Hobermansphere conservation of angular momemntum
Hoberman sphere conservation of angular momemntum
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Monday, January 25, 2021
Nikola Tesla
I do not think you can name many great inventions that have been made by married men
Albert Einstein
Imagination is more important than knowledge.
When ballerinas spin they extend their arms then pull them in, I thought the extending part was what gave them speed, now I realize I was mistaken
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I always did this in spinning chairs. You spin really fast and stick your legs out, then once it’s sledding down tuck your legs in and it doubles in speed
Can someone explain or walk me through what is going on here?
I recently learned that the Earth-Moon system made this type of change. The Earth used to spin really fast and the Moon was very close after the Theia Collision. Then the Moon slowly moved away and the Earth slowly slowed down. Days used to be only 5 hours long!
Oh shit! It’s Dr. Boyd Edwards! I miss him and his unicycling shenanigans 🙁
Angular momentum (and optics) is one of the most fucked-up things in all physics.
Credit: https://www.youtube.com/watch?v=64t-dVtDwkQ
The same thing hapens to cepheid stars as they expand and contract due to not being able to obtain an equalibrium in fuel consumption.
Mine is biggest, and i would like a cookie.
This is why neutron stars spin so quickly.
Incredible demonstration; adding this to my future dream physics museum.
Is this the same thing going on with figure skaters spinning around really quick
Absolutely could not understand the concept until seeing this gif. Wow. Makes sense now, really would have helped on my physics final.
So that’s why I spin faster in my chair when I tuck my legs in.
When net external torque is 0 angular momentum or I times *omega* become constant as radious increases moment of inertia increases to make angular momentum constant angular velocity decrease that’s why bigger structure spin slowly where in vice versa case it has high angular velocity that’s why smaller structure spin fast
If the ball were to roll, would it go the same distance when it was large as if it were small at the current speed of rotation?
That is the most beautiful thing I’ve seen all day!
It’s like when you were a kid and you would spin around in a computer chair with your legs out, and when you would pull them in the chair would spin a lot faster.
I learned this as a little kid in an office chair. Spinning around in it with my legs out was slow and I got scared I was going to hit something so I would try to curl up in a ball in the chair and spun so fast I fell over. I repeated until I eventually hurt myself
Anyone know how to make this model?
Neutron star explained
saving this for next semester when I have to learn about this
I don’t know wtf this is but it looks pretty damn cool
yeah, ice skaters do this all the time
Someone’s gonna argue that if you put water on the sphere either way it will spin off… now I’ve gone and made myself sad
Looking at this thinking “Is this like the relevant movement of galaxy’s and atoms? “
I just put my students in a spinny chair that I duct taped to the ground and had them move their arms in and out. It works just as well, with the added benefit of not costing any money. Plus, the kids got a kick out of it. 🙂
i miss going to physics class
That smirk lol.
He is so pleased with himself, this is what it looks like when you love what you do.
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ice skating 101
The little smirk at the end
Physics bro
Kind of reminds me of how the universe was made if you play it backwards.
Woahh
My favorite part is that gears work in a similar way, smaller gears rotate at higher speeds than the larger gears they are meshed with.
So we know planet earth is spinning. Could our planets core be spinning faster? To where it would follow this law too
Where can i get this thing? It looks very neat (or make it)
Ironically slows way down when it expands out again. Good job with the conservation of momentum there
That tiny smile at the end of the gif is the smile of a man that was able to successfully sneak out a fart in a public place
Nice optical illusion too: I can get my eyes to convince me the sphere is rotating in either direction.
Or shit. Maybe I need glasses.
I think i got stuck in one of those when i was a kid
This is why comets speed up as they zip around the sun.