What is Corona: Definition and 46 Discussions

Corona (Spanish for 'crown') is a city in Riverside County, California, United States. As of the 2010 census, the city had a population of 152,374, up from 124,966 at the 2000 census. The cities of Norco and Riverside lie to the north and northeast, Chino Hills and Yorba Linda to the northwest, and the Cleveland National Forest and the Santa Ana Mountains to the southwest, and unincorporated Riverside County along the rest of the border, respectively. Corona is approximately 48 miles (77 kilometers) southeast of Los Angeles and 95 miles (153 km) north-northwest of San Diego.
Corona, located along the western edge of Southern California's Inland Empire region, is known as the "Circle City" due to Grand Boulevard's 3 mi (4.8 km) circular layout. It is one of the most residential cities in the Inland Empire, but also has a large industrial portion on the northern half, being the headquarters of companies such as Fender Musical Instruments Corporation, Monster Beverage Corporation, and supercar manufacturer Saleen.

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  1. J

    I Preventing Corona Discharge from Wimshurst Machine

    Hey all, new here. Just finished my first wimshurst machine and I’d consider it to be fairly AWESOME! Having a blast so far. The thing is, I believe that given the parameters of my build (# of sectors 24, diameter 11”, etc) I’m not quite getting max voltage possible and I’ve confirmed this at...
  2. nomadreid

    COVID Need to refine an argument against an (almost) anti-vaxxer

    I am trying to build an argument against a friend (F) who is presently not an anti-vaxxer, but is heading in that direction when he told me that a friend (FF) of his told him (F) that his (FF’s) doctor told him that his Covid mRNA vaccine caused his lymphoma. Of course, FF either misinterpreted...
  3. N

    How does corona discharge create leakage current?

    In a normal circuit it's easy enough to visualize the path electrons take through a wire. Even considering leakage current in a capacitor, it's easy enough to visualize a large parallel resistance that current "leaks" through. Is there such a way to visualize corona discharge? I get that it...
  4. KyleGranger

    Current Path for Corona Discharge

    I am trying to understand the current path for corona. Assuming the corona appears on the high voltage electrode, how are the electrons actually flowing? I understand that with flashover a low resistance current path is created as the air is ionized but what is happening with corona?
  5. S

    I (See image) At what distance does the temperature of the Corona decline?

    My astronomy textbook includes this graph of the temperature of the Sun's Corona versus the distance above the photosphere. It appears to go up from 4,500 K to over 1 million K at 20,000 km above the photosphere. But at what point does it come back down? Or does it not? Does that mean the...
  6. B

    COVID China should give reparations to the world for spreading Corona virus

    I firmly believe China should give financial reparations to the world for creating and spreading Corona virus.
  7. C

    A K corona, F corona and E corona

    Particularly I could read this sentence "In the infrared, however, the small dust grains did not act like perfect mirrors and this is what made it easy to distinguish the F-corona from the K-corona". I do not understand it. I could understand a problem in separate E corona from F corona, but K...
  8. Delta2

    Medical What makes it so hard to find a cure for the Corona virus?

    Corona has come and it doesn't seem to go away that easily. Why can't modern science find some cure that will prevent so many deaths? Why for example we can't find an antibiotic for this specific virus? What about other approaches(vaccine)? I just wish a cure could be found so we may continue...
  9. BillTre

    How Do Cryo-EM Images Enhance Our Understanding of the Coronavirus?

    Here is a Carl Zimmer article in the NY Times showing some fantastic images of the corona virus. These are mostly computer generated images (pretty common these days) based on cryo-EM (Electron Microscopy) and biochemical/molecular biology type data. They are very well rendered, down to the...
  10. Stephen Bulking

    Lightning rods and Corona Discharge

    1) Q: Why does lightning strike high and sharp targets like a lightning rod? A: Assuming that there is a massive collection of charge, possibly in clouds of a thunderstorm, trying to get to the ground where there is a pool of the opposite charge through an insulator that is air. I believe this...
  11. Evo

    Corona virus, no longer considered just a respiratory disease

    This has come up in the press the last few days that they now believe Covid-19 is not just a respiratory disease. This is a very interesting article on it. It explains the virus and how it works. https://www.ucsf.edu/magazine/covid-body
  12. M

    Is Isopropyl Alcohol Safe for Ingestion and Use on Surfaces?

    I bought a can of soft drink and was wondering whether I should spray 100% isopropyl on it before putting my mouth on it to drink. I did spray and it smelt bad but I wiped it off and drank the can. Is that unsafe or is it the opposite, safer than drinking without spraying? Would it kill corona...
  13. S

    Other Remote research positions after the Corona crisis?

    Do research institutes provide remote internships/ research positions which requires programming ? If yes where is the right forum to find them? I am skilled in data science, machine learning, deep learning and computer vision. I googled but unable to find any right resource.
  14. mktsgm

    Is Sars-Cov2 cytolytic or cytopathic?

    We know viral infections result in cellular damage while they're replicating in the host cells.. Damage can be cytolytic or cytopathic. I want to know how Sars-cov2 causes such damage? Is it cytopathic or cytolytic? Do they (viruses) kill the host cells or just damage them?
  15. pinball1970

    Positive effects from Corona (yes positive)

    Not another Corona thread surely?...yes but this time it's something positive we can take forward, when it's over. Several posters @Tom O [USER=283516]@davenn and others have made reference to reduced seismic activity due to lock down. That's great for Earth sciences and reduction in RTAs but...
  16. afcsimoes

    Questions about the Corona virus

    1. are there H2O molecules inside a Corona vírus? If yes, drying the virus kills it? 2. the lipid external layer of the Corona virus acts as a glue that attach the virus to any surface? 3. how much time a Corona vírus survives in the dry air? and in a dry surface?
  17. B

    Is hydrogen peroxide effective against the corona virus?

    If oxygen is effective against bacteria virus and cancer why isn't it used against coved-19? DMSO is known to bond with certain substances and could carry HP into the blood stream and kill off COVID-19.
  18. N

    Could you focus light from Sol's corona?

    For instance, if you put a big "magnifying glass" above the atmosphere in the shadow of a total solar eclipse thus blocking out light from the "surface of the sun", could you heat an object to a temperature hotter than the surface of the sun? Applying the Second Law, one can't raise the...
  19. W

    I The light from Mercury, the Sun's corona and gravity

    The question is: The General Relativity Ideas were confirmed by the position of Mercury by Eddington. How could they be certain that the light deviation was due to gravity rather than the lens effect the Sun's corona may have had? What process was used,if any,to remove the effect of the...
  20. C

    Electrical How to maximize the efficiency of the corona discharge generator

    Hi, I have a wirmhurst electrostatic generator and I want to use it to create a corona discharge. My common sense tells me that the metal "shaft", which connects to the metal spheres should lead to significant (electron) leak, since it has a much smaller radius of curvature than said spheres. If...
  21. S

    I Exploring the Hot Corona Phenomenon in Stars Beyond G2 on the Main Sequence

    We know that solar corona is heated up although we don't know yet the mechanism. I was wondering which other type of stars, else than G2, in the main sequence suffer of the same effect? Thank you!
  22. P

    Why Does High Frequency Corona Tend to Orient Vertically?

    I noticed high frequency (greater than 800khz) corona tends to orientate vertically as if it were a flame with a strong air blower beneath it regardless of electrode positioning. This is not the case for DC and low frequency AC corona. Is there a reason why high frequency corona orientates...
  23. C

    A Is there a model for ionization of N2 in air under an electric field?

    Although I have seen values such as 3 kV/mm for the dielectric breakdown of air, I was curious if there was an analytical or semi-analytical model of the ionization of say N2 under a uniform electric field. I am aware of Peek's law. Am I correct in assuming it is empirical? How might one connect...
  24. mfb

    I Observation of Alfvén waves heating the Sun's corona

    The corona is much hotter than the surface of the Sun, contrary what you would naively expect from the heat flow. While plasma waves were long suspected as cause, the mechanism was not well understood. How are these waves produced, and how is their energy converted to heat? Scientists now...
  25. G Cooke

    Corona discharge current formula

    I'm trying to find a formula for the current flowing through a wire that is only undergoing corona discharge into air. The wire is connected to a charged sphere, which provides the voltage. So far, I've just found formulas for certain ionization coefficients and electric fields, but no current...
  26. M

    Principle of a positive corona discharge?

    Homework Statement So as I understand, a negative Corona discharge happens between an electrode/pin/rod and a plane electrode. When the sharper electrode is connected to the negative (DC) plug, electrons concentrate on the tip, when sufficient breakthrough voltage is achieved a discharge...
  27. E

    Something escapes the corona of a black hole

    http://www.blastr.com/2015-11-4/nasa-just-saw-something-come-out-black-hole-first-time-ever Saw this article and thought I'd share :) This is going to be a silly question, I'm sure, but what is the corona of a black hole? I tried to google it, but the first few pages were nothing but articles...
  28. ltl94

    Larmor Radius for an electron in the K Corona of the Sun

    1. Compute the Larmor radius for a typical electron in the K corona.2. , , m=9.11×10-31 kg, q=1.602×10-19 CThe Attempt at a Solution My problem is I don't know where to find the other two values that correspond specifically to the the K corona. Then it becomes a simple plug-and-chug problem...
  29. T

    Scientific importance of total Solar eclipses?

    I was wondering whether there is an actual scientific point of taking ground-based photographs of the Solar corona during total eclipses on Earth. It seems to attract a lot of attention from well equipped amateurs around the world and the pictures of the fine plasma structure surely look great...
  30. O

    Understanding Corona, Arc, and Spark in Fluids: Explained

    There are tons of different explanation for each of them in internet. Could someone please confrim the explanation below which I gathered from different places; If the electrical field in a fluid reaches the fluids dielectrical strenght, dielectric collapses and corona happens, but since the...
  31. z.js

    What is the sun's corona and how can it be captured in a photograph?

    I took a picture of the sun on a cloudy day with 2 layers of red cellophane on a normal camera, and edited it on the computer. There is some bright stuff around the sun in the middle. Can this possibly be the corona? :eek:
  32. jaumzaum

    Difference between Corona Discharge and Dielectric Breakdown?

    What's the difference between Corona Discharge and Dielectric Breakdown? For me both stand for the same process, but wikipedia (as many other sites) says they are different. Actually they say corona discharge occurs when the electric gradient is high but not enough to create an electrical...
  33. C

    Thermal velocity of particles in the solar corona

    Hello i have a problem with this question if anyone could help me ,that would be great. Estimate the thermal velocity of particles in the solar corona (take a distance two times the radius of the sun and assume that the particules have only two degrees of freedom), thus the thermal energy is...
  34. P

    Can Corona Discharge Occur Around Charged Glass/Dielectric?

    ...Considering there is NO dielectric breakdown or breaking of glass/dielectric..... Can there be a corona discharge ever around a charged glass/dielectric without a conductor in the vicinity? For instance; take a single-electrode glass high-vacuum tube, charge it to high voltage...
  35. P

    Why Can We See the Corona Sphere During a Solar Eclipse?

    In basic, why can we only see the corona sphere during a solar eclipse? Is there a property to the eclipse or sun that causes this?
  36. F

    How does temperature change as you move away from the sun into space?

    How does temperature fluctuate from the outer layer of the sun outwards to space? Is there any data or equations modeling this?(I'm not an astronomy or physics student, just interested)
  37. T

    Understanding corona discharge

    I understand corona discharge in electrostatic situations, but in circuits without capacitors/gaps, I don't understand why it can ever happen (since as far as I know, the electric field is virtually 0 in the air around such a circuit). So why is there corona discharge around high-voltage power...
  38. Dotini

    Icy(?) Comet Survives Pasage thru Solar Corona

    http://science.nasa.gov/media/medialibrary/2011/12/16/lovejoy_c3_anim2.gif http://spaceweather.com/ <--- archive December 17, 2011 In a rare curiosity of nature, Comet Lovejoy appears to transit the elevated temperatures of the solar corona, laughing off the sizzling encounter, seemingly even...
  39. J

    Creating an Electrical Wire Corona: Voltage, Amps & Cameras

    Does anyone know what current voltage, amps would be required to produce a corona around an electrical wire? I gather that this would also be dependent upon the wire material and size. I have seen photos of this and would like to do reproduce the process. What type of camera may these...
  40. J

    Sun's Corona Paradox: Temperature Defying Laws of Thermodynamics

    Why is the sun's corona temperature around millions of degrees celsius while the sun's surface is about 6000 degrees celsius? Doesn't that defies the laws of thermodynamics?
  41. E

    What type of camera is needed for solar corona photography?

    I want to photograph the solar corona and I don't know what type of ccd camera I need to purchase. Can anyone please help me?
  42. E

    From The Suns Core to The Corona?

    Last night I watch a show about the birth of our sun on the Science channel. At one point they talked about how it takes thousands of years for the light in the suns core to travel from the center to the Corona "outer shell", and then only 11 minutes for the light to travel from the Corona to...
  43. E

    Discovering the Solar Corona Luminosity Curve: Explained and Explored

    I've been trying to find out what's the curve for the solar corona luminosity vs distance like. I know that the corona can be practically observed up to 4 solar radii. I also found out that the curve is more or less exponential but I need the actuall equation of the curve. Can anyone help me?
  44. A

    Corona loss in bundled conductors

    can anyone tell me that how to calculate corona power loss for bundled conductor? I need formulae of it.
  45. Labguy

    Stargazing Want to see an incredible solar corona photo?

    It isn't posted here, but my solar corona photo is posted on Space.com today. Format there allows larger size. http://www.space.com/amazingimages/cte.php?guid=42d0a2dc400360.56363193&cat=s
  46. N

    Temp increase of sun from photosphere to corona

    The photosphere is 4500 K The chromosphere is 10000 K The corona is 1,000,000 K The temperature increases as the distance from the core increases. This makes no sense to me. Any ideas? Thanks Nautica