Protect IP act and SOPA

PROTECT IP Act, or (Preventing Real Online Threats to Economic Creativity and Theft of Intellectual Property Act of 2011) was introduced on May 12, 2011 by Senator Patrick Leathy to give the government and copyright holders additional tools to curb access to "rogue websites dedicated to infringing or counterfeit goods".

Here you can find all the information about this bill, and why it should be stopped.

http://americancensorship.org/

This bill will not be able to stop piracy, but will only give to government  bigger censorship powers.

For instance a website that got blocked, will be reached anyway just using the IP addres of the site. The website won't be reached by search engines, but this won't stop the activity of the site, because it could be found using different methods. Quoting Eric Schmidt, it's just an attempt to use easy solution to complex problems.

This bill will however allow the government to remove access to a certain domain, and all the hyperlinks related to it. All the social networks and search engines will therefore censor their users, because they could get closed if any of the user would post any copyright-breaking material.

Nevertheless this bill could be seen an example by other countries, that could start to apply censorship in a similar way. If all the countries in the world would apply those laws, the web would be different for every nation. The biggest form of communication of the 21th century would therefore die.

The atomic structure [5]: Heisenberg uncertainty principle

Bohr and Sommerfeld atomic models couldn't be considered exhaustive, because were based on classical mechanics, and introduced postulates, without explaining them. Experimental results weren't properly interpreted as well, and in cases different from Hydrogen, energy levels were completely different from the one proposed by those models.


The problem that was being posed now was if it could be possible to elaborate models that required the existence of precise orbits. To calculate the path of a certain dot, it necessary to know its position and speed at a certain moment.


In response to this problem Heisenberg proposed the uncertainty principle, according to which is not possible to measure accurately and contemporaneously the position and the speed of a certain particle

It means that lower is the radiation's intensity used to observed the particle, grater is the accuracy of the measurement, because the particle's path is going to be effected in a minor way. However to observe the path of an electron, a radiation of wavelength comparable to its dimension is required.  This implies a very small wavelength, that is related to high energy, and therefore great change in particle's speed, that  is several cases, will be sufficient to ionize the atom.

The atomic structure [4]: Wave-particle duality

In 1922 Compton began to study electromagnetic waves, with special interest on the interaction between X rays and a graphite target. He observed that a radiation was emitted, and its wavelength was higher than the incident one. This phenomena couldn't be explained by classical theories. They expected that the emitted radiation was characterized by the same frequency of the incident one, because it was supposed to make graphite particle oscillate with its frequency.

 Compton proposed that this phenomena could be explained as an interaction between particles: photons and electrons. Photons, interacting with graphite, are going to hit electrons, shifting part of they energy. The electron is therefore going to be emitted with a lower kinetic energy than the photon. It means that also the frequency will be lower, thus the wavelength will be higher, explaining the Compton scattering.


This new discovery, together with photoelectric effect, showed that light behaved ad a particle. De Broglie, was firmly convinced about unity in nature: if waves behaved like matter, also matter had to behave like waves. In 1924 he proposed that the motion of particles was related to the propagation of a certain wave, according to his hypothesis:

This was experimentally proved in 1927 by Davidson and Germer. For instance if an electromagnetic wave is forced to pass through a hole with radius comparable to it's wavelenght, it will create diffraction. The same behavior is observed if electrons are forced to pass through a hole of radius comparable to their de broglie-wavelength, confirming wave particle duality of light and matter.

Is it worth saving pandas?

Conservation has limited resources, and so pragmatic choices need to be made. No one  would ever want to hear of any species getting extincted, especially if the species involved are well known, and loved, by the public, but it could result to be necessary.


Those species are indeed very expensive to keep going, and most of the resources in this area are used toward them and a few others, while the best thing to do could be to preserve biodiversity hotspots. If habitat are not preserved, there's no point in talking about preserving biodiversity. So if we all the cash were not spent on those famous species but were used, for example, to buy rainforest, biodiversity might get greater benefits.

On the other hand megafauna like pandas and tigers appeal to people's emotional side, and attract a lot of attention, raising the possibility of higher money resources. It can lead to a media phenomena called single-species conservation. Those kind of advertising began in the seventies with Save the Tiger, Save the Panda, Save the Whale, and so on, but maybe this era has come to an end.


Nevertheless many species that could be "worth saving" live in a narrowly defined habitat. This mean that they don't need a big habitat to live in, and so the protected area would be restricted. In conservation terms is therefore better to try to protect the species that live at higher levels in the food web. Thus conservation will be extended to all the other species related to the protected one. 


Furthermore protecting those species  will require  the conservation of larger habitats, than the one required by "lower" species. Megafauna could hence be used as media vehicle for the habitat conservation. There are things you pull out from the picture because people can relate to them. And it does make a difference.

The atomic structure[3]:the Bohr model

Spectral emission lines of atoms resulted to be formed by electromagnetic waves varying in a discrete way. The easier spectrum to  be calculated is Hydrogen, because its atom is composed by one only electron. The formula required to calculate the frequency of those lines was proposed by Rydberg in 1888.

The problem related to the interpretation of those experimental results was solved by Niels Bohr in 1913, that modified Rutherford's model, according to Quantum Mechanics. The main ideas are:

1. Electrons move around the nucleus in circular orbits (or elliptical, according to Sommerfeld) under the action of coulombian force;
2. Electrons cannot orbit in every orbit, but only in the ones with a certain angular momentum;
3. If electrons orbit in one of the allowed orbits, it doesn't radiate energy;
4. The atom emits energy and radiations only when electrons pass from an higher energy stationary state, to a lower one.

Bohr succeeded in calculating the value of atomic radius for Hydrogen, introducing quantization of energy in the relation between coulombian and centripetal force.

There are therefore infinite allowed stationary state, because n is a natural number. This infinity is a discrete one, and not a continue one, like in classical mechanics. This result is a direct consequence of the quantization of angular momentum, that involves also the quantization of the energy of the electron.

This atomic model can be however applied only for the Hydrogen atom. For more complex atoms it is necessary to introduce another quantum number. Spectral lines of those atoms presented multiplets, that imply the presence of further energy levels, closer to each other. 

It was explained by Sommerfeld, introducing elliptical orbits. Those theories were still based on a classical idea of atom, that is far from being correct, even thought the secondary quantum number is used also on wave quantum mechanics, and represents the shape of the orbital.

The atomic structure[2]: the birth of quantum mechanics

By the end of the 19th century, Maxwell's theory of electromagnetism wasn't able to explain several phenomena, such as:

1. Black body radiation;
2. Photoelettric effect;
3. Compton scattering;
4. Emission and adsorption spectrum of atoms.

Those phenomena were interpreted using quantum mechanics, that was based on the idea that light could behave in a particle way, and not only as a wave. Max Plank was the first one to introduce the idea of quantization, that allowed to explain black  body radiation.

If we take in account any metal that melts at high temperatures, we'll see that he emits radiation in a continuous spectrum, that varies with temperature. Black body is a theoretical object that behaves in a similar way: it adsorbe all the incoming radiation, and its emission depends only on temperature. Its spectrum will present a maximal emission at a certain wavelength, that will vary according to Wien's Law.

In 1899 Max Plank succeeded in interpretating the experimental results about black body radiation. He assumed that energy could not vary in a continuous way, but that it was quantized.

In 1905 use this new idea to solve the paradox of Photoelectric effect. This effect was based on the fact that electrons are emitted from matter as a consequence of their absorption of energy from electromagnetic radiation of very short wavelength, such as visible or ultraviolet light. On experiments it was observed that electron emission took place only if the incident radiation had a bigger frequency than a certain minimum one (typical of the irradiated body). The emitted electrons had a certain kinetic energy, that varied from zero, to a maximum value, dependent from the frequency of the radiation. The intensity of emitted electrons was proportional to incident radiation's intensity, meanwhile their speed (and so their kinetic energy) was independent from it.

According to classical physics, electrons of superficial layers could be stimulated  by incident radiation, but the speed of emitted electrons should vary proportionally with the intensity of incident radiation. This was in contrast with experimental results, so a new conception of electromagnetic waves was needed.

Einstein proposed that electromagnetic waves, while interacting with matter, had a corpuscular behavior,  as if it was composed by quanta of light, photons. While intensity of radiation increases, photon's energy remains the same, and gains the number of photons per unity of surface. A photon can indeed give his energy to surface electron: if it is bigger than the minimum required, the electron will be emitted, and will assume a kinetic energy equal to the difference of photon's kinetic energy and the minimum energy required.

This explains why to an increasing intensity of incident radiation, corresponds a gaining of emitted electrons, while their kinetic energy is not  changed. This interpretation led to the introduction of wave particle duality of light.

The atomic structure [1]: the discovery of fundamental particles

Until the second half of the 18th century, the most widely accepted idea of atom was Dalton's one. His theory was based on 5 fundamental points:

1. Everything is composed by invisible and indivisible particles, called atoms. This idea was present also in Greece over 2500 years earlier, because of Democrito.
2. Atoms cannot be created and cannot be destructed;
3. In a certain element, all the atoms are equal, sharing the same mass and chemical properties;
4. Different elements are made by different atoms, with different mass and chemical properties;
5. Different atoms can combine each other to form more complex particles

It revealed to be false at the beginning of 19th century, when it was discovered that atoms weren't fundamental particles, but were composed by three other particles: electrons, protons and neutrons.

Electrons were the first ones to be discovered, because of Goldstein's researches  on cathode rays. Those one were emitted on a tube filled with rare gas and inside a strong electric field by the negative electrode (cathode), and appeared to cause fluorescence to certain elements. The fact that those particles got deflected by magnetic fields made Goldstein realize that they were negative-charged. They also resulted to form with every possible gas used., and independently by the material the cathode was made by.

In 1897 Thomson succeeded in calculating the charge/mass ratio. Later Millikan succeeded in calculating also the real value of its charge. Those discoveries led Thompson to hypothesize a model in which the atom was made by a positive charged nucleus, with electrons distributed on its surface, to justify the global neutral charge.

This atomic model resulted to be wrong in 1911, because of Geiger-Mardsen experiment. A source of alpha particles was disposed in the front of a thin sheet of gold, with a fluorescent screen, to analize their direction.  The result was that 99% of particles passed through the sheet without any deviation, a little amount were deflected, and only few were reflected.

Rutherford hypothesized that atoms were mainly empty, while most of the mass was concentrated in the nucleus, which is positively charged. Electrons had to orbit around the nucleus, in a way similar to planets one.They were on stationary state, in equilibrium between coulombian and gravitational force.  Rutherford calculated also that  the protons that made the nucleus were only half of the mass of the atom, and that electrons contributed in a very limited way. Another neutral massive particle was required, the neutron. It was discovered only in 1932 by Chadwick, because of neutral high energy radiation emitted by nucleus.

Rutherford's atomic model was however in contradiction with classical laws of electromagnetism. A charged particle moving will indeed slowly loose its energy, emitting electromagnetic waves. This is why an electron orbiting around a nucleus would loose its energy in a split second, not allowing the existence of any stable atom.