The Research Staff of the North Carolina Museum of Natural Sciences includes experts in a wide variety of scientific disciplines who conduct exciting research investigations, maintain and expand the Museum’s natural science Research Collections, and participate in the Museum’s public education and outreach mission. Check this blog often to learn about all of the great science happening at the Museum!
The Digital Smartphone Microscope seemed like a really good idea. The video circulated last year. It looked like fun, which is of course the reason to do anything sciencey. If you clicky here you can watch the original video on YouTube.
I had a couple of middle school volunteers, Andrew and Daniel, working in my laboratory last semester. We took on building three Smartphone Digital Microscopes as a project. In short, it’s a couple of pieces of Plexiglas or Lexan with an adjustable bottom piece for focus. The magnifier/macro lens is cannibalized from a laser pointer. A lot of the parts came from the store where everything was $1.
This was a good project for the middle schoolers for several reasons. First, in a lab you often have to make what you need. You make or fake it because the real deal either doesn’t exist or because it’s too expensive. Second, any project like this teaches that any problem is solved iteratively. Try it, and if it doesn’t work, try something else. Third, it was the culmination of things I had them doing which kind of fell under the heading of Playing With Polarized Light.
Most of my work involves what I call IBS:Itty Bitty…Stuff. The most common tools of my trade are the petrographic microscope, micro-infrared spectroscopy, the electron microprobe, the SEM with EDA, or with Backscatter Electron imaging, and nowadays the Field Emission SEM or microprobe. The idea of a portable petrographic microscope was appealing, so I set Andrew and Daniel to watching the video and getting together some refinements. Then we built it.
Here’s a photomicrograph from my lab scope. An image with crossed polars has a polarizer below, then the thin section, then a polarizer above the section. The above polarizer is rotated 90° from the lower one. The thin section is rotated and the petrographer observes how polarized light interacts with the sample. So how do we build it?
The first refinement the guys came up with was to use the third bolt as part of the sample stage. The one in the video was simply too floppy. The second was to leave the lens in the tube in which it came. The video has you take the lens out, which like an invitation for a fumble and a lengthy crawl-around on the floor. In the picture above, I have one of each lens mounted, one in the tube and one removed from the tube.
One of my refinements was to add a rotating stage. Polarizing film (linear polarizing material for you aficianados) goes below the stage and above the lens.
- The focal distance is very short, so specimens have to get very close to the lens. The rotating sample stage actually helps with that. But the sweet spot for getting things in focus is rather small. If you have a thick nut on the bolt holding up the top layer, you might not be able to get close enough to focus.
- Middle school boys are over-rated in terms of their destructive powers in dismantling laser pointers.
- We skipped countersinking the holes for the bolt heads in the bottom of the stand (not my best idea). As a result, if you lean on the stand by accident, you can turn it over.
- Andrew knew more about using my Smartphone camera than I did, which was kind of embarrassing.
- Getting the rotating stage centered under the lens is very difficult.
- A cheap laser pointer lens doesn’t work very well. It distorts around the edge of the lens, called a vignette in photography. Perhaps a more expensive laser pointer would have a better lens, but that kind of defeats the purpose.
- A clip-on gooseneck light from the dollar store works well. The light source is not really needed, and a bright LED light from the dollar store is too strong. This rig actually works better outside.
- This has been rattling around the back of my SUV for a while and still works fine.
- The three-point focus mechanism actually lets you focus with the sample stage slanted, so you can zoom in on side features and not just the top of the specimen.
Getting a photo through the lens takes a lot of fiddling and practice. Not to be too mercenary, but I ran up to the Museum store and bought a couple of pieces of amber with insects to play with ($5 each). Here are some of the results:
You can see here how the lens vignettes around the edges. The brown mineral in the middle is a biotite with a gray apatite crystal in the middle. Dark material is volcanic glass. Black minerals are magnetite. Fish Canyon Tuff, Colorado, crossed polars image.
Many thanks to Andrew and Daniel for their help and for all the fun!
By Roland Kays, director of the Biodiversity Lab at the NC Museum of Natural Sciences.
Originally posted on The Agouti Enterprise:
We all know the feeling – sometimes there just aren’t enough hours in the day to get all our work done. Such is the life of agoutis living in low-quality territories, who have to scrounge around the rainforest floor not only for today’s meal, but also to find seeds they can cache underground for the late rainy season when there will be even less food. To push ourselves as deadlines approach we set the alarm extra early, and have an extra cup of coffee to keep working later. Our latest discovery shows that hungry agoutis also stretch the hours of their day, but face much more dire consequences than a short-night’s sleep.
Our new paper published today in Animal Behavior, led by Lennart Suselbeek from Wageningen University, shows that hungry agoutis that wake up early or stay up late are much more likely to be eaten by ocelots, while those who have plenty of food sleep in and avoid the dangerous dusk and dawn periods.
By Meg Lowman
Although Americans represent 5% of the world’s population, we use 30% of the world’s resources, and our consumption has doubled in the last 50 years. What happens to finite supplies of fresh water, oil and soil as billions of people in India and China desire to “live just like Americans do?”
Here are a few tips to conserve natural resources, save money, and educate your family about the economics of our environment:
- Become a “locavore”: eat local foods and buy local products. In North Carolina, farmers markets sell fresh local produce. It will lower your energy footprint to buy produce that did not travel far to reach your dinner plate.
- Carpool; Americans spend over 4.5 billion hours per year in commuting alone. William Moomaw, professor at Tufts University and co-author of a recent IPCC (Intergovernmental Panel on Climate Change) Report, calculated that if daily American commuters would carpool for just one day per week, we could significantly reduce America’s carbon emissions by 2050.
- Recycle. Approximately 85% of all American household waste can be recycled. Purchase goods with less packaging, and re-use items such as boxes, paper clips, plastic bags, and packing materials. Wrap gifts in old newspaper or other recycled materials.
- Audit your household electricity. Turn off lights. Buy power strips. Turn off computers when not in use. Buy Energy Star appliances.
- Travel green. When traveling, become energy conscious by staying in energy-efficient hotels. Plan family vacations to eco-tourism destinations that inspire conservation of natural resources.
- Plant trees, especially natives. Trees act as a filter to cleanse the air, produce oxygen, store carbon, and serve as a home to other wildlife. Attractive shade trees invariably raise the value of your real estate.
- Conserve fresh water. An estimated one third of all water in American homes is used to flush toilets. Check toilets and sinks for leaks, and reduce water consumption in your daily habits.
- Go green for the holidays. Can you create special days where no one drives? Candlelight dinners? What about purchasing a live tree, and then planting it after the holidays? Buy gifts with a “green” message. Consider switching traditional outside landscape lights with the new LED ones, significantly minimizing your family’s energy footprint.
Greeting Blogophiles! Are you partial to the Paleozoic? Perhaps you are drawn to the Devonian, or maybe you are more moved by the Mesozoic and are crazy about the Cretaceous. Well, have I got a bridge for you… The third floor bridge between the Main Building and the NRC is now open and it’s about time. Walk with me, would ya?
While we’re walking, let’s do a bit of math shall we? If you were to walk from the Main Building (Nature Exploration Center) to the Nature Research Center via the third floor bridge, how long would it take you to get there (please show your work)? Using the simple equation Time = Distance/Rate or T=D/R, if you know the distance between the two buildings (140 feet) and how fast you are traveling (1 foot per second), you could easily calculate the time it would take (140 seconds or just over two minutes).
Now, let’s say you wanted your trip to take 544 million years, how fast would you need to walk? Let’s see, R = D/T. So 140 feet /544 million years means you would move approximately a quarter of a foot every million years. You’d be long dead and hopefully fossilized, before you even took your first step. Fortunately, thanks to the beautiful artwork tiles by Barbara Page, you can now travel back 544 million years in the time it takes you to cross the bridge, and live to tell the tale.
As a paleontologist, I often think about time and about fossils, but I rarely think of them as art. However, on the third floor bridge, art and science have collided in spectacular fashion, and anytime you want (when the Museum is open and the weather is decent) you can wander to the bridge and plunge into the depths of Earth’s deep time.
The concept behind the tiles is an ingenious one. If one were to turn the layers of the Earth like pages in a book, on each page you’d see something different. But because there is no place on Earth where all of its history is represented, the tiles are a composite of representative fossils found from various geologic time periods around the world. What I find really fascinating about the bridge tiles is that rather than representing what the organisms might have looked like in life, they are images of fossils you might find from rocks of that era. It’s kind of like field work without getting dirty, and everyone is guaranteed to find a fossil.
The other brilliant part of the bridge art is there is math behind it and you don’t have to do it. Barbara Page has done it for you. Each tile represents ≈2 million years, so in effect you can travel through time without worrying about your teleporter inadvertently turning you into a fly. How convenient! Also for those budding ichnology (trace fossil) enthusiasts out there, the tiles at your feet have depictions of some of the tracks or trails you might find. How cool is that?
So next time you’re at the Museum, why not slow down and visit the third floor bridge to do a little field work? It’ll be well worth your time.
To see more of Barbara Page’s artwork please visit her website: http://www.barbarapagestudio.com/index.html
by Meg Lowman
If aviation engineers could apply the wisdom of the chimney swift, several troublesome problems of aeronautics could be solved. Pilots, for example, would never have to worry about the amount of gasoline in their tanks. The chimney swift refuels on the wing, spends almost its entire waking life in the air, and never, except by accident, touches the earth.
Every autumn, many millions of birds migrate from northern breeding grounds to equatorial locations. This annual flight is not only extraordinary in terms of time and energy, but also raises questions about the physiological issue of sleep. Some birds migrate long distances, while others only shift regionally. So how do birds rest during migration, and what are the consequences for migratory sleep deprivation?
In 2011, the Swiss Ornithological Institute affixed electronic sensors to alpine swifts to monitor their movements. This species spends summers breeding in Europe, but winters in Africa, many thousands of miles away. Thanks to electronic tagging, scientists found that these birds were always aloft in the winters, feeding in the air columns. The tags only recorded data every 4 minutes, so these birds could have landed intermittently. But these results indicate that the swifts go long periods without sleep in the conventional sense.
Sleep is incredibly diverse across the animal kingdom, with some animals sleeping two hours, and others sleeping 20. Many factors influence sleep in wild animals, including food, predation, and trophic level (position in a food chain). It is generally thought that every species has a specific sleep “quota,” or an average amount that they sleep every day. However, recent research has shown that there is some flexibility in sleep requirements for some species.
Just prior to migration, white-crowned sparrows reduce their sleep time by two-thirds, yet do not show any of the cognitive impairment generally associated with sleep deprivation. This migratory restlessness has been observed in other bird species, and can be induced in the lab by artificially shortening the length of day. During the very short Alaskan summer, pectoral sandpipers stay awake for almost 2 weeks to maximize breeding opportunities. The males that sleep the least sire the most offspring – a rare case where sleep deprivation is an evolutionary advantage.
One of the big topics of discussion in my undergraduate Astrobiology class at Appalachian State University (ASU) is the question of intelligent life beyond Earth, as it is, in my view, probably the single most intriguing question in astrobiology. Indeed, the prospect of life existing beyond Earth has fascinated humankind for centuries, with the first scientific thinking on the subject dating back to the Ancient Greeks. Advanced modern technology has led to formalized study on the Search for Extraterrestrial Intelligence (abbreviated, SETI), and the popularization of this topic over the last several decades has been spurred on from the pioneers of SETI, most notably the astronomers Frank Drake and Jill Tarter of the SETI Institute in Mountain View, CA, and the late astronomer Carl Sagan.
While we have no evidence whatsoever for life of any kind, even the most simplest microbes, beyond our planet, humans seem to be drawn to this search, and in so doing, ponder the possibilities of what could be out there, and what such a discovery would mean for life on Earth. A recent boost in proponents of SETI came just earlier this month with a report from a new data analysis from NASA’s Kepler spacecraft which revealed that there could be as many as 40 billion Earth-like planets in our Galaxy, alone. This means that one out of every five Sun-like stars in the Galaxy could house a potentially habitable planet!
(You can interact with some of Kepler’s discoveries with this cool animation tool).
So, then where is everybody? This apparent contradiction in seemingly high estimates for extraterrestrial intelligent life in the Galaxy and our lack of evidence for such life was famously questioned by the physicist Enrico Fermi in 1950, and is known as the Fermi Paradox, which has several proposed theoretical solutions. In spite of this paradox, many scientists remain hopeful that extraterrestrial intelligence is out there, with a reasonable chance of detecting it, with modern estimates for potential communicative civilizations achieved through the Drake Equation (sometimes called the Sagan-Drake Equation).
Recently, I gave my Astrobiology class an assignment to write whether they thought SETI — the ongoing search for intelligence beyond Earth — was a waste of time and/or money, knowing that, with the vast distances of space, any possible radio signal from an intelligent civilization could take thousands of years (which is likely a minimum) to reach us, if they were being sent at all?
This assignment was a contest, such that the most convincing response would be published on this astronomy blog site. Below are two chosen excerpts, and a third in its entirety. All students are sophomores in ASU’s Honors College, many are non-science majors, and all illustrate several of the prevailing viewpoints that span generations of scientists today.
Student Jack Schaufler cites the large gain in SETI against the small economic cost:
SETI will continue to expand, with new detectors suitable for optimal wavelengths predicted to increase the list of SETI targets to hundreds of thousands of stars. The potential implications of contacting intelligent life are huge. It would drastically change our lives here one Earth, causing an increase in scientific interest as well as a shock throughout the religious world. The risk involved with maintaining SETI is a mere 2.5 million dollars a year, equal to the price of 5 Tomahawk Cruise Missiles out of the 830 billion dollars the US spends on defense a year. Keeping SETI operational requires much less risk than the potential reward.
As a counter view, student Zachary Lachance thinks there is probably a very low likelihood for success with SETI:
Due to the idea that older intelligent life should have already existed in the universe and the lack of evidence to support the idea that this intelligent life has made contact with Earth, it is safe to assume that SETI will fail because intelligent life should have already colonized the galaxy…. Unless intelligent life is so rare that some form of it has yet to colonize the Galaxy or communicate, SETI will still most likely fail due to the small probability of intelligent life existing or the large distance between Earth and another intelligent civilization. Once you add in all of the planets that do not, as far as we can tell, contain intelligent life, finding intelligent life would still be similar to finding a needle in a large, seemingly never-ending haystack. Therefore, the prospects of SETI seem bleak and SETI is destined to fail.
The most convincing overall response was by student Jonathan Solomon. It is pro-SETI.
The Search for Extraterrestrial Intelligence (SETI) uses radio waves as a means of hopefully finding another civilization – one that is capable of receiving, deciphering, and transmitting radio signals of their own. The entire search relies upon several assumptions about other intelligent civilizations based on the history of the evolution of the human race’s technological capabilities and curiosities. One powerful assumption is that, evidenced by the age of the universe, Earth is in its infant stages regarding technology. If there is other intelligent life out there then it is reasonable that they are much older and more technologically advanced than humans are. Humanity has only had radio waves for about one hundred years, and the technological advances achieved during that period have been astounding. Roughly forty years after the advent of radio waves came nuclear technology. That is such an infinitesimally small time on the cosmic scale between harnessing to radio waves and having the capability of annihilating intelligent life as we know it. There are other assumptions about extraterrestrial intelligence that fuel debates between SETI proponents and opponents.
Many argue that if advanced alien civilizations exist, then they should have already made contact with Earth; if not the aliens themselves, then feasibly the aliens would have some form of self-replicating robots that would be capable of colonizing the universe. If, indeed, However, it is also possible that extraterrestrial civilizations could simply be thousands of light-years away and have simply not gotten close enough to us for humans to realize their presence. Another possible explanation is that interstellar travel is much more difficult than we currently assume. For instance, considering the high speeds that interstellar vehicles would have to travel, ensuring the safety of the vehicle would be extremely difficult (Shostak, 2002).
The importance of SETI, in my opinion, is that it brings hope. Knowing that somewhere out in the cosmos some intelligent civilization could have figured out how to coexist in such a way that it did not self-destruct would prove that humanity is not doomed. Ben Zuckerman, astrophysicist at UCLA, writes about how it is ironic that humanity is looking for extraterrestrial intelligence due to the overpopulation and overconsumption of our own planet (Zuckerman, 2002). I agree with him that humans need to change our consumption patterns if we wish to survive on this planet; however, I do not believe that the allocation of such a small amount of funds, when compared to the military budget, for example, is a waste. Rather, the spending of such a small amount of money on such a high reward is like a cosmic scratch card. If we do not end up winning, we did not expend many resources, and at least we tried; but if we end up hitting the jackpot, the implications are enormous.
[References: Shostak, Seth. SETIs Prospects Are Bright. Mercury. 2002. Print; Zuckerman, Ben. Why SETI Will Fail. Mercury. 2002. Print].
One of the most thought-provoking views on extraterrestrial civilizations comes, in my opinion, from Carl Sagan. This short video is excerpted from his original Cosmos broadcasts, and to me best summarizes the profound implications of finding life beyond Earth, within the context of a strong scientific platform:
If you believe life is out there and want to help in the search for ET signals, learn more about how you can participate in the SETI@home citizen science project that uses personal computers to search for and analyze radio signals.
While there’s bound to be some disaster in my kitchen this Thanksgiving, one thing I doubt will happen is that the food will float away. This Thursday, while we’re gobbling up various treats on the table, my mind will likely wander about 250 miles above the Earth to the International Space Station (ISS) and the astronauts there with their floating bags of various Thanksgiving goodies, wondering if perhaps some cranberries flew about beyond the table, or pieces of pumpkin pie perchance got stuck to the ceiling?
A few days ago, ISS Expedition Crew 38 beamed down a Thanksgiving message to us Earth-dwellers, giving us a taste of their holiday feast enjoyed in near-Earth orbit. While the cans look vaguely reminiscent of what I gave my cat for breakfast today, I can only surmise that it is probably the view that far surpasses the cuisine.
Happy Out-Of-This-World Thanksgiving!