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Latest Posts by smparticle2 - Page 2
DNA: The next hot material in photonics?
Scientists fine-tune organic thin films with an eye toward biomedical devices
Using DNA from salmon, researchers in South Korea hope to make better biomedical and other photonic devices based on organic thin films. Often used in cancer treatments and health monitoring, thin films have all the capabilities of silicon-based devices with the possible added advantage of being more compatible with living tissue.
A thin film is just what it sounds like, a layer of material only nanometers or micrometers thick that can be used to channel light. If the film is a dielectric – that is, an insulator such as glass – it can be used without worrying that it might conduct electricity.
“DNA is the most abundant organic material, and it is a transparent dielectric, comparable to silica,” said Kyunghwan “Ken” Oh, of the Photonic Device Physics Laboratory at Yonsei University, Seoul, South Korea. In the journal Optical Materials Express, from The Optical Society (OSA), Oh and his colleagues lay out their method for fabricating the thin films in a way that gives them fine control over the material’s optical and thermal properties.
As the basis for the silica glass that makes up optical fibers, silicon has long been a dominant material in inorganic photonic devices because it’s readily available and easy to work with from the materials perspective. Oh argues that DNA can play the same role in organic photonic devices because it can be found throughout the living world. It could, for instance, be used to make waveguides similar to silica fibers to carry light within the body. Organic devices should also be easy to manufacture, more flexible than silicon and environmentally friendly.
Read more.
“I came to America when I was six years old. Mom said she brought us here so that we’d have opportunities in life. She said that back in the Bahamas, it’s only the ‘haves’ and the ‘have nots.’ She wanted us to have more choices. But I don’t think she fully understood how things work here. She was a news reporter back in the Bahamas. But the only job she could get here was taking care of oldpeople. My dad could only work construction. We moved to four different states just so they could find work. They always told me, ‘Just study hard in school and everything will work out fine.’ So that was my plan. I got all A’s up until the 11th grade– except for one B in math. My goal was to get top twenty in my class, then go to college, then get a degree, and then get a job. I realized the truth my senior year. My guidance counselor told me I couldn’t get a loan. I couldn’t get financial aid. Even if I could find a way to pay for school, I probably couldn’t get a job. I felt so mad at everyone. There were some kids who completely slacked off in school, but even they were going to college. I started having panic attacks. My dad told me not to worry. He called me a ‘doubting Peter.’ He invited all his friends over to a fish fry to help raise money. And he did get $3,000. But that wasn’t enough. So I searched really hard on the Internet and found the Dream.us scholarship. My mom was so excited when I got it. They’re paying for me to go to Queens College. Now my mom’s really scared again because DACA got revoked. She’s crying all the time at work. I try to tell her that no matter what happens, we’re not going to die. We just might have to start over.”
You must stay drunk on writing so reality cannot destroy you.
Ray Bradbury, Zen in the Art of Writing (via books-n-quotes)
“I was on a leadership team in 5th grade. At the end of the year we were supposed to take a trip to Washington DC. We held fundraisers and everything. But when it was time to go, I didn’t have the identification papers to buy a plane ticket. So our teacher Ms. Rivera decided that we’d take a bus. Just so I could go too. That trip changed my life. It made me want to be a lawyer. And Ms. Rivera became one of the closest people in my life. She always kept in touch. She basically watched me grow up. One time in high school I got in a huge fight with my mom, and Ms. Rivera came and took me on a long car ride. I started to tell her everything. I told her about a recent break-up, and how I smoked weed, and ‘I did this,’ and ‘I did that.’ She just listened to everything. Then she started telling me about her life too. She told me that she’d been in an abusive relationship. I’d always thought her life was perfect because she was a guidance counselor. But she’d been through so much too. When it was came time to apply for college, Ms. Rivera was the one who helped me apply for DACA. She told me about the TheDream.us scholarship. I didn’t even want to apply. I was ready to give up. I’d just accepted that I’d always work in restaurants like my mom. But Ms. Rivera made me apply. She said: ‘What happened to that girl who wanted to be a lawyer?’ I learned that I got the scholarship in February. They’re paying for my entire college. Ms. Rivera was so proud of me. She kept saying: ‘I told you so.’”
Theodore Isaac Rubin, American Psychiatrist (via books-n-quotes)
Have you considered that if you don’t make waves, nobody including yourself will know that you are alive?
Webb 101: 10 Facts about the James Webb Space Telescope
Did you know…?
1. Our upcoming James Webb Space Telescope will act like a powerful time machine – because it will capture light that’s been traveling across space for as long as 13.5 billion years, when the first stars and galaxies were formed out of the darkness of the early universe.
2. Webb will be able to see infrared light. This is light that is just outside the visible spectrum, and just outside of what we can see with our human eyes.
3. Webb’s unprecedented sensitivity to infrared light will help astronomers to compare the faintest, earliest galaxies to today’s grand spirals and ellipticals, helping us to understand how galaxies assemble over billions of years.
Hubble’s infrared look at the Horsehead Nebula. Credit: NASA/ESA/Hubble Heritage Team
4. Webb will be able to see right through and into massive clouds of dust that are opaque to visible-light observatories like the Hubble Space Telescope. Inside those clouds are where stars and planetary systems are born.
5. In addition to seeing things inside our own solar system, Webb will tell us more about the atmospheres of planets orbiting other stars, and perhaps even find the building blocks of life elsewhere in the universe.
Credit: Northrop Grumman
6. Webb will orbit the Sun a million miles away from Earth, at the place called the second Lagrange point. (L2 is four times further away than the moon!)
7. To preserve Webb’s heat sensitive vision, it has a ‘sunshield’ that’s the size of a tennis court; it gives the telescope the equivalent of SPF protection of 1 million! The sunshield also reduces the temperature between the hot and cold side of the spacecraft by almost 600 degrees Fahrenheit.
8. Webb’s 18-segment primary mirror is over 6 times bigger in area than Hubble’s and will be ~100x more powerful. (How big is it? 6.5 meters in diameter.)
9. Webb’s 18 primary mirror segments can each be individually adjusted to work as one massive mirror. They’re covered with a golf ball’s worth of gold, which optimizes them for reflecting infrared light (the coating is so thin that a human hair is 1,000 times thicker!).
10. Webb will be so sensitive, it could detect the heat signature of a bumblebee at the distance of the moon, and can see details the size of a US penny at the distance of about 40 km.
BONUS! Over 1,200 scientists, engineers and technicians from 14 countries (and more than 27 U.S. states) have taken part in designing and building Webb. The entire project is a joint mission between NASA and the European and Canadian Space Agencies. The telescope part of the observatory was assembled in the world’s largest cleanroom at our Goddard Space Flight Center in Maryland.
Webb is currently being tested at our Johnson Space Flight Center in Houston, TX.
Afterwards, the telescope will travel to Northrop Grumman to be mated with the spacecraft and undergo final testing. Once complete, Webb will be packed up and be transported via boat to its launch site in French Guiana, where a European Space Agency Ariane 5 rocket will take it into space.
Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Theatre time. All dancer have their own ways of getting ready for a show. I believe that a consistent routine is important to preparing for what’s ahead in a few hours. Because Forsythe’s “Artifact” is so hard on the body and I’m in every show, I tend to get to the theatre pretty early to make sure everything is ready, to put on some “normatec” boots (a compression boot for athletes that helps greatly with fatigue) and do hair and makeup. - Lia Cirio
Lia Cirio - Boston Opera House
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The Science of Smog
On July 26, 1943, Los Angeles was blanketed by a thick gas that stung people’s eyes and blocked out the Sun. Panicked residents believed their city had been attacked using chemical warfare. But the cloud wasn’t an act of war. It was smog. A portmanteau of smoke and fog, the word smog was coined at the beginning of the 20th century to describe the thick gray haze that covered cities such as London, Glasgow, and Edinburgh.
This industrial smog was known to form when smoke from coal-burning home stoves and factories combined with moisture in the air. But the smog behind the LA panic was different. It was yellowish with a chemical odor. Since the city didn’t burn much coal, its cause would remain a mystery until a chemist named Arie Haagen-Smit identified two culprits, volatile organic compounds, or VOCs, and nitrous oxides. VOCs are compounds that easily become vapors and may contain elements, such as carbon, oxygen, hydrogen, chlorine, and sulfur. Some are naturally produced by plants and animals, but others come from manmade sources, like solvents, paints, glues, and petroleum. Meanwhile, the incomplete combustion of gas in motor vehicles releases nitrous oxide. That’s what gives this type of smog its yellowish color.
VOCs and nitrous oxide react with sunlight to produce secondary pollutants called PANs and tropospheric, or ground level, ozone. PANs and ozone cause eye irritation and damage lung tissue. Both are key ingredients in photochemical smog, which is what had been plaguing LA.
Smog isn’t just an aesthetic eyesore. The two forms of smog irritate the eyes, nose, and throat, exacerbate conditions like asthma and emphysema, and increase the risk of respiratory infections like bronchitis. Smog can be especially harmful to young children and older people and exposure in pregnant women has been linked to low birth weight and potential birth defects. Secondary pollutants found in photochemical smog can damage and weaken crops and decrease yield, making them more susceptible to insects.
After the Great Smog of London shut down all transportation in the city for days and caused more than 4,000 respiratory deaths, the Clean Air Act of 1956 banned burning coal in certain areas of the city, leading to a massive reduction in smog. Similarly, regulations on vehicle emissions and gas content in the US reduced the volatile compounds in the air and smog levels along with them.
Smog remains a major problem around the world. Countries like China and Poland that depend on coal for energy experience high levels of industrial smog. Photochemical smog and airborne particles from vehicle emissions affect many rapidly developing cities, from Mexico City and Santiago to New Delhi and Tehran. Governments have tried many methods to tackle it, such as banning cars from driving for days at a time. As more than half of the world’s population crowds into cities, considering a shift to mass transit and away from fossil fuels may allow us to breathe easier.
From the TED-Ed Lesson The science of smog - Kim Preshoff
Animation by Juan M. Urbina Studios
Self-assembling nanoparticle arrays can switch between a mirror and a window
By finely tuning the distance between nanoparticles in a single layer, researchers have made a filter that can change between a mirror and a window.
The development could help scientists create special materials whose optical properties can be changed in real time. These materials could then be used for applications from tuneable optical filters to miniature chemical sensors.
Creating a ‘tuneable’ material - one which can be accurately controlled - has been a challenge because of the tiny scales involved. In order to tune the optical properties of a single layer of nanoparticles - which are only tens of nanometres in size each - the space between them needs to be set precisely and uniformly.
To form the layer, the team of researchers from Imperial College London created conditions for gold nanoparticles to localise at the interface between two liquids that do not mix. By applying a small voltage across the interface, the team have been able to demonstrate a tuneable nanoparticle layer that can be dense or sparse, allowing for switching between a reflective mirror and a transparent surface. The research is published today in Nature Materials.
Read more.
L.M. Montgomery, Anne of Green Gables (via books-n-quotes)
It’s been my experience that you can nearly always enjoy things if you make up your mind firmly that you will.
Depositing books due at the library, the grad student takes a humiliating whirlwind tour of everything his past self had planned to read.
The Six Types of Middle-Earth Names
1. Characters whose Names are Secretly Insults:
Samwise: means “Half-wise” or “Half-wit.” He is Stupid Gamgee
Faramir: Boromir’s name means “steadfast jewel”, but Faramir’s name just means “sufficient jewel.”
Sufficient.
Denethor took one look at baby Faramir and thought “eh I guess he exists or whatever” which is very in character
2. Characters who Have Way Too Many Names
Examples include Aragorn son of Arathorn son of Arador heir of Isildur Elendil’s son, descendant of Numenor, Thorongill, Eagle of the Star, Dúnadan, Strider, Wingfoot, Longshanks, Elessar, Edhelharn, Elfstone, Estel (”Hope,”) The Chieftain of the Dúnedain, King of the West, High King of Gondor and Arnor, and Envinyatar the Renewer of the House of Telcontar
Wait I’m sorry did I say “examples” plural Cuz that was all one guy 3. Characters whose parents must’ve been prophets
-Frodo means “wise by experience.” His story is about becoming wise by experience -A lady named Elwing turns into a bird (geddit)
4. Characters whose families were so lazy that they copy-pasted the same first half of a name onto multiple people
Théoden/Théodred Aragorn/Arathorn/Arador Éomer/ Éomund/Éowyn/Éorl Elladan/Elrohir/Elrond/Elros/Elwing/Elenwë/Elendil/Eldarion (the laziest family)
5.Characters whose Names are Expertly Designed so that Newbies can’t Remember Who is Who and Feel Sad
All the people mentioned in number 4 Celeborn, Celegorm, Celebrimbor, Celebrian All the rhyming dwarf names in the Hobbit Sauron and Saruman Arwen and Éowyn
6. Name so nice, you say it twice
Legoas Greenleaf: Legolas’s first name means “Greenleaf” in elvish. Legolas is Greenleaf Greenleaf (thranduil really likes green leaves ok) King Théoden’s name means King in Rohirric. Tolkien decided to name his king “King.” All hail King King this is what the fanbase means when we say tolkien was a creative genius with language
Voyager: The Spacecraft
The twin Voyager 1 and 2 spacecraft are exploring where nothing from Earth has flown before. Continuing their more-than-40-year journey since their 1977 launches, they each are much farther away from Earth and the Sun than Pluto.
The primary mission was the exploration of Jupiter and Saturn. After making a string of discoveries there – such as active volcanoes on Jupiter’s moon Io and intricacies of Saturn’s rings – the mission was extended.
Voyager 2 went on to explore Uranus and Neptune, and is still the only spacecraft to have visited those outer planets. The adventurers’ current mission, the Voyager Interstellar Mission (VIM), will explore the outermost edge of the Sun’s domain. And beyond.
Spacecraft Instruments
‘BUS’ Housing Electronics
The basic structure of the spacecraft is called the “bus,” which carries the various engineering subsystems and scientific instruments. It is like a large ten-sided box. Each of the ten sides of the bus contains a compartment (a bay) that houses various electronic assemblies.
Cosmic Ray Subsystem (CRS)
The Cosmic Ray Subsystem (CRS) looks only for very energetic particles in plasma, and has the highest sensitivity of the three particle detectors on the spacecraft. Very energetic particles can often be found in the intense radiation fields surrounding some planets (like Jupiter). Particles with the highest-known energies come from other stars. The CRS looks for both.
High-Gain Antenna (HGA)
The High-Gain Antenna (HGA) transmits data to Earth on two frequency channels (the downlink). One at about 8.4 gigahertz, is the X-band channel and contains science and engineering data. For comparison, the FM radio band is centered around 100 megahertz.
Imaging Science Subsystem (ISS)
The Imaging Science Subsystem (ISS) is a modified version of the slow scan vidicon camera designed that were used in the earlier Mariner flights. The ISS consists of two television-type cameras, each with eight filters in a commandable Filter Wheel mounted in front of the vidicons. One has a low resolution 200 mm wide-angle lens, while the other uses a higher resolution 1500 mm narrow-angle lens.
Infrared Interferometer Spectrometer and Radiometer (IRIS)
The Infrared Interferometer Spectrometer and Radiometer (IRIS) actually acts as three separate instruments. First, it is a very sophisticated thermometer. It can determine the distribution of heat energy a body is emitting, allowing scientists to determine the temperature of that body or substance.
Second, the IRIS is a device that can determine when certain types of elements or compounds are present in an atmosphere or on a surface.
Third, it uses a separate radiometer to measure the total amount of sunlight reflected by a body at ultraviolet, visible and infrared frequencies.
Low-Energy Charged Particles (LECP)
The Low-Energy Charged Particles (LECP) looks for particles of higher energy than the Plasma Science instrument, and it overlaps with the Cosmic Ray Subsystem (CRS). It has the broadest energy range of the three sets of particle sensors.
The LECP can be imagined as a piece of wood, with the particles of interest playing the role of the bullets. The faster a bullet moves, the deeper it will penetrate the wood. Thus, the depth of penetration measures the speed of the particles. The number of “bullet holes” over time indicates how many particles there are in various places in the solar wind, and at the various outer planets. The orientation of the wood indicates the direction from which the particles came.
Magnetometer (MAG)
Although the Magnetometer (MAG) can detect some of the effects of the solar wind on the outer planets and moons, its primary job is to measure changes in the Sun’s magnetic field with distance and time, to determine if each of the outer planets has a magnetic field, and how the moons and rings of the outer planets interact with those magnetic fields.
Optical Calibration Target The target plate is a flat rectangle of known color and brightness, fixed to the spacecraft so the instruments on the movable scan platform (cameras, infrared instrument, etc.) can point to a predictable target for calibration purposes.
Photopolarimeter Subsystem (PPS)
The Photopolarimeter Subsystem (PPS) uses a 0.2 m telescope fitted with filters and polarization analyzers. The experiment is designed to determine the physical properties of particulate matter in the atmospheres of Jupiter, Saturn and the rings of Saturn by measuring the intensity and linear polarization of scattered sunlight at eight wavelengths.
The experiment also provided information on the texture and probable composition of the surfaces of the satellites of Jupiter and Saturn.
Planetary Radio Astronomy (PRA) and Plasma Wave Subsystem (PWS)
Two separate experiments, The Plasma Wave Subsystem and the Planetary Radio Astronomy experiment, share the two long antennas which stretch at right-angles to one another, forming a “V”.
Plasma Science (PLS)
The Plasma Science (PLS) instrument looks for the lowest-energy particles in plasma. It also has the ability to look for particles moving at particular speeds and, to a limited extent, to determine the direction from which they come.
The Plasma Subsystem studies the properties of very hot ionized gases that exist in interplanetary regions. One plasma detector points in the direction of the Earth and the other points at a right angle to the first.
Radioisotope Thermoelectric Generators (RTG)
Three RTG units, electrically parallel-connected, are the central power sources for the mission module. The RTGs are mounted in tandem (end-to-end) on a deployable boom. The heat source radioisotopic fuel is Plutonium-238 in the form of the oxide Pu02. In the isotopic decay process, alpha particles are released which bombard the inner surface of the container. The energy released is converted to heat and is the source of heat to the thermoelectric converter.
Ultraviolet Spectrometer (UVS)
The Ultraviolet Spectrometer (UVS) is a very specialized type of light meter that is sensitive to ultraviolet light. It determines when certain atoms or ions are present, or when certain physical processes are going on.
The instrument looks for specific colors of ultraviolet light that certain elements and compounds are known to emit.
Learn more about the Voyager 1 and 2 spacecraft HERE.
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I’m never gonna finish this meme
5 cartoons/anime; 1/5 Spirited Away
Nardia - Central Park, New York City
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Outfit by @blackmilkclothing Black Milk Clothing
Fluid systems can sometimes serve as analogs for other physical phenomena. For example, bouncing droplets can recreate quantum effects and a hydraulic jump can act like a white hole. In this work, a bathtub vortex serves as an analog for a rotating black hole, a system that’s extremely difficult to study under normal circumstances. In theory, the property of superradiance makes it possible for gravitational waves to extract energy from a rotating black hole, but this has not yet been observed. A recent study has, however, observed superradiance for the first time in this fluid analog.
To do this, the researchers set up a vortex draining in the center of a tank. (Water was added back at the edges to keep the depth constant.) This served as their rotating black hole. Then they generated waves from one side of the tank and observed how those waves scattered off the vortex. The pattern you see on the water surface in the top image is part of a technique used to measure the 3D surface of the water in detail, which allowed the researchers to measure incoming and scattered waves around the vortex. For superradiance to occur, scattered waves had to be more energetic after interacting with the vortex than they were before, which is exactly what the researchers found. Now that they’ve observed superradiance in the laboratory, scientists hope to probe the process in greater detail, which will hopefully help them observe it in nature as well. For more on the experimental set-up, see Sixty Symbols, Tech Insider UK, and the original paper. (Image credit: Sixty Symbols, source; research credit: T. Torres et al., pdf; via Tech Insider UK)
“You wanna appease me, compliment my brain!” -Christina Yang
If you’ve ever watched a rocket launch, you’ve probably noticed the billowing clouds around the launch pad during lift-off. What you’re seeing is not actually the rocket’s exhaust but the result of a launch pad and vehicle protection system known in NASA parlance as the Sound Suppression Water System. Exhaust gases from a rocket typically exit at a pressure higher than the ambient atmosphere, which generates shock waves and lots of turbulent mixing between the exhaust and the air. Put differently, launch ignition is incredibly loud, loud enough to cause structural damage to the launchpad and, via reflection, the vehicle and its contents.
To mitigate this problem, launch operators use a massive water injection system that pours about 3.5 times as much water as rocket propellant per second. This significantly reduces the noise levels on the launchpad and vehicle and also helps protect the infrastructure from heat damage. The exact physical processes involved – details of the interaction of acoustic noise and turbulence with water droplets – are still murky because this problem is incredibly difficult to study experimentally or in simulation. But, at these high water flow rates, there’s enough water to significantly affect the temperature and size of the rocket’s jet exhaust. Effectively, energy that would have gone into gas motion and acoustic vibration is instead expended on moving and heating water droplets. In the case of the Space Shuttle, this reduced noise levels in the payload bay to 142 dB – about as loud as standing on the deck of an aircraft carrier. (Image credits: NASA, 1, 2; research credit: M. Kandula; original question from Megan H.)
Whisper Of The Heart Vertical Pan Shots - Dir Yoshifumi Kondo (1995)
In slow motion, vortex rings can be truly stunning. This video shows two bubble rings underwater as they interact with one another. Upon approach, the two low-pressure vortex cores link up in what’s known as vortex reconnection. Note how the vortex rings split and reconnect in two places – not one. According to Helmholtz’s second theorem a vortex cannot end in a fluid–it must form a closed path (or end at a boundary); that’s why both sides come apart and together this way. After reconnection, waves ripple back and forth along the distorted vortex ring; these are known as Kelvin waves. Some of those perturbations bring two sides of the enlarged vortex ring too close to one another, causing a second vortex reconnection, which pinches off a smaller vortex ring. (Image source: A. Lawrence; submitted by Kam-Yung Soh)
Note: As with many viral images, locating a true source for this video is difficult. So far the closest to an original source I’ve found is the Instagram post linked above. If you know the original source, please let me know so that I can update the credit accordingly. Thanks!
