we are surrounded by mysterious worlds
worlds hidden from us by their sizes too
small or too large to be noticed
but now, it's possible to see these worlds
what's changed our perception
technology extending our natural senses
taking us on a remarkable journey from
our own world through strange parallel
worlds down to the smallest and up to
the largest elements of creation
Albert Einstein said it is entirely
possible but behind the perception of
our senses worlds are hidden of which we
are unaware
Limits of Perception
we experience the world around us
through our five senses but the one we
rely on most is sight for centuries it
was the artist who recorded and
interpreted what we could see
since stephen's cathedral in vienna was
started 850 years ago in the 12th
century artists could only perceive a
very limited world with humanity at its
center but since then science has
expanded those horizons looking outward
beyond our planet and inward to the
micro worlds beneath our feet
the first microscopes revealed worlds we
never dreamed existed
and electron microscopes could take us
further into even smaller worlds
the atomic force microscope can show us
the bizarre world of molecules and even
take us to a place where common sense is
stood on its head the unimaginable world
of atoms themselves and looking outwards
telescopes in space take us beyond our
solar system beyond even our galaxy to
the farthest regions of our universe
and humanity we exist right in the
middle of all this wonder where exactly
halfway on the journey between Adam and
universe in the past artistic
imagination challenged and probed the
limits of our perceptions but now
scientific imagination paints an even
larger picture science has given us the
tools to see our lives in a truly vast
perspective as just one layer amongst
the many that make up our universe and
the first step on our journey through
these layers needs just a simple tool a
lens bending light to magnify images
in the 17th century a few simple lenses
in combination made a microscope and
reveal the world that we'd never seen
before
we found out that a whole world could
exist in a single drop of water a water
bear with legs and claws like a tiny
bear the first natural ists who saw
these images often look for parallels
with their familiar larger world
but for 400 years this was the limit of
our journey into the micro world it
wasn't until the nineteen thirties but
the next step was possible all eyes work
on the same principle as those first
microscopes by bending and focusing
light rays some birds see much finer
detail than humans and microscopes do
better than both but in the end there is
an absolute limit as to how much an
image can be magnified with light
to travel further into the micro world
we need a microscope that can see the
world in a way that's never evolved in
nature at the turn of the 20th century
technology was finally advanced enough
to do that a microscope that sees the
world not by focusing beams of light but
by focusing beams of electrons electron
microscopes reveal exquisite detail even
in everyday objects
we may be unaware of these tiny worlds
but they're all linked to each other and
to our own world everyday events in our
world can create spectacular effects in
theirs
a rainstorm just makes us wet very
inconvenient for us
get on a bronze statue the continual
wetting and drying out over the years
creates a familiar green coating a
patina
but this thin green smear is really a
spectacular landscape a landscape made
up of crystals less than a hundredth of
a millimeter across
we're watching ten years of weathering
unfolding in a matter of seconds
producing intricate tiny flower gardens
of crystals
these crystal gardens are dead inanimate
but this scale also hides a living world
a patch of MAS looks like a forest and
like any forest it hides all kinds of
strange creatures these are tiny
centipedes only a millimeter or so long
and a pseudoscorpion a minut replica of
a scorpion but at the next level 10
times smaller again the most numerous
creatures are mites thousands of
different kinds millions of individuals
many mites live on dirt and fungi but
this is a complete miniature world down
here as in our own world there are both
hunters and hunted
and the hunters here a fearsome armed
with such powerful jaws they can prey on
mites their own size with predators like
this stalking the moss
some mites use camouflage this mite has
hairs on its back and attaches all sorts
of junk to them making it look like any
other piece of dirt
other mites use armor plating turtle
mites can draw their legs up right
inside their shell
it seems there's no end to the variety
of different mites all living their
lives unseen until technology revealed
their hidden world
but smaller again the surface of a dead
leaf is yet another world covered in
tiny bacteria exploring these tiny
worlds doesn't just reveal unseen
natural worlds it shows us the way our
unfamiliar world is built up layer upon
layer
a cathedral is actually made of small
building blocks hundreds of thousands of
individual pieces of shaped stone a
human body is also made of smaller
blocks themselves but to build a human
body takes more than 30 trillion cells
creating a structure so elaborate that
every individual is unique no other
person has this pattern of cells making
a fingerprint different kinds of cells
build the different kinds of
architecture to do different jobs the
lining of the gut is folded into
elaborate structures to speed up the
absorption of food or the surface of the
tongue covered in papillae that hide the
taste buds
so a human body like a cathedral is made
up of building blocks but unlike the
cathedrals stone blocks living cells
aren't simple structures they're
miniature worlds in themselves and in
the same way the Cathedral is more than
the sum of its blocks of stone a human
body is much more than the sum of its 30
trillion cells
until the 1940s we could only make up
the vague outlines of cells so we
thought they were simply bags of
chemicals but now we can see inside
individual cells these are images of
incredibly thin slices through a single
cell and clearly they're far more than
just bags of chemicals they have their
own elaborate structure by adding
together information from images like
these we can use a computer to recreate
the inside of a single living cell this
is what it's like to swim through the
inside of a living cell and there are a
few surprises in here scattered
throughout the cell are sausage-like
structures mitochondria the power
generators of the cell but mitochondria
were originally free living bacteria
that became partners in ancient cells
now we can't live without them but over
an individual's lifetime cells are
continually dying and being created over
about seven years all the cells in our
bodies are replaced so if none of our
cells are the ones we were born with how
do we stay the same individual how do we
know who we are
the answer lies at the heart of every
cell inside the nucleus this is the next
step of our journey into the world of
molecules seen by an atomic force
microscope these are human chromosomes
each one made up from a tightly wound
folded molecule
and this is that molecule DNA unraveled
the ridges have a very molecule that
carries the code for life and each bump
on the ridge is an individual letter in
the code at this scale it would take 23
days to travel along the entire code
book every animal or plant has its own
code written in DNA a remarkable
molecule creating all the diversity of
life we see around us
the DNA molecule is so remarkable it's
even capable of creating a creature that
can build a cathedral
but molecules are not the final limit
there are other levels beyond the
structure of DNA for us to see a pencil
line is made of carbon the same element
that makes coal diamonds and most of the
human body it's even more of a
fundamental building block of life than
DNA
and these are carbon atoms seen with an
atomic force microscope arrayed in a
precise grid each atom a mere 10
millionth of a millimeter across for a
hundred years we thought atoms were the
simplest building blocks of matter but
in the 1920s even the atom was teased
apart to reveal yet other layers atoms
are made of orbiting electrons and at
the center a tiny nucleus but the world
inside an atom is a very strange one for
something that's the building block of
everything we see there isn't much to
them if the outer shell of electrons
were represented by this Cathedral how
big would the nucleus of the center be
at this scale it's so small it's the
size of this crotchet on the hymnbook so
in reality meta stuff is mostly empty
space what feels like solid matter to us
is just the interaction between
electrons but deep in the heart of an
atom even the tiny nucleus can be split
and when it is huge
unthinkable amounts of energy are
released the energy that fuels an atomic
bomb
at these levels we're beyond the limits
of what technology can measure a
threshold below which we can't
theoretically measure anything at all
but the scientific imagination can still
probe even smaller levels using the
framework of mathematics and imagination
and maths have come up with a remarkable
concept of the final building blocks of
the universe super springs these
entities are tiny Springs of energy that
vibrate like the strings of a guitar and
as guitar strings produce different
notes as they vibrate at different
frequencies so super strings vibrating
at different frequencies can create
different particles like electrons or
protons
but the superstring is a small in
relation to the nucleus as a single atom
is to our solar system something so
small might lie forever beyond the
limits of our perception so all we can
perceive is the music of super strings
the journey inwards has taken us to the
limit of our perceptions and our common
sense but what happens when we look
outwards what does the world look like
at larger scales than our familiar
viewpoint for example to our normal
senses when walking through a forest we
see a collection of trees yet we can
look down on it and see the whole forest
from above
and from here it looks like a solid
green entity covering the landscape in a
way that's also a true perception the
forest is like one organism it's linked
together at the microscopic level the
roots of the trees are all connected by
tiny fungal threads weaving through the
soil even in the largest forests a
microscopic web of living matter
connects all the elements together
but they can see the woodland from an
even broader perspective from a
satellite we can watch the whole forest
change color as autumn sweeps across the
woodland
satellites capture images of vast swirls
in the atmosphere we can watch the fly
mate as it changes
or see the vortex patterns of clouds
created by islands
using a different sense infrared we can
distinguish between different types of
vegetation even the different crops
grown by farmers
satellites give us a completely
different view of the earth
technology does far more than generate
stunning images it gives us more and
more accurate measurements even of
something as complex as the climate so
does this mean we can use this
information to make predictions can we
forecast the weather accurately
the answer is no there's a fundamental
property of the universe that stops us
chaos
there are systems so incredibly
sensitive to how they start off that the
slightest change even one too small to
measure can change the whole outcome the
weather is one of these systems it's as
if the air currents created by a
butterfly's wings are enough to affect
how the weather develops halfway around
the world phenomena that are chaotic do
follow simple mathematical laws they
just seem to behave in a random way
chaos theory goes against common sense
and it does go against 500 years of
scientific thinking there are things
that appear to behave randomly because
of what they are rather than because of
any outside effect ultimately that means
that we'll never be able to predict the
weather
chaos is everywhere even if we could
predict the weather we could never
predict the path of each raindrop or its
path as it joins a running stream
chaos has changed the way we think about
the world but seeing the earth from even
larger scales has given us yet more
surprising insights
the Apollo missions gave us a completely
new view of our planet
as Apollo 11 sped towards the moon
millions of people all across the planet
saw images of the earth as a tiny blue
sphere vulnerable and isolated hanging
in space and it's the only world we know
that supports life and some people
suggest that the earth itself behaves
like a living creature regulating the
climate to keep conditions just right
for life according to this Gaia
hypothesis it's the smallest creatures
that are the most important a green
stain in the ocean is made up from
uncountable numbers of tiny plankton
these Akaka live for each only a
fraction of a millimeter across but they
exist in such numbers they can affect
the climate if for example the earth
warms up the plankton breed faster
increasing their numbers even more but
they release a substance called DMS
which finds its way into the atmosphere
and DMS causes water to condense into
droplets making clouds so more plankton
means more clouds and as white clouds
reflect sunlight back into space the
planet cools down the earth stays in the
narrow temperature range where water
exists as a liquid a vital condition for
life itself for our planet is part of a
bigger system based around the Sun and
sunlight is the other crucial ingredient
for life all the patterns and layers of
life that we saw on the journey through
the micro worlds depend on sunlight to
fuel their diversity 500 years ago we
thought we knew that the earth was the
center of the universe but now we
understand that it orbits the Sun and
the Sun is at the center of the next
level of reality the solar system
the Sun is a fairly ordinary star and it
shines because at its centre hydrogen
atoms are squeezed so tightly they fuse
together forming helium and giving off
massive amounts of energy in the process
that energy radiation traveling at the
speed of light takes about eight minutes
to reach the earth but the radiation has
to get from the Sun's core where it's
created to the surface bouncing off the
squeezed atoms as it does so the atoms
in the Sun are so tightly packed that a
journey that should take two seconds in
a straight line actually takes ten
million years so the heat and light that
fuel life on Earth today was created
long before humanity even evolved the
Sun heats and lights the whole solar
system but just as important
it holds the whole system in place
Isaac Newton published his theory of
gravity in 1687 and his calculations
showed how gravity keeps the planets in
their orbits it seemed the universe was
a place of mechanical precision and
using Newton's mathematics the rising
and setting of the Sun and the phases of
the Moon could all be predicted this
same mathematics allowed us to calculate
the path of space probes in the past all
we could do was to point telescopes at
the sky but now we can send probes to
visit the planets close up mercury is so
near the Sun it's rarely seen with the
naked eye in 1975 the Mariner probe
showed us that mercury is a dead small
world that rotates so slowly but it's
day is longer than its year
during its day temperatures reached 350
degrees hotter than an oven and at night
more than 170 below zero the next planet
out from the Sun is Venus the evening or
morning star but although it shines so
brightly in the night sky the planet
itself is hidden by cloud the Magellan
probe used radar to see through the
clouds and found a turbulent world the
greenhouse effect of the cloud cover
keeps the surface at 450 degrees hotter
than mercury hot enough to melt lead
and then the third planet home at this
scale the earth is unique it's a double
planet its moon was once part of the
earth itself smashed off by an impact
with a lump of rock the size of another
planet the next planet from the Sun is
the stuff of science fiction Mars but
the mariner probes showed there were no
Martians no water and little atmosphere
but the surface is spectacular covered
in deep gashes including a Grand Canyon
the length of the entire United States
there are also the remains of huge
volcanoes one rising 25 kilometers above
the surface the biggest volcano in the
solar system perhaps the most famous
probes are the Voyager spacecrafts
launched in 1977 towards Jupiter the
giant gas planet
Jupiter is so big it could swallow the
rest of the planets with room to spare
it's a swirling seething ball of gas
including methane and ammonia storms
rage over its surface arrogance far more
powerful than any on earth beyond
Jupiter Voyager journeyed on to another
gas giant Saturn with its famous Rings
the Rings aren't solid they're made of
tiny fragments of ice and rock possibly
the remains of a shattered moon or
comets
beyond Saturn is Uranus an ice giant
Uranus has a very strange movement it
rolls around the Sun on its side its
moons circling it like a giant Ferris
wheel so far out that the Sun is just a
distant point of light Neptune's orbit
is so vast that a year on Neptune takes
165 earth years to human lifespans
Neptune is another ice giant like Uranus
but we know little more about it but
Newton's mathematics showed that between
the orbits of Mars and Jupiter there
should be another planet
there isn't instead there's a band of
millions of lumps of rock the asteroid
belt and in the year 2001 we even
managed to land a probe on the asteroid
eros
we have no idea how many asteroids there
are but they range in size from small
moons to house bricks and at this level
the clockwork mathematics breaks down
and chaos appears again
for the motion of the planets Newton's
laws are only approximations even the
equations for just three bodies of
similar size are hideously complicated
beyond the reach of conventional
mathematics so it's completely
impossible to predict what will happen
in the asteroid belt
we've only just begun to realize how
many asteroids there are and how close
some of them come to earth extending our
limits of perception doesn't always make
us feel comfortable meteorites
rocks from outer space pieces of other
worlds captured behind glass for us to
see they've been wandering the solar
system for millions maybe billions of
years some of them visit us from further
than its outer edge it took a major
change in how we perceive the world to
realize that the Sun is just another
star and our solar system is part of
even bigger structures to even think
about the size of these structures we
had to invent a new way of measuring
distance a light second is the distance
light travels in one second about
300,000 kilometers and distances within
the solar system are measured in light
minutes or light hours earth lies about
8 light minutes from the Sun
it takes light 43 minutes to reach Earth
from Jupiter so we're seeing it as it
was 43 minutes ago
Saturn lies just over one light hour
from Earth but distances beyond the
solar system are measured in lightyears
the distance light travels in one year
to find out what lies beyond the solar
system we sent a probe to look the two
Voyager spacecraft set off in the 1970s
Voyager 1 is now traveling at 96
thousand kilometres an hour and is 11
light hours away still transmitting
signals back to earth it carries our
signature onboard information about who
we are and where we live in case the
probe meets other intelligent life
Voyager 1 has a new mission to find the
heliopause the boundary where the solar
wind particles streaming out from the
Sun are beaten back by the interstellar
wind it's heading for the edge of the
solar system itself but before it gets
there it has to pass through the Oort
cloud a motley collection of comets and
rocks that it'll reach in 20,000 years
but it'll be travelling for a hundred
thousand years before it meets the Suns
nearest neighbor Alpha Centauri four
light-years away not one star but a
group of three
as we look further and further into
space we're looking further and further
back in time distant stars are so far
away their light takes thousands of
years to reach us we're seeing them in
the past at a time before human
civilization existed
but beyond the stars is a bigger
structure the galaxy
the galaxy is thousands of light-years
across a huge spiral structure of
billions of stars
we live in one of the spiral arms the
Orion Arm about two-thirds of the way
out from the center from Earth we see
the disk of the galaxy edge on as the
Milky Way across the sky
scientists are only now coming to terms
with the scale of the universe but
artists have always explored the
infinite the world beyond the one which
meets our eyes the hidden the mysterious
as William Blake said if the doors of
perception were cleansed everything
would appear as it is infinite
worlds within worlds worlds without end
looking up at the stars takes us out of
ourselves gives us a sense of
perspective
but there's a problem with looking up at
the night sky the atmosphere limits our
view the answer is to put a telescope as
high in the atmosphere as possible on
top of a mountain mount akia in Hawaii
where the Gemini telescopes are so
sophisticated that computers actually
distort the mirrors to compensate for
the atmosphere they can stop the stars
from twinkling and produce stunning
views of space clouds of dust and gas
creating magnificent abstract images
but there's another solution put the
telescope itself in space the Hubble
Space Telescope is gazing outwards
towards the edge of the universe seeing
further than ever before and revealing
layers of the universe we could never
have imagined
the new generation of telescopes have
shown how dynamic our galaxy is we can
watch the birth and death of stars
themselves
when Hubble was turned to look towards
the constellation of Orion it could see
deep inside the Eagle Nebula it saw
these massive towers of gas star
nurseries in each of the pillars gas is
condensing an igniting nuclear fusion
and new stars are born
we can also witness the death of stars
as the stars hydrogen fuel runs out it
starts to fuse helium into other
elements calcium potassium and carbon
eventually no more reactions are
possible and the star dies throwing the
elements of in a spectacular cloud of
gas our bodies are made up of these
elements we are literally Stardust
but the biggest stars don't go quietly
they explode with unbelievable energy a
supernova for a fleeting instant a
supernova outshines a whole galaxy of
stars in 1054 Chinese astronomers
recorded a supernova as a star that
shone so brightly they could see it in
daylight a thousand years later we see
the leftover cloud of gas as the Crab
Nebula still expanding at thousands of
kilometers a second
all this drama takes place within our
own galaxy but when Hubble was pointed
at an empty patch of space and took an
image with an exposure of four days this
is what we saw not black space but more
galaxies our galaxy is only one of
billions galaxies come in different
shapes spiral like our own elliptical or
just irregular blobs
all the galaxies are racing apart from
each other as the universe expands but
sometimes gravity wins out and galaxies
collide but galaxies are so vast and the
stars within them are so far apart that
the galaxies just fused together
it seems there's no end to the layers of
structure within the universe galaxies
themselves are part of bigger structures
clusters and superclusters our own
galaxy is part of a small group of six
which includes Andromeda and the mega
Lanna clouds but this group is racing
towards the center of the Virgo
supercluster made up of more than a
thousand galaxies the super clusters
themselves are linked into one vast
shape the shape of the known universe
there might be more but for now
everything we know is here this is the
outer limit of our perceptions is it the
nearest we'll ever come to the creators
view of the universe
and at the opposite end of the scale
will we ever find out what composed the
music of the super strings
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