Forest Definition and 25 Threads

Paper here. https://www.lyellcollection.org/doi/abs/10.1144/jgs2023-204 Article here https://phys.org/news/2024-03-earth-earliest-forest-revealed-somerset.html "The record of fossil forests, where tree bases are preserved where they were living, so far dates back to those discovered in New...

The Big Burn - In the summer of 1910, the largest fire in American history raged in the Northern Rockies. https://www.pbs.org/wgbh/americanexperience/films/burn/#part01 https://en.wikipedia.org/wiki/Great_Fire_of_1910 https://en.wikipedia.org/wiki/Ed_Pulaski Wallace, Idaho has an interesting...

I really don't want to get into politics, I am sick and tired of smelling and breathing the smoke from the forest fire in N Calif even I am living in the silicon valley. Trump said because Calif refuse to clear fire break lines, clear the debriefs, then once the fire started, there is no break...

Dark forest is the title of the second book of Three Body Problem, IMHO, a masterpiece of science fiction. Dark Forest theory is a really scary answer to the Fermi paradoxon. Cixin Liu's book has the following axioms: - life grows exponentially, but there is limited amount of matter in the...

Summary: If a forest is scorched, after a while it will regrow(wont it?); but if it is periodically burnt to ashes, could it eventually die? (as a ecosystem) What is the time-scales in order to recover a forest after a blaze? Hello, If a forest is scorched, after a while it will regrow (wont...

Into an extra-galactic physics course, I don't understand well the "Gunn - Peterson" effect on the spectrum of high redshift quasars (z greater than 3 or 4, up to the current limit of z = 6-7 I think) The observed fact is that there is an almost total absorption for the photons of the blue part...

Hi, I'm currently trying to wrap my head around how the Ly-α forest works. This is what I have so far; A distant quasar produces these Ly-α photons, which occur when a hydrogen's electron drops from n=2 to n=1, and has a wavelength of around 121nm (depending on the exact transition). This...

Hello everyone! We observe the so-called Lyman-alpha forest in the spectrum of distant quasars and it is said that these multiple absorption lines are due to the presence of intergalactic HI clouds that absorb light at the wavelenght of 1216 A , the Lyman-alpha transition. My question is the...

I am trying to figure out the difference between a carbon sink and a carbon reservoir. The definition for a carbon sink from wikipedia is that “carbon sinkis a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period. ” And the...

I am trying to figure out the difference between a carbon sink and a carbon reservoir. The definition for a carbon sink from wikipedia is that “carbon sink is a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period. ” And...

Hello My name is Nina and I dropped out of high school bc of disease. Last year I "re-entered the game" by beginning studies with an HF. Oh yeah, and I live in Denmark - born and raised. An HF is a sort-of high school degree. I live with my parents and my younger brother near a giant forrest...

I just spent 5 minutes getting a problem wrong, only to stop for a second and try again to realize the problems answer was completely obvious, and very, very simple and I wanted to know what I could do to help prevent spending time on things that are obviously not wrong and see right off that...

Homework Statement Suppose that there is a negligibly thin tree in the forest of infinite length that begun tipping over. Negating frictional effects from the pivoting, does the tree ever hit the ground? Homework Equations My approach was to solve the problem for a tree of length l and...

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Hello everyone. I am the author of "Wormwood Forest: A Natural History of Chernobyl" and stumbled upon your very interesting forum when googling Genn Saji, a Japanese nuclear scientist who has been sending out daily email updates about Fukushima. I am fortunate enough to be on his list and...

Hello ! I'm studying the forest fires, and I found an equation but there is something I don't understand. The equation is obtained thanks to energy conservation, and it is something like this : ρC dT/dt = h(T-T0) - Q Ys Aexp(-Ea/RTs) The first term is the volumic enthalpy, the second is due...

Homework Statement You are observing a high redshift (z ≥ 5) quasar. Suppose that there are n(z) = n_{0}(1+z)^3 damped Lyman-alpha (DLA) clouds per Mpc3 at redshift z, each with cross-sectional area a. Explain why we expect to see through n(z)al of them along a length l of the path towards...

High school stats: 1860 Sat 87-88 GPA Top 33% No extra currics. I got into a nice state school but couldn't afford it (I got 20K but still came short by 10-15K). Now I am at a Community College. I am taking Bio 102/Pre Calc/Engl 101/Speech 101. I want to finish my 2 year Associates in...

1. Homework Statement Suppose that in sherwood forest, the average radius of a tree is equal to R= 1m and the average number of trees per unit area sigma = 0.005 m^-2 . If Robin Hood shoots an arrow in a random direction , how far , on average, will it travel before it strikes a tree? 2...

I'm trying to put an end this age old question, but I want to translate it into form of an equation. SOME SAY: No, because "sound" is ears interpretation of those waves. I SAY: Yes, because it makes a "sound" (as defined by the vibrations). I'm going by textbook definition. It makes sound...

I was wondering how the distribution of Lyman alpha absorbers (as seen in the "forest" of absorption lines of a quasar spectrum) varies with red-shift (corresponding to evolution with the age of the universe). I've found various sources which mention in passing that the frequency of absorbers...

Homework Statement Suppose that in sherwood forest, the average radius of a tree is equal to R= 1m and the average number of trees per unit area sigma = 0.005 m^-2 . If Robin Hood shoots an arrow in a random direction , how far , on average, will it travel before it strikes a tree...

http://www.newscientist.com/article.ns?id=dn8419

I saw a show, UFO Invasion at Rendlesham at 9/8C on SciFi, and they came to these conclusions: -There were two landing sites. -the new one was out of the lighthouse's veiw, so the lighthouse theory is out. -The depressions on the ground were supposed to be exactly 12ft center to center...

After the recombination epoch neutral hydrogen was formed in the universe. Since neutral hydrogen absorbs radiation in the Lyman-alpha transition, a dark epoch begun, which was finished with the reionization of hydrogen due to radiation sources. The electromagnetic spectrum from quasars...