Science questions not worth a thread I: I'm a moron!

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Wow ! Thanks for that . But did you just sit on the sidelines laughing while I did my inane experiments before chiming in with the answer ? Speaking of mixed nuts , I've often felt there was a market for premium mixed nuts (no peanuts) offered at a premium price .
 
Have you tried mixing the cheese before you open it (shaking the package)? Than let it sit and see if the water appears aswell.
 
rugbyLEAGUEfan said:
Wow ! Thanks for that . But did you just sit on the sidelines laughing while I did my inane experiments before chiming in with the answer ? Speaking of mixed nuts , I've often felt there was a market for premium mixed nuts (no peanuts) offered at a premium price .
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You can buy them like that in the USA. With or without peanuts.
 
Considering the size requirements of the moon relative to the sun during solar eclipses: are solar eclipses a distinct Earth event only? What are the odds that other planets experience solar eclipses with their satellites?
 
As you get further away from the star a moon would likely appear larger than the star so solar eclipses would be more common, surely.
 
Dreadnought said:
In my mind at least, wouldn't that moon just "block" the sun completely and not have much of an effect?
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Well that's the effect of an eclipse. Earth has a special point of view due whole sun-moon-earth distance. Which enables the moon to occult sun but leave it's outer atmosphere to be seen from earth
 
Dreadnought said:
Considering the size requirements of the moon relative to the sun during solar eclipses: are solar eclipses a distinct Earth event only? What are the odds that other planets experience solar eclipses with their satellites?
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Eclipses happen on the gas giants. For instance, a triple eclipse on Jupiter (where they're rather frequent as they orbit on the same plain as the sun):


Link to video.

Of course, the sun looks a lot smaller in the sky at those distances than it does in our sky, so an eclipse doesn't take a body as large as the moon. For comparison:

 
Speaking of the Sun, I faintly recall hearing that the sun expands and shrinks slightly every six minutes or so, like a beating heart. Why is that? What causes that?
 
Quackers said:
How the hell does a television picture work?
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It depends on the technology---cathode ray tube (CRT), LCD, LED, Plasma, etc.. And also there are "projection" technologies: "front projection" or a "rear projection" set-up.

It's probably more useful to go way back to the CRT, and read up on the history of television: http://en.wikipedia.org/wiki/History_of_display_technology http://en.citizendium.org/wiki/History_of_television_technology

The original television's were CRT's in which a cathode ray tube projects a stream of electrons at a chemical plate. The electrons hit the plate, exciting it, which then causes it to emit a photon of particular frequency (seen as color). The CRT is a "gun" that is programmed to project an array that encodes the message. Note this wasn't "projection" technology in itself, it was the original CRT tube television.
 
Going back further, the first televisions were mechanical. Those are really cool.
 
PlutonianEmpire said:
Speaking of the Sun, I faintly recall hearing that the sun expands and shrinks slightly every six minutes or so, like a beating heart. Why is that? What causes that?
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I would expect that the pulsations take a lot longer than six minutes... my own assumption would be that they cannot be faster than the speed of sound inside the Sun (which would be high, but not THAT high).

Typically, these sorts of pulsations are caused by uneven hydrogen 'burning'. The rate of fusion within the Sun is very sensitive to the temperature... much more sensitive than the temperature itself is to the rate of fusion. If the energy output in the core falls slightly, the temperature will drop slightly, and the pressure will fall. The Sun's central regions then contract slightly, boosting the pressure and temperature and 'turning up the thermostat'. The central regions then re-expand, causing them to cool again... and the cycle starts again.
 
Question!

So, I recently read a definition of the sun as the surface being the point where light is emitted without being reabsorbed and bounced around. Since there's no solid surface of a star (don't quote weird stuff like neutrino stars) what we would define as the surface is dependant on the wavelength at which we're viewing it, correct? If so, how much of a difference would it make? How much larger is the sun when "viewed" at long wavelengths like radio waves, compared to x-ray light? Or did I reverse that... I figured shorter wave lengths would escape the plasma earlier than long wave lengths, so that the sun would look smaller in those wavelengths.
 
I guess it's like asking how big a fart is: if your nose can't smell it then the blast radius won't seem as big to you. Or if a kid pees in the pool, but the urine is clear, how do you know how wide it's spread?

Sent from a phone, apols for any mistakes.
 
contre said:
Question!

So, I recently read a definition of the sun as the surface being the point where light is emitted without being reabsorbed and bounced around. Since there's no solid surface of a star (don't quote weird stuff like neutrino stars) what we would define as the surface is dependant on the wavelength at which we're viewing it, correct? If so, how much of a difference would it make? How much larger is the sun when "viewed" at long wavelengths like radio waves, compared to x-ray light? Or did I reverse that... I figured shorter wave lengths would escape the plasma earlier than long wave lengths, so that the sun would look smaller in those wavelengths.
Click to expand...

Not noticeably I think. Most of the high energy radiation gets absorbed and reemitted(loosing energy in the process) inside the sun for millennia before getting out of the sun as visible light.
 
Blue Emu said:
At 5.500 degrees C or so, only about 1/10th of 1% of the gas should be in the form of plasma... if it follows a typical distribution of energy levels.
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You cannot just use the temperature, you have to consider density as well. And the photosphere of the sun is not very dense, so you are well into the realm of plasma physics. Anyway, the neutral atoms are not relevant for the question as their energy levels are discrete and are just responsible for the Fraunhofer lines. The radius of the sun has to be determined by the continuous emission of the plasma, because otherwise the result would be extremely frequency dependent.

I expect the imaginary part of the refractive index for solar plasma to be determined by n/f^2, where n is the density of the plasma and f is the frequency of the light. So blue light would indeed escape the sun earlier than red. However the density of the sun should go exponentially with the radius, so the effect shouldn't be that big, as the density decreases too fast for a large effect.

My knowledge of astrophysics is rather limited, so without spending some time I am not able to give numbers but Wikipedia suggests that the difference is just dozens to hundreds of kilometers, which is usually neglected compared to to the sun's diameter of over a million kilometers.
 
I don't think it matters very much. In astrophysics it's often more important (and difficult enough) to determine the order of magnitude of these quantities than to determine their precise value.
 
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