When we speak of life forms, we tend to think of human, animals, flowers, plants, etc. In fact, life in this world may exist in ways we are unable to see or imagine. Here are a few examples: 1) Unusual life deep in the sea According to news released on October 20, 2006, researchers from Princeton University discovered some unique bacteria about 2 miles below sea level. These bacteria do not rely on the solar energy, but instead live on radioactive decay in the rock. Based on such studies, scientists speculate that life may exist in many unexpected places, including under some extreme conditions. The discovery site was near a gold mine in South Africa. The life form there was thought to have been isolated from our ecosystem for several million years. The metabolic energy was totally from surrounding rocks. This research was published in Science on October 20. The researchers were from 9 different institutions, and they obtained the samples about 2,800 meters under the water. From this discovery, one can speculate that life may exist in many uncommon places, such as on other planets inside the solar system or even outside the solar system. It is very likely that their existence has nothing to do with our ecosystem. Similar discoveries were also made in the past. According to news in Science Daily on December 18, 2002, scientists collected samples at the heights of 20-41 kilometers above the earth's surface. Analysis showed that microorganisms were found even in the samples collected at 41 kilometers high. On the other hand, scientists also found microbes in Lake Vida, an Antarctic "ice-block" lake. This lake is covered by ice and snow all year round, with water containing a high amount of salt, several fold higher than seawater. Scientists think this harsh environment is comparable to that on Mars. Regarding the existence of life, exactly how much do we know? 2) Worms in stone At around 8 a.m. on October 3, 2006, a resident surnamed Li was working at a quarry site near Jujia Village of Baoquan Town in Anqiu City, Shandong Province, China. He found a piece of violet rock about one yard on each side. The rock was very hard, and it took him a long time to cut it into two. When Mr. Li continued to cut the smaller piece, he was very surprised to find a small pit inside the rock, in which were two small worms. After close examination by experts in medicine from the local area, the worms were identified as Shixia Worm, which are extremely rare but nonetheless recorded in some ancient books including Compendium of Materia Medica (a traditional Chinese medicine book written by Li Shizhen in Ming Dynasty). However, it remains unclear what medical effects these worms have, and how they survived in the isolated rock. Five years earlier, one resident in Xingshan Village of Baoquan Town also found a Shixia Worm in a quarry site, which seemed effective in treating eye disease. It is a mystery how the worm could live in such as hard and isolated environment. 3) The 3-meter high "Terror Bird" When it comes to prehistoric creatures, people often think of dinosaurs. In fact, during that period of time there were many giant animals on earth besides dinosaurs. On October 26, 2006, the discovery of the "Terror Bird" was published on Nature. This creature was about 3 meters high, with head as big as that of a horse. The National Geographic website also carried this discovery on October 25. As the biggest birds that people have known so far, they could eat a dog in one swallow. The fossils were unearthed in the 19th century and are believed to have a history of about 15 million years. Dinosaurs and "Terror Birds" are not alone. Scientists have also discovered numerous other giant creatures, such as geese in Australia, sloths in North America, and crocodiles in Brazil and Africa. 4) Giants and dwarves once co-existed with us We have just briefly talked about some unusual microorganisms, worms and animals. In fact, even for human beings, there are many mysteries. For example, scientists have discovered the dwarf elephants on the island of Flores in Indonesia, with height of only 90 centimeters. On the same island where dwarf elephants were discovered, fossils were also found that are very likely from extinct dwarf humans. Many people now consider these Flores dwarves as another kind of human being, different from us. In 2004, many small-sized tools were also found in the area where Flores dwarves were discovered. The delicateness of those tools is comparable to the ones we have used. Numerous pieces of evidence also point towards the existence of giants. In the Ica Stone Museum located in Nazca, Peru, there are over 10,000 stones with inscription. These inscriptions are astonishing since they describe a technically advanced prehistoric period, including some describing humans co-existing with dinosaurs. From these inscriptions, the humans were comparable in size to the dinosaurs, just like we stand next to modern-day livestock. Could it be possible that the dinosaurs were once livestock for those giants? 5) Summary Regarding the complexity and wonders of our world, what we know now is very, very limited. Exactly how many forms are there for life to exist? This will probably be a mystery to us forever. The bottom line is that, since we have the opportunity to live in this world with so many beings, we need to cherish them.