What follows is an interesting exchange between two bubble pros, and it brings up some very interesting points. Until this point in history, most bubblers made up their own bubble related vocabulary. Solutions could be thin, light, brittle, fast, heavy, slow, thick... Bubbles tricks could be just as uniquely named, often referring to the same trick: Bubble chains & caterpillars, cubes and square bubbles, carousels and space ships. Personality played into it. Now, especially on the Yahoo Bubble group, I've noticed a struggle to understand what each other are talking about, even as we are talking about the same thing. What follows is an excellent example of this problem. It's also an excellent example of two bubblers hashing out differences and trying to work together to solve a problem. Would that we were forever so open with our "secrets".
Note: The following are posts to SOAPBUBBLEFANCIERS on yahoo. These are used with permission from the authors. Enjoy...
<<In this post, Tom is talking about a video, recently posted on KellyO's big bubble site, showing him bubbling outdoors and turning a circle with his wand to get a doughnut bubble formed around his body.>>
"Tom Noddy"
Date: Sun Sep 11, 2005 4:37 pm
Subject: [Soap Bubble Fanciers] Re: Video sample
| From: |
Nice clip Kelly. You know how I do the "Torus Bubble", have you ever had one of your donuts love together to make the torus? Tom Noddy |
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"bubbler0000"
Date: Mon Sep 12, 2005 5:24 pm
Subject: Re: Video sample
| From: |
... Tom Noddy asked regarding his ""Torus Bubble", have you ever had one of your donuts love together to make the torus?" I have seen the "Torus". My memory, however, is questionable. I'm thinking the "Torus" is the one where a donut has no hole or maybe one or more bubbles in the middle hole. Is "love" in the quote above a typo or a way of saying the donut shrunk in on itself until it had no hole? If so, The next level of challenge (as I see it) after making a Donut, is to get out of the middle (and take a bow next to the masterpiece, of course). Usually, I'm too fat/lazy (and it makes too much dust) to run around the outside while donuting (so that I'm outside the donut when it is created). The Donuts are always shrinking and the hole does want to collapse into what may be a "Torus". I am usually in the way of "Torus" formation. They tend to be heavy and fall while shrinking. I have only succeded in getting out of the middle once (thanks to an updraft). These are tough critters to make and do not last long (for me to play with them after they exist). Feel free to ask again if I did not answer the question you were asking, KellyO |
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From: "Tom Noddy"
Date: Tue Sep 13, 2005 1:29 pm
Subject: Torus shaped bubble
Kelly,
I got lost in the exchange about the torus/doughnut. That's my fault,
I'm so use to the terms that I use for the way that bubbles act and I
failed to define my terms when asking my question.
Let me first define what I meant when I asked if the ends of the
bubble "loved" together:
When I do the "Love Bubble" I take two round bubbles (usually one
clear, one smoke) and bounce them together a few times. I show on my
face that I'm disappointed with the results as the two bubbles simply
bounce off of each other and I make jokes about these failed efforts
to attain the level of "true love" which I define as "when two become
one". I make excuses: "Love is the most difficult trick" and "Well, to
get love you have to overcome surface tension" and then, usually on
the third try, I do it correctly and the two bubbles become one bubble
(not a double bubble, a single sphere). The smoke mixes with the air
and the new larger bubble wobbles and adjusts itself into a sphere.
A torus is the geometrical term for the shape of a doughnut or an
inner tube.
To do the torus bubble I use a rigid hoop and swing it through the air
in a circle until the front end meets the back end, similar to what
you do in your video -- except that I do the circle in the air going
up and around and then down and back up -- instead of around myself as
you do. The final product is a circular figure that is upright and
perpendicular to the ground, not horizontal to it like yours is.
Naturally, I'm not in the middle of it ... There is a picture of this
on my website at: http://tomnoddy.com/press.html
When the two ends of the bubble meet, one of three things can happen.
1. The bubble might pop ... if so, I think that it's unrelated to the
meeting of the two ends, it's popping for one of its many reasons for
popping (too much stretch too fast, dry hand or dry something
intervening, dust, etc.).
2. The two ends could join with a wall between them. This would be the
equivalent of a double bubble with a wall between them. I get that
sometimes. This is what I think that I see in the video that you have
on line. I could be wrong about that.
3. The two ends could "love" together -- that is, the two ends join
and the wall breaks out but the bubble holds up -- similar to the
trick that I do called the Love Bubble. For a short time there is a
torus shaped bubble free in the air. It was a photo of me doing this
bubble that was printed in New Scientist magazine a while back
answering a scientific query presented to mathematicians by that magazine.
The torus, as soon as it comes into existence, begins a process of
collapsing down toward a sphere shape. This is the problem that you
are referring to when you talk about the bubble coming in to pop on
you. In my case, nothing is in the middle and instead of necessarily
popping when it collapses down it usually becomes one big bubble (the
result of the outside part of the torus becoming a sphere) with a
smaller bubble caught inside (the result of the inside part of the
torus collapsing down and trapping some of the air that was the
doughnut hole).
My own guess to my question to you is that the two ends probably often
"love" together. This process if real common with big bubbles. I'm
sure that all of the people here who do big bubbles are use to seeing
two big bubbles in the air hitting together and melding to become one
very big bubble. With smaller bubbles it's much less common. I figure
that this is related to the pressure difference between the big and
small bubbles.
The air pressure inside of a bubble is directly proportional to the
curvature of the bubble wall. The smaller the bubble, the greater the
curvature and then the greater the air pressure inside.
When the bubble gets bigger, the curvature of the wall comes closer
and closer to zero -- that is, the wall is almost flat instead of
rounded (relatively speaking). At that point, it doesn't take much to
get two bubbles to join. With the teeniest bubbles they might readily
come together to make little suds but you never see them joining into
single bubbles.
On a good day, I can make apple-sized or even lemon-sized bubbles love
together but only because I'm good at it. On a difficult day I go for
the grapefruit sized ones.
Tom Noddy
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"bubbler0000"
Date: Wed Sep 14, 2005 2:41 am
Subject: Re: Torus shaped bubble
| From: |
I can see how, with a stiff wand, you can twist your wrist and merge
the bubble ends without your wand being in a place that cuts the
bubble as you pull away. Hmmm...I might be able to do this with my
limp wand. Another goal to entertain myself with.
> The torus, as soon as it comes into existence, begins a process of
> collapsing down toward a sphere shape. This is the problem that you
> are referring to when you talk about the bubble coming in to pop on
> you. In my case, nothing is in the middle and instead of necessarily
> popping when it collapses down it usually becomes one big bubble (the
> result of the outside part of the torus becoming a sphere) with a
> smaller bubble caught inside (the result of the inside part of the
> torus collapsing down and trapping some of the air that was the
> doughnut hole).
My donuts do not (so far) last long enough to show this interesting
end point. I can tell you the torus begins shrinking toward circular
oneness even before it exists as a complete donut. Any tube or curved
tube is trying to "get round". As for the endpoint being a sphere, I'm
not so sure Scientific American has it totally correct. With a self
healing mix, your right they would collapse into a sphere. I think a
non selfhealing mix that does not love together easily might hold it's
hole open. I could easily be mistaken, however, I think ther are
forces on the inside of the hole tring to hold it open. In that area,
the bubble wall is curved away from the center and is trying to get
round away from the middle. I wonder if "anti-selfhealing" is
basically surface tension - and it might be this surface tension forse
that could be strong enough (in the right mix) to hold the hole open?
> The air pressure inside of a bubble is directly proportional to the
> curvature of the bubble wall. The smaller the bubble, the greater the
> curvature and then the greater the air pressure inside.
If I ever knew this, I had forgotten it. It is such a useful piece of
info to know when trying to understand these criiters and their
husbandry. As a donut shrinks in the center, the wall curvature may be
distorted into a less curved shape and lose it's power to keep the
donut hole open? Or maybe it gets more curve and has more power to
hold the hole open? I do think I am still talking about surface
tension forces (being affected by bubble wall curvature - ?) and so I
might be off on a different tangent (as Tom was talking about air
pressure and that would probably be related to average bubble
curvature rather than local curvature at one spot on the bubble?
I'm getting a bit spacey, even for me, better get some rest, KellyO
| Wow Tom,
I'm so happy I did not "get" the question the first time. That 2nd version was very educational. > I asked if the ends of the > bubble "loved" together: "loved", merged, became one. Cool bubbling term. OK so to answer. First I'll say I think it is still one bubble (rather than a double) whether they love together or not. An interesting ?mathmatical? reality for one to merge into one? Mine usually do not love together. I think that will change with the new more self healing formulas we are starting to use. It seems the more self healing a bubble mix is, the easier to love bubbles together. I'm not used to it as I did not use these kinds of mix before. I like making doubles and triples and such. Now with this new mix they do tend to love together all the time and "ruin" certain tricks people love. That said, the big donuts do not usually love together for me (yet). I can think of at least four reasons that may explain this. One, I think the surface of one end gets dryer (or a different concentration or...?) over time and by the time I get around the circle, they do not merge as easily due to this dryness of the surface of the first end. Second, for the big ones I do not think I want a really selfhealing mix. If it is too self healing it breaks up into smaller bubbles. I am still wondering if we are moving away from the largest size bubbles as we add the self healing lubes and dawn complete. Bubbling gets easier and is still very magical and impressive. I could be imagining this "maximum size limitation" dilemma. I need more time bubbling in great weather with multiple mixes to test the theory. Third, you probably smack 'em together pretty hard to get them to love each other. With big bubbles (and their low internal pressure), it gets harder to smack 'em together forcefully. This is especially true when they are big and old and you have to treat them so carefully. I do smack em pretty good sometimes to get a good connection, however Fourth, even if they do love together, as you finish the circle, when you lift the wand away you cut them back apart (into one, not two- very triveally interesting). If they are self healing enough they may well "relove". I will have to pay closer attention to this issue in the future. > you do. The final product is a circular figure that is upright and > perpendicular to the ground, not horizontal to it like yours is. > Naturally, I'm not in the middle of it ... There is a picture of this > on my website at: |
From: "Tom Noddy"
Date: Wed Sep 14, 2005 5:08 pm
Subject: Re: Torus shaped bubble
Right Kelly, this curvature thing is only about the air pressure force
and is unrelated to the surface tension force.
The surface tension is the same for the big bubble, middle sized
bubbles, and teeny weeny bubbles (to use the technical term). That
force may well change when you add different ingredients to your mix
but with any given mix, the surface tension force remains constant
when you do different things with the bubbles.
That, of course, is the force that is trying to minimize the shape of
the various bubbles and films. Really, given a chance, that force
would prefer to reduce each one into a single spherical drop of liquid
with no air inside ...
But there is that air and it has its own concerns. The air is really a
collection of atoms that each have a charge and their own comfortable
distance from other charged atoms.
The push of the surface tension forces them closer together and they
resist that push. The resistance is the air pressure.
Between them, the surface tension and the air pressure help to make up
the size and shape of a bubble floating free in the air.
With small bubbles the air pressure inside is so great that most
outside forces (like blowing wind) are unable to distort the shape
that the surface tension and air pressure arrived at.
But those big ol' bubbles that you wave out with lots of air inside
and only gently curving soap films squeezing the air bits closer
together ... well, those babies will distort just from their own
weight or the air resistance of their falling, even if you can detect
NO wind. A bit of a blow and it can distort into those amorphous
shapes that hardly make people think of soap bubbles when they see
them in photos.
Those teeny weenie bubbles, with the exact same surface tension but
much higher air pressure are probably the closest thing that you've
ever seen to a perfect sphere.
Ain't liquids fun?
Tom Noddy