In the ancient walled city of Sana’a, mud skyscrapers rise high into the sky. The towering structures are built entirely out of earth and decorated with amazing geometric patterns. The local mud architecture is so unique that the city has been recognized as a UNESCO World Heritage site.

“As an outstanding example of architecture reflecting the spatial (空间的) characteristics of the early years, the city in its landscape has an extraordinary artistic quality,” UNESCO writes in its description of Sana’a. “The buildings also show exceptional craftsmanship (工艺) in the use of local materials and techniques.”

Even though the buildings in Sana’a are thousands of years old, the ancient structures are still inhabited today and most remain private houses. It is easy to see why these mud buildings have not lost their appeal—they are well-insulated (隔热的), sustainable and extremely adaptable for modern use. “It is the architecture of the future,” says Damluji, co-founder of the Mud Brick Architecture Foundation.

Architects around the world are reviving (复兴) raw-earth construction as they seek to construct sustainable buildings that can survive extreme weather events such as flash floods and intense heat. Could this ancient form of architecture influence the design of our future homes?

The construction industry accounts for 38% of global carbon dioxide emissions. The building sector has an important role to play if the world is to meet the goal of reaching net zero by 2050. Concrete, a common modern construction material, has a huge carbon footprint. Replacing concrete with less polluting materials is important to achieving our climate goals, scientists warn.

The ancient material, mud, could be the perfect sustainable replacement for concrete, according to Damluji. Constructing with mud has a very low impact on the environment and the material itself is fully recyclable, she says. “If you want to pull down a wall or change the design, you can recycle all the materials.” An added benefit is that mud buildings are warm in the winter and cool in the summer. This reduces the need for air conditioning units, which consume large amounts of electricity and contain refrigerants (制冷剂) that make up greenhouse gas emissions. Mud structures are also incredibly strong and resistant to extreme weather, such as heatwaves, floods and droughts, which scientists say will become more frequent and intense as temperatures continue to rise.

Therefore, people who wish to live in a modern, comfortable home should consider one made of mud. Overall, it makes for highly advanced as well as sustainable design.

By 2035, NASA wants to land humans on Mars. But reaching the red planet, on average around 140 million miles away, will be difficult. Colder than Antarctica and with little to no oxygen, Mars is an unfriendly environment. Besides, the longer it takes astronauts to get there and the longer they stay, the more they are at risk.

That's why scientists are looking at ways to reduce trip time. Seattle-based company Ultra Safe Nuclear Technologies (USNC-TECH) has offered a solution: an NTP engine that could get humans from Earth to Mars in just three months. Such an engine takes advantage of nuclear technology. Currently, the shortest possible trip for an unmanned spacecraft is seven months, but a manned mission is expected to take at least nine months. Shorter missions would limit the astronauts exposure to space radiation, but there is still concern about the radiation sent out from the nuclear reactor inside the spacecraft. This would be mitigated through the rocket's design, which would help ease the scientists’ concern.

To protect people on the ground, the NTP spacecraft would not lift off directly from Earth, Jeff Sheehy, a NASA scientist, adds. Instead, a regular chemical rocket would carry it into orbit, and only then would it fire up its nuclear reactor. Once in orbit, it could do little harm, as heat radiation cannot move through a vacuum(真空). If disaster struck and the rocket’s reactor broke up, pieces would not land on Earth— or any other planet—for thousands of years. By that time, the radioactive substance would have ''naturally got to the point where it wasn’t dangerous anymore”.

Michael Eades, director of engineering at USNC-TECH, says that nuclear-powered rockets would be more powerful and twice as efficient as the chemical engines used today, meaning they could travel further and faster, while burning less fuel. "Nuclear-powered rockets will be key to opening up the solar system but it could be at least two decades before they are used widely,9, he says, adding that numerous demonstrations and tests would need to be carried out before an astronaut is sent to Mars in an NTP rocket.

Can we vibrate (振动) ourselves healthy? That’s the basis behind a form of treatment called Whole Body Vibration (WBV). The idea is simple: Standing on a vibrating plate forces our muscles to do work, which could lead to countless health benefits. But, despite years of research and hundreds of studies, the true benefits of WBV are still unclear.

In a 2003 study, researchers saw an increase in vertical (垂直的) jump height after participants simply stood on a vibrating plate several times a week for eight months. But shaking is not a fitness panacea. A study found that subjects who did leg exercises on a vibrating platform for 11 weeks had no increase in their jumping ability. Other early studies found no effects of WBV.

More recent work suggests whole body vibration could offer important benefits to people unable to perform normal workouts. A 2016 Scientific Reports study of 40 people with cerebral palsy (脑瘫) found that the participants could both walk and stand up better after 20 weeks of WBV. A 2017 study in the Journal of Biomechanics found that whole body vibration had a greater effect on older people’s muscles than it did on those who were younger, an indication that it might offer benefits to seniors. A number of research groups have found some indications that WBV could help with cardiovascular health, and a group from Rio de Janeiro State University has shown it could help fight osteoporosis.

These results are encouraging, says Silmara Gusso, a senior lecturer in exercise sciences at the University of Auckland in New Zealand, but more research is needed. And, she warns, not every kind of vibration is helpful to our bodies, so the commercially available vibration plates may not work as advertised.

“We cannot imply that the results obtained with certain equipment can be applied to other equipment,” Gusso says. “Some types of vibration might even cause harm.”