# Tag Info

7

For the first question, yes. Because the surface of the sun is close to a blackbody emitter, it radiates at all wavelengths below the peak. So radio waves are included. However, the longer the wavelength, the less the power that is put into that portion of the spectrum. Radio is so far from visible light on the EM spectrum that the solar radiation in ...

7

You don't even need highly specialised equipment to see the colour separation of the sun at low sun angles, a decent zoom lens on a camera will see it, and it's the origin of the "green flash" effect as the sun drops below the horizon. This site offers a good image: http://www.atoptics.co.uk/atoptics/gf15.htm

5

There are better answers than this, but I just want to contribute. As Joshua said, The quantification of how much light bends when transferring from one medium to another is called the "index of refraction," and air's index of refraction is very very close to that of a vacuum, so the bending of the light is very small, and the spreading apart of the ...

1

If we incident a monochromatic light (assume red light) on a glass layer starting from thinner to gradually thicker and thicker layers of glass, partial reflection increases to $16\%$ and returns to zero-a cycle that repeats itself again and again. If the the layer of glass is just the right thickness, there is no reflection at all! And it is to be noted ...

1

The fact that you see the sun as red means that the shorter wavelengths (green, blue, purple, etc.) were significantly attenuated as the sun rays traversed the atmosphere, due to having undergone scattering. It seems to me that while some rainbow effect indeed theoretically takes place, the extent to which it happens is relatively small. Adding this to the ...

15

First, it must be said that the picture you provided in your question is extreme. The concept of light bending is true, but the amount that the light bends is nowhere near as large as the picture shows it. The quantification of how much light bends when transferring from one medium to another is called the "index of refraction," and air's index of ...

0

Depends on the size of the sun. If it's capable of illuminating the entire surface of the earth at once, then the transition would be sudden. Take a torch, and a coin, and sit in a dark room. Shine the torch obliquely onto one face of the coin. You can then choose whether the coin spins so alternating faces are exposed to the torchlight, or the torch ...

1

Well, assuming a lot of things aren't true, then no. For example, if the Earth was shaped like a pizza, and the sun revolved around it, then it would have the same transition.

6

That's not quite correct. You may have noticed that during summer the days are longer (and the nights shorter) than during winter. That is because the earth's axis is tilted about $23^o$ from the plane of it's orbit around the sun. With this tilt, as the earth travels around the sun the northern hemisphere gets longer days is the north pole is tilted ...

2

The 6 months day/night cycle is exactly happening only at the poles (as pointed out in comments). Between the poles and the arctic circle you have a gradual change from 6 month cycle to the 24 hour cycle. Greenland is partially in this area (south Greenland is actually outside the arctic circle). It is happening because the Earth rotational exis is tilted, ...

0

You are mixing tow different things. First, it is true that, other things being equal (such as SUN surface temperature), more spots would mean less total brightness and more contrast between surface and spots. But the issue is that the solar conditions for a maximal number of spots happens when the Sun atmosphere is in a more exited state, an pretty bright ...

5

The obvious answer is hydrogen and helium plasma but the nuclear fusion can also create heavier elements. Are these heavier elements a significant portion of the core? As said in dmckee's answer, no, the core of the Sun is much too cool (about ~15 000 000 K) to burn any other than hydrogen into helium. The triple-alpha process, which converts helium ...

4

Herein a filler answer until one of our experts gets around to giving us a more detailed picture. The short answer remains "hydrogen and helium", plus what every metalicity the star started with. The reason is that at the temperatures of the sun's core production of the next stable step (carbon) is many orders of magnitude slower than helium production. ...

2

The gaps just need to be smaller than the wavelength of the UV radiation. Waves can only pass through gaps larger than their wavelength. In symbols $$L < \lambda$$ Where $L$ is your gap length, and $\lambda$ is the wavelegnth of the UV radiation. Typically this from is $400$ to $10$ nm, with UVA in the $400$ to $320$ nm range, UVB in the $320$ to ...

9

What is probably being referred to here indirectly is the fact that air with moisture in it is less dense that dry air. The question becomes, is the buoyancy force of an empty egg with the optimal moisture content of air sufficient to overcome it's weight? Searching around I see that water vapor has a density of 0.804g/Land dry air has a density of 1.27 ...

9

As you said, a star explodes as a supernova when it runs out of fuel for nuclear fusion. The Sun is unlikely to go supernova, instead it is most likely to end as a red giant, then shed its outer layers and result in a white dwarf. Leaving that aside, if you want to extend the lifetime of a star, the key thing to do is increase the amount of time before it ...

0

First off, our sun isn't massive enough to go supernova. It would take a star equivalent to five of our own to reach the mas necessary for supernova to occur. Secondly, no. Your idea would not work at all. Nuclear weapons are no where near the same level of energy as a start and could not extend its life. Third, the sun undergoes nuclear fusion while ...

1

The Sun is far too small to undergo such a supernova explosion. What it will do is swell up to a Red Giant, engulfing Mercury, Venus, and possibly the Earth (we'll be deep fried whether or not the Sun actually engulfs us). No amount of energy we could add to a star would have more than a tiny effect on what it's doing. It's just too big.

1

No. For the same reason that you can't pick yourself up by your shoelaces. However, if you were to fill a container with water and close off the escaping steam with the eggshell, it would be possible to "levitate" the eggshell with the rising steam.

1

Kp is not really supposed to be a real-time index. The definitive Kp is calculated by GFZ Potsdam, often several weeks after the fact, based on data from 13 fixed magnetic observatories. These do not all report their data in real time. I believe the wing_kp data you linked to is a model based on ACE solar wind data: not actual geomagnetic measurements. ...

0

There are broadly 2 types of solar wind: Fast bulk flow speed ~ 750 km/s temperature ~ 7.5e5 K density ~ 3 cm^-3 source regions: mostly from coronal holes where the solar magnetic field extends out a long way into the solar system Slow bulk flow speed ~ 450 km/s temperature ~ 1.5e5 K density ~ 5 cm^-3 source regions: near equatorial streamer belt ...

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