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Under the scope

A scientist uses a high-powered microscope to create works of art

A scientist uses a high-powered microscope to create works of art

January 04, 2009|By CRYSTAL SCHELLE

Chambersburg, Pa., resident Greg Paulson's images might look like a yet-to-be-discovered foreign world.

What seems to be the valley of the Red Planet is actually the wing of a dragonfly.

What looks like an extraterrestrial being is actually a pollen basket.

What looks like a scene from "Alien" is really a parasitic wasp jumping out from its host, a psylla.

Actually, the Shippensburg (Pa.) University biology chair said, every image comes from Earth.

And to Paulson, 53, who is an entomologist, every hair, every curve, every thorn-like object is a piece of art.

"I like the abstract beauty of it all," he said.

Paulson creates images using an expensive "brush," a scanning electron microscope (SEM) that is housed at the university.

"Not too many people have a $300,000 microscope," he said with a laugh.

Where a traditional light microscope would use light to form an image, Paulson said the SEM actually uses electrons. What this allows, he said, is the ability to see the image at a high magnification and resolution.

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Paulson started using the SEM in 1981, while he was working on a research project at the University of Hawaii and earning his master's degree.

The SEM allowed Paulson to see the specimens differently. "I noticed that the hair on the back of a fly, if I zoomed in, that it wasn't just a solid shaft, but it had a pattern to it," he said.

Paulson went on to have his images published. The first one, of the parasitic wasp, was for the National History Magazine in the 1991. Since then, Paulson has published hundreds of other photos, winning awards along the way. In the fall of 2008, Paulson won first place in the National Geographic Ultimate Photography Contest in the Space category. His photo of a dragonfly wing was published in the December 2008 edition.

The subjects from which he creates images are from anywhere he can find them. He said he hopes to make a manual on insect morphology that will include images he has taken over the years. He said he wants to show students the internal and external structures of insects, similar to how a medical student uses an anatomy textbook.

What he said he enjoys about the process most is how people react to discovering what the object is in the photos.

"They're just blown away," he said.

The process of creating a single piece takes a lot of preparation.

"It's a similar process to preparing a microscope slide," he said.

First, a subject, say a cicada, has to be fixed in formaldehyde, then dehydrated. The subject is then attached to a specimen stub, which is about the size of a shirt button. Next, the subject is coated with a thin layer of gold. "They look like little gold bugs glued onto stubs," he said.

The space in the SEM chamber limits the size of Paulson's subjects. The largest has been a beetle about the size of a thumb. He guesses the smallest subject he ever scanned was a free-living algae.

Before the gold-coated bugs are put into the vacuum, Paulson said it's important that the specimens are completely dry and coated with gold. If not, the result looks like what a death ray gun might do in a sci-fi movie.

"They'll burn right up," he said.

The specimens that aren't properly grounded with gold "glow" before vaporizing, he said.

Although the subject is mounted to the stub, Paulson can adjust the SEM - such as by rotating or titling it - allowing him to manipulate the image. This allows Paulson more creativity in getting the shot he wants.

It's a process that Paulson teaches in his own classes.

"I have a good eye, so I can try to teach a student how with an electronic microscope to take a picture that is aesthetically pleasing," he said.




 





Photos and captions by Greg Paulson

Note from the artist: Scale bars can be found on all of the images, they are in mm or microns. There are 1000 mm in a meter, 6 mm is approximately 1/4 inch, there are 1 million microns in a meter so 6000 equal approximately 1/4 inch.




This is an image of a parasitic wasp emerging from its host. The host is a pear psylla nymph. Pear psylla can be pretty serious pests in pear orchards. A female wasp lays her egg inside of a psylla nymph, The wasp larva lives inside the nymph feeding on non-essential parts of the nymph. When the nymph starts getting ready to change into an adult, the change triggers the wasp larva to kill the nymph by finishing the job of eating the insides of its host. It then pupates and a few days later the new adult chews a hole in the mummified nymph and crawls out. That moment was captured in this image.




This is pollen on the edge of the wing of a bumblebee. The prominent structure in the middle is a hamulus. Hamuli (plural) are hooklike structures found in a row on the front edge of the back wing of some insects. They hook into a fold on the back edge of the front wing. This firmly connects the wings and facilitates them working in unison as one wing surface.




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