A bubble contains all the colours of the visible spectrum.
There´s no other thinner object
that can be seen at a glance.
Any living being
of just some nanometers thick
requires a microscope to be seen.
Despite their short life,
bubbles are great teachers of science
To learn from them
we just have to watch them carefully and, if possible,
closely.
It has never been generated such a spectacle
in just a few seconds of life.
When I was little,
I really enjoyed visiting the house of one of my grandparents
because the shower soap they used
was different from the one I had at home.
It was ideal for the creation of soap bubbles.
I remember myself as a kid blowing soap bubbles, and I´ve got that memory
linked to my childhood and, particularly to my grandparents house
where they used that soap.
Soap bubbles have been my life.
I´ve dedicated myself to them for more than 16 years.
So, a bond is created with those transparent beings
As a kid I was fascinated by soap bubbles,
as any kid. That perfection, that sphere, those colours
I also remember that back then, in Sesame Street
there was this guy that would blow soap bubbles
and he would do wonderful things with them.
I think it was Pep Bou
Fairy was launched around
1979, 80, I think.
At least I found out about it then and it was by washing dishes that
I realized that soap bubbles were not that small bubble children played with,
I started to see possibilities to make them bigger.
I wanted to take to stage something that could be created in situ,
that would be created live, really, as a real experiment,
almost handcrafted because I always loved craftsmen.
I realized that soap bubbles were a didactic material.
They´re a very valuable didactic material.
First, because their playful side draws a lot of attention.
Kids at school are really attracted to them, and as Mathematics,
I can use bubbles to visually explain very complex problems.
I first knew about surf when I was 14.
I instantly fell in love with it.
In winter, when we had less daylight, I would hang out with some surf friends
One day it occurred to me I could take some soap bubbles with me, and we started to blow bubbles.
To be honest we had a great time.
I started to make liquids, different tools
and I would take them with me in the evenings to play with them
As years passed, it was a hobby in winter
to go back to soap bubbles, and I slowly perfected it
until we managed to blow bubbles so big, beautiful, wonderful
that they looked like waves, ephemeral art.
The molecules on the surface of a liquid
don´t behave as the rest.
What force makes them so different?
Surface tension is a characteristic that liquids have
that depends on how their molecules are attracted to one another.
In liquids, molecules are attracted, but not the ones that are outside the liquid.
Those, logically, are attracted only to the ones inside,
and that creates a tension that generates a film.
Water is made of H2O molecules that are connected
by hydrogen bonds, covalent bonds.
As we tell children, they are together as rugby players in a scrum.
They are like holding one another
and also, somehow, these molecules are like more at ease when they´re with other water molecules
than when they´re with air molecules.
Then, particularly on the part where they collide with the air
it looks like they don´t want to be there, and that force is even greater.
And that is what makes that, for example, when we fill a glass of water,
the water rises, rises, rises and rises and sometimes thereÕs even more water than glass
Why so?
Because the molecules are grasping each other there, with that force,
like the one in the rugby players scrums.
This force that bonds some molecules with others, makes the contact surface of water
with air behave like a membrane.
The soap bubbles components,
water, soap
glycerine that can be added or not,
and the air that it contains, they are in a perfect balance.
Water is a fascinating liquid
that has an excessively high surface tension.
Its molecules are strongly attracted to one another.
If I want to make a soap bubble, I need something that decreases
the surface tension; a surfactant. And soap is a surfactant
The air, which is the other element, is contained within and exerts pressure
on the walls. That is what makes the bubble spherical in the end.
It´s not that there´s a layer there, but
the force among them, if there´s something that it´s not
too heavy, like an insect, when it leans on it
that force prevents it from sinking, it stays there like surfing
on the water.
When we blow bubbles in a place protected from the wind
we see that all the bubbles,
specially the smallest ones, have a spherical shape.
Let´s see what the cause of this sphericality is.
Soap bubbles are spherical
because everything in nature tends to go to the lowest energy state,
and that shape ensures the lowest energy to the system, which is characterized
by being the smallest surface able to enclose the air volume that it contains.
If human hair was the size of a football pitch,
the soap bubble, the film, would be like
my pinkie.
Studying soap bubbles
is something very interesting because they teach us a lot
about the minimization problems, about how to determine minimums.
Seeing how bubbles behave
help us identify those minimums.
Let´s imagine, for example,
that we want to install an automatic irrigation system on a giant estate.
It´s obvious that we have to place sprinkler heads
on, let´s say, 50 trees. How do we make that system carry water
to the 50 trees using as few pipes as possible?
Well, that is a problem
that soap bubbles solve almost by themselves.
You place those 50 points in a sheet, immerse it in soapy water
and the membranes that are created
start moving until they find those minimum solutions.
That´s tremendous, of course, because a computer or a math algorithm
would need a very long time to calculate that structure which has a name.
It´s called the Steiner Tree of minimum length
which would be that tree connecting all those points,
but using the minimum length.
When soap bubbles combine,
they do so by following the same principles that generate
a soap bubble: they minimize the free surface.
So, when you combine two soap bubbles, they share a surface.
That free surface depends on the size of the bubble.
For example,
if the bubbles are the same size as the surface, it is usually flat.
If one bubble is bigger than the other, the surface of the smallest one
usually goes inside
the big bubble because the internal pressure of the small bubble
is greater, so it tends to go in.
When some bubbles are grouped, or they are formed together,
geometric shapes, hexagons or pentagons, are created
at the interphases of each bubble.
This answers to the same reason why bubbles are spherical,
it´s the state in which the energy is lower, minimum.
120 degrees is not any number, no, it´s what makes this angle
as symmetrical as possible.
Symmetry usually goes hand in hand with a state of calm,
a relaxed state.
And bubbles do tend to have the minimum energy
to be as comfortable and as little stretched as possible.
So, when bubbles intersect at an angle of 120 degrees,
as they are creating flat films, it´s very natural.
They don´t form hexagons like bee nests.
Hexagons are a shape in nature so very common
and they tend to minimize the energy
and stabilise it all in a much better way.
Soap bubbles
have been used a lot in architecture precisely because
they are extremely big constructions in proportion to their material thickness.
That is for architects they say,
if I follow that radius of curvature of a dome, I need thinner materials,
not as thick
And we, mathematicians, amuse ourselves saying hey, look here,
they intersect like this, forming 120 degrees,
it´s the same I get with my calculations.
That makes us really happy.
And the bubbles last moment arrive.
Its energy is exhausted, its water gets evaporated
and the bubble dies.
Few structures
are beautiful even at the moment of their own death.
Soap bubbles say goodbye to us
showing us their last rainbow.
A bubble dies when
when its energy has been exhausted.
That´s the concept,
an essential concept, very, very human too.
When it exhausts its energy, when it hasn´t got any left
to resolve its structural problems.
Once again, I´m speaking about soap bubbles as if they were living beings.
A soap bubble is short-lived, as everybody knows, and it can die
for different reasons.
If we don´t touch it with a finger and pop it,
it usually happens when part of the water
that exists on the surface layer of the bubble evaporates.
The soap bubble stability depends essentially
on not evaporating much water
and on not touching other surfaces, or at least not surfaces
that are dry or coarse which can alter the soap bubbles film.
And, finally, when the soap layer is very, very thin,
when it´s much smaller than the wavelength of light,
-that´s between 400 and 700 nanometers, so, letÕs say for example, 20 or 25 nanometers-
one starts to have interference,
discrepancies, destructive interferences of all the wavelengths
and the result is that you see an off-white colour or no colour at all.
This anticipates that the soap bubble is unfortunately close to an end
To have a soap bubble lasting a long time
what we, artists devoted to this, do
is to control the humidity and temperature.
When there´s high humidity,
soap bubbles take longer in evaporating that water film.
For that reason, although they suffer a lot,
(and we make them suffer greatly in the show,
we do.)
they last longer.
With heat it´s the same, heat dries that water membrane too.
So, the less heat, the better.
When light passes through two grilles, the waves superimpose on one another
producing interference patterns
that are very curious.
On very thin materials films, the ray that is reflected
on the upper part also superimposes on the one reflected below.
These are the so-called thin-film interferences,
where iridescences appear.
A soap bubble is, in essence, an air volume enclosed by
a double film
of soap.
We´ve got two layers of soap that enclose water,
which is the layer that generates the bubble.
So, these two surfaces are facing each other:
The surfactant molecules heads, hydrophilic, and among them
there´s a certain amount of water molecules.
So that film extends along a surface
that is usually spherical but, logically deforms
due to the airflow and other circumstances.
And that is, in essence, a soap bubble.
Soap molecules have like two parts, let´s say,
one that likes water and one that doesn´t.
That´s a very curious thing because if you´re there in the water
it´s like they have a duality there,
they´re like bipolar. They´re literally bipolar.
In fact, that´s why we use soap to clean
because it seems that soap traps fat
The part that hates water tucks inside
and the part that loves water
points outward and that encloses fat
and it´s removed from what we´re cleaning.
In a soap bubble something similar happens.
The part that loves water tucks inside,
the part that hates water, that prefers the air
points outward both in the outside
and in the inside of the bubble, because actually there´s air in the bubble.
Then, a membrane generates where all those molecules are placed
so that the hydrophilic part, the part that prefers water,
goes to the inside and the part that is hydrophobic, the part that repels water
goes to the outside of the membrane.
The bubbles colours
are produced by the light interference when it falls upon it.
In reality, we are seeing the light reflected in the bubble
and if we light it up with sun light, with white light
we don´t see white light because some colours are cancelled out
due to the interference in that layer.
So, colours depend on thickness.
In fact, if we watch how the bubble evolves,
there´s an area that seems redder, others turn blue.
What that is telling us is that
what is varying along time is the bubble thickness.
It also varies because liquid tends to drop to the lower part
as it´s attracted by gravity.
When we look at a bubble
from the outside, aside from those colours, movements can be seen.
Those movements are produced by the bubble formation itself.
In the end, bubbles are formed by blowing air
in a liquid and that produces a movement in it, a turbulence.
Those turbulences last a very long time. ItÕs a fluid that
is moving.
When the bubble doesn´t show any colours, We don´t see it, but there´s also flow.
We simply don´t see the colours and we don´t see the thickness
which is, ultimately, a witness of the existing flow beneath.
We aren´t seeing it, but it´s happening all the same.
So, the movements produced in the fluid, in the inside
of the two layers of soap can be perfectly assimilated to the movement
of any other fluid.
And in this case, we also have the added value of seeing it in a very beautiful way
through the interference pattern that gives us those iridescent colours
that are so fascinating.
A soap bubble, well, it has an intrinsic magic
It´s like very fragile, very short-lived, and also very perfect.
As everybody knows, the sphere is the most perfect shape in the universe.
Look, don´t you see?
Our planet is a sphere.
Just to see a perfect sphere already excites us.
But, of course, in the case of a bubble, it´s like very fragile and like very...
you blow it and it moves, it deforms and it comes back to the same, it reflects...
there, we see the colours, we see movements that we can´t explain
very well why they are there, but they enchant us
From a chemist, physicist
point of view,
it´s a beautiful and fascinating structure in which there´s a conjunction
of balances among the forces of interaction of water with itself
soap with itself, and the pressure exerted by air.
And at the end, it´s a structure that you know itÕs going to die soon.
So, you enjoy more seeing it.
I´ve been 23 years blowing bubbles and IÕm still in love with them.
Each time we blow bubbles either in daytime
or nighttime, with coloured lights, with special effects it´s something magical.
Extraordinary elements are created,
full of colours, of shapes, of movements that dazzle you,
that stand out, and that are a wonder to behold.
We had children in some shows that, when the spectacle was over,
came closer and told us, Today´s been the best day of my life.
Then, you´re greatly touched you´re like a dog with two tails,
and you say, you know? This job is worth it.
For me bubbles are very hypnotic, very seductive
And this is my path, to amaze people, that they are mesmerised
by what can be done with soap bubbles.
Everyone knows that children like very much popping them
but adults like seeing what can be done with them.
I greatly enjoy looking for those limits; working with smoke, vapour, fire, helium,
and trying to introduce music, also lights to draw attention
and to have the soap bubble do what I intended.
I find that soap bubbles are fascinating
because of their softness, the curvature they´ve got, the colours
In that sense, as any other person, I´m attracted by the fact that
shapes so subtle can exist briefly and randomly fly through the air,
and they can offer us that fascinating rainbow range of colours
which also gets deformed creating fascinating patterns.
Inside the soap bubble a lot of fundamental physics processes happen.
So, the fact that they minimize the surface, that they combine
creating hexagons or pentagons, is, in my view,
an absolutely fascinating and incredible thing.
Enchanting everybody by means of soap bubbles
is easy, to be honest, because they have all the appeal themselves.
That aesthetical quality, their beautiful side itself
make us all stand like this, open-mouthed.
So, I´ve just been a medium, I´ve done my job conscientiously
on stage and then, any person that has seen it has been delighted with it.
But soap bubbles are the ones that get the prize.
Soap bubbles are an element of nature.
Nature is fascinating, something that we are passionate about
precisely because we´re not accustomed to it, because
we don´t live in nature and when, all of a sudden,
we find something that we can´t conceptualize
-as we always do assimilating the things we work with-
then it happens what Kant said
the sublime arrives.
The physical laws are already written
and those physical laws that stabilise
the movements of all those planets, which seems incredible
that all those huge masses of matter would turn around each other
and not get attracted and make it all collapse and disappear.
Well, those are the same laws that apply to the soap bubbles structure,
where the bubble is extremely thin and can be enormous compared to its thickness
and yet, it can last for a long time.
Studying soap bubbles can be used for many things
because there´s a lot of physical phenomena involved,
the surface tension, the curvature independent pressure,
the colours generated in the bubbles, how composition affects stability,
the effects of air temperature
The currents we see in seas, or oceans or, for instance, in the air
in those satellite photos, the patterns clouds make.
they are described by fluid mechanics.
Fluid mechanics works the same way on a broad scale
than on the small-scale of a soap bubble;
in the inside of the two soap films
there´s a fluid in motion.
Everything must obey the same laws.
The same processes that we can observe in the atmosphere, in the sea water,
can also be observed in the colours of a bubble
if we are lucky to see constructive interference.
Holidays are here.
On a sunny morning our young group of friends gather in the park
to have fun making soap bubbles with very different tools.
Sometimes they manage to blow bigger bubbles,
sometimes they´re lengthened, but all the children enjoy blowing soap bubbles.
Well, almost all of them.
Now that we know some of the secrets that bubbles guarded,
let´s go back in time to see bubbles again
through the eyes of a child.
This way only, we´ll be amazed by their beauty,
as we were when we were children.