Diamonds are considered the most famous and valuable jewel in the world. The precious stone for its great value is believed to be the symbol of wealth. Diamonds were made as a result of great volcanic beat and pressure. When a volcano is active, it sometimes explodes and causes great damage to the nearby towns.

    However, at the same time of such a disaster, diamonds were pushed towards the surface of the earth by a number of great volcanic explosions millions of years ago. Thus, it may be very likely to find a diamond after a volcanic eruption. Besides, diamonds are also found among the sand and stones of certain river beds, and in a few places on the floor of the sea, for they were washed down the mountain sides by the rain.

    Diamonds are very rare. There are not many places that produce such precious things in the world. During the last century adventurers from Europe went to Brazil, because they had heard that there were diamonds in the River Amazon. Many of these early diamond miners died of illness or were lost forever in the great forests. But some returned home rich.

    The earliest known diamonds were found in India many centuries ago. The most recent and exciting discoveries have been made in eastern Russia. But most of the world's diamonds now come from the Congo, from Tanzania-which has the largest diamond mine in the world and also from South Africa.

    20 years ago, a couple of ecologists, Daniel Janzen and Winnie Hallwachs, convinced Del Oro, a large orange juice producer, to donate part of their forestland to a national park in exchange for the right to dump (倾倒) massive amounts of orange peels on a 3-hectare piece of land within the national park, at no cost. Dealing with tons of waste peels usually involved burning them or paying to have them dumped at a landfill, so the proposal was very attractive.

    A year after the contract was signed, Del Oro dumped around 12,000 tons of sticky orange waste in the land. However, another juice company and rival of Del Oro challenged the deal in court, arguing that their competitor was “polluting the national park”. They ended up winning, and the deal between Del Oro and the national park fell through. The 3-hectare piece of land virtually covered with fruit waste was completely forgotten.

    Then, in 2013, Timothy Treuer, a scientist at Princeton University visited that piece of land 15 years earlier. What he found shocked him. “It was completely overgrown with trees and vines,” Timothy Treuer recently said, “the difference between fertilized and unfertilized areas was visually surprised us a lot! We needed to come up with some really good standards to evaluate exactly what was happening there.”

    To confirm that the fruit waste was responsible for the revival of plant life, Treuer and his team spent months picking up samples, analyzing and comparing them. They found “dramatic differences between the areas covered in orange peels and those that were not. The area fertilized by orange waste had richer soil, greater tree-species richness and greater forest coverage. In a sense, it's not just a win-win between the company and the local park—it's a win for everyone.”

    The effect the orange peels had on the land is probably not that surprising to people familiar with composting (堆肥), but what is shocking is that a judge actually called this particular example polluting the national park and stopped it from going forward. Now that Timothy Treuer's study has received worldwide attention, this type of polluting is being seriously considered as a way of bringing tropical forests back to life.

    Physics is a different world now. Will there ever be another Einstein?

    Scientists say a new Einstein will appear, but it may take a long time. After all, more than 200 years separated Einstein from his nearest rival (对手) , Isaac Newton. Many physicists say the next Einstein hasn't been born yet, or is only a baby now. That's because the searching for a unified(统一的) theory that would explain all the forces of nature has pushed current mathematics to its limits. New math must be created before the problem can be solved.

    But researchers say there are many other factors working against another Einstein appearing anytime soon. For one thing, physics is quite a different field today. In Einstein's day, there were a few thousand physicists worldwide, and fewer theoreticians. Education is different, too. One extremely important aspect of Einstein's training that failed to be considered is the philosophy he read as a teenager. It taught him how to think theoretically about space and time.

    And he was a skilled musician. The interplay between music and math is well known. Einstein would fiercely play his violin as a way to think through a knotty physics problem.

    Today, universities have produced millions of physicists. There aren't many jobs in science for them, so they go to Wall Street and Silicon Valley to apply their analytical skills to more practical and rewarding efforts.

    Besides, those who stay in science don't work alone. It's very difficult to imagine an independent person like Einstein ever tolerating this.

    When many people are worried that there are no more heroes in the modern times, two university students who lost their lives to rescue drowning children have shown that heroes still exist (存在).

    According to the Inner Mongolia Morning Post. the tragedy (悲剧) occurred on the afternoon .December 14,2002 when three school students skating on a frozen lake in Qingcheng Park in Hohhot fell through the ice into the freezing water. More than 20 university students who happened to be near the Spot immediately went to the rescue of the children. Two children were quickly rescued, but the third died. The child's body was not found for three hours. Two of the rescuers, Liu Ye and had Longbiao, also died of cold and exhaustion. The body of Hao who took the lead in jumping into the lake was not found until the next day. A student who was unwilling to tell his name said he and his Classmates from the local college were taking photos at the lake. When they heard the children's criestor help, they went to the ice hole hand in hand to rescue the children. But the ice kept breaking, causing most of them to fall into the icy water.

    Local residents held mourning ceremonies (祭莫仪式) at the lake. Eight of the students were seriously affected by the freezing water and were being kept in hospital for further observation, but their lives were no longer in danger.

    Since the sex of a sea turtle(海龟)is determined by the heat of sand hatching the eggs, scientists had suspected they might see slightly more females. Climate change, after all, has driven sea temperatures higher, which, in these creatures, favors female children. They found female sea turtles from Raine Island, the Pacific Ocean's largest and most important green sea turtle living area, now outnumber males by at least 116 to 1. "This is extreme," says turtle scientist Camryn Allen.

    Biologist Michael Jensen wanted to know if climate change had already changed turtles' sexes. By using genetic(基因的) tests, he'd figured out that he could follow turtles of all ages. Still, his research data would lack an important detail: sex. Only after a turtle matures is it possible to tell its sex from the outside -- mature males have slightly longer tails. By then turtles can be decades old, so scientists often use Iaparoscopy(腹腔镜检查)，sending a thin tube into each animal, but that's not so practical if you're hoping to examine hundreds of creatures. Fortunately, at a turtle conference, he met Allen, and all she needed was a little blood.

    They compared their results with temperature data for nesting beaches. What worries them is that Raine Island has been producing almost female turtles for at least 20 years. This is no small thing. More than 200,000 turtles come to nest there. During high season, 18,000 turtles may settle in at once. "But what happens in 20 years when there are no more males coming up as adults? Are there enough to maintain the population?" says Allen. They also found cooler beaches in the south are still producing males, but that in the north, it's almost entirely females hatching. These findings clearly point to the fact that climate change is changing many aspects of wildlife biology.

    But how widespread is this phenomenon -- and what is the consequence?

    For several decades, there has been an organized campaign intended to produce distrust in science, funded by those whose interests are threatened by the findings of modern science. In response, scientists have tended to stress the success of science. After all, scientists have been right about most things, from the structure of the universe to the relativity of time and space.

    Stressing successes isn't wrong, but for many people it's not persuasive. An alternative answer to the question "Why trust science?" is that scientists use the so-called scientific method. But what is called the scientific method isn't what scientists actually do. Science is dynamic: new methods get invented; old ones get abandoned; and at any particular point, scientists can be found doing many different things. False theories sometimes lead to true results, so even if an experiment works, it doesn't prove that the theory it was designed to test is true.

    If there is no specific scientific method, then what is the basis for trust in science? The answer is the methods by which those claims are evaluated. A scientific claim is never accepted as true until it has gone through a long process of examination by fellow scientists. Scientists draft the initial version of a paper and then send it to colleagues for suggestions. Until this point, scientific feedback is typically fairly friendly. But the next step is different: the revised paper is submitted to a scientific journal, where things get a whole lot tougher. Editors deliberately send scientific papers to people who are not friends or colleagues of the authors, and the job of the reviewer is to find errors or other faults. We call this process "peer review" because the reviewers are scientific peers—experts in the same field—but they act in the role of a superior who has both the right and the responsibility to find fault. It is only after the reviewers and the editor are satisfied that any problems have been fixed that the paper will be printed in the journal and enters the body of "science."

    Some people argue that we should not trust science because scientists are "always changing their minds." While examples of truly settled science being overturned are far fewer than is sometimes claimed, they do exist. But the beauty of this scientific process is that science produces both creativity and stability. New observations, ideas, explanations and attempts to combine competing claims introduce creativity; transformative questioning leads to collective decisions and the stability of scientific knowledge. Scientists do change their minds in the face of new evidence, but this is a strength of science, not a weakness.