On May 17, 2009, according to the plan, Mike Good and I would take a space walk to the Hubble Space Telescope to repair an instrument. The power supply on this instrument had failed, so it could no longer be used. I would be the person doing the repair and Mike my assistant.

    Working in space is more difficult than you can imagine. As there is no gravity, you can't stand and any slight push can result in tragedy -you can be pushed into space, never be back.

    We got to the telescope. Before we could replace the power supply, we would have to remove from the telescope a handrail fixed with four screws. Having taken out the first three, I found the fourth stripped. I realized that the handrail would not come off, which meant we could no longer be able to replace the power supply and repair that instrument, which meant scientists could no longer look at the universe and find life on other planets.

    I tried all kinds of things, and nothing worked. Then Houston, the control centre on the earth, called up and told me to use the tape to tape the bottom of the handrail and pull it off the telescope. They said it was going to take about 27 kilograms of force for me to do that.

    I knew what it meant: The handrail could be completely pulled off and the safety tether might break, and I might therefore be pushed into space.

    Mike was next to me in his space suit but he could not take over my role. I turned and looked into the cabin where my five crewmates were, and nobody in there had a space suit on. However, I knew they were all looking at me. "Come on Mass, we are all behind you." The telescope must be repaired.

    "Bam!" The handrail came right off. The rest of the walk went well. We finally got the new power supply in. They tried it; turned it on from the ground. The instrument came back to life.

    At the edge of darkness, after about eight hours, I turned around and saw the Earth from our altitude at Hubble, 568 kilometers up. I saw the huge round pure blue globe home planet. It's the most beautiful, magnificent thing I've ever seen. It's like looking into heaven. It's paradise.

    Radios, telephones and televisions are widely used in the world. When you switch on the radio, you can listen. But when you use the telephone, not only can you listen to others, but also you can chat with them. However, you cannot see anything at all. Television is much better than both of them. People can watch TV and listen to it, but they cannot take part in what they see.

    Today, some people are using a new type of telephone called vision phone. With it two people who are talking can see each other. Vision phones can be of great use when you have something to show the person whom you are calling. It may also have other uses in the future. Some day you may be able to call up a library and ask to read a book right over your vision phone. You may be able to do the shopping through it too. Perhaps in the near future, vision phones will come into our everyday life.

    Imagine a world with no more animals: no elephants, no tigers or lions. To some people, that thought is too terrible for words. So they are doing something about it. Tiffany Soechting is one of them.

    Being among wild animals—feeding them and caring for them—is all Tiffany Soechting has wanted to do with her life. And that is exactly what she does!

    Soechting is the human "mother" to the 500 animals that live on her family wildlife farm in San Antonio, Texas. On the farm, she cares for animals from around the world. Soechting says she loves them all. However, two reticulated giraffes(网纹长颈鹿) take up a special place in her heart. Their population in the wild has become smaller by 80% in the last 15 years. "I'm so glad to get help from five wildlife researchers that took giraffes up to a higher level. All our hard work helps protect giraffes living in the wild."

    Besides her animal caring, Soechting also holds monthly classes, where she teaches school children about the animals.

    Soechting also opens the farm to the public. Visitors not only learn about the animals, they can also get close to them. And the animals are not against that. For them, people are part of their natural environment.

The farm is part conservation(保护) area, part educational center and part animal park. As the animals walk peacefully around the grounds, it is easy for them to forget that San Antonio, a busy city, is just a few minutes away.

    Virtual (虚拟的)reality is a way to create a computer-made environment that brings the user into a virtual world. If you ever have put on a VR headset, you would know exactly what I am talking about. From an experiential view we do understand the idea, but what about the technical backend that goes into making it all possible? In this blog, we will understand the technology behind virtual reality and the basic terms about the development of a virtual ecosystem for a VR headset.

    The primary subject of virtual reality is simulating (模拟)the vision. Every headset is to perfect their method to create an immersive (浸人式)3D environment. Each VR headset puts up a screen or two in front of eyes, keeping the user away from any interaction with the real world. Two autofocus lenses (自动对焦镜片)are generally placed between the screen and the eyes that change based on eye movement and positioning. The vision appears on the screen either by using a mobile phone or HDMI line connected to a PC.

    To create a truly immersive virtual reality, there are certain requirements a frame rate (帧 率)of at least 60 fps, a refresh rate and at least 100﹣degree field of view (though 180 degrees is perfect). If either of these doesn't work according to the standards, the user will experience too big of a time difference between their actions and the response from the screen. We need the response to be less than 20 ms (1/1000 second) to fool the brain which is achieved by joining all the above in the right proportion (比例).Another matter that needs to be looked at here is to prevent netsickness because of the differences between the frame rate and refresh rate.

    Apart from the image, there are certain other things that go into creating an immersive VR experience, holding the user's attention completely in the virtual environment. For example, sound effects, when put with the image, can create very attractive effects. By using a headphone and 3D sound effects, the user can totally believe in the virtual environment. While perfecting sound effects, proper care needs to be taken about the consistency (一致)between the pictures and the sound. If you start playing frightening music in the background of a happy scene, it will just put the user off.

    In future, we will see rapid progress in creating a truly immersive digital experience. With leading players like Google, Microsoft, Oculus, and HTC making great efforts to improve the capabilities (性能),we are not far from achieving a virtual reality that would feel so much better than the real world. If you would like to develop a VR app for your business, then feel free to get in touch. With over 10 years of experience in mobile technologies, we can make every dream a reality.