【推荐1】When Alex Petrie went to stay with his father, he noticed that the 75-year-old walked around several times during the night. This was worrying: his father lived alone and had recently been diagnosed with Lewy body dementia (路易体失智症).

“I was feeling quite nervous about it and wondered if he was doing it every night,” says Petrie. “It‘s not nice to think that he's worried or can't sleep properly.”

But Petrie had recently installed (安装) a smart home system, Howz, in his father's flat. It uses sensors to track movements, feeding the data into an app that family members and close friends can access. Once the Howz system has analysed and established someone's habitual way of doing things, it will send alerts (警报) to the app if there are any changes. For example, if a sensor usually senses movement before 8 am each day — signalling the time the person normally gets up — an alert will be sent if there has been no movement by that time. Relatives can then call in to make sure everything is okay.

Using the app, Petrie could see that his father usually got a good night’s sleep and very rarely walked about during the night. With this knowledge, he was able to provide the right kind of support and care when his father did have a sleepless night.

Howz, which was developed by Intelesant, a Manchester-based health tech company, aims to help people live independently in their own homes and provide peace of mind for their relatives.

Petrie set up two sensors in his father’s flat: one on the front door and another in the hall. “The door sensor is important as I can see whether his carers have visited. It doesn’t tell me who has visited but it’s easy to find out by the time of the day. The sensor in the hall covers the most commonly used area of the flat. It gives us a near-continuous view of whether he's up and about. It’s a little safety net,” says Petrie.

【推荐3】So far, the use of underwater cameras has been limited. Some must be stuck to power wires. Others rely on batteries, which don’t tend to last long. Such limits have kept scientists from exploring most of the ocean world. But now researchers have found a way around these problems — underwater cameras can get a new power source from sound.

The camera has two sensors on the bottom. Each is made of multiple layers of a piezoelectric material. When sound travels through the water, it creates waves of pressure, which cause the material to vibrate (振动). And the material changes these vibrations into electrical energy and stores it in a capacitor. Once the capacitor has enough energy, it turns on the camera and takes a picture. Then, it lets the second sensor tap into more sound energy to send the picture. In this way, the sensors not only power the camera, but broadcast the data carrying its images.

Any sound can power it — from swimming fish to a passing ship. One of the sensors can focus on collecting energy for the camera while the other focuses on communication. How quickly the system takes to recharge depends on how loud and close the sound is. In a quiet setting, the camera will take about 10 to 12 seconds. With improved sensors, the camera will charge in less than a second by using sounds from more than 100 meters away.

To record an image, the camera flashes a series of red, blue and green lights. The system then combines what it sees into a single color photo. To communicate, the camera has an internal switch, which controls whether a sensor uses incoming sound for broadcasting. That switch is like a mirror being moved into and out of position. When that switch is in position, the system will use some sound to carry the photo’s digital data to a receiver. That receiver picks up the camera’s broadcast and assembles the data into an image. And then the undersea photo shoot is done.

【推荐1】Our brains consist of soft matter bathed in watery cerebrospinal fluid (CSF) inside a hard skull. An impact on the hard skull is transmitted through the thin layer of CSF to the soft brain matter. In Physics of Fluids, Qianhong Wu and co-authors describe studying another system with the same features, an egg, to search for answers. An egg resembles the brain.

Considering that in most brain injuries, the skull does not break, Wu wanted to find out if it was possible to break the center of an egg without breaking the eggshell. The researchers did a simple experiment, from which they could see that rotational force (旋转力) can easily break the egg yolk and make it mix with the egg white. Two types of impacts can be imposed on the outer container. A translational impact is one that hits the container directly, while a rotational impact occurs when the outer container is accelerated or decelerated. The latter arises naturally in sports when helmets are not round.

The researchers discovered something quite surprising. Direct translational impact does not cause the egg damage, while rotational deceleration causes great egg yolk damage. This finding explains why boxers will very likely faint if hit on the chin. “Considering the chin is the farthest point from the neck, hitting on the chin could cause the highest rotational acceleration/deceleration of the head,” Wu said.

When it comes to concussions (震荡), “it remains unclear how the brain is injured and how to avoid such injuries. Critical thinking, along with simple experiments within the kitchen, led to a series of systematic studies to examine the mechanisms that cause egg yolk damage,” Wu said. “We hope to apply the lessons learned from it to the study of brain biomechanics (生物力学)as well as other physical processes. ” As the first study of its kind, this work will interest those designing helmets.

【推荐3】Taylor Swift showed very early promise as a singer of country songs, performing from the age of nine. She learned the guitar and persuaded her family to move to Tennessee so she could further her career. She holds numerous records for achievements in music, has been named among the top 100 most influential people on more than one occasion and was named as Woman of the Decade and Artist of the Decade in the 2010s. Swift’s musical style has evolved from country to pop and her fans number in the millions.

Taylor Swift has a firm belief that we should all be ourselves. She tempers this by saying that we must be respectful of others, honest and strong-willed. Strength of purpose will carry a person through life and see them achieve great things. Do not, she says, be average. Stand out and be the best person that you can.

Her view of life is simple. We each have one life, and we must make sure we do not waste it. Life is there to be enjoyed and to be fulfilled. Only we can control what happens in our lives, and must not allow others to judge us or create false opinions of us.

To live a life that has meaning, we must be prepared to learn from mistakes and failures and deal with them without getting discouraged or distracted from our path. No one should tell you what you can’t do, and you must not let a mistake tell you that either. When someone tries to stop you from doing something, be eager to prove them wrong. Be keen, too, to show that your mistakes won’t hold you back.

Taylor Swift puts great store in happiness. Seeking happiness is a wonderful ambition, and everyone should see it as an aim. Success without happiness is a meaningless achievement. Aiming for happiness can go along with other goals too. Swift doesn’t rest when she has achieved one goal, but picks up another and pursues that with the same vigor and determination.