You may have already seen robot waiters in restaurants: waist-high machines that can greet guests, lead them to their tables, deliver food and drinks and carry dirty dishes to the kitchen. But are they the future?

Many think they are the solution to the industry’s labor shortages. Sales of them have been growing rapidly in recent years, with tens of thousands now working in dining rooms. But others say they have a long way to go before they can replace humans. They can’t take orders, and many restaurants have steps and other physical challenges they can’t adapt to.

Still, the robots are increasing. Redwood City, Califomia-based Bear Robotics, introduced its service robot in 2021 and expects to have 10,000 used by the end of this year worldwide. The lack of labor sped up the adoption of robots globally. In the US, the restaurant industry employed 15 million people in 2022, but that was still 400,000 fewer than before the pandemic. In a recent survey, 62% of restaurant operators told the National Restaurant Association they don’t have enough employees to meet customer demand.

Public recognition of robot servers is already high in Asia. The US was slower to adopt robots, but some chains are now testing them. But not all chains have had success with robots. Chili’s introduced a robot server named Rita in 2020 and expanded the test to 61 US restaurants before abruptly stopping it last August. The chain found that Rita moved too slowly and got in the way of human servers. And 58% of guests surveyed said Rita didn’t improve their overall experience.

It’s expected that about 30% of restaurants will continue to have human servers and be considered more luxurious (豪华的), while the rest will rely on robots in the kitchen and in dining rooms. Economics are on the side of robots; the cost of human labor will continue to rise, but technology costs will fall. But that’s not a future everyone wants to see. “Humans don’t go to a full-service restaurant to be served by technology,” said Saru Jayaraman, president of One Fair Wage. “They go for the experience of themselves and the people they care about being served by a human.”

Researchers at Stanford University have developed a new material that can move heat out of buildings and into space. The researchers say the material can cool buildings even on hot days. The cooling material is a very thin sheet with many layers that could be placed on a roof like solar panels (板). However, instead of turning sunlight into energy as solar panels do, the material turns heat into infrared (红外线的) radiation.

Shanhui Fan is an electrical engineering professor at Stanford University. He says that the panels have a layer of material that is like sand. The panels act like a mirror. They take heat out of buildings and reflect the light from the sun. And he says both the heat and sunlight are sent 100 kilometers into outer space. “It's a structure that cools itself without electricity input, even under the sun. So, what it does is basically radiate heat to outer space and also reflect the sunlight so it doesn't get heated up by the sun.” Mr Fan says it is like having a window into space. The heat is sent directly into space without increasing the air temperature.

He says buildings in developing countries that do not have electricity or air conditioning could use the panels. “In areas where electricity is out of reach for many people, there is a potential benefit for storing medicine or even food. In many of these situations, being able to reduce the temperature is important. And this would provide a way to do it.”

The researchers say the main problem is creating actual cooling systems using the high-tech panels. They say it may be possible to develop a cooling spray (喷涂) that could be used on present solid structures. They believe the cooling spray technology could be developed in the next three to five years. They say as much as 15 percent of the energy used in the United States is spent providing power to air conditioning systems.

If you're daydreaming of future travels while stuck at home during the Covid-19 outbreak, why fantasize about the beaches of Ball or the canals of Venice when vacationing in space could be in your future?

Back in 2019, Californian company the Gateway Foundation released plans for a hotel that could one day float above the Earth's atmosphere. This futuristic concept was scheduled to be fully operational by 2027.

Now the hotel, Voyager Station, is set to be built by Orbital Assembly Corporation, a new construction company run by former pilot John Blincow, who also heads up the Gateway Foundation.

In a recent interview, Blincow explained there had been some Covid-related delays, but construction on the space hotel is expected to begin in 2026, and a hotel in space could be a reality by 2027.

"We're trying to make the public realize that this golden age of space travel is just around the corner. It's coming. It's coming fast," said Blincow.

Space tourism is becoming an increasingly hot topic, and there are several companies trying to make it happen — from Virgin Galactic to Elon Musk's SpaceX.

The team behind Voyager Station have said they're hoping to eventually make a stay at the hotel equal to "a trip to Disneyland ".

The team are also hoping to build research stations and spark space tourism and commerce opportunities. They imagine the government or private companies might use the space hotel for training crews heading to the moon, Mars and beyond.

The eventual goal, as the team put it in 2019, is "to create a starship culture where people are going to space, and living in space, and working in space. And we believe that there's a demand for that."