Sensei

Misleading Frame of Reference in Special Relativity. Suppose so we're on board of rocket R, traveling in cosmos from object B to object A. To simplify let's assume that A and B are stationary each other. Object A is sending red photons with wavelength 700 nm. Object B is sending violet photons with wavelength 400 nm. (you can choose any other pair) Rocket after acceleration can reach such velocity, that red photons from source A are blueshifted to the same energy as violet photons from source B are redshifted. Blue shift equation in Special Relativity: [math]f=f_0 \sqrt{\frac{1+v}{1-v}} = f_0 (1+v) \gamma[/math] Red shift equation in Special Relativity: [math]f'=f_0 \sqrt{\frac{1-v}{1+v}} = f_0 (1-v) \gamma[/math] We need situation when f=f' to solve for v. [math]f_R \sqrt{\frac{1+v}{1-v}} = f_V \sqrt{\frac{1-v}{1+v}}[/math] [math]f_R (1+v) \gamma = f_V (1-v) \gamma[/math] [math]f_R (1+v) = f_V (1-v)[/math] [math]f_R+f_R v = f_V - f_V v[/math] [math]f_R v + f_V v = f_V - f_R[/math] [math]v(f_R + f_V) = f_V-f_R[/math] [math]v=\frac{f_V-f_R}{f_R + f_V}[/math] Convert [math]\lambda_R \lambda_V[/math] to [math]f_R f_V[/math]. And solve equation. It'll give v=0.27272727c [math]f=f_0 \sqrt{\frac{1+0.27272727}{1-0.27272727}}= 529.15 nm[/math] If somebody would wake up, have amnesia, born etc. in the middle of travel, and would see green photon from A, and green photon from B, or even entire blackbody spectrum from A, and from B, but at completely different temperatures (thus different peak), he/she could get (misleading) conclusion that there is no relative motion, and either A, B and R are stationary each other.

I loaded photo "The Waving Flag" from your link, to Photoshop, and used magic wand tool, with 0 tolerance, to check what are colors in black cosmos space area. And this is what I got: On the right Info panel there is mentioned color f.e. 1,1,1 (RGB) or 1,3,2. JPG is introducing errors in image after compression/decompression, so single pixel difference will be blended to a few pixels around it. Does it look familiar to somebody, some star constellation, especially 4th screen-shot from the top.. ?

You're thinking about larger usage of oil for tractors, but farmers could make their own fuel from f.e. wastes from previous years, turn them to ethanol or other fuel, and burn it in modified engines of their devices.

Escape of the planet.. ? Global warming is result of burning coal, oil and gas, not exactly result of larger population of humans. Production of more food require more CO2 from the air. You're making equal sign between overpopulation and over-consumption (of things other than food). Nobody needs new smartphone every year. Except the large companies making them, advertising them, supporting them,etc, and their shareholders. It's burning fuel and making plastics (that's later throw away instead of turning back to usable hydrocarbons) what is the main problem now. Solutions for this are simple: 1) electric cars, trains, devices 2) electric from the Sun or other renewable source 3) solar panels at the roof of every house 4) returnable plastic bottles 5) gathering and turning plastics to usable hydrocarbons 6) free public transportation, at least in city, will reduce cars, traffic, optimize usage of buses,trains, if people won't have to look at pocket while entering them In China it didn't work as everybody wanted to have boy, and now have result of this, in absence of females for their males.. http://edition.cnn.com/2012/11/14/opinion/china-challenges-one-child-brooks/ "As a result, approximately 30 million more men than women will reach adulthood and enter China's mating market by 2020."

Reaction of Lithium with water: Lithium floats on the surface of water, so it has smaller area contact with water than if it would sink. Comparison of alkali metals video https://www.youtube.com/watch?v=HvVUtpdK7xw

But it's unstable isotope and will decay to Ar-38. Half-life 37.24 min. Chlorine-38 -> Argon-38 + e- + Ve + 4.91645 MeV

You made statement, so it's your job to support it by data. "Believe" is good in Religion section. We're not in this section. Have you been personally at Fukushima after accident happened and instructed rescue teams what they have to do.. ? Sea water has obviously NaCl, Cl has two stable isotopes Cl-35 (~75%) and Cl-37 (~25%). If you will bombard Cl-37 by free neutrons, there will be created Cl-38.

In the classic physics, two charges the same sign, repel with force that's inversely proportional to square distance between them. The shorter distance, the stronger repelling force. Force between two point charges: [math]F=k_e\frac{q_1 q_2}{r^2}[/math] (you can easily show it in scalar and vector form) Remove one q from equation to outside: [math]F=q_1 k_e\frac{q_2}{r^2}[/math] [math]F=q_1 E_2[/math] This gives electric field equation around 2nd point charge: [math]E_2=k_e\frac{q_2}{r^2}[/math] and second one around 1st point charge: [math]E_1=k_e\frac{q_1}{r^2}[/math] If you can program C/C++, make 3D OpenGL application which is visualizing them as vectors-arrows pointing in one or other direction, in 3D array, with editable point charges, and instant update of arrows representing forces at various distances around them.

Bad. See where are areas were is more sense building such installations: they have small population which could use energy produced this way. If NY area has 5 times smaller power per area unit, it means 5 times more installations will be needed to have the same result as in "hot areas". Map of population is nearly inverse of "hot-cold areas map" from 2nd post.

Have you seen map "geothermal power potential united states" with scale watts per m^2 NY area has 4-5 times smaller potential than the hottest area..

You would need induced radioactivity https://en.wikipedia.org/wiki/Induced_radioactivity f.e. Deuterium can be split on demand to free proton and free neutron, it requires 2.22 MeV energy at least, free neutron is absorbed by some other element around, but newly produced isotope can be unstable, and decay soon releasing even more energy than invested to split Deuterium in the first stage. Neutron activation https://en.wikipedia.org/wiki/Neutron_activation

It's great to see that Portuguese are so pro ecologic. It's exactly reverse direction to which we are heading, because of incompetence and stupidity of current government..

If you play a game, does game exist? (not talking about CD/DVD/disk memory used to store code&data) Code loads data from disk, or generate stuff on the fly, or both. Then game is run and everything is displayed. Does 'game' exist.. ?

Well, that's very easy to calculate. [math]P{( r )}=\frac{P_0}{4\pi r^2}[/math] [math]P=\frac{E}{t}[/math] [math]E=\frac{hc}{\lambda}[/math] Remember that P0 is initial quantity of photons multiplied by their average energy, divided by time 1s. After dividing by area, unit is W/m^2 Solve r for E=h*c/532nm=2.32 eV (average visible photon energy) [math]r=\sqrt{\frac{P_0 \lambda * 1s}{4\pi h*c}}[/math] [math]r=\sqrt{\frac{P_0 * 532*10^{-9}m * 1s}{4\pi 4.135667*10^{-15} J*s * 299792458 \frac{m}{s}}}[/math] Detector with area 1m^2 should detect 1 photon with average energy 532 nm every 1 second at this distance from ideal light point source.

People would have to know (and remember) how not simulated Universe is working to being able to compare to simulated version of it, to find differences.

Then you should have no problem providing links and examples here on forum so we will learn about these "nonsenses".. Waiting to see data you're talking about.

After adding death sentence to codex. It's just a matter of time when this punishment will be used to kill "traitors", anyone who is upset at the government, which means killing the all democratic/non-democratic opposition. In Turkey judges have been arrested or replaced, the rest terrorized, scared to obey orders or they will end up the same.. What meaning will have sentence given by such "judge" that remained in office.. ?

Radioactive materials are everywhere. Also in your body. The questions are 1) in what quantity 2) what is half-life 3) what is decay energy 4) whether products/byproducts are radioactive or not 5) do you have luck or do you not. Theoretically just one decaying particle is needed to destroy DNA in such way that it'll start mutating in unpredictable way. Couple common places were you can find radioactive materials f.e.: - Americium-241 smoke detector https://en.wikipedia.org/wiki/Americium-241 - Potassium/Carbon rich food https://en.wikipedia.org/wiki/Potassium-40 Banana https://en.wikipedia.org/wiki/Banana_equivalent_dose For an exercise one can calculate amount of Carbon-14 and Potassium-40 which will give 1 W.

Because of destruction of democratic institutions S&P downgraded ratings on the Republic of Turkey. http://www.marketwatch.com/story/sp-downgrades-turkey-sending-it-further-into-junk-status-2016-07-20

Polishing makes microscopic scale scratches. Which under microscope would looks like mountains and valleys. Photons are reflected and bounces from them in random directions. You might try heating carefully with blowtorch to melt the outermost layer instead.

Turkey (Ottoman Empire) used to be islamic, and war with everybody around was their the most liked joy.. https://en.wikipedia.org/wiki/List_of_wars_involving_the_Ottoman_Empire Have you heard about Battle of Vienna @ 1683 ? https://en.wikipedia.org/wiki/Battle_of_Vienna

"Earth-sized object" is term which you rather should not use, it's too vague and confusing, because "size" is related to radius and volume of object, but does not say anything about mass of object. Newtonians equation takes mass of object as input, not its volume (although you could rearrange formula m=V*p, when volume/radius of sphere is known and average density is known). Earth-sized object, made of water, will have the same radius, the same volume, as our Earth, but its mass will be 5.5 times smaller than our Earth. Earth-sized object, made of iron, will have mass 43% higher mass. So suppose so you by "Earth-sized object", you meant the same mass as Earth. [math]F=\frac{GMm}{r^2}[/math] where G=6.67*10^-11 N*m^2/kg^2 M = mass of Earth, m = mass of small object, significantly smaller than Earth's mass m<<M r = variable, at different distances from object will give different force/acceleration Center of mass in such system is located near center of massive body, in our case Earth. But if m=M=Earth mass, center of mass will be outside of each body, somewhere in the middle distance between them. And either "Earth" will be orbiting around this center of mass location. Acceleration toward one object, is cancelled by acceleration toward other object. You can also find location were both accelerations cancels nearly perfectly and average F is close to 0. Situation in which one-Earth-sized object is so close to other-Earth-sized object smaller distance ( r ) than 2*6371 km = ~ 12742 km is not possible (draw two circles with one common point, min distance between centers of circles will be 2r). Any closer distance would be collision.

Water (and carbon dioxide) are the most typical products of fire.. You make them while burning f.e. hydrocarbon compounds. f.e. CH4 + 2 O2 -> CO2 + 2 H2O That's true. But it's fuel for f.e. car engine. Electricity (or other process) splits water molecule to gaseous Hydrogen and Oxygen, then Hydrogen and Oxygen gases are exploding, and piston is moved, spinning axis.

AFAICS the subject was not show differences between them, but to show them at all.. I just gave example device for showing magnetic field lines. Which can be used to show magnetic field created by electromagnets or permanent magnets. Treat is as addition (rather than replacement) to what you said (what would be sense repeating the same anyway?). I have device showing diamagnetic levitation. Composed of couple permanent neodymium magnets, and very tiny Pyrolytic carbon, maybe 1-2 mm^2. https://en.wikipedia.org/wiki/Pyrolytic_carbon After placing carbon above magnets, it's levitating. Tried to make photo for forum members (for different thread) but distance it levitate above magnets is so small, it's barely/not visible on photo.. But getting it would be harder than compass array. And less useful. It's one time show. Your head has to be 10 cm from it to even see it.. It's levitating maybe 0.1mm at most above magnets.. I think so visualization of magnetic field lines, when we not dont pass current through electromagnet, pass current in one direction, and pass current in reverse direction, and observation how compass array arrows are spinning is quite interesting and entertaining experiment.. Well, you have to visualize magnetic field, in the first place.. And that's job of compass array..

IMHO you should start from making admin's panel, logging in and out, then to teacher's panel, adding/removing/editing teachers, then to student's panel, adding/removing/editing students. I don't recommend using teacher's/student's row index as id, because if you remove element in the middle of table, all ids below it will be no longer pointing to the right entries. Ids should be unique, auto-incremented without repetitions, or randomized value checked in db to find it's really unique. When you will have above, return back to us.