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Breakthrough Gives 3-D Vision of Dawn of Life
butterwise writes "MSNBC reports that a new scanning technique could revolutionize paleontology. The new technique is allowing researchers a virtual dissection of half-billion-year-old fossilized embryos." From the article: "The Chinese, Swedish, Swiss and British researchers on Donoghue's team used a 1,640-foot-wide (500-meter-wide) particle accelerator in Switzerland to scan the minute fossils, and then fed the information into a computer that generated complete 3-D images of the internal structures in fine detail."
...When they read the photo summary that mentioned the "Penis Worm"?
That'll teach me to RTFA.
Even people that believe in pre-destiny look both ways before crossing the street.
From the article...
"The results are truly orgasmic," Donoghue said.
The whole embryo thing makes that funny on so many levels.
A series of images, created using a new scanning technique, shows the interior or fossil embryos of an ancient relative of the penis worm known as Markuelia. The creature lived in China and Siberia in the Cambrian Period.
Markuelia? I call mine Ivan the Terrible.
"ancient relative of the penis worm"
"The results are truly orgasmic," Donoghue said.
I am definitely not old enough to read this. In fact, I don't think I ever will be. Penis worm, and Orgasmic. They should never be together.
Who is this that even the wind and the waves obey Him? Surely this computer must submit also!
Tiny fossils are easy to get back to the lab, unlike, say, a multi-metre-long Tyrannosaurus rex, which takes a big excavation.
The 3D reconstruction of fossils isn't new. That's been done for, oh, probably close to 100 years. In the early 20th century, it was done by grinding down a fossil specimen millimetre by millimetre, sketching or photographing each surface, and then putting together a wax or paper model of each section until the 3D shape is reconstructed. It's been done for everything from fossil plants to fish and other vertebrates. Very laborious work.
More recently, people do the same thing, but take a digital picture of the sections and use software to assemble a 3D volume and select and render parts of it. If the object is relatively large (say, centimetres in size and larger), it can alternatively be subjected to medical CAT and other types of non-destructive 3D imaging techniques. This is routine for specimens such as dinosaur skulls, in order to see the interior without destroying the specimen. If the fossil is small and transparent, 3D imaging can be done with laser scanning confocal microscopy. But opaque, small (say, require the destructive serial sectioning method, meaning you have a nice, scientifically valuable 3D reconstruction at the end of the procedure, but no specimen anymore.
The new part in this technique is therefore the *non-destructive* 3D reconstruction of such tiny fossil specimens. That's where the particle accelerator becomes necessary to get sufficient resolution to be useful. This is much higher resolution than typical 3D medical imaging. The general technique isn't that unusual, because it has existed for years too. It is the application to microfossils that is relatively new (Nature registration required to view that last article).
Oh, and if people are wondering what "penis worms" are (the jokes are piling up by now), the technical term is Priapulida. More details at the linked page.
Yeah, I know. I'm spoiling the fun.
Well, what an imagination you have! What are *your* nanites built out of that they can slip between molecules without disturbing them...? (Hint: The next thing smaller than a molecule is an atom. Single atoms aren't nanites, and when you stick several together you have a molecule...)
Although I don't do microtomography myself, I am a synchrotron scientist. I've managed to convince my boss that I qualify as "someone with expertise". ;-) Minerals are quite robust when exposed to x-rays -- even from a highly intense, highly brilliant source like the synchrotron in Switzerland used for this experiment. There is not, in fact, much power put on the sample in one of these experiment. It's on the order of miliwatts, maybe tens of miliwatts, so the sample does not heat up at all. The dominant interaction, indeed the interaction used to probe the fossils in this experiment, is the interaction of a photon and an electron tightly bound to some atom. This interaction is very short-lived and rarely changes the chemistry of the sample. The thing that is actually measured is a secondary emission of a photon that is a by-product of the primary interaction. While not 100% non-invasive, the photons are, in fact, almost completely non-damaging. Indeed, that is one of the primary benefits of x-ray tomography. After the x-ray guys are done, the sample is in the same state as when they started.
If you poke around the web sites of any of the synchrotrons (google for them: in the US their names are APS, NSLS, SSRL, and ALS; in Europe: HASYLAB, DESYLAB, ESRF, ANKA, Diamond, Soleil, and the SLS; in Japan: SPring8 and the Photon Factory) you will find lots of information about x-ray tomography. It's really a very cool technique. 3D pictures of things without having to open them up!