Mystery Definition and 897 Threads

First I thought of posting this on the random thoughts thread, but I need an answer to this bugging question. Why the hell a microwave (the cooking device) makes that fanlike noise? While an infrared device (electric heater), visible light device (a flashlight), x-ray machine do not make any...

Whence "Charm"? The quarks have very quirky names! All of them have an origin: * (up, down) refer to isospin states. * strange refers to "strange decays" that were, well, strange! * (bottom, top) are derived from "beauty" and "truth" ("Beauty" still is used synonymously with "bottom")...

Homework Statement My teacher used soda to power up a clock. He used a magnesium and copper wire, and soda (sierra mist) I have to explain why and how this happened. Homework Equations n/a The Attempt at a Solution My teacher said it had something to do with...

Kenetic energy! [PLAIN]http://img190.yfrog.com/img190/2899/42256198.jpg alright for the basketball question, I don't understand why the KE doesn't drop to 0.The correct answer is B..and I picked A! because when the PE is max KE is 0.

Hi, I am struggling with finding info on Electrical Phases. I understand that Single Phase is simply one ac signal, and I understand that 3 phase is 3 independent ac signals, all of which are exactly 120 degrees out of phase. My struggle comes in when I think about 220 volt dryer hookup in my...

what is Theta? Cot (2theta) = 2 I have no idea how to get the answer. algebraically or in my calculator

Any ideas with this one? It's a part of an optional assignment I have been working on for extra credit. Everything else is complete and I have been milling this one over for about a week without coming up with a solution that I am confident in. You are studying a heritable form of cancer that...

Hi People all know that a neutral atom has no net charge. Well, does that mean that it neither creates an electric field nor is affected by any electric field? I wonder whether it's correct or not, because the distance between a test charge outside this atom is closer to its electrons...

Trying to Understand Where this Constant Came From in the "X component of Momentum" After asking for help on this problem, my professor showed me how to derive the forumla needed to solve the following question. However, it sliped my mine to ask where the "-2" came from. Homework Statement...

[SIZE="2"]why is the light from the sun called white light?

Here is a name I found that was proposed but never used to name something. It is quite long, 83 characters I believe, and is eight words appended to one another. Your job is to tell me what it was proposed to name (Hint: associated with physics, a single word). However, there is a...

have been told there is a way to make this mystery below work and can't figure it out. I know it wouldn't be up to code and i would never do it but if someone could hook me up with a wire diagram of how its done i really appreciate it. I am pretty sure switching the neutral is involved...

Why do negative numbers which are squared by a even number always return as a negative while using a calculator? e.g. (-1)^2 = 1, except calculators say -1, even though -1*-1 = 1 :S:S

I don't know the answer to this because i can't find it on the net or textbook, i need to know a type of fluid that is one where density varies throughout the fluid system? (Eg, a fluid system of oil and water among others) Thank

Homework Statement Bill gets into an elevator on the 40th floor of a building and it begins moving at t = 0s. The figure shows his apparent weight over the next 12s. Is the Elevator moving up or down originally? What is his weight? How far does he travel over the first 12 seconds...

I am having trouble figuring out how an integration works. Consider the function, y = x2 . The antiderivative is x3 / 3 or in other words its x2 (x/3). How come multiplying the original function by (x / n) (where n represents the exponent + 1) will lead to the area under the curve. Put in...

Homework Statement A bird has gathered electrical charge of .0001C by rubbing against another bird(I have no idea why the bird is doing this but...) and it is flying to a certain point where there is a thunderstorm brewing and a vertical electrical field of 5000N/C. What is the electrical...

Can anyone explain to me what this "neural network" nonsense is all about? Everyone and their mother is doing research in this area, but nobody seems to know what "neural networks" are or why they would be useful. It sounds like pure hype to me.

Why do the stars blink, but the planets do not? I need good explanation, please!

Does light have a definite shape? (this may be stupid question but from many days this question is hanging in my brain Thanks

This delightful video shows an orangutan playing with a dog, not to mention an elephant. http://video.aol.com/video-detail/the-orangutan-and-the-hound/1234581161 I know very little about animal behavior, so maybe someone knows? As far as I’ve read, orangs are solitary animals. In the...

I've been confused on why mass is such an essential component to understanding the physical relationships that we experience. From my limited understanding I want to believe that I can recognize the significance of general relativity, special, the various quantum functions, among recent...

Why the 4[FONT="Garamond"][SIZE="4"]π in Coulomb's Law, SI version? The CGS version does well without it...:confused: \mbox{thanks in advance!}

You can call time an unfolding of events... but what if there were no events as in a pure emptyness without objects... or objects present yet never changing in any way? Then there could still be time because you might have a consciousness that was watching the nothingness. That mind might be...

My wife informs me that next weekend I want to see the new Sherlock Holmes movie with her. She likes murder mysteries in general and she especially likes the Sherlock Holmes series with Jeremy Brett. I don't mind seeing all those dead bodies on the TV, but I wish she wouldn't take notes while...

Homework Statement this time i have posted two questions on a post, instead of me creating posts all over the forum. a)cot^2x + cosec^2x = 7 b) (2 cosec^2)2x + cot2x =3 find out the solutions. Homework Equations cosec^2 = 1+ cot^2 The Attempt at a Solution a) cot^2x + cosec^2x =...

Ed Witten is the kind of genius other incredibly intelligent theorists and mathematicians will look up to in awe, that's how scarily smart the guy is. He clearly knows his stuff when it comes to QFT, string theory and any related mathematics. As someone taking graduate courses in QFT and...

"Egg Cleansing" A friend of mine, whose mother grew up in a small village in Mexico, related to me her mother's story of the local "Bruja". Among other things, this woman performed an "egg cleansing" on people to rid them of bad mojo they had collected. She would rub a common chicken egg over...

I saw this equation on one of the walls of my local physics library and I cannot make sense of it. L = \bar {q} (i \gamma ^{\mu} D_{\mu} - m_{q} ) q - \frac {1}{4} F^{a}_{\mu \nu} F^{\mu \nu} _{a} I tried assuming that L was the Lagrangian, m was mass, F was the Faraday tensor...

Is our moon slowly receding? is it getting further from us? if so why?

How is it that we can play back sounds in our heads? I'm a musician and I can compose works in my head. It's a mystery to me why I can hear sound, but bypass my ears. "If a tree falls in the woods..." Hell, I can hear them all.

I have been searching internet for a legitimate source for this graph (I made one like that myself orginally): But this one was found by Skyhunter, so there can be little doubt about it's legimaticy. It shows the comparison of the delta 18O records of the ice cores, which is supposed...

Homework Statement They're two boxes on a ramp. Box 1 (on the bottom) is 8.60kg and has a coefficient of kinetic friction of .35 with an incline plane. Box 2 (on top of Box 1) is 1.3kg and has a coefficient of kinetic friction of .45 between the boxes. The two boxes are connected through a...

If there is a "red" color ball people told me that if i shine white light on it the "red" color ball absorbs all the light and reflects "red" photons hence we perceive it as "red" colored Is this true? if this is right i want to know more details... what does reflect mean here? what does...

Hey, not really homework but I am just having a total mind blank and would be grateful if someone could help me. \int\left(\frac{dx}{dt}\right)^{2}dt=? I even have the answer my brain is just refusing to play along though and I just can't picture how to work it out properly at the moment...

Limit is 0/0 ?? Homework Statement limit as x approaches -2 of: (x+2)/(x3+8) The Attempt at a Solution I plugged -2 into the eq'n and I got 0 for both the numerator and denomenator, so I thought the answer would be 1. Apparently it's supposed to be 1/12 ... is the text wrong?

OK the game is like this. I will tell you a story. And you should figure out what happened by asking questions. I will give yes or no answer (maybe some others) to question. Should be fun. Story: One morning a man was watching TV. In the TV he saw something terrible. He was so shocked and...

Homework Statement A very silly person, intent on catching pigeons on the roof of an apartment building, trips and falls a distance of 44.6 m. She lands on a metal garbage can, crushing it to a depth of 0.422 m and walks away without having been seriously hurt. What acceleration did she...

Homework Statement A wheel of radius r is rolling along a muddy road with speed v, and particles of mud are being continuously thrown off from all points of the wheel. ignoring air resistance, what is the trajectory of a mud glob thrown off the wheel when it is at angle (theta) to the...

I took this photo in the Rijksmuseum Amsterdam. I hope it can be seen but the reflection of this silver thing is different colours in the different panes of glass. (Blue behind it, orange/red to the sides). What causes this effect? And why the particular colours...

I've always found entropy a hard concept to grasp. Some time I read something that seems to make it more clear, then another time I read something else which completely disturbs my understanding of the idea. My current problem with entropy is the violation of the the conservation laws. And...

I have a question, at this looks like the most likely place to get an answer. My son wrote an equation on his wall when he was 8 yrs old. He has a learning disability, and could not know this kind of math... Dr. Claude Swanson is working on it right now, but I was hoping someone else could help...

Does someone know the mass of the mother star WASP-18b is circling around as well as the rotation speed?

Does anyone know why you can see the smoke coming from dry ice? Is it actually CO2? It does not make sense to me, why could I see CO2 evaporating, but I cannot see it normally? Is it the moisture in the air that I can see reacting with the cold CO2?

Light OR Sound! When we clap, we hear a sound..The reason is that on clapping sound waves are produced... My question here is why? Why Does Clapping produce a sound wave and not a light wave...Or when we light a torch, why are sound waves not produced... Also, When a electron jumps from...

i found the average specific heat of a metal through an experiment it is 200. my only problem now is identifying it. i have tried many website but can't find anything useful please make some suggestions

One of my professors told me a story about a physicist and I can't remember who it was. It's driving me crazy. This is what I remember about the story. Apparently this physicist was a new faculty member and he had a seemingly brilliant plan for some experiment. All of the older faculty members...

Homework Statement Marks: 1 In a recent mystery, the hero saves himself by spreading out a windshield tarpaulin to reduce his terminal velocity. A skydiver of 75 kg mass has a terminal velocity of 60 m/s. If the hero has the same 75 kg mass, the same density as the sky diver, and a drag...

Could someone give me a quick explanation what Boltzmann brains are? Does it have something to do with the landscape?

ALl the books say that g is constant near the Earth's surface but how is this even possible if it is dependant on the distance from the centre of the earth? because it depends on where we are why does it stil remain constant?