【推荐3】Promising 42,000 new homes across five residential districts, the eco-town of Tengah will be the 24th new settlement built by Singapore’s government since World War II. It is, however, the first with centralized cooling, automated trash collection and a car-free town center, which conservationists hope offers a road map for slashing carbon emissions in the Southeast Asian city-state.

Although comparatively small, with a population of under 6 million people, Singapore’s per capita emissions are higher than those of the UK, China and neighboring Malaysia, according to the country’s National Climate Change Secretariat. That’s due, in part, to air conditioning, which accounts for more than a third of typical household energy consumption. The Meteorological Service Singapore (MSS) has predicted that, by the end of this century, average daily temperatures in the city-state may be at least 34.1 degrees Celsius “almost every day”   during the eight warmest months of the year.

As such, keeping cool will, increasingly, be a necessity for residents. Rather than demonizing air conditioning, Tengah’s planners have instead sought to reimagine it. Cold water, chilled using solar power, will be piped through the district’s homes, meaning residents don’t need to install inefficient outdoor AC condensers. According to the town’s energy provider, SP Group, this will generate carbon dioxide savings equivalent to taking 4,500 cars off the roads each year.

Planners used computer modeling to simulate wind flow and heat gain across the town, helping to reduce the so-called urban heat island effect. Elsewhere, “smart” lights will switch off when public spaces are unoccupied, and trash will be stored centrally, with monitors detecting when garbage needs collecting. All residents will have access to the app allowing them to monitor their energy and water usage. Digital displays in each block will meanwhile inform occupants of their collective environmental impact, which could even encourage competition between residential blocks.

Regardless of whether the use of smart technology can significantly reduce greenhouse gas emissions or not, engaging residents with their own consumption could encourage behavioral change, according to Perrine Hamel, an assistant professor at Nanyang Technological University’s Asian School of the Environment. “Changing behavior is going to be an integral part of achieving climate targets and, of course, urban design is the first way to affect and change behavior,” she said.

【推荐1】When astronauts land on Mars, a couple of decades from now, perhaps, they’ll need to find a way to communicate-with each other, with equipment on and around the planet, and with mission control back on Earth. Despite living so far from home, they’ll no doubt want to connect with loved ones, or stream their favorite shows or music.

But setting up a Wi-Fi connection to Earth’s internet won’t be a choice. Earth is simply too far away—around 55 million to 400 million kilometers, depending on where the planets are in their orbits. We will need another strategy.

Establishing good communication equipment is essential for human missions to Mars. Researchers are testing ways to upgrade existing networks, along with some far-out alternatives. For example, NASA’s Psyche mission, which lifted off in October with the job of exploring an asteroid (小行星) between Mars and Jupiter, will also test the communication using lasers. Lasers could carry far more data than the radio waves that have been used from the earliest days of space travel.

There is no strategy which can get rid of the time lag in communications between Earth and Mars; a message moving at the speed of light takes anywhere between 4 and 24 minutes for a one-way trip. In other words, a quick ping to mission control is out of the question, not to mention a WhatsApp call home.

There’s also the issue of solar conjunction (聚合), says Parfitt, when the sun comes between Earth and Mars. This happens for a couple of weeks every two years or so, cutting off communications between the planets. The last one took place in November.

But new approaches could open possibilities that make communications on Mars more like what we experience here on Earth. At least one research team has wondered: What if Mars had its own internet?

【推荐3】Remember solar roadways, where solar panels were fitted in roads? I thought it was the worst transportation idea ever until Musk’s Boring Company came along — the only place where solar panels were fitted was under my basement floor. Although, now I would say putting solar panels in Musk’s tunnels(隧道) is worse.

However, placing solar panels in roads is available due to the fact that this resource is everywhere in the sun and that there will be a lot of electric cars someday. But there is another kind of road called the railroad that might be a better place for solar panels. And that’s what is happening in Germany, where solar panels are being fitted between the rails.

As estimated, 100 kilowatts of electricity can be generated every one kilometer of railway line. Since the rail network in Germany is over 60,000 kilometers long, the power to be generated is comparable to the output of five nuclear power plants in total.Undoubtedly, the potential could be huge.

Therefore, I think putting solar panels in railways better than roadways. First, trains generally stay on the rails, so there is no need to have solar panels designed to take any serious load. Although there is a serious amount of vibration(振动), the panels wouldn’t shake apart because they are not connected to the tracks. On the other hand, the power from solar panels can be supplied to overhead lines to train stations or to the consumer and buildings alongside the rail lines.

German railways have been trying to show good reasons for using hydrogen-powered trains because it was too expensive to electrify many of their lines, so turning their rail beds into power sources might change the economics. Besides, railways are much wider than the track, and it makes sense to place the panels next to the track, pointing in a suitable direction instead of lying flat.

But still, solar railways make sense in a way solar roadways have never done.