Science News
Headlines
. Our own galaxy has a black hole at its centre and we've seen it!
. Blowing bubbles is good for rivers too
. All the plastic you are eating
. A mammoth in my living room?

Read on to find out more about these.

. An image of a black hole in our house
Well, not quite our house. Astronomers have finally assembled an image of the "supermassive" black hole right at the centre of our Milky Way galaxy. Known as Sagittarius A*, this black hole appears as a dark blur against the glowing material that surrounds it. The region right around the black hole is turbulent.
A bright ring surrounding the darkness: that is the telltale sign that scientists look for, that is how they recognize a black hole. No single observatory could get such a good look at Sagittarius A*, or Sgr A* for short. It required a large network of radio dishes all over the world. That telescope network is called the Event Horizon Telescope, or EHT. It also produced the first image of a black hole, released in 2019. That object sits at the center of the galaxy called M87. It is about 55 million light-years from Earth.
At 27,000 light-years away, Sgr A* is the closest giant black hole to Earth. Yet Sgr A* and others like it remain some of the most mysterious objects ever found. A black hole’s gravity traps light that falls within a border called the event horizon. Any object (including light) that falls into that border can never come out again; it is like a one-way street. EHT’s images of Sgr A* and the M87 black hole look at light coming from just outside that inescapable edge. That light is given off by material swirling into the black hole, which forms a disk of glowing material, called an accretion disk. The black hole’s shadow against this glowing disk is what we see in EHT images of black holes. Astronomers want to know more about how the disk works.
By black hole standards Sgr A*'s disk is pretty quiet and faint. It seems to constantly flicker and simmer, like a froth on top of ocean waves. The big question is whether EHT could see something changing in those waves. There is a lot of analysis to be done.
For many astrophysicists, this is an exciting image. According to one, these are like early pictures astronauts took of Earth from the moon. That's our closest friend and neighbour among all black holes!
Source: Astrophysical Journal Letters, May 2022.

. Blowing bubbles is good for rivers too
We have all loved to blow bubbles, children and adults, all ages. Watching bubbles is great fun. Now Dutch engineers have developed an energy-efficient solution for using bubbles to trap and remove plastics from waterways. Think of the waterway as a large tank.
A bubble curtain is created by pumping air through a perforated tube on the bottom of the waterway. The bubble curtain creates an upward current which directs plastic to the surface. By placing the Bubble Barrier diagonally across the river, the natural flow of the water will push the plastic waste to the side and into the catchment system. The catchment system is designed to work in harmony with the bubble curtain to collect and retain plastics. Following collection, it is removed for processing and reuse. In a busy city like Amsterdam where waterways can attract a lot of trash, this system is proving to be amazingly effective.
Fish can swim right through the bubbles. In fact, as in a fish tank, oxygen released by the bubbles would help keep the water well aerated. The compressor used to blow the bubbles can run on solar energy. They also use water wheels to use renewable energy. 
Source: unescogreencitizens.org

. All the plastic you are eating
Plastic in food? No way! But yes, your bloodstream may be littered with the plastic you have eaten. Four different chemical types have now turned up in human blood, according to a scientific study.
Scientists have found bits of plastic contaminating certain foods and bottled waters. We might inhale microscopic bits of the plastic that floats in the air. But no one has known whether that plastic moved much past our gut or lungs, until now. A study has just turned up microplastics in human blood.
Once microplastics get into the bloodstream, blood can then move the little bits throughout the body. And that is what makes the new discovery worrisome. Microplastics may also carry toxic chemicals, that can affect our hormonal and reproductive system. 
Finding microscopic plastic particles in blood is not easy. You cannot just look through a microscope and count them. Scientists collected blood, processed the sample to remove big cells. This left a liquid. They then filtered out particles bigger than 700 nanometers across. For perspective, the width of a human hair is more than 100 times that size. Afterward, the researchers looked for polymers that make up five different types of plastic.
One in every four samples of tested blood had polyethylene. It is a particularly common plastic used in a very broad range of products, from shopping bags and bottles to toys and laminate coatings. Half of the people sampled PET in their blood. That is short for polyethylene terephthalate. It is used in polyester fabrics and plastic bottles. Polystyrene appeared in one-third of the samples. It is the basis of some types of insulating foam, computer cases, scientific labware, plastic forks, hair combs and more. Shockingly, children's blood samples showed traces of microplastics too, and this has caused great worry among scientists.
Source: Environment International, March 2022.

. A mammoth in my living room?
The Natural History Museum in Los Angeles in California, USA has done just that! Scientists have brought a herd of Ice Age animals back to life — in the virtual world. You can interact with these creatures safely using a smartphone. This is a technology known as augmented reality, or AR. Experiencing this is more like entering a 3-D movie, where you are part of the action.
Without a time machine, we will never know exactly what Ice Age animals looked like. Artists often try to show us. But if their images are not scientifically accurate, they can misrepresent the ancient world. For instance, many people think velociraptors were large, leathery, dangerous predators. That is, after all, how the movie Jurassic World portrayed them. In fact, these dinosaurs were actually the size of turkeys and covered in feathers.
This work was accomplished by a team of paleontologists, artists and computer scientists. The paleontologists shared detailed instructions on how the animals should look and move. Artists drew the shape of the model, then animated it. The Los Angeles team reviewed the process along the way. They also documented the decisions they used to create these new models. For example, they knew from fossils the size of saber-toothed cats. They had to guess, however, on the sound of their roar. Along the way, the team noted which decisions were based on established science and which were based on some educated guess.
To make the models work on mobile phones, the team chose a cartoonish look for their animals. It is called low poly, short for low-polygon views. (Polygons are the shapes used to represent 3-dimensional details in digital representations.) This simplified the models while still keeping them scientifically accurate.
It is not just animated dinosaurs that you can see with AR. You can now watch a ground sloth getting stuck in tar on a hot road!
Source: Palaeontologia Electronica, March 2022.