Five problems for classical physics
...on certainly will. (The hard you hit the metal does not determine the speed which the electrons will be ejected, just the amount of electrons. On the other hand, the faster the wave is will determine the strength with the electron will be ejected) • Albert Einstein explained this theory saying that each electron, on the hit metal, will absorb a quantum of energy from the incident radiation. 3. Some need more heat to get hot. • The classic physics predicts the molar heat capacity of a substance (the amount of energy which, when absorbed by a mole of substance, will rice by 1K), but it just work for a few materials. • When Einstein faced this problem he just fit the equation of the classic physic to accept the Planck theory. 4. Atom diameter. Why 10-10 m? (An odd question?) • Some experiments had indicated that the atoms that made up the different chemical element each had a diameter of 10-10. Is there a real problem?, is valid to ask why atoms have a certain size? Shouldn’t the typical size be taken as being a fact of nature? • Niels Bohr discovered that the electrons follow an orbit around the nucleus of the atom. • The classic physic determines that an object which produces electromagnetic radiation, will gradually change his acceleration. According to this law the electrons would spread causing the atom to disappear. Bohr founded that the electron’s orbit radius was a constant and it corresponds to the place were the electron doesn’t emit radiation. This orbits are know as energy levels. • This constant was found thanks to the Plank’s ideas, and explain why the atoms has an radius of 10-10. 5. Light diffraction. Spectral lines. • When you pass sunlight through a prism, you get a continuous spectrum of colors like a rainbow. When light from an atom was passed through a prism they found a dark background with discrete lines. The problem was that they don’t knew, why the elements emit light of some specific wavelengths. • When Bohr stabilized that the atoms has specific energy levels where they have specifics amounts of energy, he was able to explain why the spectral lines where unique for each element. • When atoms absorbed the energy, the electrons became excited and jumped from low energy levels to high energy levels. The excited electrons would fall back to their original levels and emit energy as light. Because there were specific differences between the energy levels, only specific wavelengths of light were seen in the spectrum. 6. The seeing problem • Whit the help of an Scanning Tunneling Microscope, we are able to see atoms. i. A current is supplied to the tip while the scanner rapidly moves the tip across the surface of a conducting sample. ii. When the tip encounters an atom, the flow of electrons between the atom and the tip changes. iii. The computer registers the change in current with the x,y-position of the atom. iv. The scanner continues to position the tip over each x,y-point on the sample surface, registering a current for each point. v. The computer collects the data and plots a map of current over the surface that corresponds to a map of the atomic positions. • The Schrödinger cat i. We put a cat in a box whit a device, which would kill the cat when a change in an atom occurred. ii. If we open the box the device will be trigger and the cat would die. iii. In a determined time the device will kill the cat due the affect of the radiation in the box. iv. How can we know that the cat is aliv...