Atomization is the process of breaking a liquid into a spray of fine droplets. There are many methods to accomplish this, including jet impingement, pressure-driven nozzles, and ultrasonic excitement. In the images above, a drop has been atomized through vibration of the surface on which it rests. Check out the full video. As the amplitude of the surface’s vibration increases, the droplet shifts from rippling capillary waves to ejecting tiny droplets. With the right vibrational forcing, the entire droplet bursts into a fine spray, as seen in the photo above. The process is extremely quick, taking less than 0.4 seconds to atomize a 0.1 ml drop of water. (Photo and video credit: B. Vukasinovic et al.; source video)

Physicists propose Superabsorption of light beyond the limits of classical physics.

In a well-known quantum effect called superradiance, atoms can emit light at an enhanced rate compared to what is possible in classical situations. This high emission rate arises from the way that the atoms interact with the surrounding electromagnetic field. Logically, structures that superradiate must also absorb light at a higher rate than normal, but so far the superabsorption of light has not been observed.

Now in a new paper published in Nature Communications, physicists Kieran Higgins, et al., have theoretically shown that superabsorption can be demonstrated using quantum engineering techniques. Structures capable of superabsorption could have applications including solar energy harvesting, novel quantum camera pixels, and wireless light-based power transmission.

"If you had a ring comprising 40 atoms, this would absorb light 10x faster than any classical approach," Higgins, at Oxford University, told Phys.org. "The key thing in this work is that it’s a fundamentally different way of absorbing light. So if you want to design the most efficient possible absorber and you have a certain number of atoms, this is a new and better way to do it using quantum physics. The atoms behave as if there’s more of them than there actually are, which is the really cool thing."

As the physicists explain, superabsorption is the reciprocal of superradiance. Superradiance was first introduced 60 years ago by the physicist Robert Dicke, and since then has found a variety of applications, including a new class of laser. Physically, superradiance occurs when a system of excited atoms decays and moves down a ladder of states called the “Dicke” or “bright” states. As a result, light can be emitted at an enhanced rate that is proportional to the square of the number of atoms.

In natural systems, light emission dominates over light absorption, which is why superabsorption has not yet been observed. But in the new paper, the scientists have shown that atoms in close proximity and with a suitable geometrical arrangement can interact with each other in such a way as to exhibit superabsorption.

^ A comparison of absorption: Independent atoms (red line) absorb excitons linearly, while a proposed superabsorption scheme (green line) could absorb excitons superlinearly (ideally, N2). The yellow and blue lines represent superabsorption when accounting for costs in different ways.

The key to achieving superabsorption is to use quantum engineering techniques to ensure that most state transitions take place within a specific frequency (which the scientists call the “good” frequency, in contrast with the “bad” frequencies that should be avoided). Photons can then be trapped so they are not emitted back out. Although the system would likely deviate from the “good” frequency over time, there are a few reinitialization schemes that would periodically monitor and correct the system’s frequency.


"You want a physicist to speak at your funeral. You want the physicist to talk to your grieving family about the conservation of energy, so they will understand that your energy has not died. You want the physicist to remind your sobbing mother about the first law of thermodynamics; that no energy gets created in the universe, and none is destroyed. You want your mother to know that all your energy, every vibration, every Btu of heat, every wave of every particle that was her beloved child remains with her in this world. You want the physicist to tell your weeping father that amid energies of the cosmos, you gave as good as you got.

And at one point you’d hope that the physicist would step down from the pulpit and walk to your brokenhearted spouse there in the pew and tell him that all the photons that ever bounced off your face, all the particles whose paths were interrupted by your smile, by the touch of your hair, hundreds of trillions of particles, have raced off like children, their ways forever changed by you. And as your widow rocks in the arms of a loving family, may the physicist let her know that all the photons that bounced from you were gathered in the particle detectors that are her eyes, that those photons created within her constellations of electromagnetically charged neurons whose energy will go on forever.

And the physicist will remind the congregation of how much of all our energy is given off as heat. There may be a few fanning themselves with their programs as he says it. And he will tell them that the warmth that flowed through you in life is still here, still part of all that we are, even as we who mourn continue the heat of our own lives.

And you’ll want the physicist to explain to those who loved you that they need not have faith; indeed, they should not have faith. Let them know that they can measure, that scientists have measured precisely the conservation of energy and found it accurate, verifiable and consistent across space and time. You can hope your family will examine the evidence and satisfy themselves that the science is sound and that they’ll be comforted to know your energy’s still around. According to the law of the conservation of energy, not a bit of you is gone; you’re just less orderly.”

-Aaron Freeman

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The holographic universe explained. 

Silly physicists. You think that size, distance and dimension matter. Quark or galactic cluster. All the same. Size and distance are relative concepts. This is what is messing up your mathematics. This is why things don’t add up. 

The world is very old, and human beings are very young. Significant events in our personal lives are measured in years or less; our lifetimes in decades; our family genealogies in centuries; and all of recorded history in millennia.

But we have been preceded by an awesome vista of time, extending for prodigious periods into the past, about which we know little – both because there are no written records and because we have real difficulty in grasping the immensity of the intervals involved.

—  Carl Sagan, The Dragons of Eden

A peek into the Tarantula Nebula - 30 Doradus

Like lifting a giant veil, the near-infrared vision of NASA’s Hubble Space Telescope uncovers a dazzling new view deep inside the Tarantula Nebula. Hubble reveals a glittering treasure trove of more than 800,000 stars and protostars embedded inside the nebula.

These observations were obtained as part of the Hubble Tarantula Treasury Program. When complete, the program will produce a large catalog of stellar properties, which will allow astronomers to study a wide range of important topics related to star formation.

Credit: NASA/Hubble

 An Isochrone curve is the curve for which the time taken by an object sliding without friction in uniform gravity to its lowest point is independent of its starting point. The curve is a cycloid, and the time is equal to π times the square root of the radius over the acceleration of gravity.

- A ball set on an Isocrone (or Tautochrone) curve will reach the bottom at the same length of time no matter where you place the ball, so long as there is no impeding friction.

[Gif] - Four balls slide down a cycloid curve from different positions, but they arrive at the bottom at the same time. The blue arrows show the points’ acceleration along the curve. On the top is the time-position diagram.



Electric Fields Made Visible

Physics educator James Lincoln helps people understand the natural world. The gifs above are from a Youtube video he made on how to “see” an electric field, the region around a charged object where electric force is experienced. When the object is positively charged, electric field lines extend radially outward from the object. When the object is negatively charged, the lines extend radially inward.  

Click the gifs for more info or see the full video below.

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