Have you ever heard that we humans use only ten percent of our brains? This opinion holds a certain appeal because if it were true, then we could instantly become ten times more intelligent just by firing up that sleepy majority of the brain!

The idea that we use only a small part of the brain dates back to animal experiments in the 19th century. When scientists stimulated (刺激) a specific part of the brain,   the animal moved its leg or tail. If a tiny part of the brain could do something so great, what was the use of the rest of the brain? Some scientists assumed that large parts of the brain were simply useless.

Then, in the early 20th century, scientists observed that stimulating certain parts of the brain had no physical effects. They named these seemingly useless parts of the brain the “silent cortex.” Today we know that in humans, much of the “silent cortex” is actually devoted to complex activities like language, learning, and imagining.

Brain scans have shown that different parts of the brain become much more active as we shift (切换) our attention and focus, but even as we sleep, many areas of the brain are extremely active. Would you be smarter if your entire brain constantly worked to maximum capacity (能力)? Interestingly enough, the opposite is probably true. The less brain activity you need to perform a given task, the more the brain as a whole is able to do.

Wood has many great characteristics that make it the perfect building material. It is cheap, durable(耐用的), easily available, and most importantly, environmentally sustainable. The one thing it is not, is transparent(透明的).Now thanks to a team of scientists at Stockholm’s KTH Royal Institute of Technology, the material may even be able to add that feature to its already impressive list.

Lead researcher Dr. Lars Berglund said he was inspired to create the transparent wood after learning how Japanese researchers had developed a see-through paper for use in flexible display screens for electronic devices.

The team began by pulling out the wood’s lignin (木质素). The lignin-free wood was then dipped into a polymer (聚合物) and baked at a temperature of 158F for four hours. The result was a hybrid product that was not only stronger and lighter than the original wood but also, almost transparent. The researchers were able to adjust the level of transparency by varying the amount of the polymer injected and also by changing the thickness of the wood.

While scientists have previously created a see-through wood for small-scale applications like computer chips, the transparent wood is the first one being considered for large scale applications. The researchers, who revealed their findings in Biomacromolecules on April 11, picture using the transparent wood in buildings to allow for more natural light, or to create windows that let in the desired amount of light without sacrificing privacy.

Wood that allows light to pass through could lead to a brighter future for homes and buildings. Berglund also thinks the wood could play a significant role in the design of solar panels. The semi-transparent material would be able to keep light longer and give it more time to interact with the conductor, thus resulting in better solar efficiency.

Additionally, substituting the currently used glass with this new product would help solar energy manufacturers improve their carbon footprint and lower the cost. They are now experimenting with ways to scale up the manufacturing process so that the transparent material is cost-effective to make and easy to use.

As temperatures drop, leaves begin to turn for us to enjoy glorious autumnal colors. When temperatures rise again in spring, the growing season for trees starts again. Throughout the warmer months, trees take carbon dioxide from the atmosphere and store it, releasing oxygen as a byproduct. This is the process of photosynthesis (光合作用). The more photosynthesis, the more carbon is locked away.

Carbon dioxide is a major driver of climate change, so the more is taken out of the atmosphere by plants, the better. With the warmer climate leading to a longer growing season, some researchers have suggested more carbon dioxide would be absorbed by trees and other plants than in previous times. But a new study has turned this theory on its head.

The researchers, led by Deborah Zani at the Swiss Federal Institute of Technology, studied the degree to which the timing of colour changes in autumn tree leaves was determined by the growth of the plant in spring and summer.

Traditionally, temperature and day length were accepted as the main factor determining when leaves changed colour and fell, leading some scientists to assume that warming temperatures would delay this process until later in the season. However, in a new study about deciduous (落叶的)European tree species, researchers recorded how much carbon each tree absorbed per season and how that finally affected when the leaves fell. They found that as the rate of photosynthesis increased, leaves changed colour and fell earlier in the year.

In a world with increasing levels of carbon in the atmosphere, these new findings imply that warmer weather and longer growing seasons will not allow deciduous trees to take in more carbon dioxide. The study's predictive model suggests that by 2100, when tree growing seasons are expected to be between 22 and 34 days longer, leaves will fall from trees between three and six days earlier than they do now.