How To Cut a Drop of Water In Half
This may not sound like a particularly difficult task, but a lot of science has gone in to producing an easier way of doing so. Antonio Garcia of Arizona State University has made “knives” for this task by coating zinc or polyethylene in hydrophobic chemicals such as silver nitrate and a superhydrophobic solution known as HDFT.
The implications of being able to cleanly cleave a drop of water is in biomedical research where it could make separating proteins in biological fluids much easier.
For the right flow speeds and incidence angles, a jet of Newtonian fluid can bounce off the surface of a bath of the same fluid. This is shown in the photo above with a laser incorporated in the jet to show its integrity throughout the bounce. The walls of the jet direct the laser much the way an optical fiber does. The jet stays separated from the bath by a thin layer of air, which is constantly replenished by the air being entrained by the flowing jet. The rebound is a result of the surface tension of the bath providing force for the bounce. (Photo credit: T. Lockhart et al.)
So the sky is blue because short wavelengths of light coming from the Sun (blue, etc.) are scattered more than long ones (yellow, red, etc.), reflecting the short wavelength light into our eyes instead of it passing through the atmosphere as part of white light. Sunsets are red for the opposite reason … but yeah, why isn’t it violet?
Violet has an even shorter wavelength than blue light. So does indigo, whatever that is. There’s a good logical case for a purple sky, right?
Want to know the answer? Why the sky isn’t violet?
The truth is that the sky is both violet and blue. But the color receptors in our eyes don’t see violet very well, so we get the (incorrect) impression that the sky is just blue. Some birds actually see well into the violet and ultraviolet, so the sky must look trippy as hell to them.
Researchers Create World’s Smallest Reaction Chamber
Scientists from New Zealand, Austria and the UK have created the world’s smallest reaction chamber, with a mixing volume that can be measured in femtoliters (million billionths of a liter).
Using this minuscule reaction chamber, lead researcher Peter Derrick, professor of chemical physics and physical chemistry and head of the Institute of Fundamental Sciences at Massey Univ. in New Zealand, plans to study the kind of speedy, nanoscale biochemical reactions that take place inside individual cells. This work appears in the latest issue of the European Journal of Mass Spectrometry.
Read more: http://www.laboratoryequipment.com/news/2012/12/researchers-create-world%E2%80%99s-smallest-reaction-chamber
If, in some cataclysm, all of scientific knowledge were to be destroyed and only one sentence passed on to the next generations of creatures, what statement would contain the most information in the fewest words?
I believe it is the atomic hypothesis (or the atomic fact, or whatever you wish to call it) that all things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another.
In that one sentence, you will see, there is an enormous amount of information about the world, if just a little imagination and thinking are applied"
Large Hadron Collider creates new kind of matter
Particles collisions inside the Swiss atom smasher have created matter called color-glass condensate, a liquid-like wave of sticky gluon particles.
Astronomers have seen a distant galaxy that blasts away material with two trillion times the energy the sun emits — the biggest such eruption ever seen. That ejection of matter could answer an important question about the universe: why are the black holes in the centers of galaxies so light?
Image: Artist’s impression of the huge outflow ejected from the quasar SDSS J1106+1939 Credit: ESO/L. Calçada
Computer models of the early universe usually produce a virtual cosmos that looks like ours except for one thing. The ratio of the mass of black holes in galaxy centers to the rest of the matter in galaxies is larger in the simulations than in the real universe.
Scientists think somehow galaxies are ridding themselves of much of the mass that would have ended up falling into their central black holes. However, until now researchers have been at a lack for an explanation of how this might happen.
To expel matter from galaxies takes energy. “We needed some input of energy from supermassive black holes,” Nahum Arav, an astrophysicist at Virginia Tech.
Supermassive black holes are obvious candidates, because they are the most energetic objects known. Some galaxies containing active black holes, called quasars, shine more brightly than anything else in the universe. “Our simulations showed that if we allowed the quasar to release a lot of mechanical energy, then the masses of galaxies would match observations,” Arav said.
Arav led a team that observed a quasar, called SDSS J1106+1939, which dates back to when the universe was only 3 billion years old (it is now about 13.7 billion years of age). Most quasars are millions or even billions of light-years distant, which means we see them as they were long ago. As such, they offer a unique window back in time, to when galaxies were young.
There are the rushing waves…
mountains of molecules,
each stupidly minding its own business…
…yet forming white surf in unison.
Ages on ages…
before any eyes could see…
year after year…
thunderously pounding the shore as now.
For whom, for what?
…on a dead planet
with no life to entertain.
Never at rest…
tortured by energy…
wasted prodigiously by the sun…
poured into space.
A mite makes the sea roar.
Deep in the sea,
all molecules repeat
the patterns of another
till complex new ones are formed.
They make others like themselves…
and a new dance starts.
Growing in size and complexity…
masses of atoms,
dancing a pattern ever more intricate.
Out of the cradle
onto dry land…
here it is standing…
atoms with consciousness
…matter with curiosity.
Stands at the sea…
wonders at wondering… I…
a universe of atoms…
an atom in the universe.
Recent tests aboard the International Space Station have shown that fire in space can be less predictable and potentially more lethal than it is on Earth. “There have been experiments,” says NASA aerospace engineer Dan Dietrich, “where we observed fires that we didn’t think could exist, but did.”
Image: A composite false-color image of fire in space. The bright yellow traces the path of a drop of fuel, shrinking as it burns, producing green soot Credit: Paul Ferkul / NASA
That fire continues to surprise us is itself surprising when you consider that combustion is likely humanity’s oldest chemistry experiment, consisting of just three basic ingredients: oxygen, heat and fuel.
Here on Earth, when a flame burns, it heats the surrounding atmosphere, causing the air to expand and become less dense. The pull of gravity draws colder, denser air down to the base of the flame, displacing the hot air, which rises. This convection process feeds fresh oxygen to the fire, which burns until it runs out of fuel. The upward flow of air is what gives a flame its teardrop shape and causes it to flicker.
But odd things happen in space, where gravity loses its grip on solids, liquids and gases. Without gravity, hot air expands but doesn’t move upward. The flame persists because of the diffusion of oxygen, with random oxygen molecules drifting into the fire. Absent the upward flow of hot air, fires in microgravity are dome-shaped or spherical—and sluggish, thanks to meager oxygen flow. “If you ignite a piece of paper in microgravity, the fire will just slowly creep along from one end to the other,” says Dietrich. “Astronauts are all very excited to do our experiments because space fires really do look quite alien.”
Such fires might appear eerily tranquil to people accustomed to the capricious nature of earthly flames. But a flame in microgravity can be more tenacious, capable of surviving on less oxygen and burning for longer periods of time.
Quantum Kisses: Measuring the World at the Scale of Single Atoms & Molecules |
Even empty gaps have a colour. Now scientists have shown that quantum jumps of electrons can change the colour of gaps between nano-sized balls of gold. The new results, published today in the journal Nature, set a fundamental quantum limit on how tightly light can be trapped.
The team from the Universities of Cambridge, the Basque Country and Paris have combined tour de force experiments with advanced theories to show how light interacts with matter at nanometre sizes. The work shows how they can literally see quantum mechanics in action in air at room temperature.
Because electrons in a metal move easily, shining light onto a tiny crack pushes electric charges onto and off each crack face in turn, at optical frequencies. The oscillating charge across the gap produces a ‘plasmonic’ colour for the ghostly region in-between, but only when the gap is small enough.
Team leader Professor Jeremy Baumberg from the University of Cambridge Cavendish Laboratory suggests we think of this like the tension building between a flirtatious couple staring into each other’s eyes. As their faces get closer the tension mounts, and only a kiss discharges this energy.
In the new experiments, the gap is shrunk below 1nm (1 billionth of a metre) which strongly reddens the gap colour as the charge builds up. However because electrons can jump across the gap by quantum tunnelling, the charge can drain away when the gap is below 0.35nm, seen as a blue-shifting of the colour. As Baumberg says, “It is as if you can kiss without quite touching lips.” continue reading