A group of YouTubers have created a remarkable retractable lightsaber that they classify as “potentially hazardous.”.

HeroTech recently released a video outlining their intention to develop a lightsaber that mimics the retractable nature of the lightsabers seen in the Star Wars movies, as opposed to the currently available models with fixed extended blades.

The team stated on YouTube that they were well aware of the challenges they would face when embarking on the project to create an actual retractable lightsaber. “Our primary obstacles were evident: achieving complete containment of blade extension and retraction, creating a compact hilt design that is proportional to the original, and producing a blade and sound that closely resemble reality.”

Creating a retractable lightsaber proved challenging, but the team successfully accomplished this by utilizing a magician’s cane, a tool that can contract to a compact size and extend to a length of over 0.9 meters (3 feet). After extensive tinkering, the outcome is a remarkable lightsaber that elongates upon activation.

The team clarifies on their website that this lightsaber showcases a dazzling blade of light that genuinely extends from and retracts into the hilt. “Equipped with a 12V COB LED strip, 4S LiPo battery, the Proffieboard V3.9, and a high-performance speaker, this lightsaber delivers authentic lighting effects and lifelike sound effects.”

The team also aimed to enable others to construct the lightsaber in their own homes, by furnishing their subscribers with comprehensive instructions on how to do so. Nevertheless, they have strongly cautioned against attempting it.

“This lightsaber is an experimental model and has the potential to be hazardous if attempted to be made by oneself,” they mention on their YouTube channel. “Although I am actively working towards improving this situation, I am unable to currently endorse this product for individuals lacking engineering proficiency and the determination to spend several hours resolving technical issues.”

Disney has developed its own collapsible lightsabers specifically for use in performances at Disney World, although they are probably not produced at a low cost.

Neither of the blades is capable of cutting through stormtroopers, as they are purely ornamental. Nevertheless, an inexperienced YouTuber successfully constructed a functional lightsaber with the ability to retract, earning a place in the Guinness Book of World Records in 2022.

Alex Burkan, the proprietor of the YouTube channel Alex Lab, engineered a contraption capable of generating a plasma blade measuring 1 meter (equivalent to 3.28 feet) in length upon activation. The blade, which reaches a temperature of 2,800°C (5,072°F), possesses the ability to effortlessly slice through steel.

“An electrolyser is the crucial element of my lightsaber,” Burkan informed Guinness World Records. An electrolyser is a device capable of producing a substantial quantity of hydrogen and oxygen, and it can compress the gas to any desired pressure without the need for a mechanical compressor.

However, in contrast to an authentic lightsaber or the ones demonstrated by Disney, the blade has a limited operational duration of approximately 30 seconds at maximum intensity. Consequently, lightsaber duels are brief unless they occur in close proximity to charging stations.

Burkan also mentioned that occasionally the lightsaber may explode in your hand due to a hydrogen flashback.

A new study looked at the safety of self-driving cars (AVs) and found that while they are better than humans in some everyday driving tasks, they are not yet as good as humans when it comes to turning or driving in low light.

We need to know that our cars are safe before we can just get in and let them take us where we need to go. The hope is that one day they will be able to drive better than humans. Cars don’t get tired, irritable at other drivers, or lose focus while thinking about something else, after all.

Tests of the technology have been done all over the world, and we now have a lot of information from semi-autonomous systems in cars that are used in real-life traffic situations. The new study from the University of Central Florida looked at accident data from 35,113 human-driven vehicles (HDVs) and data from 2,100 Advanced Driving Systems and Advanced Driver Assistance Systems. The goal was to find out how safe AVs and HDVs are in different situations.

In general, the team found that AVs are safer than human drivers, though there are a few big exceptions.

“The analysis suggests that accidents involving vehicles equipped with advanced driving systems generally have a lower chance of occurring than accidents involving human-driven vehicles in most of the similar accident scenarios,” the team said in their paper.

AVs did better than HDVs at routine traffic tasks like staying in their lanes and adjusting to the flow of traffic. They also had fewer accidents while doing these tasks. Sideswipe accidents were 0.2% less likely in AVs, and rear-end accidents were 0.5% less likely in AVs.

In other traffic situations, though, humans are still better than AI.

“Based on the model estimation results, it can be concluded that ADS [automatic driving systems] in general are safer than HDVs in most accident scenarios for their object detection and avoidance, precision control, and better decision-making,” the team said.

“However, the chances of an ADS accident happening at dawn or dusk or when turning are 5.250 and 1.988 times higher, respectively, than the chances of an HDV accident happening at the same times and places.” The reasons could be a lack of situational awareness in difficult driving situations and a lack of experience driving an AV.

Finding these key problem areas could help researchers improve how well AVs work. It would be helpful to think about finding dangers in new ways right now.

“At dawn and dusk, for instance, the sun’s shadows and reflections may confuse sensors, making it hard for them to distinguish between objects and identify potential hazards,” they wrote. “Furthermore, the fluctuating light conditions can impact the accuracy of object detection and recognition algorithms used by AVs, which can result in false positives or negatives.”

The study might disappoint supporters of self-driving cars. They may be waiting for the crossover point where AVs are better than human drivers. But if performance gets better, it can be sent to all AVs at the same time. Researchers who find a way to make turning better can use it on these kinds of vehicles through software updates, which is something we can’t do with people.

We hope that one day we can get into AVs without having to worry about lights changing or other people on the road getting distracted.

Nature Communicationsis where the study can be found.

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.