On Tuesday, India’s Prime Minister Narendra Modi launched a series of new high-producing crop varieties, including herbicide-tolerant (耐除草剂的) rice that can be directly planted into the soil, cutting the huge expenses on water and farm workers.

In India, the world’s biggest rice exporter, the traditional method of rice growing requires farmers to grow seeds in nurseries, and then wait for 20 to 30 days before transplanting the small plants by hand into the fields that are ankle-deep in water.

With the new seed varieties developed by the state-run Indian Agricultural Research Institute, farmers only need to water the field once to moisten (使湿润) the soil before planting the rice. Besides, the traditional method also uses a lot of water to control weeds as herbicides are costly and often do not distinguish between the rice and the unwanted weeds.

Government scientists said the new rice varieties contained a gene that would allow farmers to spray a common, inexpensive herbicide without worrying about any side effects. “Our focus is very high on new seeds that can be adapted to new conditions, especially in changing climates,” Modi said.

Water conservation is likely to be the main attraction of the new rice varieties in India, where farmers rely heavily on monsoon (季风) rains. The traditional method uses 3,000 to 5,000 liters of water to produce 1 kg rice. The new varieties could cut water use by at least 50% to 60%, farmers and government officials say. “For farmers like us, the main concern was the management of water, and the new varieties take care of that concern,” said Ravindra Kajal, who grows rice on his 9-acre farmland in the northern state of Haryana. India is also the world’s biggest rice producer after China.

All living organisms are uniquely adapted to the environment in which they live. Scientists are studying the design and the biological processes of these organisms to get ideas for products and technologies. This field of study is called biomimetics. Here are two examples.

Toucan Bills and Car Safety

Toucan usually has enormous bills. Scientists have found that the toucan's beak is designed to be both strong and light. The surface is made of keratin, the same material in human fingernails and hair. But the inside of the bill has a foam-like structure and is made up of a network of light, thin pieces of bone. It contains a lot of air, and some areas are hollow, not solid. This design makes the bill hard but very light.

The design of the toucan bill can be used to make cars and planes safer. Studies show that the beak's structure can absorb high energy impacts very well. Car body panels that mimic toucan bills may offer better protection to motorists involved in crashes.

Shark Scales and Swimsuits

Shark skin may look smooth, but it's actually rough. Sharks are covered in scales made from the same material as their teeth. Viewed up close, the scales actually look like tiny teeth. These scales protect the shark and help to keep it clean. They are also flexible and can turn or bend in the water. This movement reduces the waters drag on the shark and helps it to swim quickly.

Scientists discovered that the shortfin mako's scales vary in size and flexibility over its body. For instance the scales on the sides of the body are tapered — wide at one end and narrow at the other. They can turn up or flatten to adjust to the flow of water around the shark and to reduce drag.

Scientists believe that shark scales can inspire designs for machines that experience drag, such as airplanes. Designers are also getting ideas from shark scales for designing swimwear and coating ship bottoms.

War is expensive and it is bloody. That is why America's Department of Defence wants to replace a third of its armed vehicles and weaponry with robots by2015. Such a change would save money, as robots can be much cheaper to replace than people. Just as importantly for the generals, it would make waging war less prey to the politics of body bags. Nobody mourns a robot.

The US military already routinely uses robotic aero planes known as unmanned aerial vehicles ( UAVs ). In November 2001 two missiles fared from a remote-controlled Predator UAV killed Mohammad Atef, al-Qaeda's chief of military operations and one of Osama bin Laden's most important associates, as he drove his car near Kabul. But whereas UAVs and their ground-based equivalents, such as the machinegun-toting Sword robots, are usually controlled by distant human operators, the Pentagon would like to give these robots increasing amounts of autonomy, including the ability to decide when to use lethal force.

To achieve this, Ronald Arkin of the Georgia Institute of Technology, in Atlanta, is developing a set of rules of engagement for battlefield robots to ensure that their use of lethal force follows the rules of ethics. In other words, he is trying to create an artificial conscience. Dr Arkin believes that there is another reason for putting robots into battle, which is that they have the potential to act more humanely than people. Stress does not affect a robot's judgment in the way it affects a soldier's.

His approach is to create what he calls a "multidimensional mathematical decision-space of possible behavior actions". Based on inputs ranging from radar data and current position to mission status and intelligence feeds, the system would divide the set of all possible actions into those that are ethical and those that are not. If, for example, the drone from which the fatal attack on Atef was launched had sensed that his car was overtaking a school bus, it might then have held fire.

There are comparisons to be drawn between Dr Arkin's work and the famous Three Laws of Robotics drawn up in the 1950s by Isaac Asimov, a science-fiction writer ,to govern robot behaviour. But whereas Asimov's laws were intended to prevent robots from harming people in any circumstances, Dr Arkin's are supposed to ensure only that they are not unethically killed.

This is an admirable goal in theory, but even if ethics can be neatly encoded into software, pitfalls remain. Although a completely rational robot might be unfazed by the chaos and confusion of the battlefield, it could still make mistakes. Surveillance and intelligence data can be wrong, and conditions and situations on the battlefield can change.