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The invisibility cloak is becoming a reality

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Invisibility is one of the marvels humans always wanted to achieve. It has been reflected in books, movies like The Invisible Man or Predator, but now scientists are getting closer and closer in tricking the human eye.

We see things because the light waves bounce back from these, being distorted. We only capture the so called visible light part of the electromagnetic spectrum; that’s between 400 and 700 nanometers of wavelength. Besides that the human eye can’t see anything without special devices like radars.

An invisibility cloak is designed to bend light around an object making it invisible. But until now these cloaks worked only to conceal very tiny objects and only from specific angles. A team of scientists from Lawrence Berkeley National Laboratory designed the first ultrathin invisibility cloak. It is made of a 50 nanometers layer of magnesium fluoride, coated with a pattern of 80 nanometers thick gold antennas.

The researchers wrapped the invisibility cloak around a 36 micrometer object and channeled a beam of light with a wavelength of 730 nanometers (near infrared) towards it. The light scattered bounced back, but the object remained invisible as if there was a mirror there. This happened thanks to the tiny gold antennas that controlled the scattering of the light and reflect it in such a way that it preserved the light’s phase and frequency.

Xiang Zhang, the lead researcher said that the new invisibility cloak, although scatters light at only 730 nanometers of wavelength, it can be improved to cope with the whole electromagnetic spectrum. And in the next few years it can be scaled up to rend invisible a tank, for example. And the uses range from military, to computing, bio-medicine displays and energy harvesting.

Other scientists are skeptical. Andrea Alu, associate professor of electrical engineering from the University of Texas, Austin argued that: “They had a small object, a little bump. With a larger object, I can’t take advantage of that … when I illuminate it, a portion is not illuminated; it’s in shadow. As such, the illusion of the perfect reflector would be broken.”

Zhang told that with a little work the tiny antennas can be calibrated to control the phase and frequency of various wavelengths and that it is a matter of time when we can see (or not) an invisibility cloak that can make a human sized object invisible.

Who doesn’t enjoy listening to a good story. Personally I love reading about the people who inspire me and what it took for them to achieve their success. As I am a bit of a self confessed tech geek I think there is no better way to discover these stories than by reading every day some articles or the newspaper . My bookcases are filled with good tech biographies, they remind me that anyone can be a success. So even if you come from an underprivileged part of society or you aren’t the smartest person in the room we all have a chance to reach the top. The same message shines in my beliefs. All it takes to succeed is a good idea, a little risk and a lot of hard work and any geek can become a success. VENI VIDI VICI .

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Engineering

To get gold back from electronic waste, the Royal Mint of the UK is using a new method

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There are hidden mountains of gold in the junkyards, full of old smartphones, computers that don’t work anymore, and broken laptops. A new project in the UK wants to find and use these hidden riches.
The Royal Mint, which makes British coins for the government, has agreed to work with the Canadian clean tech startup Excir to use a “world-first technology” that can safely get gold and other precious metals out of electronic waste (e-waste) and recycle them.

Electronic devices have circuit boards that have small amounts of gold in their connections because gold is a good conductor. These boards also have useful metals like silver, copper, lead, nickel, and aluminum.

In the past, getting the metals was hard, but Excir’s new technology can quickly and safely recover 99 percent of the gold that is trapped in electronic waste.

They prepare the circuit boards using a “unique process,” and then they use a patented chemical formula to quickly and selectively remove the gold. The liquid that is high in gold is then processed to make pure gold that can be melted down and formed into bars. Palladium, silver, and copper could also be recovered with this method.

“Our entrepreneurial spirit has helped the Royal Mint do well for over 1,100 years, and the Excir technology helps us reach our goal of being a leader in sustainable precious metals.” The chemistry is completely new and can get precious metals back from electronics in seconds. “It has a lot of potential for The Royal Mint and the circular economy, as it helps to reuse our planet’s valuable resources and creates new jobs in the UK,” said Sean Millard, Chief Growth Officer at The Royal Mint.

At the moment, about 22% of electronic waste is collected, stored properly, and recycled. But with this kind of new technology, the problem of old electronics could be lessened.

Every year, the world makes about 62 million metric tons of electronic waste, which is more than 1.5 million 40-tonne trucks’ worth. That number will go up by another 32% by 2030 as more people buy electronics. This will make it the fastest-growing source of solid waste in the world.

The World Health Organization says that e-waste is hazardous waste because it contains harmful materials and can leak harmful chemicals if it is not handled properly. For example, old electronics can release lead and mercury into the environment, which can affect the development of the central nervous system while a person is pregnant, as a baby, as a child, or as a teen. Also, e-waste doesn’t break down naturally and builds up in nature.

Aside from being a huge waste, this is also a big problem for the environment. There could be between $57 billion and $62 billion worth of precious metals in dumps and scrap yards.

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Nanotechnology

The British Army shows off its brand-new “Speed of Light” laser weapon

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On top of a British Army combat vehicle, the UK government fired what it calls a “speed of light laser weapon” in a test run.

The Land Laser Directed Energy Weapon (LDEW) Demonstrator program of the UK Ministry of Defense produced the weapon. It has now been tested at a firing range in Porton Down, Salisbury. The Ministry of Defense says the “ground-breaking” test went well, and the laser was able to destroy targets more than a kilometer (0.6 miles) away.

A “speed of light laser weapon” was used in the press release for the new test, which led to some confusing headlines.

https://twitter.com/GrampsToolshed/status/1815863904196542816?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1815863904196542816%7Ctwgr%5Edd1d335d3045427cc34f21557b4e642a2d2026be%7Ctwcon%5Es1_&ref_url=https%3A%2F%2Fwww.iflscience.com%2Fbritish-army-shows-off-new-speed-of-light-laser-weapon-75249

All lasers move at the speed of light, which is also the speed that all massless particles must move. This may sound impressive to people who fell asleep in physics class. If you want to sell water, you shouldn’t say “very wet” in the ads.

Still, the laser is impressive if you like shooting down enemy drones. This weapon’s best features are that it is small and light, which lets it be used for the first time on land vehicles.

The successful testing of this powerful laser weapon is a major step forward in our efforts to improve the British Army’s future operational capabilities, according to a press release from Matt Cork, who is in charge of the Defence Science and Technology Laboratory. “This technology offers a precise, powerful and cost effective means to defeat aerial threats, ensuring greater protection for our forces.”

Army members will test the “light speed laser weapon”‘s abilities and benefits in “real-world scenarios” later this year.

 

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Engineering

A groundbreaking type of cement has the potential to transform homes and roads into massive energy storage systems

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For lack of a better word, concrete is awful for the environment. Beyond water, it’s the most-used product in the world, and its carbon footprint shows that making cement and concrete alone is responsible for 8% of the world’s CO2 emissions, or more than 4 billion metric tons of greenhouse gases every year.

But MIT researchers have come up with new material that might be able to help solve that issue. After mixing water, cement, and a sooty substance called carbon black, they made a supercapacitor, which is like a big concrete battery and stores energy.

Admir Masic, a scientist at MIT and one of the researchers who came up with the idea, said in a statement last year, “The material is fascinating.”

“You have cement, which is the most common man-made material in the world, mixed with carbon black, which is a well-known historical material because it was used to write the Dead Sea Scrolls,” he said. “These materials are at least 2,000 years old, and when you mix them in a certain way, you get a conductive nanocomposite. That’s when things get really interesting.”

The amazing properties of the material come from the fact that carbon black is both highly conductive and water-resistant. To put it another way, as the mixture hardens, the carbon black rearranges itself into a web of wires that run through the cement.

According to the researchers, it’s not only a huge step forward in the move toward renewable energy around the world, but its recipe also makes it better than other batteries. Even though cement has a high carbon cost, the new material is only made up of three cheap and easy-to-find ingredients. Standard batteries, on the other hand, depend on lithium, which is limited and expensive in terms of CO2: “particularly in hard rock mining, for every tonne of mined lithium, 15 tonnes of CO2 are emitted into the air,” says MIT’s Climate Portal.

Since cement isn’t going anywhere soon, putting it together with a simple and effective way to store energy seems like a clear win. Damian Stefaniuk, one of the researchers who came up with the idea, told BBC Future this week, “Given how common concrete is around the world, this material has the potential to be very competitive and useful in energy storage.”

“If it can be made bigger, the technology can help solve a big problem: how to store clean energy,” he said.

How could that be done? One possible solution is to use it to pave roads. This way, the highways can collect solar energy and then wirelessly charge electric cars that drive on them. Because they release energy much more quickly than regular batteries, capacitors aren’t very good for storing power every day. However, they do have benefits like higher efficiency and lower levels of performance degradation, which makes them almost perfect for giving moving cars extra power in this way.

One more interesting idea is to use it as a building material. The researchers wrote in their paper that a 45-cubic-meter block of the carbon-back-cement mix could store enough energy to power a typical US home for a year. To give you an idea of how big that is, 55 of them would fit in an Olympic-sized swimming pool.

The team says that a house with a foundation made of this material could store a day’s worth of energy from solar panels or windmills and use it whenever it’s needed because the concrete would stay strong.

Franz-Josef Ulm, a structural engineer at MIT, said, “That’s where our technology looks very promising, because cement is everywhere.”

“It’s a fresh way to think about the future of concrete.”

The paper is now out in the journal PNAS.

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