@ The original post
We are all human, but not everyone is the same. I can say that a large part of our community is driven by the basics of life, just look at what most people worry about or strive to. (Reproducing themselves, having enough food on the table, and enjoy themselves whilst achieving this) When I see the statistics on obesity in the world, I pretty much lose all my faith in humanity. People are eating the amount for three persons instead of just one, they have no control over themselves, indicating that if a real problem suddenly pops up the world will sink into chaos. (they don't do stuff for the greater good, or think about mankind as a whole that needs to survive for a much longer than only this snapshot in time. People are just too selfish, and therefore do not see the need to solve problems with which they are not confronted). Most of my friends refuse to use their bike to go to work, or to go shopping even though I'm faster with my bike than they with their car on the same small stretch, again selfishness that kills the globe. And we all are (including me) too materialistic, which means we are using earth's recources for the wrong purposes. (Including labour, if we put the same effort in curing diseases, or solving the energy problem as we do in making cars we would chuckle at the simplicity of those problems, once we've solved them. But hey! You can make way more money with cars than doing something pro Bono, so those problems will lay on a shelf untill they get financial attractive to solve) And the last nail in the coffin of hope is when I see how much votes the populistic (racist) party gets in my country. I mean they find it more importand to get rid of all the foreigners, which we need anyway, than solving the current financial crises ... .
The reason why I still have hope is mainly psychological. I'm more of an realistic optimist, than a pessimist that mocks all day long. I think the way Italy is handeling their financial crises - by installing a technocratic government which focuses only on solving the financial crises, instead of getting their asses re-elected and remaining populair amongst the people, is a textbook example for all the other countries in the world. They have seen that they are in need of a government which is not influenced by any lobby, or by their own prestige, so that it makes decisions based on facts and statistics to choose the best available sollution. Another beacon of hope is the speed of the current technological development. I am convinced that we are capable of solving every major issue in a matter of decades, as long as we don't destroy ourselves fist. We have stopped the increase of the ozon gap by working together, we are able to do the same with the green house gasses once the situation gets urgent enough. And apart from that humans can change their habits, they only need a bit of steering in the right direction and that is what our governments should do. (Fast food taxes, stimulating people to use public transportation, or bikes instead of their cars etc. etc. etc.)
Hey, I am currently studying for my physics exam, but this has nothing to do with my homework. Whilst learning I was wondering why sound travels at different speeds through different gasses. At 273 K all the gasses have + - the same amount of molecules per m3. So in my 'logic' thinking the molecules would pass on the waves at the same speed, because of the same molecule density. But apparently this is not the case. T= 273K Speed of sound through: Helium: 0.965 * 103 m*s-1 CO2: 0.259 * 103 m*s-1 Air : 0.332 * 103 m*s-1 I could not get a nice answer with google, so could someone properly explain to me why sound does this? Thanks