Boardman Tree Farm

Moonlight

Seeing stable topology using instabilities

We are most familiar with the four conventional phases of matter: solid, liquid, gas, and plasma. Changes between two phases, known as phase transitions, are marked by abrupt changes in material properties such as density. In recent decades a wide body of physics research has been devoted to discovering new unconventional phases of matter, which typically emerge at ultra-low temperatures or in specially-structured materials. Exotic “topological” phases exhibit properties that can only change in a quantized (stepwise) manner, making them intrinsically robust against impurities and defects.

In addition to topological states of matter, topological phases of light can emerge in certain optical systems such as photonic crystals and optical waveguide arrays. Topological states of light are of interest as they can form the basis for future energy-efficient light-based communication technologies such as lasers and integrated optical circuits.

However, at high intensities light can modify the properties of the underlying material. One example of such a phenomenon is the damage that the high-power lasers can inflict on the mirrors and lenses. This in turn affects the propagation of the light, forming a nonlinear feedback loop. Nonlinear optical effects are essential for the operation of certain devices such as lasers, but they can lead to the emergence of disorder from order in a process known as modulational instability, as is shown in Figure 1. Understanding the interplay between topology and nonlinearity is a fascinating subject of ongoing research.

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The Art of Lying

Lava flows like these Hawaii’an ones are endlessly mesmerizing. This type of flow is gravity-driven; rather than being pushed by explosive pressure, the lava flows under its own weight and that of the lava upstream. In fact, fluid dynamicists refer to this kind of flow as a gravity current, a term also applied to avalanches, turbidity currents, and cold drafts that sneak under your door in the wintertime. How quickly these viscous flows spread depends on factors like the density and viscosity of the lava and on the volume of lava being released at the vent. As the lava cools, its viscosity increases rapidly, and an outer crust can solidify while molten lava continues to flow beneath. Be sure to check out the full video below for even more gorgeous views of lava.  (Image/video credit: J. Tarsen, source; via J. Hertzberg)

Pleasantville (1998)

“I always wanted to be a mental health therapist.  Ever since high school, I’ve enjoyed encouraging people and giving them hope.  But I lost my way.  I got caught in a world of addiction.  I lost ten years of my life to drugs.  I stopped when I became pregnant with my child, but by that time it was too late to go back to school.  I started working as an office manager.  I never completely lost my dream.  But I just put it on a shelf for thirty years.  Then five years ago I to…ok it off the shelf.  I heard a lady in my choir talking about how she enrolled in community college.  I drove there the very next day.  I was so nervous when I filled out the application.  I was so nervous the first day of class.  All the old voices were telling me: ‘You never finish anything.’  But I said ‘fuck you’ to the old voices.  And I started getting A’s.  On my first test, I got the only perfect score in the class.  I graduated at the age of 50.  I got my Masters at 55.  And just last night I completed a mental health first aid course.  I’m so close now.  There’s still fear there.  I used to be afraid of it never happening.  Now I’m afraid of it happening.  The old voices try to come back sometimes.  They tell me: ‘You can rest,’ or ‘You’ve earned a break.’  But I’m not stopping this time.  Somebody out there is waiting for me to finish because they need my help.“

Chemists discover structure of bacterial enzyme that generates useful polymers

MIT chemists have determined the structure of a bacterial enzyme that can produce biodegradable plastics, an advance that could help chemical engineers tweak the enzyme to make it even more industrially useful.

The enzyme generates long polymer chains that can form either hard or soft plastics, depending on the starting materials that go into them. Learning more about the enzyme’s structure could help engineers control the polymers’ composition and size, a possible step toward commercial production of these plastics, which, unlike conventional plastic formed from petroleum products, should be biodegradable.

“I’m hoping that this structure will help people in thinking about a way that we can use this knowledge from nature to do something better for our planet,” says Catherine Drennan, an MIT professor of chemistry and biology and Howard Hughes Medical Institute Investigator. “I believe you want to have a good fundamental understanding of enzymes like this before you start engineering them.”

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How to Beam ➝ Noemi Makra Style

Love this man.