You’ll probably never go to Mars or sing on the stage with the Rolling Stones. But if virtual reality (VR) ever lives up to its promise, you might be able to do all these things—and many more—without even leaving your home. Unlike real reality, virtual reality means simulating(模拟) bits of our world. Apart from games and entertainment, it’s long been used for training airlines pilots and doctors and for helping scientists to figure out complex problems such as the structure of protein molecules.. Then how does it work?

Close your eyes and think of virtual reality and you probably picture something like this: a man wearing a wrap-around headset and data gloves wired(用线连接) into a powerful workstation or supercomputer. What makes VR different from an ordinary computer experience is the nature of the input and output. Where an ordinary computer uses things like a keyboard, mouse, or speech recognition for input, VR uses sensors(传感器) that find out how your body is moving. And where a PC displays output on a screen, VR uses two screens (one for each eye), surround-sound speakers, and maybe some forms of touch and body feedback(反馈) as well.

VR has been generally used by scientists, doctors, dentists, engineers, architects, archaeologists, and the army for about the last 30 years. Difficult and dangerous jobs are hard to train for. How can you safely practice taking a trip to space, making a jump from an airplane, or carrying out a brain operation? All these things are obvious applications of virtual reality.

Like any technology, virtual reality has both good and bad points. Critics always warn that people may be addicted to alternative realities to the point of ignoring their real-world lives—but that criticism has been leveled at everything from radio and TV to computer games and the Internet. Like many technologies, VR takes little or nothing away from the real world: you don’t have to use it if you don’t want to.

To help you understand what 5G is, and what it means to you, we’ve put together a handy guide here.

What is 5G?

【小题1】At its most basic level, 5G will be used to make calls, send texts, and to simply get online. But it’s going to be significantly faster than previous generations, and could open the door up to a range of exciting new uses.

【小题2】

5G will use new higher radio frequencies to send out data, which are less cluttered (挤了) and carry information much faster. While these higher bands are faster, they don’t carry information as far. That’s to say, smaller multiple input and output antennas (天线) will be used—promoting both signals and capacity (容量).【小题3】

Why is it better than 4G?

5G is expected to be faster than 4G, with some firms claiming it could be as much as 100 times quicker. The fastest 4G networks can deliver peak download speeds of around 300 Mbit/s.【小题4】In real life, this could allow you to download a full HD film in less than 10 seconds!

【小题5】It means there will be very little—if any—delay when you carry out tasks on a device. While this will help improve things like gaming experiences, it could also pave the way for safer self-driving cars—in which even a short delay could be life-saving.

Finally, 5G will have a larger capacity, meaning networks will be able to deal with several apps at once. Generally, this should mean that devices have a faster, more stable connection.

Disasters almost always arrive unexpectedly. But there are apps to help people prepare for disasters. Some apps alarm users when a disaster has taken place. Other disaster apps can be used when people need rescue or other help.

The   free   SirenGPS   Mobile   app   connects   users   to   emergency   services.   The   app   will   let emergency workers know where the person in need is. The app works over cell networks. But it also works on Wi-Fi if cell networks are down after an emergency. Users can create a personal health report on the app to share with emergency services. This will provide information important to treatment decisions.

Guardly is an app that can help keep people safer in places such as businesses and universities. This app permits workers and students to report about unsafe conditions. Reports can be made to an organization’s own security division as well as to government emergency services. The reporter’s location can be sent with the report so security or emergency services help can arrive more quickly. The app is free, but Guardly charges for its services.

The Life360 app provides a service to keep loved ones connected. Users can set up a network of people to share their location, chat, and get a warning when they are near someone in their network. The app helps users communicate when they are in a disaster. The location share function can be forbidden when desired. The Life360 app is free, with some services available for a fee.

When a person is in a dangerous situation, the Red Panic Button app might help. This app can send a text message or email to chosen contacts providing the user’s location. You can also add a voice or video message or photo to your text and email. Red Panic Button is free, but extra functions are available for a fee.