For all of human history, eating meat has meant killing animals. But scientists behind lab-grown meat say that's no longer necessary. They produce meat by growing cells obtained from an animal's body.

Lab-grown meat, also called “cell-cultivated” or “cultured” meat, is made by feeding a mix of nutrients (营养物) to animal cells in steel tanks in labs. The idea is to create an alternative to agriculturally raised meat. And unlike other meat substitutes which are made from plant proteins and other ingredients, lab-grown meat is real meat. When ready, the meat is formed into shapes such as sausages or nuggets, and looks, smells and tastes like any other grocery store version.

Recently, the U.S. Department of Agriculture (USDA) has given two companies approval to sell lab-grown chicken. The approval launches a new era of meat production aimed at eliminating harm to animals, and reducing the environmental impacts of grazing (放牧) and growing feed for animals. Scientists warn that the typical way meat is produced now, in concentrated animal feeding operations, is a risk factor for the emergence of diseases. Lab-grown meat is more sustainable and can be produced without antibiotics, and without producing greenhouse gas emissions linked to animal agriculture.

“Everything we know about how meat can be made is going to change. But don't expect to see cultivated meat in grocery stores just yet,” said Uma Valeti, CEO of UPSIDE Foods. Lab-grown chicken is much more expensive, because it cannot yet be produced on the scale of traditional meat.

“To make cultivated meat, energy use needs are high,” said Bruce Friedrich, president and founder of the Good Food Institute, a nonprofit group that promotes alternative proteins. However, those high energy needs will be offset by the reduction in land and water use and other benefits. If cultivated meat is produced on a large scale, it could also offer a solution to feeding the world's growing population.

Four remarkable inventions

For more than half a century, the Consumer Electronics Show (CES) has been the place for companies and inventors to display their newest and coolest gadgets.

Here are our picks for some of the most interesting and creative inventions.

The Sweet Little Rolling Robot

Sangsung has released Ballie, a tennis-sized robot that can follow you around the house, answer your questions, and entertain your pets. Since it’s equipped with a camera, it can keep an eye on your home while you’re away. It’s like a smart assistant that goes wherever you do, rolling into your bedroom to ring your wake-up alarm, rolling to the kitchen to turn on the toaster and giving you the weather report as you brush your teeth.

The Insoles to Pick Up Your Pact

Any runner knows the right shoes are key to your speed. But Nurvv insoles promise more than mere cushioning. The insoles transmit data to a coaching app, which offers information on your technique and performance. It measures your foot strike and assesses your injury risk. The app then generates personalized workouts to set targets and help you beat your best speeds. Half marathon, here you come!

The No-Studio-Needed Yoga Class

Can’t keep up your commitment to a yoga studio membership? The Yoganotch personal yoga assistant lets you drop into a virtual class any time you want. Follow along with a set series while 3-D sensors tell you whether you need to straighten your legs a bit more. The idea it that it improves your from while reducing the risk of injury.

The Dau-Enhanced Grill

While working by sight, smell and feel, a chef may appreciate Weber’s new Smart Grilling Hub. It can monitor your pork and turkey while an app gives advice about cooking technique and safe temperatures.

Though doing washing is relatively effortless, most people hate the work, which is probably why this new shirt produced by an American company, called Wool & Prince, is producing so much interest.

According to Mac Brown, the shirt’s creator, the seemingly ordinary shirt can be worn for 100 straight days without washing! Of course, any shirt can be worn for that long, if smell is not a problem. However, the Wool & Prince shirt is different because it remains as fresh smelling as it was — the first day it was put on. And it never needs ironing, because it never wrinkles.

While that may sound magical and even impossible, it is true. The secret to their success lies in the raw material used to make the shirt — wool instead of cotton.

Not only are wool fibers about four times stronger than cotton, but thanks to the natural crimp (皱褶), they also do not wrinkle as easily. But most importantly, the fiber is better at allowing moisture to escape. Sweat in itself is not smelly. It just gets that way when in contact with the human skin. Therefore, the fact that the fabric allows it to go off gives the shirt the “super power” to stay fresh after so many wears.

You can get this magical shirt for $98, which is the current selling price on fund-raising site Kickstarter. The company hopes to use the funds collected to begin producing the shirts. If things go well, Wool & Prince is planning to introduce other clothing, including similar dresses for women.

Well, you’ve got your favorite pair of jeans already. You might as well add your new favorite shirts you’ll never have to wash or hang up either. They are surely a perfect match!