Engineering
Highway to Heaven – space elevators might change the way we travel to space sooner than you think
Even with all the improvements in terms of cost efficiency over the past few decades, getting stuff into space is pretty expensive. With the Space Shuttle, the cost was $10,000 per pound, now SpaceX’s Falcon Heavy can bring stuff into orbit for a comparatively modest $800. But still, $15,000 for a person isn’t exactly cheap, not to mention the fact it’s still quite dangerous. Almost a century after the first rocket flight, we still have no better way of going to space that strapping astronauts and cargo to containers with thousands of tons of highly flammable fuel and hoping for the best. It’s hard to come up with a sensible, practical way of escaping our planet’s grip and reaching orbit – so scientists, engineers, and science-fiction writers had to come up with a non-sensible one: building a space elevator!
The basic idea is really simple: all you need is a very long cable made from some high-tech, ultra-strong material which goes from the surface of the Earth to a satellite in orbit, and of course a climber, the elevator itself. While this might seem far-fetched, the science works out, and we actually have most of the knowledge, as well as the materials to do it. Now all that’s left is for the economics to work out, too.
The key component of the entire structure is the cable or tether, which has to be strong enough to support its own weight, as well as that of the climber and the cargo contained within it on the extremely long ascent into space. The most promising candidate is carbon nanotube technology. Carbon nanotubes are basically sheets of carbon one atom thick which are folded into tiny cylinders, with some really amazing properties: they are incredibly light, yet a lot stronger than steel, and are extremely good conductors of heat and electricity. As you might expect for such a high-tech material, production isn’t exactly booming, so it will still be a while until we get all the material we need to actually reach space – nevertheless, it’s only a matter of time until the industry reaches the maturity required for these kinds of projects.
While carbon nanotubes are intriguing and everything, the large scale production of this material is merely a logistics problem, so it isn’t all that interesting. It’s a lot more interesting to think about what keep the Space Elevator from falling to Earth, like a whip dozens of times the radius of the planet, something which would cause unspeakable amounts of damage (always a good to think about these things before embarking on such a project). Well, that’s where our friend physics comes in. The Space Elevator will have to be built in such a way that its center of mass will be at 36,000 km, where the main docking station will be located. This height isn’t chosen at random – 36,000 km above ground at the Equator is where geostationary satellites orbit, because this is the point where orbital velocity is equal to the rotational velocity of the Earth (this, by the way, means that the Space Elevator will have to be anchored somewhere along the Equator, either on land or over the ocean). In other words, something orbiting our planet at this height will always remain above the same spot above ground – which is important if you want to keep that cable straight.
The Space Elevator doesn’t stop there, however. Thousands of kilometers above the main docking station there’s a counterweight, which can either be something we sent up there, or even a small asteroid we’ve commandeered (clearly the more awesome option!). In much the same way that if you tie a rope around an object and you start to swing it through air, the rope becomes straight, the Space Elevator’s tether becomes taut, under the effect of the centrifugal force. No rockets or ion thrusters or any other sci-fi propulsion technology needed – simple physics principles keep the Space Elevator stable! Also, since the cable can go as far into space as 47,000 km (or even 144,000 km!), objects can easily be launched from there into outer space, to the Moon, Mars, or beyond, since the escape velocity at those heights is much lower than it is closer to home.
The basic concept of the space elevator. Image: ESA.
Finally, there’s the issue of how the container itself will be brought up to the docking station in orbit. Compared to the previous issues I’ve mentioned, this seems almost trivial. Lasers or magnetic levitation technology (like what is used to power high speed trains in Japan and South Korea) are readily available today and could do the job perfectly. It would nevertheless be a long ride, which would most likely take a few days, but it would be safer and more comfortable than rocket flight, not to mention a lot cheaper, opening up space travel to a lot more people.
Building a structure that actually goes from the surface of our planet into space is one of the most ambitious feats of engineering ever envisioned. And yet people are actually starting to seriously consider it, not just because this is exactly the kind of mind-blowing project humans regularly embark on, but also because it has the potential to change the way we work in and explore space. When asked when would space elevators become a reality, Arthur C. Clarke (who wrote a novel which popularized the concept called The Fountains of Paradise) is said to have replied “about ten years after they stop laughing.” Though the task is still an immensely challenging one, it appears at least that people now have their game faces on.
Artificial Intelligence
Google DeepMind Shows Off A Robot That Plays Table Tennis At A Fun “Solidly Amateur” Level
Have you ever wanted to play table tennis but didn’t have anyone to play with? We have a big scientific discovery for you! Google DeepMind just showed off a robot that could give you a run for your money in a game. But don’t think you’d be beaten badly—the engineers say their robot plays at a “solidly amateur” level.
From scary faces to robo-snails that work together to Atlas, who is now retired and happy, it seems like we’re always just one step away from another amazing robotics achievement. But people can still do a lot of things that robots haven’t come close to.
In terms of speed and performance in physical tasks, engineers are still trying to make machines that can be like humans. With the creation of their table-tennis-playing robot, a team at DeepMind has taken a step toward that goal.
What the team says in their new preprint, which hasn’t been published yet in a peer-reviewed journal, is that competitive matches are often incredibly dynamic, with complicated movements, quick eye-hand coordination, and high-level strategies that change based on the opponent’s strengths and weaknesses. Pure strategy games like chess, which robots are already good at (though with… mixed results), don’t have these features. Games like table tennis do.
People who play games spend years practicing to get better. The DeepMind team wanted to make a robot that could really compete with a human opponent and make the game fun for both of them. They say that their robot is the first to reach these goals.
They came up with a library of “low-level skills” and a “high-level controller” that picks the best skill for each situation. As the team explained in their announcement of their new idea, the skill library has a number of different table tennis techniques, such as forehand and backhand serves. The controller uses descriptions of these skills along with information about how the game is going and its opponent’s skill level to choose the best skill that it can physically do.
The robot began with some information about people. It was then taught through simulations that helped it learn new skills through reinforcement learning. It continued to learn and change by playing against people. Watch the video below to see for yourself what happened.
“It’s really cool to see the robot play against players of all skill levels and styles.” Our goal was for the robot to be at an intermediate level when we started. “It really did that, all of our hard work paid off,” said Barney J. Reed, a professional table tennis coach who helped with the project. “I think the robot was even better than I thought it would be.”
The team held competitions where the robot competed against 29 people whose skills ranged from beginner to advanced+. The matches were played according to normal rules, with one important exception: the robot could not physically serve the ball.
The robot won every game it played against beginners, but it lost every game it played against advanced and advanced+ players. It won 55% of the time against opponents at an intermediate level, which led the team to believe it had reached an intermediate level of human skill.
The important thing is that all of the opponents, no matter how good they were, thought the matches were “fun” and “engaging.” They even had fun taking advantage of the robot’s flaws. The more skilled players thought that this kind of system could be better than a ball thrower as a way to train.
There probably won’t be a robot team in the Olympics any time soon, but it could be used as a training tool. Who knows what will happen in the future?
The preprint has been put on arXiv.
Engineering
New concrete that doesn’t need cement could cut carbon emissions in the construction industry
Even though concrete is a very common building material, it is not at all the most environmentally friendly choice. Because of this, scientists and engineers have been looking for alternatives that are better for the environment. They may have found one: concrete that doesn’t need cement.
Cement production, which is a crucial ingredient in concrete, ranks as the third most significant contributor to human-caused carbon emissions globally. Nevertheless, in recent years, a multitude of alternative techniques for producing more environmentally friendly concrete have surfaced. One proposed method involves utilizing industrial waste and steel slag as CO2-reducing additives in the concrete mixture. Another suggestion is to utilize spent coffee grounds to enhance the strength of the concrete while reducing the amount of sand required.
However, a certain company has devised a technique to produce cement-free concrete suitable for commercial enterprises.
The concrete has the potential to have a net reduction in carbon dioxide and has the ability to prevent approximately 1 metric ton of carbon emissions for every metric ton used. If this statement is accurate, the cement-free binder will serve as a noteworthy substitute for Portland cement. According to BGR, the new concrete also complies with all the industry standards of traditional cement concrete, ensuring that there is no compromise in terms of strength and durability.
While it is still in the early stages, the situation seems encouraging. C-Crete Technologies, a company specializing in materials science and holding the patents for a novel form of concrete, has utilized approximately 140 tons of this new cast-in-place (pourable) concrete in recent construction endeavors.
In September 2023, the company was granted an initial sum of almost $1 million, promptly succeeded by an additional $2 million, by the US Department of Energy to advance the progress of its technology. In addition, it has garnered numerous accolades that are facilitating its growth in operations.
The widespread adoption of cement-free concrete in future construction projects has the potential to significantly alter the environmental impact of the industry. Although C-Crete seems to be one of the few companies currently exploring these new alternatives on a large scale, it is likely that others will also start embracing them in the near future.
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.
- Gadgets9 years ago
Why the Nexus 7 is still a good tablet in 2015
- Mobile Devices9 years ago
Samsung Galaxy Note 4 vs Galaxy Note 5: is there room for improvement?
- Editorials9 years ago
Samsung Galaxy Note 4 – How bad updates prevent people from enjoying their phones
- Mobile Devices9 years ago
Nexus 5 2015 and Android M born to be together
- Gaming9 years ago
New Teaser For Five Nights At Freddy’s 4
- Mobile Devices9 years ago
Google not releasing Android M to Nexus 7
- Gadgets10 years ago
Moto G Android 5.0.2 Lollipop still has a memory leak bug
- Mobile Devices9 years ago
Nexus 7 2015: Huawei and Google changing the game