My subjective take on issues in and around science. Profiles of interesting scientists, etc. Also, juicy videos of nature, physics, and chemistry, etc.
A fascinating glimpse at the first Americans via genetics. They crossed the Bering Strait and shot off in all directions. A body from Nevada turns out to be very closely related to a body found in Brazil, across the equator…a few hundred years later. Close relationships were found between people who lived 10,000 years apart.
Crossing From Asia, the First Americans Rushed Into the Unknown
By CARL ZIMMER November 8, 2018
Three new genetic analyses lend detail, and mystery, to the migration of prehistoric humans throughout the Western Hemisphere.
Some early peoples came 20,000 years ago and died out, their DNA never found again. Some stayed in Alaska or doubled back to it later, apparently soured on the American dream. This article describes the adventure and sweep of this virtual gold-rush of a migration.
A ‘star drop’ refers to the patterns created when a drop, ﬂattened by some force, is excited into shape mode oscillations
Abstract: “These patterns are perhaps best understood as the two-dimensional analogs to the more common three-dimensional shape mode oscillations. In this ﬂuid dynamics video, an ultrasonic standing wave was used to levitate a liquid drop. The drop was then ﬂattened into a disk by increasing the ﬁeld strength. This ﬂattened drop was then excited to create star drop patterns by exciting the drop at its resonance frequency. Diﬀerent oscillatory modes were induced by y varying the drop radius, ﬂuid properties, and frequency at which the ﬁeld strength was modulated.”
“Shape oscillation of a levitated drop in an acoustic ﬁeld,” by W. Ran & S. Fredericks (Clemson University, Department of Mechanical Engineering)
These images were taken with a Scanning Electron microscope (SEM). The surface of a specimen is scanned by a beam of electrons that are reflected to form an image. Color is added later.
“Plenty of Room at the Bottom” is the title of an article written by the American genius, Richard Feynman in 1959. He worked on the Manhattan Project that delivered nuclear weapons to our military before the end of World War II. In the 1980s he was the scientist who figured out why the space shuttle Challenger exploded. In “Plenty of room at the bottom” he visualized the core ideas of Nanotechnology 2 or 3 decades before it became a widespread big idea.
“It is a staggeringly small world that is below. In the year 2000, when they look back at this age, they will wonder why it was not until the year 1960 that anybody began seriously to move in this direction.” Richard Feynman
We’re talking about a bustling industry where objects are measured in nanometers and micrometers.
- A nanometer =1 billionth of a meter and is represented by the symbol ‘nm.’. A sheet of paper is about 100,000 nanometers thick.
- A micrometer = 1/millionth of a meter (symbol: μm) A sheet of paper is 70 to 180 μm thick.
- One millimeter is equal to 1000 micrometers or 1000000 nanometers. A millimeter is equal to approximately 0.039370 of an inch. (mm)
In this video, we begin focused on a shrimp at a scale of 1 mm. We zoom down and in toward the top of the head where we see a microscopic sea plant, which eventually fills the screen. We close on a single bacteria, atop the seaweed zoomed from 1mm to 0.5um.
The remarkable chain drive below was built by the Department of Energy’s Sandia National Laboratories. The distance between chain link centers is 50 microns. The diameter of a human hair is approximately 70 microns. This is one example of thousands of separate projects and experiments laying the foundation of Nanotechnology.
A cuttlefish transmitting social information via pattern and color change. Apparently, this display means he’s really pissed off. Watch till the end and you’ll be in no doubt.
All cephalopods; cuttlefish, squid, and octopus use the same remarkable technique to communicate among their kind and camouflage themselves.
Close up of a squid’s color-changing cells called chromatophores. Amazingly these cells blend shades to create colors outside their individual range much as we can blend red, green and blue to create any color. Odder still, all cephalopods appear to be color blind.
Finally, here’s an octopus giving a practical demonstration of using chromatophores for camouflage.
The scientific model is a glorious invention for exploring our universe. The simple rules, if honestly applied, are self correcting, grounding us always in a testable connection to truth. In establishing any fact, it unburdens us of ignorance about that fact not just now, but forever. It moves our piece that many squares forward. Best of all, new and meaningful questions arise which can be explored from that knowledge. Science fractures the unknown, then explores all the cracks and finds unforeseen goodies everywhere: Telescopes, antibiotics, vaccines, better food. You could say “Like magic!” except, you know…it isn’t. As science got rolling, and gained momentum it also gained the respect that comes from undeniable results.
Science is earthy and practical and performed by people with an improbable and hard to explain love for things like soil or beetles or cancer cells. To the extent that any of us not actively working in science actually “Fucking love science” it’s probably due to the purity, passion and goodness of these nerds. They are the real and lovable thing. (my later complaints about “sciencey culture” are not about these guys) I don’t mean they are all adorable geeks out of central casting, but they have the temperament and interest to patiently keep close company with small simple details of experiments as they change across time, recording them accurately, and leaving a trail that could be followed later. They always understand what the experiment COULD mean in this outcome or that one but they play no favorites, knowing that to do so IS NOT SCIENCE. Therefore there is a core of disciplined virtue within every well conducted experiment. Every honest recording of a disappointing outcome is a public service, promoting the health and strength of the community. There’s no big reward for that, it’s just doing the job as it must be done. How many jobs utterly depend upon carefully documenting and sharing the truth? Continue reading
Yes, 100 Billion frames per second. We now have the technology to see light moving!