Schlieren image of shock waves created by a T-38C in supersonic flight captured by using the sun’s edge as a light source and then processed using NASA-developed code.
Our sun is ever-changing, and a satellite called
the Solar Dynamics Observatory has a front-row seat.
On February 11, 2010, we launched the Solar Dynamics
Observatory, also known as SDO. SDO keeps a constant eye on the sun, helping us
track everything from sunspots to solar flares to other types of space weather
that can have an impact on Earth.
After seven years in space, SDO has had a chance to do what few
other satellites have been able to do – watch the sun for the majority of a
solar cycle in 11 types of light.
The sun’s activity rises and falls in a pattern that lasts
about 11 years on average. This is called the solar cycle.
Solar activity can influence Earth. For
instance, it’s behind one of Earth’s most dazzling natural events – the aurora.
One of the most common triggers of the aurora is
a type of space weather called a coronal mass ejection, which is a billion-ton
cloud of magnetic solar material expelled into space at around a million miles
an hour.
When these clouds collide with Earth’s magnetic field, they
can rattle it, sending particles down into the atmosphere and triggering the
auroras. These events can also cause satellite damage and power grid strain in
extreme cases.
The sun is in a declining activity phase, so coronal mass
ejections will be less common over the next few years, as will another one of
the main indicators of solar activity – sunspots.
Sunspots are created by twisted knots of magnetic field. Solar
material in these tangled regions is slightly cooler than the surrounding areas,
making them appear dark in visible light.
The tangled magnetic field that creates sunspots also causes
most solar activity, so more sunspots means more solar activity, and vice
versa. Humans have been able to track the solar cycle by counting sunspots
since the 17th century.
The peak of the sun’s activity for this cycle,
called solar maximum, was in 2014.
Now, we’re heading towards the lowest solar
activity for this solar cycle, also known as solar minimum. As solar activity
declines, the number of sunspots decreases. We sometimes go several days
without a single visible sunspot.
But there’s much more to the story than sunspots
– SDO also watches the sun in a type of light called extreme ultraviolet. This
type of light is invisible to human eyes and is blocked by our atmosphere, so
we can only see the sun this way with satellites.
Extreme ultraviolet light reveals different layers of the
sun’s atmosphere, helping scientists connect the dots between the sunspots that
appear in visible light and the space weather that impacts us here on Earth.
SDO keeps an eye on the sun 24/7, and you can see near real-time
images of the sun in 11 types of light at sdo.gsfc.nasa.gov/data.
Scientists at Orfield Labs have created “the world’s quietest room,” a room that has a Guinness world record-holding -9 decibels as compared to the usual 30 decibels for quiet spaces. These scientists study the effects of the room on people as well. Every area of the anechoic room absorbs sound so completely that subjects have been able to hear their own organs and even hallucinate. Most are so discomfited by the room that one person has only been able to stay in there for forty-five minutes. The room is normally used to test the sound level of products, such as lighting.
Dr. Ian Crozier survived Ebola, only to have his normally blue left eye turn green because of inflammation. Though the rest of his body, including his tears, was Ebola-free, his eye was teeming with the virus.
It turns out Ebola can hide out in eyes, testicles, the uterus, the spine.
“It presents a huge challenge, because how do we get enough antivirals into these sites?” says Ilhem Messaoudi, a viral immunologist and professor of biomedical sciences at the University of California, Riverside, who is studying how the virus works in the human body.“How do we eradicate those reservoirs? And why do some people end up developing these reservoirs and other people don’t?”
Neurogastronomy 101: The Science of Taste Perception
[…]To truly comprehend what neurogastronomy is about, it’s important to
understand the basics of how we physiologically perceive taste. Not
surprisingly, it all begins with our mouths and ends with our brain.
When you chew on a blueberry, enzymes in your saliva break down the
fruit. Fragments of the gnawed blueberry will come in contact with your
tongue’s papillae — the thousands of wart-like bumps under the mucous membrane of the tongue. Each papillae
has anywhere from 50 to 100 taste buds, which have chemical receptors
that identify the five basic tastes: bitter, sweet, salt, sour, and
umami. The papillae also have many sensory cells that recognize
and analyze the morsels in your mouth, and transmit the information to
your brain by activating nerve cells.
This, on a macro level, explains how we go from popping a blueberry
in our mouth to recognizing whether it is sweet or sour. The micro level
is far more multifaceted, as many other parts of our body play a role in how we perceive taste, from our olfactory senses to the sensation of touch. Understanding the complex brain processes that help us grasp why, what, and how we eat is, simply put, the exploration of neurogastronomy.
These are microscopic balls of tin, imaged under scanning electron microscope (SEM) at 2500x (about 25x more magnification than the strongest optical microscope can manage). These very cool-looking tin samples are good for looking at when you’re trying to calibrate the SEM to produce the best images possible - since the spheres come in all different sizes, you can start with the large spheres for rough calibration, since the tiny spheres are invisible if the microscope isn’t properly calibrated.
In the UCSD cleanrooms we used carbon tape and specks of dust for calibration, because they’re almost always part of our sample anyways, so we don’t have to change between the calibration sample and the sample we’re interested in - usually our SEM time slots are short, and returning the system to vacuum between samples takes too much time. But I can see how the spheres would be very nice, particularly for detecting astigmatism, an effect that would stretch the spheres into little footballs.
Tin Balls by FEI Company Via Flickr: Image of tin balls, which are used to calibrate scanning electron microscopes (SEMs). The image was taken at a tilt of 57 degrees.
Courtesy of Mr. Daniel Oldfield , RMIT University
Image Details
Instrument used: Verios
Magnification: 2500X
Horizontal Field Width: 170um
Voltage: 10kV
Spot: 6.3pA
Working Distance: 4.0
Detector: SE
Non-Newtonian fluids are capable of all kinds of counter-intuitive behaviors. The animations above demonstrate one of them: the tubeless or open siphon. Once the effect is triggered by removing some of the liquid, the fluid quickly pours itself out of the beaker. This is possible thanks to the polymers in the liquid. The falling liquid pulls on the fluid left behind in the beaker, which stretches the polymers in the fluid. When stretched, the polymers provide internal tension that opposes the extensional force being applied. This keeps the fluid in the beaker from simply detaching from the falling liquid. Instead, it flows up and over the side against the force of gravity, behaving rather more like a chain than a fluid! (Image credit: Ewoldt Research Group, source)
Unlike popular belief that there exists an infinite number of shapes that snowflakes can occur in, there are only 35! Albeit no snowflake is the same from an atomic standpoint, these are the 35 shapes of snowflakes which have been documented thus far to occur in nature.
Squid have tiny organs in their skin called chromatophores. When these organs expand, they reveal more color pigment. When they contract, the color shrinks.
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[…]To truly comprehend what neurogastronomy is about, it’s important to understand the basics of how we physiologically perceive taste. Not surprisingly, it all begins with our...](https://66.media.tumblr.com/1c9d4eb8c7ff976a97002e7c175bb8c7/tumblr_nwj53qZ55T1rd1n1oo1_r1_500.jpg)
