Thought that these deserved their own thread.

These shots are from the wedding I shot 2 weeks ago. Both of these girls work for me and are good friends of mine, they happen to spin fire for fun and the entertainment of others. They had the audience, and me, enthralled.



















And the rest are here: http://tardypizza.com/Images/firedancing/

that first one is just incredible. I know you have no control over what you get fire wise, and that's what makes the first one my favorite. Looks like a dragon or something.

How do they do that BTW?

Little buckets on chains that hold some material that soaks up kerosene. Light them on fire and spin furiously to the beat of a good tune. It's really hard work for the girls and they're very dedicated to putting on a good show. Everyone was amazed.

so it's centrifugal force but only ON FIRE!!!!

some might say centripetal, even :P

weird, I think we're both right:
http://en.wikipedia.org/wiki/Centripetal_force
http://en.wikipedia.org/wiki/Centrifugal_force



with the diagram for yours I thought I was wrong, but then reading mine it says it's what's used in amusement park rides and to generate fake gravity in space... Also it's how we cast some white metal here (by spinning)...

You're less right though, Ben. :P

yeah, the weird part though is I always thought is was centrifiCal force...

anyway, it is centripetal force... I guess my physics teach was horrible afterall.
http://regentsprep.org/Regents/physi...if/centrif.htm
http://regentsprep.org/Regents/physi...if/default.htm

meh they're both there but acting in opposite directions

one is keeping her from getting burned, the other is keeping her from being pulled over.... IT'S THE CIRCLE OF LLLLLLLLLIFE AND IT MMMMOVES THE SSSSSSSSSSSOUL

Originally Posted by jblaze5779

one is keeping her from getting burned...

Yeah, but that's not an actual force. There is no force pulling the fire away from the chain. The bucket's inertia wants to carry it away in a straight line but the chain constantly accelerates it in a circle. Centrifugal force is entirely made up to describe what humans feel on merry-go-rounds.

yeah, and that's the best part... it's entirely made up... it's not real, yet the way we cast uses it's name... So we cast using ghost forces... It's pretty Fed up that so many people misuse the term... My physics professor in HS used it wrong.

Originally Posted by tardypizza

Originally Posted by jblaze5779

one is keeping her from getting burned...

Yeah, but that's not an actual force. There is no force pulling the fire away from the chain. The bucket's inertia wants to carry it away in a straight line but the chain constantly accelerates it in a circle. Centrifugal force is entirely made up to describe what humans feel on merry-go-rounds.

Yeah it's an actual force, if that chain where to break where do you think the fire would go? The fire bucket has mass and it's accelerating away from her, that's a force.

blaze, read this:
http://regentsprep.org/Regents/physi...if/centrif.htm

Originally Posted by jblaze5779

that's a force.

Sorry, but that's inertia.

I refuse to believe any animation that uses tapes as examples...


I'm going to have to get out my statics book

It's confusing because from everything you've sensed about similar situations (ie carousels or merry-go-rounds) , you really want there to be a force pulling the bucket out, because that's what it would feel like if you put yourself in that situation. Now, you could say that there is an equal and opposite force between the fire bucket and her hand (the bucket is exerting the exact same force on her hand as her hand is on the bucket, by means of the chain) but there is no force pulling the bucket itself outwards.

Anyway, I want to know the name of the force that pulled this thread off the tracks.

I think in this case the centrifugal force is real. If you have centripetal force pulling the body toward the girl you must have something pulling away from the girl. This example and the example using the car are two different situations.

If that object she was spinning was going fast enough and was heavy enough it would break the chain or whatever it is being held by. Something is pulling it away from the center, it's own mass by its acceleration outward.

There are real and fictitious situations.

Originally Posted by jblaze5779

If that object she was spinning was going fast enough and was heavy enough it would break the chain or whatever it is being held by. Something is pulling it away from the center, it's own mass by its acceleration outward.

There are real and fictitious situations.

What you're describing is inertia and not a force. Inertia is affected by forces, not the cause of them. The only force in action is the centripetal force accelerating the fire in a circle. Sounds nitpicky but it's true.

http://staff.washington.edu/aganse/b...s/centrip.html

So to conclude, centripetal force and centrifugal force are really the exact same force, just in opposite directions because they're experienced from different frames of reference.

That car example and this are two different situations. You don't just have tension on a rope without an equal and opposite force opposing it.

Originally Posted by jblaze5779

That car example and this are two different situations. You don't just have tension on a rope without an equal and opposite force opposing it.

That's why I said this above:

Originally Posted by tardypizza

Now, you could say that there is an equal and opposite force between the fire bucket and her hand (the bucket is exerting the exact same force on her hand as her hand is on the bucket, by means of the chain) but there is no force pulling the bucket itself outwards.

There are equal and opposite forces between the bucket and her hand keeping tension on the rope. But there is no actual force pulling on the bucket.

Think of a satellite orbiting the Earth. The centripetal force keeping the body in orbit is gravity. There is an equal an opposite force between the craft and the Earth, ie they are each pulling on each other in equal amounts. But there is no force acting to pull the satellite away from the Earth. If gravity suddenly ceased, the satellite would fly away because of its inertia, not because of some force. In fact, it would fly away because of a lack of a force acting on it.

What causes the string to break if you twirl something too heavy too quickly?

Inertia. The mass of the object and it's innate desire to be left alone by forces. You're absolutely correct that there is an equal/opposite force in the string keeping it taut, but that is in the string alone. What causes it to break is not a force, it's the inertia of the spinning mass. It's the property of the mass to want to continue in a straight line. The centripetal force keeps it in a circle, but if there was no force (ie, the string breaks or you let go) the mass will stop accelerating and its inertia will carry it away in a straight line.

Inertia is what forces act upon. It cannot be considered a force itself.

Sorry 'bout that, I get carried away at times. It was quite a spectacular train wreck though!

I got sidetracked by work

so is this NSOP's treadmill then?

I feel like emailing Dr Borst, Texas Tech's finest/germanest/meanest physics professor to sort all this out. Physics nazi will set this straight.

Originally Posted by jacobsen1

so is this NSOP's treadmill then?

It flies dammit!

I will agree, that bitch is takin off

Centripetal Force explained in video

I heard some other kids in the UK did this and one was killed.

The shots are very nice, number 1 being my favorite.


Centrifugal force is fictitious and does not exist, Mathematica knows more then jblaze
http://scienceworld.wolfram.com/phys...ugalForce.html

Oh crap, here we go again.

THE PLANE TAKES OFF!!!!!!!!

:shakes head: