A minor cabbage larva bites and swallows a piece of leaf. Immediately afterwards, a wave of light propagates in what remains of the plant, as if to signal the attack in progress. This is the alarm system that plants use to activate hormonal defence mechanisms, the last bastion against parasites. This signalling mechanism is nothing more than the “nervous system” of the plants.
Most of us spend most of our day indoors, like the workplace. Often without even doing much physical exercise. This condition can, in the long run, lead to more or less important health problems. But it only takes a few minutes a day to take a “green bath” and recover from the daily routine. Among the benefits of contact with nature there are: stress reduction, increased vitality and creativity, increased attention in children and also improved memory.
Surviving fires is not easy, yet nature does it better than humans. Fire has an important and often negative impact on wild plants and animals, but some systems have adapted to it. And, paradoxically, some species cannot live without fire. In an environment adapted to the fire, in fact, once the fire is extinguished, nature can resume the lost ground. Moreover, some species, even with a fire, do not die and can grow back very quickly.
The word rainbow comes from the Latin arcus pluvius. This shows that even our ancestors understood its physical origin: there can be no rainbow without rain. But how are rainbows formed? They occur when sunlight – i.e. all wavelengths of light, which together appear as white light – passes through water droplets. And how many color do they contain? That really depends on us. Some scientists even think that perception can be a cultural issue.