In our daily life, it has never been easier to understand time: The National Institute of Standards and Technology (NIST) broadcasts the time to points across the country and then it’s fed through computer networks and cellphone towers to our personal devices. The time from NIST keeps society organized and increases economic productivity.

“Growing up, a lot of us are fed with this concept of absolute time,” says Chanda Prescod Weinstein, a theoretical physicist at the University of New Hampshire. “But the time we’re experiencing is a social construct. Real time is something quite different. In some of the corners of the Universe, space and time can stretch and slow-and sometimes even break down completely.”

For many people, his idea of time is unbelievable. But true time is actually much more flexible than most people realize. According to Einstein’s general theory of relativity, space and time are tied together, and space-time can bend and curve (弯曲). As time stretches, it slows.

The best-known force that stretches time is gravity. The more gravity somebody experiences, the slower time passes for them when compared to someone in a lower gravitational field. In places where gravity is very strong, time as we understand can break down completely. At the edge of black holes, for example, the gargantuan gravitational pull slows time dramatically.

“Upon crossing the black hole’s point of no return, known as its event-horizon, you end up in a region where time breaks down entirely, ”Weinstein says. “At that point time has no real meaning. There is no direction. There is no future. ”

The scientists at NIST are well aware of all the problems with time. “Just as humans keep improving their maps, we must improve our clocks. Better clocks can make GPS more accurate, computer networks faster, and much, much more,” says John Kitching, one of the NIST scientists. “But it’s pretty hard to define time in a satisfactory way.”

Kitching agrees with Weinstein that time as we experience it is a technology rather than a fundamental part of the Universe. “From a physics sense, it doesn’t have that much value,” he concludes.

One recent report found that adults in the US check their phones, on average, 344 times a day — once every four minutes — and spend almost three hours a day on their devices in total. The problem for many of us is that one quick phone-related task leads to a quick check of our email or social media feeds, and suddenly we’ve been sucked into endless scrolling (滚屏).

It’s a vicious circle. The more useful our phones become, the more we use them. The more we use them, the more we lay neural pathways in our brains that lead to picking up our phones for whatever task is at hand — and the more we feel an urge to check our phone even when we don’t have to.

What we do know is that the simple distraction of checking a phone or seeing a notification can have negative consequences. This isn’t very surprising; we know that, in general, multitasking harms memory and performance. One of the most dangerous examples is phone use while driving.

In another recent study, researchers asked participants to either put their phones next to them so they were visible (like on a desk), nearby and out of sight (like in a bag or pocket), or in another room. Participants then completed a series of tasks to test their abilities to process and remember information, their problem-solving, and their focus. They were found to perform far better when their phones were in another room instead of nearby — whether visible, powered on or not. That held true even though most of the participants claimed not to be consciously (有意识地) thinking about their devices.

The mere proximity (靠近) of a phone, it seems, contributes to “brain drain”. Our brains may be subconsciously hard at work in controlling the desire to check our phones, or constantly monitoring the environment to see if we should check our phone (eg, waiting for a notification). Either way, this diverted attention can make doing anything else more difficult. The only “fix”, the researchers found, was putting the device in a different room entirely.

When it comes to strategies for slowing down the aging process, don’t ignore the power of mind over matter. Recent research shows that several personality traits predict who will enjoy health into their 80s and beyond. According to studies, the link between personality and longevity is strong.

People who’re conscientious-organized and responsible-tend to live longer. Being conscientious may help overcome major risks to health, such as living in poverty. Besides, many conscientious people seem to have better coping strategies for stressful situations, said Turiano, leading to less inflammation (炎症), which in turn slows down aging.

People can become more conscientious through support from friends, coaches and psychologists. Smart phone apps may help, too. For example, participants in a study increased their conscientiousness significantly by using a digital coach called PEACH. This app strengthens personality change through tips, like reminders to reflect on progress toward one’s goals by keeping a diary.

Another good quality for longevity is being purposeful, or having a direction in life with clear goals that energize you. Many types of purposes are beneficial. “It’s so unique to the individual,” said Patrick Hill, a psychologist at Washington University in St. Louis. Some derive purpose from their jobs, while retirees (退休人员) report feeling more purposeful during the evening if they socialized that day, according to Hill’s research.

Optimism is also associated with exceptional longevity, according to research by Lewina Lee of Boston University. Actually, people who see the positives in aging live an average of 7. 6 years longer. Becca Levy, a psychologist at Yale’s School of Public Health, said they enjoyed this longevity advantage due to exercising more and eating more healthily. You can boost optimism by regularly writing about your best possible self.

Being sociable or outgoing is another trait that can lengthen your span of health. According to Susan Charles of the University of California-Irvine, social butterflies tend to be more active, which protects their health. Adopting a healthier lifestyle has been shown to make people more comfortable in social situations.