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Misconceptions about Slovenia:Slovakia, yes?!Most of the time when I say that I am from Slovenia, people tell me with the spark in their eyes: ‘’Ahaa, former Czecho-Slovakia! Bratislava yes??’’ And I always have to disappoint their confidence with a boring historical explanation.There are as well times when people have no clue what is Slovenia and that it exists. It happened to me even in our dear neighbour Italy :). Or in India, but there I met some people who thought Europe is a country so they are forgiven ;).At some rare occasions it also happens that people do know Slovenia and possibly they have even been in my country before.You probably speak Russian?We do not speak Russian and we are not even close to Russia in any way - except being Slavic nation but this is really as close as it gets. Neither politically or culturally Slovenia is close to Russia. We speak Slovenian language, and most of the people speak at least one or more foreign languages. Almost everybody knows English, but Russian is probably as common as it is in US or any other country that was not under Soviet Union.Do you still have communism?Nope, since the independence from Yugoslavia in 1991 our political system is not communist. In the past however, Slovenia was part of Social-Communist Federal Republic of Yugoslavia which also had different, much more relaxed kind of communism than Soviet Union. We were not part of Soviet Union (which partly explains the previous question) and Tito (Yugoslavian leader) also rejected to be ally with Russia. Rather he was leading a Non-Aligned Movement.Cold weatherOften people assume Slovenia must be a cold country. However, we have 4 seasons among which winters are cold (between -15℃ and 5℃) and summers are as hot as 36℃. Autumn and Spring are of course something in the middle. Being located in the middle of the Europe (another surprise!) and having continental, Alpene and Mediterranean climate explains that. The following photos are all from Slovenia:These are some of the most common misconceptions about Slovenia. If you want to know more feel free to drop a comment or better, to visit and see all first hand ;)Cheers!

Temperature can be negative on the Kelvin scale, but, in order for that statement to mean something, we have to understand what temperature is in a more precise way than "do I need to put on a coat" or "the number on my thermometer."If I take two different systems and put them next to each other so that they can exchange energy, temperature is the thing that tells me which way the energy will go: It'll go from the hotter system to the colder one. But that's not a good enough definition. We want to have a quantitative idea of what temperature means. This idea of observing energy flow will tell us which system is hotter, but it won't tell us how much hotter. We want a number.In general, the more energy a system has, the more possible states it can be in at that energy. If I put two systems next to each other, they'll tend to exchange energy so that the number of possible configurations of the combined system is as big as possible. For example, let's say that system 1 starts off with M states, and that if I take away a small amount of energy, say 1meV, it'll have 0.99M states. Let's say that system 2 starts of with N states, and that if I add 1meV, it'll have 1.05N states.The original number of states of the combined system is MN. If I transfer 1meV from system 1 to system 2, then the number of states of the combined system will be (0.99M)(1.05N) ≈ 1.04MN. The number of states will increase, so we can expect that if we let the systems exchange energy by themselves, at least 1meV of energy will spontaneously flow from system 1 to system 2.We've found a quantity that tells us which way energy will flow between two systems! Add a small amount of energy ΔU to the system and observe the change ΔN in the number of states. Then compute [math]\frac{\Delta N/N}{\Delta U}[/math]. For system 1, since we subtracted energy, this computation yields 0.01/meV. For system 2, this computation yields 0.05/meV.This number is a measure of how much the number of states increases when we add energy, which, in turn, tells us which way the energy will flow. The bigger the number, the faster the number of states of a system grows with energy, and so the more energy will want to flow into that system.That's exactly the sort of quantity we were looking for! There's one small issue: Energy is flowing from system 1 to system 2, but the number we found for system 1 is smaller than the number for system 2. That's backwards from what we want from temperature, so we fix it by taking the reciprocal. Now, the number we write down for system 1 is meV/0.01=100meV, and the number we write down for system 2 is meV/0.05=20meV. Now, system 1 has a bigger number than system 2, and energy flows from system 1 to system 2, like we want.The last optional thing to do is to change units to Kelvin by dividing by Boltzmann's constant. System 1 is at about 1200K, the temperature of a campfire, and system 2 is at about 230K, the temperature of a cold winter day in Alaska. Energy will flow from the campfire into the cold air, as expected.So what's up with negative temperature? For some systems, there are situations in which, as we add energy to the system, the number of possible states of the system will actually decrease. In this case, the quantity we'll get with the above calculation will be negative.But what does that mean for the system? Systems tend to change in ways that increase the total number of possible states, so energy will want to leave this system, which would increase the number of possible states. If we let this system exchange energy with a "normal" system whose number of possible states increases as we add energy, then energy will always flow from the negative temperature system into the normal system.In this sense, negative temperature systems are hotter that normal systems, and the only reason this fact is counterintuitive is because we work with temperature instead of its reciprocal, which is the more fundamental quantity. As we saw, the bigger the reciprocal temperature, the more energy "wants" to be in that system, so if the reciprocal temperature is negative, then energy will want to run away from that system.See also Negative temperature.

If you have a system that is under going motion near the frequency of the light, you can cause significant resonance.Now the frequency of gamma rays are [math]\omega = \hbar/E[/math] with E > 1 MeV (gamma rays are usually defined to be photons above 1 MeV in energy. This gives [math]10^{-23}[/math] seconds. To give a sense of how fast this is, an electron circles its atom roughly every [math]10^{-18}[/math] seconds. So no system made out of atoms can resonate with gamma rays.In practice, moving mechanical systems aren’t very good resonators with electromagnetic radiation. Usually, you spatially resonate with the wavelength which are called resonant cavity — microwaves are good examples.Resonant cavities for gamma rays still aren’t possible because the distance scale is subatomic, nearly nuclear distance scales — so again you can’t construct a resonant cavity for gamma rays out of atoms.