wallacepolsom

tannertan36
Lint Roller? I Barely Know Her
Three Goblin Art

PR's Tumblrdome
Keni
One Nice Bug Per Day
todays bird
Mike Driver

No title available
d e v o n
Monterey Bay Aquarium
almost home

Janaina Medeiros
Today's Document
Cosimo Galluzzi
Claire Keane

roma★

ellievsbear

if i look back, i am lost

seen from United States

seen from Australia

seen from Australia

seen from United States

seen from Australia
seen from United States

seen from United States
seen from United States

seen from Malaysia
seen from United States
seen from Malaysia
seen from Malaysia
seen from United States

seen from Australia

seen from Malaysia
seen from Canada

seen from Malaysia
seen from United States

seen from United States
seen from China
@punkrockpariah
these are getting weird
1. A dog is full of joy
The spell master: God damn it, where on earth is my magic crystal ball????
The suspiciously hungry and round bug:
What is this thing
shoutout to my fellow Ornate Amphipod enjoyers
some of you would be a lot happier if you didn't use 4chan words
people got more hyoped over this dodole than a 60+hr spread i posted right after LMAO
i got that dog in me but it's poorly socialized and i don't take it on as many walks as i should
A 50-kilogram anvil floats perfectly on the surface of mercury, because the density of the steel from which it is made is almost half the density of mercury.
damn that shit is light lmfao
Fun fact! Many lighthouses with especially large fresnel lenses would have huge fucking tubs of liquid mercury in the lantern room because it’s a super easy way to make these giant lenses rotate quickly!
Shockingly, however, spending most of your time in close proximity to 500 pounds of liquid mercury is Not Great For One’s Health and tons of lighthouse keepers started to go crazy from the whole. Mercury poisoning thing. Hence why there are a lot of “haunted” lighthouses or wickies that lose it and maybe do a bit of manslaughter.
Anyway, people saw a bunch of lighthouse keepers go crazy and get sick and got empirical evidence that it was in fact related to the 500 pound mercury bath they have to visit every day and then they decided nah it’s fine actually. So we’ve kept the liquid mercury thing and I think that’s beautiful
I love how it is so dense it does not "wet" the anvil, the drops all run and leave with nothing behind them unlike water, oil, sauce... it's super satisfying it's like in cartoons
In a letter written on April 19, 1825, Augustin Fresnel proposed the use of mercury to reduce the friction in revolving lenses. His statement follows: “I propose to float our rotating devices, of the first order, in a bath of mercury, instead of placing them on rollers. This project won't present many difficulties; nevertheless, as I have not put it into execution, I won't require you to adopt it for your first lighthouse.”
Fresnel’s plan for mercury flotation was not put into practice until 1890 when Monsieur Leon Bourdelles, Chief Engineer of the French Lighthouse Service, designed and built a workable mercury flotation system. The mercury bath allowed the lens to operate in an almost frictionless environment and, additionally, allowed the speed of rotation to be dramatically increased.
Lens Rotation by Thomas Tag | United States Lighthouse Society
Ah to be a sailor in 1890 who has to turn to his fellow men and ask "is it just me or are the lighthouses flashing faster?"
They had been slowly getting faster for decades.
It mattered for optics reasons.
Under less-than-ideal conditions, you can only see the beam when it’s pointed more or less directly at you. In-between beams you would not be able to see anything. One solution to this was to create multiple beams, and the lenses Mr Fresnel designed usually created 8 beams. But, even still, duration between flashes could be as long as one minute in the old mechanical roller systems.
The nearly frictionless operation of the Mercury suspension system allowed the lenses (large pieces of precisely ground glass weighing several hundred pounds in some cases) to rotate fast enough that they could be redesigned to create fewer (usually 3) beams. Fewer beams from a similar light source will be proportionally brighter, and the gains in speed were sufficient that duration between flashes could still be reduced to as little as 10 seconds.
This was a big upgrade. It didn’t just make the lighthouse signal faster, it allowed them to completely overhaul the lens and derive more visibility from a light source.
What’s a little Madness, in the face of Progress?
mods are asleep, post the fresnel lens
Every single person I know who did football in high school, without exception, has a chronic injury. Many regret what it's done to their knees and back, even major organs like the brain.
There is no serious legislative push to ban high school football.
Also, like, if you want to talk about social pressure on minors to undertake activities that will result in regrettable, irreversible damage to their bodies:
No one, *ever*, tried to persuade me to transition.
My gym teacher tried to persuade me to try out for the football team almost every single day that I was in junior high.
#i firmly believe that the reason why concussions and brain damage in general#are not taken nearly as seriously as they should be#is because of football#if we take concussions and brain trauma seriously then we have to acknowledge the risks that children are undertaking at even#high school level football#but we can't do that#because the kids need to play football in high school so they can play football in college so they can join the NFL#This time I'm really gonna queue it.
I recently watched this video by hydn called “The Great Concussion Denial” and holy fucking shit. Made me sick to my stomach. The tldr is that it’s all the NFL pushing football on kids but that’s really diluting the story
such loud smacks
im so hungry i could eat a meal
just met a three month old pomeranian named horchata. her paw was the size of my fingertip. she looked like half a dandelion fluff
this just got a hockey rpf tag. due to the nature of this website
other hockey rpf enjoyers now expressing skepticism and disbelief at the choice of man referenced above and tagging it with their preferred and more horchataesque men. i love it here and i'll leave when i die
"you don't like mpreg?" i don't even like fpreg
plans are particles. they change and adapt. i didn't intend to spend 4 hours in the dark tunnel and take an edible I found in my backpack, but saturday guided my hand and here we are
i might have fallen asleep in the tunnel but i had nemo guarding me so it's fine