkey flowers and wild mice specifically? What conclusions have you drawn thus far in your research?
I decided to study monkey flowers when I was interviewing for graduate school. I visited a lot of different labs that studied plants, but the monkey flowers were by far the most captivating. They are bright yellow, happy little things and closely related species live in an incredible range of different environments from old copper mine tailings to salty coastal sand dunes. They are just really cool plants. I became interested in wild mice because of the work my post-doc advisor had done on the genetics of mouse coloration. He found the genetic changes that caused light colored desert mice to become dark when they lived on black rock outcrops. The mice that live on the dark rocks can then blend in to their surroundings and are less likely to be eaten by predators. I like making hypotheses more than drawing conclusions, but I would say that the main conclusion I have drawn from my research so far is that organisms are often adapted to their local environment and that these adaptations are genetically based. I have also concluded that biology is very complicated 
4) What is your ultimate goal in studying the genetics of adaption and speciation?
My ultimate goal in studying the genetics of adaptation and speciation is to understand better how the world around us works. I want to understand which genes are involved in important traits and if the same genes are used repeatedly to evolve the same traits in different organisms. In short, I want to know if the genetic basis of adaptation is predictable in any way. I also just generally want to contribute new knowledge to the scientific community. A better understanding of the genetic basis of ecologically important traits like drought tolerance or coat color can also be used by scientists in applied field to help improve agriculture or medicine. 

Dr. Katie Ferris, UC Berkley
To learn more about the genes and species’ adaptation to extreme environments, join us on Wednesday, April 1st for Dr. Katie Ferris’ seminar, “From Monkey Flowers to Wild Mice: A Tale of Genes, Adaptation and Extreme Environments” in Room 207 at Terra Linda High School in San Rafael. For more information, visit Marin Science Seminar’s Facebook page: https://www.facebook.com/events/850586588342167/
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Why Matter Matters for the Large Hadron Collider

by Talya Klinger, Homeschooler

After the discovery of the Higgs Boson in 2012, the Large Hadron Collider (LHC), near Geneva, Switzerland, shut down for upgrades so that it would be able to accommodate even higher-energy collisions.

Dr. Lauren Tompkins, a physicist and assistant professor at Stanford University who worked on the ATLAS experiment at the LHC, conducts research on subatomic particles and what they can tell us about matter in general. She spoke to Marin Science Seminar on March 25, 2015 about her work.  What’s next for the LHC when it comes back online in spring, 2015?

In Dr. Tompkins’s words: 

First things first: what made you decide to become a physicist?

I became a physicist for several reasons, but the earliest motivation for me was the fact that in all of my science classes, I kept asking the annoying question: “But, why?”  If you keep asking why in biology (“why do the cells organize that way?”), then you end up with chemistry, and if you do the same with chemistry (“why do the molecules have that structure?”), you end up with physics. Particle physics, in my opinion, is the ultimate way to ask that question through experimentation.

Can you share a bit about your experiences of working on the ATLAS experiment?

I started working on the ATLAS experiment as a post-bac student in 2004, and have been loving it ever since. It’s such a massive project that I’ve been able to work on everything from software to hardware, from analysis of the simplest possible proton interactions, to simulations of what crazy new physics models would look like to us. I was lucky enough as a graduate student to be at CERN, in the experiment control room, taking detector operation shifts during the first few months of high energy collisions. That was pretty special.  

Another aspect of working on ATLAS that I love is the fact that I have over 3000 collaborators from all over the world. I get to work collaboratively with a large fraction of the scientists in my field of research. If I were doing a different type of science, I would probably be competing against them. And, although I’m a pretty competitive person, I would much rather work together on a team and build something great than try to do everything myself.

Once the Large Hadron Collider is back in operation, what’s next? 

We’ll have two main objectives. First, we need to study the newly discovered Higgs boson in much greater detail. It’s the first new fundamental particle we’ve discovered since 1994, and its properties–specifically how it interacts with other particles–will be key to understanding the larger structure of matter. Secondly, we are going to be searching for evidence of physics beyond the Standard Model of particle physics (our theory of how particles interact). For example, from astronomy and cosmology, we know that dark matter exists, but we can’t find a place for it in the Standard Model. So we are going to be looking for it at the LHC and trying to figure out how it connects to normal matter–the stuff that you and I are made of. We are also going to be looking for evidence of extra dimensions, trying to find hypothesized super-partners of the standard model particles and searching for signs that perhaps there is something smaller than quarks.  

How does your research on subatomic particles relate to matter on a larger scale? In other words, how do you answer people’s questions about why your research on matter matters? 

That is always a tough question to answer because there are so many challenges in the world right now and sometimes it’s hard to draw the line from the LHC to solving those problems. But, I do firmly believe that striving to understand the natural world is such a fundamental part of humankind that we need, and are driven, to do research like the LHC. In fact, given its scale and the sheer number of people involved, the LHC is such a beautiful example of that drive. And, of course, in trying to push the boundaries of human knowledge, we produce technologies that make their way into the public sphere as well. Personally, I anchor my work on the LHC to expanding access to science and technology careers to people who have traditionally been excluded from it. There is no reason that these explorations should be reserved for the overwhelming white and male population who have traditionally been dominant.

Do you have any advice to share with high school students who are interested in studying particle physics?

Particle physics is wonderful because there is so much of it that you can understand by reading. So, read popular science books, like those by Lisa Randall and Sean Carrol.  And watch the film Particle Fever. It does an amazing job of capturing what it’s like.  Also, take as much math as possible and don’t be afraid of it!  Math is a lot of work, but it is the language of science–you need to be fluent in it!  And, just like you aren’t born “being good” at speaking or reading, you aren’t born “being good” at math. Math takes just as much hard work as learning to speak or read; we just learn it slower because we don’t use it as much.  

Finally, do you have a favorite subatomic particle? (I’m partial to the neutrino, myself.) 

I love all my particles equally! But, if I had to choose, I guess it would be the Z boson.  We’ve learned so much about the Standard Model by studying it, and it is pretty democratic in its decays. 

http://cms.web.cern.ch/news/first-z-bosons-detected-cms-heavy-ion-collisions

Figure 1: Candidate Z boson decaying to two electrons (two tallest red towers) in a lead-lead heavy ion collision at CMS. The other red and blue towers indicate energy deposits in CMS from other particles produced.


Figure 2: Candidate Z boson decaying to two muons (two red lines) in a lead-lead heavy ion collision at CMS. The green indicates energy deposits in CMS from other particles produced.

 Image Sources:
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The Magic of a New Large Hadron Collier

by Angel Zhou, Branson School

Large Hadron Collider,  Switzerland
This week, the Large Hadron Collider, or LHC, will restart after a two-year hiatus. The pause was intentional, giving technicians and engineers time to ramp up the collision energy intended to push the laws of physics to their limits. 
The LHC, completed in 2008 by the European Organization for Nuclear Research (CERN) at a cost of around $10 billion, is the world’s largest particle accelerator: an extremely long underground tunnel that allows physicists to conduct some pretty intense experiments. In essence, these experiment involve shooting beams of particles around the ring, using enormous magnets to speed them up to 99.9999 percent of the speed of light, then crashing them together. Sophisticated sensors capture all sorts of data on the particles that result from these collisions. In particle collisions, the higher the energy, the bigger the payoff, as the energy of the colliding particles gets translated into the masses of the debris, following the E=mc^2 prescription. As particles collide, their energy morphs into a shower of new particles that come flying off from the collision point.
The LHC’s biggest finding so far was the discovery of an elementary particle called the Higgs boson. Since the 1960s, the Higgs boson was thought to exist as a part of the Higgs field: an invisible field that permeates all space and exerts a drag on every particle. It had been calculated that after being formed during a collision, the Higgs boson would immediately decay into other particles in a specific ratio. Data collected after protons were crashed together showed evidence of these particles in the ratio predicted. In 2012, after three years of experiments at the LHC, physicists confirmed the Higgs boson does indeed exist. 

Higgs Boson
All the experiments conducted at the LHC so far are part of “run one.” After several years of upgrading the LHC’s magnets, which speed up and control the flow of particles, and data sensors, it’ll begin “run two”: a new series of experiments that will involve crashing particles together with nearly twice as much energy as before. These more powerful collisions will allow scientists to keep discovering new and perhaps larger particles, and also look more closely at the Higgs boson to observe how it behaves under different conditions.
To learn more about the what scientists hope to discover with the updated Large Hadron Collider, such as mini black holes, more higgs bosons, extra dimension, and perhaps, pink elephants, join us on Wednesday, March 25th for Dr. Lauren Tompkins’ seminar, “Extra dimensions, mini black holes and.. Pink Elephants?: Exciting times ahead at the Large Hadron Collider” in Room 207 at Terra Linda High School in San Rafael. For more information, visit Marin Science Seminar’s Facebook page: https://www.facebook.com/events/1426190077679597/
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Interview with Steve Croft, Ph. D. on Black Holes

By Angel Zhou, Branson School


Black holes. Don’t let the name fool you: a black hole is anything but empty space. Rather, it is a great amount of matter packed into a very small area. Scientists can’t directly observe black holes with telescopes that detect x-rays, light, or other forms of electromagnetic radiation. They can, however, infer the presence of black holes and study them by detecting their effect on other matter nearby.

Steve Croft, an astronomer at the University of California, Berkeley, uses a new radio telescope, the Allen Telescope Array to study. He grew up in England, where he received a PhD in astrophysics from Oxford University in 2002, before moving to California to work as a postdoctoral researcher at the Lawrence Livermore National Laboratory.

Read the following interview to learn more about Dr. Croft’s life and work as an astronomer.  


Steve Croft, Ph. D.

1) How did you decide to enter your field of work?
I’ve always been fascinated to understand how things work. We’re all born scientists and explorers at some level. Even as babies we learn about the world around us by trying things out, taking things apart, and performing experiments. I got particularly interested in space when a neighbor bought me a book about astronomy when I was probably about eight years old. My parents bought me a small telescope at about twelve that I used to look at craters on the Moon and the rings of Saturn. I continued to read astronomy books and watch astronomy TV shows, as well as being fortunate to learn math and science from some great school teachers.
I chose to study astrophysics for my undergraduate degree at University College London in the UK, and particularly enjoyed hands on experience with large telescopes at the University of London Observatory. That really confirmed for me that I wanted to be an observational astronomer, so I ended up doing a PhD at Oxford University, using some of the world’s largest telescopes to study the growth and environments of supermassive black holes. I moved to California in 2002 and worked at the Lawrence Livermore National Lab for 5 years where I was a member of a small astronomy research group. I got to use the Keck Telescopes in Hawaii – the largest optical telescopes in the world – as well as the Hubble Space Telescope and many others. I’ve been at Berkeley since 2007, and I’m currently working on one of the most cutting edge radio telescopes in the world as part of a big international team. 
2) Describe your typical day at work as an astronomer. What are your favorite and least favorite parts of your job?
I travel a lot for work. I just got back from a month in Australia. I spent most of the time there working with colleagues at the University of Sydney, but I also traveled to Melbourne for a couple of days to give talks, as well as out to the site of the telescope I’m working on, in the remote Australian outback. Last year I traveled to South Africa and Italy for conferences, as well as several trips within the US for meetings. The travel is one of my favorite parts of the job. Meeting new people and exploring new ideas, as well as seeing new places, are important to me.

When I am in the Bay Area I go into the office most days, although sometimes I work from home or have meetings offsite. I work in a regular office which I share with another astronomer. Most of my work is done using an iMac computer with two big screens, but I log in remotely to more powerful computers (including one with 256 GB of RAM and many TB of storage) to analyze the data from the telescopes I’m using. More often than not I’ll have a meeting or two, or attend a seminar. Sometimes I’ll have informal discussions with colleagues over lunch. I read papers written by other astronomers to keep up on research in my field. I also do a lot of education and outreach programs, including working with high schoolers. Last year we launched two high altitude weather balloons with GoPro cameras attached to the edge of space. That was really exciting.

I guess my least favorite part of the job is that I always have so much going on, including a ton of emails waiting for me to respond to. It’s great to be in a job that’s stimulating but sometimes I feel like I will never get to the bottom of my to-do list.
4) What are black holes and why do they play an important role in the universe?
There are two main varieties of black holes. One kind is about the same mass as our Sun. These result from the violent deaths of massive stars. There are probably millions of these in our Galaxy. The other kind, the ones that I research, are supermassive black holes that can be millions or billions of times as massive as the Sun. These monsters lurk at the centers of galaxies, typically only around one per galaxy, and we’re starting to understand that the way they get to be so big has a profound influence on the galaxies themselves. The forces that they produce are so incredibly powerful that they can rip stars apart and send out blast waves that shape the gas and stars that make up the galaxies in which they live.
5) What aspect of black holes are you particularly fascinated by and why?
One thing that I’d like to understand better is why some black holes lurk around not doing very much, sometimes for billions of years, and then switch to violent phases of growth. Understanding how they launch jets of material moving at close to the speed of light, and how collisions of black holes disturb spacetime itself, are areas of active research that I hope we’ll get closer to understanding with the new generation of telescopes that we’re building.
Join us on Wednesday, March 11th for Steve Croft’s seminar, “Snacking, Gorging, and Cannibalizing: The Feeding Habits of Black Holes“ of UC Berkley in Room 207 at Terra Linda High School in San Rafael. For more information, visit Marin Science Seminar’s Facebook page: https://www.facebook.com/events/1540138222921928/.
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Expanding Horizon: How Black Holes Grow

By Talya Klinger, Homeschooler


Contrary to popular opinion, black holes do not exist solely to swallow up your socks, keys, and the last scoop of Rocky Road you were saving for a late night snack. Rather, a black hole is an object with such a large mass in such a small volume that nothing, not even light, can escape its gravitational pull. The black hole’s gravitational pull absorbs whatever is in its reach.

The outer limit of a black hole is an imaginary surface called its event horizon, where the black hole’s gravitational pull is just strong enough that not a single photon can escape, creating a large dark space. According to Einstein’s theory of general relativity, even light rays that pass by the event horizon are bent and distorted by the black hole’s gravity in a process called gravitational lensing. 

This simulation of a spinning supermassive black hole from the movie Interstellar is approximately what a black hole would look like, according to general relativity.

As black holes absorb more and more objects, their mass grows. Not all black holes grow to a similar size, however. Depending on their mass, black holes generally fall into two radically different size categories: stellar mass and supermassive. Most stellar mass black holes, which are 10 to 24 times the size of the sun, are isolated and difficult to detect. Supermassive black holes, on the other hand, are millions or billions of times the size of the sun and are found at the center of most large galaxies, such as the Milky Way. Even when supermassive black holes are not absorbing matter, scientists can observe the effects such black holes have on the stars and gases around them. While stellar mass black holes are more difficult to detect unless they are in the process of absorbing matter, scientists know more about how they form than they do about the formation of supermassive black holes.

 
A simulation of gravitational lensing around a black hole and a galaxy

Many of the properties of black holes are well documented, yet the formation and growth of supermassive black holes are on the cutting edge of astrophysics. Black holes usually form out of supernovas – the explosions at the end of a star’s lifespan. In young or middle-aged stars, the energy created by nuclear fusion counteracts gravity, and keeps a star from collapsing into a black hole. When a massive star reaches the end of its lifespan (when it has burned all the fuel inside of it), it explodes in a phenomenon known as a supernova. Because fusion cannot occur in the remnants of a supernova, when there is not enough energy for the supernova to counteract gravity, there is nothing to prevent the remaining matter from collapsing into a dense object, such as a black hole. By astronomical standards, only supermassive stars have enough matter to become black holes, so small stars, including our sun, merely compact into white dwarfs or neutron stars. (Spoiler alert: the sun will eventually become a white dwarf, so there is no danger of it becoming a black hole.) Scientists know more about the creation of stellar-mass black holes than about the creation of supermassive black holes, but there is a possibility that stellar-mass black holes can grow to a supermassive size by rapidly consuming the matter around them.

Once a black hole forms, it can continue to grow by absorbing more and more matter. The following is theoretical. For example, in binary star systems containing two large stars, the first star to become a black hole will absorb matter from its companion star until the younger star vanishes. When black holes are too far from stars to absorb their matter, they consume the dust and gas floating around them. When two black holes collide, it has been hypothesized that they merge together to become an even larger black hole, producing a whopping amount of energy and sending ripples known as gravitational waves through the universe. 
 A stellar-mass black hole in a binary star system

So far, the only observations of gravitational waves have been contradicted by other, more detailed observations. However, as pairs of supermassive black holes at the centers of distant galaxies spiral closer and closer to each other, the chances are good that we will eventually be able to observe and study such dramatic black hole growth.

In the upcoming Marin Science Seminar, “Snacking, Gorging, and Cannibalizing: The Feeding Habits of Black Holes,” astrophysicist Steve Croft, Ph.D. will discuss how innovative telescope technologies make it possible to observe the growth of black holes in a new way, and perhaps, track disappearances from laundry baskets, tables, and refrigerators once and for all. 

For more information, come to the next Marin Science Seminar at Terra Linda High School from 7:30-8:30 p.m. on March 11th, 2015.

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