inflector
  • Member for 11 years, 1 month
  • Last seen more than 5 years ago
Why is the bell, well, bell shaped?
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29 votes

The bell is typically bell-shaped for two reasons, first because the circle is structurally strong and this allows bells to be struck with greater force than if the shape was flat or had sharp edges ...

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How does load affect frequency on the power grid?
Accepted answer
27 votes

The physics is actually much easier than it seems at first glance. Power generators are engines just like the everyday ones we see all around in our cars, lawnmowers, snowblowers, etc. Except for ...

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Would you be weightless at the center of the Earth?
21 votes

The simplest way to think about it is that there is mass all around you in the center of the Earth so you get an equal gravitational "pull" from all directions. The pulls cancel out so you get no ...

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What is the most efficient way to destroy the universe?
21 votes

Kill all the turtles on which it rests.

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Best books for mathematical background?
10 votes

I found Mathematical Methods in the Physical Sciences by Mary Boas to be a very good broad book covering the basics. You'll need other books obviously but if you are looking for one book for a solid ...

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Is there a light source that emits all wavelengths of visible light at the same time?
10 votes

Blackbody radiation for a white hot object emits the spectrum from infrared to ultraviolet. See: http://en.wikipedia.org/wiki/Black_body Graphite is a decent approximation of a blackbody radiator. ...

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Why does an airplane have more lift near the ground?
5 votes

Ground effect is caused by the increased pressure under the wing because the vortex at the end of the wing which normally just twists behind the wingtips for long distances runs into the ground itself ...

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Why do rockets have multiple stages?
4 votes

The easiest way to think of it is this, imagine all the mass left over when a rocket has burned 85% of it's fuel. The mass of most of the tank and structure is now overkill and waste. It would be nice ...

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Why can you see a light in the location that the light source just left?
3 votes

The human retina and visual perception system of the brain display in combination what is known as "persistence of vision." The eye and brain retain a visual image for somewhere between 1/30th and 1/...

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Can we measure the "Tilt-A-Whirl" effect of the Earth+Sun orbiting the galactic hub?
Accepted answer
3 votes

The force that you feel in a Tilt-A-Whirl is not possible in a galaxy and does not correspond to anything in our solar system. In a Tilt-A-Whirl, you are subject to two additional constraints that ...

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Why does a car engine not do work if the wheels don't slip?
3 votes

Unless you are talking about in the very limited sense where at the molecular level some number of molecules of the tire must rub off in order to transfer a force to the car, the statement: "if the ...

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What are the arguments towards the Life-and-Entropy relation?
2 votes

Entropy and the Second Law of Thermodynamics relate to life because life is made possible by the flows of energy implicit in the second law and the selective storage and manipulation of the ...

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What is the role spin-networks play in Loop Quantum Gravity?
2 votes

I have found the LQG introduction references here: http://www.physicsforums.com/showpost.php?p=2868468&postcount=244 to be quite useful. Marcus is a very nice guy, knows most everything going on ...

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When water climbs up a piece of paper, where is the energy coming from?
2 votes

The previous answer tells you why the water moves up but doesn't explain where the energy comes from. In order for water to move up and thereby gain gravitational potential energy, you need to have ...

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What happens if a black hole sucks up a massive amount of oxygen and hydrogen?
1 votes

No, it would not. An explosion of any power involves matter which has mass and cannot even reach the speed of light. And even the speed of light is not fast enough to escape a black hole. So the ...

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