Solar Definition and 1000 Threads

What is the population density of ##H^-## hydrogen anions in the Sun's atmosphere, how stable are they, what limits their numbers, and since they are the dominant source of opacity in radiative transfer in stellar atmospheres, what do they effectively "hide"?

I cannot understand the solution at https://www.aapt.org/physicsteam/2015/upload/E3-2-5-solutions.pdf, because the solution is terse and skip steps (at least i think so). I figured out that the name of this transfer is "Hohmann-Transfer Orbit". A detailed walkthrough would be appreciated. If I...

Question 1; a) P=E/t E=5.796*10^7 J energy produced per day during the summer However, I am not certain how to calculate the time period, since although this concerns the energy produced per day, the sun does not shine for the entire duration of this 24 hour period. Also, I am unsure of the...

I learned that solar panels have their maximal power output at a particular voltage and current level. If we want to get the max power, we have to connect a load with a specific resistance. However, in reality, how does the solar plants solve this problem? I guess they won't allow the power...

I was thinking to myself, how come are particles coming from the sun gets deflected the way they do due to Earth's magnetic field? They are getting pulled toward the poles, but if we think in terms of classical Lorentz force, they should not just follow the magnetic field lines, but rather start...

If I take away the planets in the solar system and leave the sun alone, would the sun have less energy than before?

Stumbled across this and found it interesting. Solar System Dynamics pages at JPL (Jet Propulsion Lab)/NASA. Has Bodies, Orbits, Physical Data, Tools, etc. https://ssd.jpl.nasa.gov/?site_map Cheers, Tom

Hello, I am building a dual-axis solar tracker for educational purposes and I need to determine the required torque to move the solar panel in both the azimuth and elevation directions in order to determine what size motors to use. I have attached a simple sketch illustrating the mechanical...

Hey everyone, I just came across a competition that was run nearly 10 years ago and I was just wondering if anyone here has any interesting ideas on how it could be done. These were the criteria: Store 4kWhr for 18 hours. Temperature for cooking at least 200C. Powered by sunlight. Locally...

This article: Overbuilding solar at up to 4 times peak load yields a least cost all renewables grid. I'm normally among those who think that renewable advocates lack realism when they advocate 100% wind+solar grid. This article is the first I've seen that comes close to being plausible. I do...

Was there a published report of exactly which stars which were supposed to be at position A but were observed at position B, etc.?

I am writing a space opera, that is meant to be hard, except some alien magic. So far, i have the following points : asteroid belt is the most valuable for rare material mining, there they live in O Neil cylinders. Travel is done by fusion ships, that can maintain miliG-s of constant...

Can a single star with 6 to 8 solar masses end up as a supernova 1 (having a remnant mass slightly above the Chandrasekhar limit) and being completely disrupted? This idea is presented by John Gribbin in his books “Stardust” and “The Universe”, but I can’t find any other reference or source...

hi guys for a solar cell i know that the fill factor is given by the following relation : $$ FF = \frac{Vm*Im}{Voc*Isc}$$ but when solving the following example : the book used the following relation in the problem?! : where this Ln relation came from ?

Greetings, how do - the velocity distribution of the solar wind at 1 AU - the velocity distribution of the solar wind in our line of sight look like? I have found the 400 Km/sec but no further information. Is it an average values? Is this radially on the sun the same? Links with graphs are...

The objective: Determine the daily power draw of a Raspberry Pi (Watts per Day) and determine the average daily power generation of a solar panel. Will energy generated be greater than energy drawn? Lets begin, I have a 9 Watt, 18 Volt solar panel. This solar panel is charging a sealed lead...

I have one project in my mind bu tI have no eductaion in this topic. please help. question is: if there is container of water. and we have certain number of solar rays getting into this container how does process of water warm up look like comparing: 1. direct sun rays into water vs 2. on...

Hi everybody, I'm working on a Solar Energy project and I'm a newbie in this field. Could you suggest some good intro books/articles and PV system simulation books? (I'm using MATLAB) Note that my major in university are Solid State Physics and Computational Physics so I will not hesitate to...

OK, this is more on history of astronomy than anything else. I hope someone has an insight on how they were thinking of things back then. The Ptolemaic model of the Solar system, i.e. the Geocentric model, placed Venus inside the sun's orbit around the earth. And to account for the retrograde...

1. Photons having enough energy to transmit an electron from the conduction band to the valence band must fall on the solar cell. 2. The cell is composed of a flat PN diode with the n-type layer on top. 3. As photons hit the n-layer, electrons and holes get formed. 4. Due to the voltage barrier...

After concluding an investigation about the coriolis effect, I wondered how this phenomenon affected the solar system and in particular the moon. Since the moon is a body that moves within the rotating system formed by the sun and the earth, an apparent deviation in the moon's path would be...

Hi all. Recently I purchased two portable USB solar panels, which are rated at 5 watts each. They both came with a 'battery bank' consisting of a single battery all running on 5 volts. I also purchased a 5 volt USB computer fan. My question is; can plug all these things in together so that...

I just bought a Coronado and, typically, there are no sunspots to look at. If there were, then I could compare what I see in that dim dark red image with what my basic Baader shiny filter delivers. I understand that there's a learning process involved and I imagine all first-time users have had...

Since acceleration due to Newton's law decreases as the inverse of distance, it becomes very weak at large distances. Our Sun was unable to pull in matter in the Oort cloud in over 4 billion years. Above about 0.11 light years, using modified Newtonian dynamics equations, gravity decreases by...

I'm interested in doing more detailed photos of the Sun using my solar filter and a 1.25" Hydrogen Alpha (Ha) filter. Is this possible to do or is it best to purchase a Coronado telescope?

I know typically the hot cathode of an electron gun or vacuum tube is heated either directly or indirectly by electric resistance heating. What if the tungsten (cathode) were heated by another means, say focused sunlight? Electrons would still boil off through thermionic emission. If a small...

There will be a solar eclipse on 26th December that can be viewed from my city. In addition to buying safety glasses, I also want to prepare my camera, if possible. The camera is a Panasonic FZ-70. I have a UV protector and four ND filters - 2, 4, 8, 16. I am also buying a circular polarizer...

The publication will be released half an hour before. Press release, link to live stream and so on. The panel: It is now 8:00 UTC, so this is in 1 day 10.5 hours.

Hiya Hiya. I'm trying to build a solar system simulator for research purposes, and this does not seem to be all that easy. As in, my firsts tests have the moon shooting out of the solar system... I was wondering if you folks could offer some guidance. So, since it's for research, accuracy is...

Hello all! Hope everyone's been doing well! My question relates to the nebular theory of solar system formation. It is generally accepted that via the nebular hypothesis, matter in a nebula contracts on its own gravity and begins to spin, but I'm having trouble understanding why it must begin...

From what I've understood, we know sun's activity well enough that we can make some good predictions about it for a decade or so to the future. But is it theoretically possible that all the measurements that we have been able to make about the solar cycles and their effect on our climate, are in...

what will be the joules per meter using thermal gain and wattage gain from a solar cell if the cell is in an insulative vacuum not counting the thermal degredation of 25% for wattage loss due to heat gain

Hello, I am looking at using solar panels to accomplish two things: -I want to power a heating element submerged in a water tank to act as a thermal battery for heating a chicken coop -I want to also charge a relatively small 12V battery by connecting the panels to charge controller...

Total Solar Energy Rejected (TSER) = The percentage of total solar energy rejected by filmed glass. The higher this value, the less solar heat is transmitted. Here is something puzzling. I bought two tints to try on windows. The lower one on the left (NR Smoke 20) has Total Solar Energy...

I want to put solar panels on top of my RV, getting the panels to move in order to track the sun make them nearly 40% more efficient than being static. I have worked out the electronics to control the motors to move the panels by programming an arduino board with light sensors etc but I need...

From my understanding, for an observer to see a total solar eclipse, 1) the Moon's orbit has to be near aligned with the Earth's Orbit, 2)such that the New moon's Umbra falls on Earth, and 3) the observer must be within this cast umbra. But for a partial solar eclipse, since the Penumbra of the...

I am building a planet that will orbit a sun and I need help My world has 11 planes/asteroids. the planet Le Bear has multiple life forms on it. It takes 378 days to rotate around the sun. My planet has a circumference of 8199.49 miles. there are 12 months of 28 days and then 1 1/2 months of...

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I visited a friend who has a very nice solar installation. He also has the software to do data collection and presentation. I thought it would be nice to share some of his data here. Perhaps we can link to this post as a reference in future solar discussions. First, some background. The...

Hello All, This is my first post on this forum and I am here because I need help with an idea that I have. I am thinking of a pressurized vessel with two unidirectional valves. One for water intake, and another for steam release. The vessel will have a small sealed borosilicate glass “window”...

Hydroelectric power, effected usually by damming a river, is ordinary considered an example of energy produced by gravitational potential. However, from an ultimate perspective, hydro power is actually an example of solar power. Water must drop to a lower gravitational potential to extract...

Although I have over the years seen reports about simulations of the the Earth's moon's origin by a variety of possible mechanisms, none of these reports have ever reported the probability of such events. What is a reasonable estimate of the fraction of solar systems that have a planet of a size...

While The martian written by Andy Weir is a really hard stuff, but the effects of the storm at the beginning arent. But i wonder could a real solar/sandstorm actually help a prison break on Mars (from a remote penal colony)? Could it mask tracks in the dust? Could it create enough interference...

The solar constant is only on one side of the Earth, however it moves around and the Sun gives out it's energy/heat all over the Earth in 24 hours. And the seas and land have heated up over time. However I got told this, No its not. By definition the solar constant is referring to a 2...

Hi. I am studying the effect of plasmonic nanoparticles on solar cells. Is there a way to calculate absorption efficiency in different layers of tandem solar cells in COMSOL Multiphysics.

Hi all, I am working on perovskite solar cell related studies. J-V curve (current density-voltage curve) is one of the important measurements to determine the performance of the device. In practice, we perform the reverse scan first then then followed by the forward scan. There is usually a...

Does direct radiation increase as the zenith increases? I know the diffuse radiation increases as zenith does, but is it the same for direct Also is it right to say that when diffuse radiation increase, the direct should decrease and vice versa? edit: My book says diffuse increases as we...

Summary: Looking for input on either floating or sinking a large sheet of dark screen for solar absorption in a pool Looking for input on either floating or sinking a large sheet of dark screen for solar heat absorption in a pool. My though its that screen would be very user friendly to roll...

Suppose there is a 1 million solar mass black hole. A 1.022MeV photon near a nucleus produces an electron-positron pair a distance=A from the event horizon. The positron’s vector is directly “up” away from the singularity. It doesn’t have escape velocity. It reaches an apogee at distance=B from...

So Juno is on her downhill run towards Jupiter. Only doing about 8k right now, but by the time she rounds Jupiter she'll be doing 100k or more. We are going to get so much science from Juno. Personally I am eagerly awaiting the results of what Jupiter looks like under all those clouds.