Those of you who work in analytical laboratories and work extracting analytes from soil samples:
Many procedures involve spiking a soil sample first with various standards, shaking the soil sample, THEN adding a solvent like methanol or acetone to break up the sample matrix and remove moisture. My question is, does it make any difference whether or not you spike first or add the acetone/methanol first? Does either one result in better recoveries? Why? I know one other procedure for PCB/PAH compounds has the soil samples sitting in methanol already, after which it is simply spiked and then shaken to break up the soil. The procedure I'm particularly curious about is used to extract BNA from soil, but these samples are not kept in methanol unlike the PAH/PCB extraction. Why is this?
Really curious about this because everyone in the lab was arguing over whether or not it matters with all kinds of ideas being thrown around.
sup /sci/fags, Las Vegas anon here. i just saw something pretty strange and was wondering if one of you could answer what it was for me.
i was standing outside with my doggo looking at stars in the sky, along with planes and helicopters, close by planets etc. i looked down at my dog for a second and then i looked back up and i suddenly saw this huge, single bright white point in the sky get brighter for half a second, and then the spot was completely dark a second later.
i am certain that this was not a plane or helicopter. you know in Pokemon when Jesse and James get thrown into the sky and a star twinkles and then fades afterwards? it was just like that. https://www.youtube.com/watch?v=ib084tzN8H0
>humans will never go to Mars >humans will never leave earth >humans will never make contact with extraterrestrial life >humans will go extinct on this planet
So I live in Boulder, Colorado. Its a city of 100k so I don't think I'm doxing myself. This probably sounds kind of faggy or schizo but I workout late and one of my favorite things in the world is after my workouts on the walk home to look up at the moon, feel its silver light shine down on me, and say a quiet prayer to her. Anyway Boulder is a temperate but very dry area. Most nights there's barely a cloud in the sky. Despite this I very rarely see the moon despite the fact my phone says the moon phase should have it be out very bright and prominent. I sometimes see her peak out very late at night though a bit above the horizon line.
Why don't I see the moon when she should be out? The best I can figure is it has something to do with the elevation. Will this change later on in the year as the earth or will I need to move somewhere else to see the moon more?
So you have a neutron star, let’s say it’s spinning at 10,000 rotations per second.
It consumes enough mass to collapse into a black hole, which is said to be a singularity.
As the neutron star shrinks, it begins to spin faster and faster. At a certain point in the collapse, the outside of the star would need to be spinning faster than the speed of light to continue collapsing into a singularity.
Some of you may be familiar with the Wallis sieve, the geometric realization of the Wallis product to get pi/4
But did you know that that's not just a random multiple of pi, but actually meaningfully the area of the fractal's bounding box's inscribed circle?
And did your know that the same holds for a generalized sieve in N dimensions, giving the volume of the N-ball?
I've never seen a general proof, does /sci/ know something about this?
