Science & Technology


Scientists witness black hole swallowing star for first time ever

© NASA/M. Weiss (Chandra X -ray Center)
In this artist's illustration, turbulent winds of gas swirl around a black hole. Some of the gas is spiraling inward toward the black hole, but another part is blown away.
Black holes are known for their voracious appetites. These bodies -- formed when a massive star collapses upon itself -- have occasionally been described as the "vacuum cleaners" of the universe and are notorious for their tendency to wreak havoc on the usual laws of physics that govern the rest of the cosmos.

Now, for the first time ever, scientists have witnessed a black hole swallowing a star and ejecting a flare of matter moving at nearly the speed of light -- a rare event that occurs when a star stumbles across a black hole's gravitational well.

"It's the first time we see everything from the stellar destruction followed by the launch of a conical outflow, also called a jet, and we watched it unfold over several months," Sjoert van Velzen, a Hubble fellow at Johns Hopkins University, said, in a statement released Thursday. "Previous efforts to find evidence for these jets, including my own, were late to the game."

Evil Rays

Li-Fi could be replacing Wi-Fi in the near future

© YouTube Screen Capture
Developments in wireless networking over the past few years have seen Wi-Fi become faster and more reliable than ever. It's still far from perfect though, and now new tech known as 'Li-Fi' threatens to supersede it, boasting 100 times greater performance.

Li-Fi replaces the radio waves of Wi-Fi with light signals. Wi-Fi typically uses the 2.4GHz or 5GHz radio bands, both of which have a tendency to slow down as more devices are added.

Li-Fi solves this problem by boasting 100 times greater performance than the typical Wi-Fi connection today. Pocket-Lint reports lab tests have pushed peak transfer rates to an astounding 224 gigabits per second. In a real-world experiment conducted this week, researchers saw 1GB per second being pushed through the network.

Li-Fi is based around a protocol known as Visible Light Communication (VLC). It essentially involves toggling a light switch thousands of times every second to create a stream of "on" and "off" pulses that can be interpreted as binary bits. It works in a similar fashion to Morse code and currently uses the 400 and 800 THz (terahertz) bands.

Blue Planet

Earth's geomagnetic field intensity is twice the historical average

© Huapei Wang
Artistic impression of latitudinally more widespread aurora as an expected consequence of geomagnetic field strength much lower than today’s.
New research from MIT shows that the Earth's geomagnetic field intensity is double the long-term historical average, indicating that the current field intensity has a long way to fall before reaching an unstable level that would lead to a reversal.

The intensity of Earth's geomagnetic field has been dropping for the past 200 years, at a rate that some scientists suspect may cause the field to bottom out in 2,000 years, temporarily leaving the planet unprotected against damaging charged particles from the sun. This drop in intensity is associated with periodic geomagnetic field reversals, in which the Earth's North and South magnetic poles flip polarity, and it could last for several thousand years before returning to a stable, shielding intensity.

With a weakened geomagnetic field, increased solar radiation might damage electronics — from individual pacemakers to entire power grids — and could induce genetic mutations. A reversal may also affect the navigation of animals that use Earth's magnetic field as an internal compass.


The hottest white dwarf in the Galaxy

© Philipp Richter/University of Potsdam
Diagram of the Milky Way showing our Sun, the white dwarf, and the gas cloud relative to our neighbor galaxy, the Large Magellanic Cloud (adajcent to it the Small Magellanic Cloud). The white dwarf RX J0439.8-6809 and the gas cloud are between us and the Large Magellanic Cloud.
Astronomers at the Universities of Tübingen and Potsdam have identified the hottest white dwarf ever discovered in our Galaxy.

With a temperature of 250,000 degrees Celsius, this dying star at the outskirts of the Milky Way has already even entered its cooling phase. The researchers also were the first to observe an intergalactic gas cloud moving towards the Milky Way -- indicating that galaxies collect fresh material from deep space, which they can use to make new stars. These findings are published in the latest Astronomy & Astrophysics.

Relatively low-mass stars -- like our Sun -- get extremely hot towards the end of their lives. The Sun's surface temperature has been fairly constant at around 6000 degrees Celsius since its birth 4.6 million years ago. Immediately before its source of nuclear energy is exhausted in about five billion years, the Sun will reach thirty times that temperature, going to 180,000 degrees before cooling down as a white dwarf. Computer simulations suggest that stars can become even hotter than that. The highest temperature of an observed dying star was measured to be 200,000 degrees.

The researchers' evaluation of ultraviolet spectra taken by the Hubble Space Telescope points to a new record of 250,000 degrees -- a temperature which can only be reached by a star some five times more massive than our Sun. The white dwarf, RX J0439.8-6809, has already entered the cooling phase. It appears to have reached its maximum temperature of 400,000 degrees about a thousand years ago. Its chemical composition is not yet understood. Analyses show that carbon and oxygen are present on its surface -- the products of the nuclear fusion of helium, a process which normally takes place deep in the core of a star.

Comet 2

Comet fragments best explanation of mysterious dimming star?

© NASA/JPL-Caltech
This illustration shows a star behind a shattered comet. Observations of the star KIC 8462852 by NASA's Kepler and Spitzer space telescopes suggest that its unusual light signals are likely from dusty comet fragments, which blocked the light of the star as they passed in front of it in 2011 and 2013. The comets are thought to be traveling around the star in a very long, eccentric orbit.
Astronomers have responded to the buzz about a mysterious dimming star by studying data from NASA's Spitzer Space Telescope. They conclude the dimming was probably caused by a family of comets passing in front of the star.

Was it a catastrophic collision in the star's asteroid belt? A giant impact that disrupted a nearby planet? A dusty cloud of rock and debris? A family of comets breaking apart? Or was it alien megastructures built to harvest the star's energy?

Just what caused the mysterious dimming of star KIC 8462852?

Massimo Marengo, an Iowa State University associate professor of physics and astronomy, wondered when he saw all the buzz about the mysterious star found by citizen scientists on the Planet Hunters website.

Those citizen scientists were highlighting measurements of star brightness recorded by NASA's Kepler spacecraft. Tiny dips in a star's brightness can indicate a planet is passing in front of the star. That's how Kepler astronomers -- and citizen scientists using the internet to help analyze the light curves of stars -- are looking for planets.


3D-bioprinted thyroid gland implant pioneered by Russians proves functional in mice

© Ruptly
A Moscow laboratory has conducted the first successful organ translation using a unique Russian 3D-printing technology. The breakthrough could potentially help millions suffering from thyroid disorders - and paves the way for printing other human organs.

The thyroid, a butterfly-shaped gland in the neck, can have a dramatic impact on a huge variety of human bodily functions. The groundbreaking operation, thus far only in rodents, was performed by a team from the 3D Bioprinting Solutions Laboratory in the Russian capital some three months ago.

"Then we were monitoring them over eight weeks and the level of the hormone continued growing," said Elena Bulanova, 3D Bioprinting Solutions Laboratory Head.

The thyroid glands in mice were first killed by a radioactive iodine injection, before the research team transplanted newly-printed organs into their subjects.Three weeks into the experiment, the team, headed by Vladimir Mironov, observed "higher" levels of the hormone T4, which is responsible for growth and the metabolism, and measured higher body temperatures, Bulanova said.After 11 weeks of monitoring the subjects' 3D printed thyroid glands, they were fully functional with completely restored thyroid function.

"All in all we consider experiment to be successfully conducted because we managed to raise the level of hormone T4," Bulanova said.


Indestructible tardigrade (water bear) found to have foreign DNA

© Eye of Science
Tardigrade in Moss
Tardigrades, already made of indestructible win, have shown up again in the scientific weirdness Hall of Fame this week, thanks to a new study that sequenced the first tardigrade genome and found that 17.5% of it came from other species. Otherwise known as water bears, tardigrades are actually a large group of related species which have a key trait in common: They're impossible to kill. Tardigrades are the only species ever observed to survive outside Earth's sheltering atmosphere. Now scientists are speculating that horizontal gene transfer, the phenomenon identified by a team of researchers at UNC as the reason for the unprecedented proportion of foreign DNA discovered in the tardigrade genome, may also be responsible for some of the tardigrade's famous durability.

Comment: See also:
  • Tiny water bears become first creatures to survive in space [link]
  • Study documents new rare creatures in Smokies [link]
  • Horizontal gene transfer [link]


NASA study: Antarctic temperatures cooled over past six years

Heimdal Glacier southern Greenland, from NASA's Falcon 20 aircraft at 33,000 feet above sea level.
ANTARCTIC temperatures have cooled over the past six years, according to US space agency NASA

An intensive scientific study of both Earth's poles has found that from 2009 to 2016 overall temperature has dropped in the southern polar region.

NASA's Operation IceBridge is an airborne survey of polar ice and has finalised two overlapping research campaigns at both the poles. In the last few weeks NASA has revealed the overall amount of ice has increased at the Antarctic and the amount of sea ice has also extended. Coupled with the latest announcement of slight cooling in the area, it has fuelled claims from climate change deniers that human industrialisation is not having the huge impact on global tenperature as often is claimed.

Christopher Shuman, a University of Maryland, Baltimore County glaciologist working at Goddard, said: "Field data suggests that there's been a modest cooling in the area over the 2009 - 2015 time period, and images collected during that time by the Moderate Resolution Imaging Spectroradiometer on the Terra and Aqua satellites show more persistent fast ice (sea ice that is attached to the shore) in the Larsen A and Larsen B embayments"

However, Mr Shuman warned that in some areas of the Antarctic, glaciers continued to melt at significant levels, despite the slight temperature drop. At the south polio, the mission observed a big drop in the height of two glaciers situated in the Antarctic Peninsula. Mr Shuman added: "These IceBridge measurements show that once the ice shelves collapse, even some cooling and a good deal of persistent sea ice is not able to hold back these larger glaciers and they continue to lose mass overall."

Comment: See also:


Researchers create lamps powered by plants and bacteria to help Peruvian communities

A lamp powered by microorganisms in dirt.
Researchers in Peru have a new way to capture electricity from plants and bacteria to help rainforest communities.

Researchers at the Universidad de Ingeniería y Tecnología (UTEC) have developed a technique for capturing the electricity emitted from plants. Actually, to be fair, it's Geobacter— a genus of bacteria that live in the soil — that do the grunt work. Robby Berman at Slate explains the process:
"[N]utrients in plants encounter microorganisms called 'geobacters' in the dirt, and that process releases electrons that electrodes in the dirt can capture. A grid of these electrodes can transfer the electrons into a standard battery."

Comment: See also: New technology being developed to create energy from living plants


Study finds wild birds willing to forego reliable food sources to stay with their partners

© taviphoto/Shutterstock
Research shows mating pairs of great tits would rather stay together and be a little hungrier than dine alone.
Wild birds are love birds. A recent study found great tits pairs were willing to forego reliable food sources in order to stay together.

Using a unique bird feeding experiment, researchers at the University of Oxford revealed the great tits' commitment to love. Scientists designed feeders to only allow access to birds tagged with the matching radio frequency transmitter.

Some great tit pairs were tagged so mates were unable to access from from the same feeder. One bird would have access to only certain feeders, while the other would have access to others -- no overlap.

Compared to pairs allowed to feed at the same feeder, separated pairs spend less time feeding. Presumably, they couldn't bear to be apart.

Of course, this isn't simply sentimentalism, but an evolved form of self-preservation and species perpetuation. Birds need each other to survive and reproduce.