Assuming A is a 2x2 matrix how many different matricies exist such that A^2=I ?
I am 99% sure the answer is 4 but after putting that down as an answer with supporting evidence I was marked wrong (or atleast not fully correct) so I am stumped as to where to jump and whether or not the grader may...
Top of the day to ya,
I monitor the development of the International Space Station and I have some idea of what the daily routine of the crew looks like but I am missing a cruical piece of information which seems to be never mentioned. What exactly are the astronauts doing up there? What do...
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So I am autodidacting myself through the world of (quantum) physics, just the concepts of course, no math and I finally got to a stage where I can use my present knowledge to (partially) deduce...
There is supposed to be a switch of magnetic poles in several thousand years which already started 150/200 years ago. This gave me an idea. Can the changing magnetic orientation cause the whales (and other large mammals living in the sea who use the Earth's magnetic field) to "crash" on shores...
Ok here is a thing I don't understand: How can a black hole exist? There are several things bugging me about black holes:
1) The more concentrated the matter is, the more deformed spacetime is and the slower the time is (from our point of reference). How can Black Hole be created in finite...
what youre saying is that it pops in and out of existence so fast that it causes no hassle? That it basically borrows energy from the future and repays it later when it disappears again?
But then what about Hawking radiation? And Casimirs effect, the plates move. That means the particle...
Can someone enlight me? I heard something about the "vacuum energy" causing the Casimirs effect or Hawking Radiation. New particles are popping out into existence, but doesn't that contradict the conservation of energy?
Google please save us!
http://www.google.cz/search?client=firefox-a&rls=org.mozilla%3Acs%3Aofficial&channel=s&hl=cs&q=astronomy+exercises&lr=&btnG=Vyhledat+Googlem
Recently I heard someone mentioning a new invention, a kind of resistor with memory which was the missing link in artificial intelligence. A kind of analog computer if you will. The resistor somehow remembers in what state it has been in.
I was very interested in what he said but I didn't...
Thats the point I wanted to make. Hawking radiation is the black hole killer. However I don't fully understand the ending point of evaporation. Hawking radiation happens only to very massive objects like black holes, but if they evaporate enough they stop being black holes no? And therefore...
Every spaceship in sci-fiction movie I watch has some kind of artifical gravity. But is that possible? Are there any theories on how can be some kind of artificial gravity created without having a planet/black hole stucked at the bottom of your spaceship or everything magnetised?
So far I only...