Dancing Pocket Monsters

Fuzzy Dancing Squee

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fuckyeahfluiddynamics:

Frisbees are a popular summertime toy, but they involve some pretty neat physics, too. Two key ingredients to their long flight times are their lift generation and spin. A frisbee in flight behaves very much like a wing, generating lift by flying at an angle of attack. This angle of attack and the curvature of the disk rim cause air to accelerate over the top of the leading edge. Airflow over the top of the disk is faster than that across the bottom;  thus, pressure is lower over the top of the frisbee and lift is generated. Aerodynamic lift and drag aren’t enough to keep the frisbee aloft long, though. Spin matters, too. If the frisbee is launched without spin, gravity acts on it through its center of mass, but lift and drag act through a point off-center because lift tends to be higher on the front of the disk than the back. This offset between gravitational forces and aerodynamic forces creates a torque that tends to flip the frisbee. By spinning the frisbee, the thrower gives it a high angular momentum acting about its spin axis. Now instead of flipping the disk, the torque caused by the offset forces just tips the angular momentum vector slightly. Physically, this is known as spin stabilization or gyroscopic stability. Tomorrow we’ll take a closer look at airflow over the frisbee.  (Image credit: A. Leibel and C. Pugh, source video; recommended papers by: V. Morrison and R. Lorentz)

fuckyeahfluiddynamics:

Frisbees are a popular summertime toy, but they involve some pretty neat physics, too. Two key ingredients to their long flight times are their lift generation and spin. A frisbee in flight behaves very much like a wing, generating lift by flying at an angle of attack. This angle of attack and the curvature of the disk rim cause air to accelerate over the top of the leading edge. Airflow over the top of the disk is faster than that across the bottom;  thus, pressure is lower over the top of the frisbee and lift is generated. Aerodynamic lift and drag aren’t enough to keep the frisbee aloft long, though. Spin matters, too. If the frisbee is launched without spin, gravity acts on it through its center of mass, but lift and drag act through a point off-center because lift tends to be higher on the front of the disk than the back. This offset between gravitational forces and aerodynamic forces creates a torque that tends to flip the frisbee. By spinning the frisbee, the thrower gives it a high angular momentum acting about its spin axis. Now instead of flipping the disk, the torque caused by the offset forces just tips the angular momentum vector slightly. Physically, this is known as spin stabilization or gyroscopic stability. Tomorrow we’ll take a closer look at airflow over the frisbee.  (Image credit: A. Leibel and C. Pugh, source video; recommended papers by: V. Morrison and R. Lorentz)

(via sagansense)

Filed under science frisbee spin

39,006 notes

sashayed:

silvermoon424:

poppypicklesticks:

billybatsonandjameshowlettsbro:

cosmicallycosmopolitan:

billybatsonandjameshowlettsbro:

james-winston:

The Titanoboa, is a 48ft long snake dating from around 60-58million years ago. It had a rib cage 2ft wide, allowing it to eat whole crocodiles, and surrounding the ribcage were muscles so powerful that it could crush a rhinoTitanoboa was so big it couldn’t even spend long amounts of time on land, because the force of gravity acting on it would cause it to suffocate under its own weight.

I’m so glad they aren’t around

omg me too. I’m scared enough of 26 ft long anacondas. I’m so happy Megalodons, those giant sharks, aren’t alive either

Praise natural selection

I remember watching Walking with Beasts or something similar, or some British tv show about evolution

The subject was something like a 12 foot long water scorpion

I was so startled by its sudden appearance and narration that I yelped: “12 fucking feet?!?!  I’m fucking glad it’s extinct!” 

Dude, prehistory was home to some fucking TERRIFYING creatures. For some reason, everything back then was enormous and scary. Extinction doesn’t always have to be a bad thing!

And Poppy, what you saw was an arthropod known as Pterygotus (it was actually featured in Walking With Monsters). Not only was it as big (or maybe even bigger) than your average human, it had a stinger the size of a lightbulb. REALLY glad that bugger isn’t around anymore.

Also, Megalodon deserves to be mention again, because just hearing its name makes me want to never be submerged in water ever again.

GOD, I HATE THIS POST. HOW DO WE EVEN KNOW THAT SHIT ISN’T STILL AROUND? LURKING? EVOLVING? WE DON’T. WE DON’T KNOW SHIT ABOUT SHIT DOWN THERE. THE OCEAN IS A PRIMEVAL HELLSCAPE NIGHTMARE AND WE ALL JUST DIP OUR STUPID FRAGILE UNPROTECTED FETUS BODIES AROUND THE EDGES OF IT LIKE THAT’S NORMAL. FUCK THE OCEAN.

(via cyrreblogs)

1,491 notes

fyeahscienceteachers:

amroyounes:

This might be useful to students as they get ready to go back to school.

Load up your scholarly ninja bag with some tips and tricks on getting more out of google!

Also, a couple of tricks to hack the youtube videos so you can download them or mp3-ize them in case you do not already know.

For teaching: how to find things out