Cats usually purr when they feel happy, but no one can explain how that happens. When cats purr, we cannot even hear their heart beating! According to the scientists, cats produce the vibrating sound using their vocal chords. That sound accelerates the healing and reduces pain, which explains why cats purr when they are hurt or stressed.
Some species we know have no ancestors, which means that we do not know when amphibians evolved from fish as the first land animals had well-developed limbs and heads. We know that dinosaurs became extinct as a result of a natural cataclysm that occurred 65 million years ago. At that very time, species of mammals have appeared from nowhere.
Thanks to Google Earth, scientists managed to study thousands of cows and their behavior. They discovered a very strange pattern as 70% of the cows used to turn their heads to the north or south while eating or drinking. That strange fact was observed on all continents, no matter the weather, the terrain, or any other factors.
One very unusual phenomenon has occurred in Oakville, Washington. It happened in August 1994, when all of a sudden it started raining. Yet, the raindrops resembled jelly-like substances. On the very next day many people got flu-like symptoms. According to the scientists, the substance contained two types of bacteria, one usually found in the human digestive system. No one could explain the connection between the bacteria and the mysterious epidemic.
of the universe consists of dark matter, which does not interact or emit with electromagnetic radiation and thus is not possible to detect it. Scientists presented the first theories about dark matter some 60 years ago, yet they have not given any direct evidence of its existence yet.
According to the scientists and as Pluto was excluded as an official planet, we are led to believe that there are eight planets and the Kuiper belt that is beyond Pluto consists of icy objects. The scientists have discovered thousands of objects in that area and some of them were are even bigger than Pluto. In addition, they also noticed a large gap in the Kuiper belt
— a planet that is as big as Earth which pulled all the stones from the belt to itself.
Most people on earth (from 70% to 95%) are right-handed, while the rest (from 5% to 30%) are left-handed. The ambidextrous people are of indeterminate number. Scientists say that genes have an influence
, however the "left-handed gene" is not identified. Some social environments are believed to be of an influence as well: when left-handed kids are trained to write with their right hand, some of them become right-handed.
The giant animals we know from the past, called megafauna, have disappeared some 10 000 years ago. Some scientists say that the climate change killed those huge animals, yet there is no serious evidence about that. Another theory claims that the animals died due to starvation, however scientists in Alaska have found preserved mammoths
whose stomachs were full of undigested greens.
Some scientists believe that dreams are a combination of random images and brain waves. Others consider them to be subconscious desires, experiences or unsolved problems. Oneirology is the study of dreams. Many people think that dreams symbolize the things hidden deep in the human psyche, but no one knows what exactly.
Back in in 2006, when scientists were studying young stars they suddenly heard mysterious roars. The sound cannot travel through space, yet the radio waves can. But no one could explain wherefrom they came? The researchers stated that the waves didn’t belong to stars or to any known cosmic phenomena.
There are several blood types and they have different antigens in the blood cells. These are signals of antibodies that destroy the foreign cells in the body. However, scientists give no explanation why they are different. There is a suggestion that they are related to diseases and immunity. For example, people with type B blood are more susceptible to E. coli
; while people with type O blood are at less risk of dying from malaria.