The National Science Fair

Nobel Light

But curiously it had to one another work that it gained the prize Nobel. In fact, Einstein was so brilliant the point to be for backwards of the two pillars of the modern physics. With its ' ' outro' ' work, Einstein explained the photoelectric effect, the phenomenon that will allow in them to incase these concepts and to understand the question of the cellular ones. The photoelectric effect was observed for the first time in 1887 for the German physicist Heinrich Hertz, who noticed that when shining a light on certain metals, them emitted electrons. We know today that it is easy to pull out metal electrons because they are weakly on its atoms. That is, they have low an energy of linking. To the first sight we could assume that if the intensity (brightness) of the light is increased, the speed of electrons also ejected will increase, since more energy is being supplied they (it is imagined kicking a ball and later kicking with force weakly).

But this did not happen. Instead of this, the ejected electron number increased, but its speed continued fixed. On the other hand, it can be observed that the speed of agitated electrons increases if the frequency of the emitted light is increased e, equivalent, its speed decreases if the frequency of the light is diminished. In fact, at the measure that the frequency of the used light is diminished, it is arrived a point where the speed of emitted electrons falls for zero and them they stop of being ejected of the surface, exactly that the intensity of the light source is blinding. For some reason, the color of the emitted light – not its total energy – determines if electrons are ejected or not; if they are, the energy that they have (figure below, continues below). Einstein was the first person to explain what we said above, namely, that each individual photon of light has a specific energy, that is determined by its frequency.