How big is Earth in the Lunar sky?
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- Опубліковано 8 лип 2021
- To err is human, but mathematics is the language of the Universe. I'm paraphrasing, but you get the idea.
This video is a small and unrequested annotation to "Star Talk: Albedo"
• Neil deGrasse Tyson Ex...
NASA Moon Fact Sheet
nssdc.gsfc.nasa.gov/planetary... - Наука та технологія
Well done, quick, clear and concise!
My immediate reaction to when he said 16x was "oh, he's talking about the surface area!", because the surface area of an object increases by the square of the increase in an objects dimensions. (I've also been messing around with some math involving areas recently, so it was on my mind). An increase in diameter by a factor of 4 results in an increase in surface area by a factor of 4^2, which is 16.
Now, it's not super clear to be why he chose surface area to reference, but I would guess it's because the surface area of an object is much more closely linked to it's luminosity, though it's probably not as intuitive to interpret. In his defense the term 'larger' is pretty loosely defined (it could have theoretically even been referring to volume!), it's just that diameter is the easiest thing to visualize.
Oh, and also there wasn't really any need for the angular diameter calculations because the distance is the same, so if you're just interested in the ratio between their apparent diameters in the sky then just literally taking the ratio between their physical diameters should suffice (this isn't strictly true, it breaks down a bit when you get to spheres with absurdly large diameters, but the equation breaks down at that point as well - for example try calculating what it would look like to stand on the surface of a planet by setting the diameter equal to twice the distance, it gives 114.6 when in actuality it's 180).
(this isn't meant to be a dig at you or anything btw, you're great! I'm just seeing if I can shed some insight into Dr. Tyson's thought process here)
Enjoyed immensely
Spot on! The size of the Earth as seen from the Moon is FOUR times larger than the size of the Moon as seen from the Earth. (Size = angular diameter.)
Thank you Alien Planetology.
You explained/ calculated it well by using a simpler formula and objective data.
Asante sana!!!
Moral of the story: use data, fact check stuff.
Hypothetically if the moon had oceans how much would earth's gravity affact them?
Someone should send this video to the great and mighty Dr. Tyson so we can see what he thinks of it. Mostly since it's not his field of expertise (but more mine), we should also have a similar deal calling out the blatant historical and factual errors regarding soft sciences in his remake of Cosmos and the follow-up series Possible Worlds.
For instance, Michael Farraday didn't get in trouble with his teachers for merely having rhotacism, but for seemingly putting on airs since such speech was intentionally put on by the aristocracy at the time. As for the flashback to what I think was Pavlov's childhood, Slavs don't whoop clothing. You always take the strap over bare skin over there. Also, Giardano Bruno was burned by the Inquisition not for believing in a heliocentric model or the plurality of worlds, but for denying the Trinity and reading Jewish literature. Those are just the ones I've noticed that all get brought up a lot in history buff forums.
hello, when would it be the turn of tatooine, or darwin 4, both desert planets with 2 suns, greetings.
@@AlienPlanetology Excellent, I have always had doubts about how a binary system would be maintained, and more like a desert planet, without seas or forests, it can maintain an atmosphere rich in oxygen, thank you very much I look forward to
Well done!