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rasp
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Why didn't the Earth get dark? Apparently, even in a total eclipse the moon doesn't block out the total circumference of the sun. Is it a matter of geometry?
rasp said:Why didn't the Earth get dark? Apparently, even in a total eclipse the moon doesn't block out the total circumference of the sun. Is it a matter of geometry?
A full moon + dusk, since the shadow(umbra) is only 70 miles in diameter, the rest of the Earth and atmosphere are illuminated, creating a dusk-like look all the way around.phyzguy said:Where were you? Were you in the path of totality? If you were in the path of totality, the moon covered the entire photosphere of the sun (the bright part) but it never covers the solar corona, which is much larger. The total light from the corona is (I think) about equivalent to the light from the full moon, so it doesn't get totally dark.
Yes, it is exactly a matter of geometry. As has already been explained, you clearly don't understand the geometry. The path is only across a tiny part of the Earth's surface.rasp said:Why didn't the Earth get dark? Apparently, even in a total eclipse the moon doesn't block out the total circumference of the sun. Is it a matter of geometry?
Why are you referencing this thread in this thread? Seems weird. If you just mean to reference my post, you can use the quote button.rasp said:
rasp said:Phinds reiterated what I had already conceded, "you clearly don't understand the geometry", without giving me an answer. It seems geometrically strange that I, being in a location with 82% totality saw the sun in the sky as brighter than a normal day. It was a cloudless day and the corona was intense! Only way anyone knew it was an eclipse was by looking through special glasses. It wasn't even close to dusk, but it did get a little cooler and the humidity dropped. I could only imagine that even if I was in 100% totality, the sun would not appear dark because the corona is not blocked.
Reference https://www.physicsforums.com/threads/todays-solar-eclipse-a-dud.923386/
Thanks for that clarification. My common perception going in (like teethwhitener shared) was to think that 82% of the sun being blocked would result in a noticeable darkening. In this week's eclipse with the glasses on, we could see the traditional bright crescent and the majority of the sun dark, but without the glasses the sun's corona was blindingly bright and perfectly spherical.phyzguy said:You misunderstand how much brighter the main part of the sun is than the corona. The corona is about 1 million times fainter than the main body of the sun. So if you were in a region where 82% of the sun was blocked, the sun's brightness was reduced to 0.18 times normal. This is not much different than a cloud passing in front of the sun, so you don't notice much. If you had been in the region of totality, the sun's brightness would have been reduced to 0.000001 times normal, more like nighttime with a full moon. Being in the path of totality is waaaaay different than being in the partial eclipse region.
rasp said:My common perception going in (like teethwhitener shared) was to think that 82% of the sun being blocked would result in a noticeable darkening.
Our eyes see and compress a wide dynamic range; better than a camera. So things have to change a looot in brightness to notice.rasp said:Thanks for that clarification. My common perception going in (like teethwhitener shared) was to think that 82% of the sun being blocked would result in a noticeable darkening. In this week's eclipse with the glasses on, we could see the traditional bright crescent and the majority of the sun dark...
You can't see the Sun's corona except during totality. That was just you being temporarily blinded. Like looking into a car's headlights.but without the glasses the sun's corona was blindingly bright and perfectly spherical.
I can't argue against that, although I don't believe it! My eyes told me the sun was super bright! If my eyes lied to me, well what the heck, I had no other means to argue. Although I don't believe your hypothesis, I am troubled by my own perception. Because from my perspective, the vast majority of solar eclipses over history would have been a dud, a non- event and gone unnoticed. Yet, that is not the case. Solar eclipses are recorded through- out history as very dramatic events. I'm still puzzled.Drakkith said:Your eyes and brain adjust to the falling light and so you perceive it to be about the same level of brightness as normal, despite the fact that the brightness had dropped significantly. If you had been inside during the eclipse and then looked outside you most likely would have noticed the drop in brightness. I commented to someone that the partial eclipse was brighter than I thought it would be and they said that when they looked out their window it looked like clouds had covered the Sun.
Visual perception is a tricky business...
rasp said:we could see the traditional bright crescent and the majority of the sun dark, but without the glasses the sun's corona was blindingly bright and perfectly spherical.
Why ??rasp said:Solar eclipses are recorded through- out history as very dramatic events. I'm still puzzled.
rasp said:I can't argue against that, although I don't believe it! My eyes told me the sun was super bright! If my eyes lied to me, well what the heck, I had no other means to argue. Although I don't believe your hypothesis, I am troubled by my own perception. Because from my perspective, the vast majority of solar eclipses over history would have been a dud, a non- event and gone unnoticed. Yet, that is not the case. Solar eclipses are recorded through- out history as very dramatic events. I'm still puzzled.
Also keep in mind that, with the exception of yet-undeciphered Olmec (edit: forgot about the Mayans) and Rapa Nui writings, all of written history until ~500 years ago was confined to Eurasia and North Africa. So if last Tuesday's eclipse had happened in the year 1400, there would possibly be an oral tradition among Native Americans about it, but there would not have been any written documentation of the event, even though thousands of people would likely have seen it.Drakkith said:Still, with thousands of eclipses, plenty of total eclipses fell on inhabited areas, and those are the ones that were recorded.
That was also my experience:TeethWhitener said:I actually mentioned to my wife (after hearing a lot of chatter at, e.g., my kid's daycare, etc. about how the sky was going to go dark--we're in DC, so about 80% coverage here) that if this were a representative sample of the population at large, a whole lot of people outside the path of totality were going to be pretty disappointed at the eclipse.
Also, as @phyzguy mentioned, if you were outside the path of totality, you didn't see the corona.
OmCheeto said:...
So many of my friends seem to be fine with 99%, and no amount of picto-graphics that I generate, has changed anyones mind.
Oh well. Less traffic for me.
rasp said:I can't argue against that, although I don't believe it! My eyes told me the sun was super bright! If my eyes lied to me, well what the heck, I had no other means to argue. Although I don't believe your hypothesis, I am troubled by my own perception. Because from my perspective, the vast majority of solar eclipses over history would have been a dud, a non- event and gone unnoticed. Yet, that is not the case. Solar eclipses are recorded through- out history as very dramatic events. I'm still puzzled.
The term "dud" refers to something that did not live up to expectations or was a disappointment. In this case, the solar eclipse may be considered a dud because it did not meet certain criteria, such as being a total eclipse or being visible in certain areas.
There are several factors that can contribute to a solar eclipse being considered a dud. These include the eclipse not being a total eclipse, being visible in limited areas, or being obscured by clouds or other weather conditions. Additionally, people's expectations and the hype surrounding the event can also play a role in determining whether it is considered a "dud".
No, today's solar eclipse was not visible to everyone. Solar eclipses are only visible in certain areas of the world, and even then, the visibility may be limited to certain regions within those areas. The path of totality, where a total eclipse can be seen, is often quite narrow and can only be seen by those in specific locations.
It is important to properly prepare for a solar eclipse to ensure your safety and to fully experience the event. Looking directly at the sun during an eclipse can cause permanent eye damage, so proper eye protection should always be used. Additionally, knowing when and where the eclipse will occur and making travel plans if necessary can help you have the best view possible.
The next solar eclipse will occur on October 14, 2023. This will be a partial eclipse and will be visible in parts of North America, South America, and Antarctica. However, a total solar eclipse will not occur until April 8, 2024, and will be visible in parts of North America and Mexico. It is important to note that the exact dates and locations of future eclipses may vary slightly, so it is best to consult a reliable source for the most accurate information.