Why Do Dogs Watch--and React to--TV?

Domestic dogs can perceive images on television similarly to the way we do, and they are intelligent enough to recognize onscreen images of animals as they would in real life-even animals they’ve never seen before-and to recognize TV dog sounds, like barking.

A 2013 study published in the journal Animal Cognition showed that dogs could identify images of other dogs among pictures of humans and other animals, using their visual sense alone.

However, there are some differences between ourselves and man's best friend-for one, dogs' eyes register images more quickly than do ours. So older television sets, which show fewer frames(帧数) per second than modern televisions, would appear to a dog to be flickering(忽隐忽现的) like a "1920s movie," said Nicholas Dodman, a veterinary behaviorist(动物行为学家) at Tufts University, in Massachusetts.

Dogs also have dichromatic vision, which means they see a range of two primary colors, yellow and blue. Human vision is trichromatic, so we see the full range of colors, according to Binghamton University's Ask a Scientist web page.

DogTV, an HDTV cable channel designed for dogs, interests canines(犬) because HDTV has a much higher number of frames per second and is specially colored to accommodate dogs' dichromatic vision, said Dodman, who is the channel's chief scientist.

DogTV has modes for relaxation, which shows images like dogs recreate themselves in a grassy field; stimulation, which depicts scenes like dogs surfing in southern California; and exposure which shows things like a dog reacting to a ringing doorbell and obeying commands to adapt to such situations at home.

As free as they make us, mobile phones still need to stay close to a power source. Soon that may change with "green" power.

Three Chilean students got the idea for a plant-powered device(装置) to charge their cellphones, while sitting in their school's outdoor courtyard during a break from exams, with dead mobile phones. Then, one of them had an "aha" moment.

“It occurred to Camila to say about plants, "said inventor Evelyn Aravena. "Why don't you have a socket, if there are so many plants? 'After that, we thought, why don't they have a charging outlet? Because there are so many plants and living things that have the potential to produce energy, why not? ' "

Their invention — a small biological circuit called E-Kaia - uses the energy plants to produce during photosynthesis(光合作用). A plant uses only a small part of that energy and the rest goes into the soil, and that's where the E-Kaia collects it. The device plugs into the ground and then into your phone.

"It's the most amazing project I've ever seen in my life, plain and simple. They brought this original model, and it worked — and that's when it all changed, at least from my personal point of view and I began to support them. " said Mauricio Cifuentes.

The device solved two problems for the engineering students — they needed an idea for a class project, and an outlet to plug in their phones.

"Looking for a place to charge the notebook, which had no power, and the mobile phones, we weren't able to find anything because all the other students were in the same state of madness trying to find a place to charge their devices," said Aravena.

But plants are everywhere, and the biocircuit makes the best of their excess(过多的) power.

The E-Kaia doesn't carry much charge but it's powerful enough to completely recharge a mobile phone in less than two hours.

The student inventors have applied for patents on their technology, and expect the E-Kaia to go on sale in December 2016.

Zero gravity looks cool. But what about the thing no one likes to talk about? Yes, that is right: going to the bathroom. Zero gravity makes this everyday task quite a challenge. Astronauts have to be toilet-trained all over again.

The Apollo astronauts raised themselves off the seat of their chairs and stuck a clear plastic bag to their back sides with sticky strips. A second astronaut watched closely to be sure no waste matter escaped the seal. (You would not want that stuff floating around the cabin!) When the deed was done, the astronaut cleaned up with a piece of plastic attached to the inside of the bag, removed the bag, dropped a disinfectant(消毒剂) pill in with the waste matter, and put the whole thing, sealed, into a special container.

Donald W. Rethke, an engineer for Hamilton Standard Space Systems, developed a more private way to answer nature’s call: the space toilet. It is somewhat like the kind of toilet one would find on commercial airplanes--with unique adaptations for zero gravity, of course. For instance, it has thigh bars that keep the astronaut from floating off the seat.

The astronaut (male or female) defecates (排便) in a bag and urinates (排尿) in a hose. Solid and liquid wastes are kept separated because at least 85% of the urine is recycled and, yes, after careful filtration(过滤), used for drinking and other purposes. (Water is always in demand in space.) A vacuum sucks the waste materials into the toilet, where the waste is compacted into hamburger-like patties for easy storage. Although not exactly like an earthbound visit to the toilet, it is at the very least much more private than in the early days of space travel.