- Usually, we only ever see the outside of something,
but the term, don't judge a book by its cover
applies to inanimate objects as well as each other,
as so many items have amazing interiors
revealed by their cross sections.
Using laser cutting and other techniques,
we're able to investigate the inside
of objects better than ever before.
- Number 20: Golf balls.
White and pitted on the outside,
we all know the texture features
of the golf ball's exteriors.
Inside and out, they're actually
and undergo many analytical tests
to assess how far they travel,
how stable they are in the air,
and how quickly they rise and fall.
These are partly controlled by the ball's dimples,
which create turbulence around its surface,
but what forms their weighty interior?
Photographer James Freedman took these great photos.
These sliced golf balls have been perfectly cut in half
to reveal their colorful cores,
which are akin to gobstoppers or model planets.
Some clearly have layers of different materials,
which are color-coded, depending
on their intended effects on a golfer's game.
One thing is for sure,
golf balls are exquisitely built for something
so frivolously hammered up the range,
though not all of them are built equally.
Number 19: Bowling balls.
If golf balls were planets, then this ball is the sun.
Cutting open a big old bowling ball
reveals a hard core of weighty resin,
or different shaped weights,
which effect the way the bowling ball travels.
There are two things that a bowling ball needs to do.
Roll quickly and precisely.
They feature a characteristically smooth surface
to help them glide, and are weighted between 6 to 16 pounds.
To help them make up this weight,
the cross section reveals a resinous interior,
but some bowling balls feature metal
or resin weights inside them too.
These aren't always spherical either.
Some weights are elliptically shaped,
like eggs, or are shaped like bulbs.
This is to influence the momentum of the bowling ball,
supposedly helping it to accelerate
all the way up to the pins for maximum impact.
Number 18: Bullets.
Bullets are formed from many components.
They're pieces of precision engineering,
as they need to fly through to their trajectory,
and, most importantly, fire in
the first place and not backfire or jam.
When you pull the trigger, the first component
that's engaged is the metal firing pin
in the bottom of the cartridge.
This ignites a small explosive,
which then ignites the propellant,
which is a big explosive, usually gunpowder,
which you can see filling most of the bullet.
Lots of energy is generated very quickly in the tiny space,
and the sudden pressure pushes
the bullet from the cartridge at extremely high speed.
300 meters per second or a thousand feet per second
is typical for a handgun.
Once fired, the cartridge itself is ejected from the gun.
Number 17: Aloe Vera.
This plant has been used medicinally for thousands of years,
and when you see it's cross section,
you realize why it's so soothing when you get a sunburn.
It's a type of plant called a succulent,
and this cross section illustrates why.
It's full of awesome gel sap,
which can be rubbed on wounds or rashes to sooth them.
Number 16: Camera lens.
Here's some more mechanical intricacy.
This cross section reveals that a camera lens
is an astoundingly complex bit of kit
that comprises of many interlinked lenses
that move in tandem in order to focus light
onto a camera's film, or digital sensor.
Number 15: Shell.
Nature's cross sections always provide interesting forms.
Shells are particularly complex,
and when studied as a cross section,
the wonderful patterns are revealed in all their beauty.
Some shells follow near perfect logarithmic scales,
namely the golden ratio in accordance with Fibonacci.
Whether shells perfectly follow this phenomemon
or not, they're still mystifying.
A mollusk, who once called a shell
you find on the beach home, excreted,
maybe millions of years ago, calcium carbonate,
which solidifies in strangely perfect patterns,
spirals with twisting interior chambers
and colorful, smooth, or knobbly exteriors.
But why are they so complex?
It's not easy to answer, but at some point,
they may have evolved these complex shells
to adapt better to their environment.
Number 14: Jawbreaker.
They're rock solid, and have a rocky, banded interior,
where the multi-colored layers of sugar
stack up to form these mammoth-sized sweets.
This amazing cross section reveals
the gobstopper's sugary colored layers.
Number 13: Pot noodle.
Cutting an unassuming food packaging to reveal its contents
often shows how little you actually get for your money.
This pot noodle contains a couple
of inches, tops, of pot noodles.
Okay, it's still a snack, and kind of tasty one at that,
but it's a big pot that misleads you
into thinking you're getting a big meal when, actually,
you're just getting a small amount of noodles.
Number 12: Zippo Lighter.
A small little device, zippos have been around for ages,
and have a classic look when you
take their interior in a cross section.
They're tried and tested, and are made
in the same way now as they ever were,
with a wick drawing fluid up from a reservoir,
to where it's ignited with the flint.
Number 11: Tortoise Skeleton.
Want to really behold nature's complexity and beauty?
The logical way is to go and cut
a tortoise's skeleton in half, of course.
Tortoises and turtle shells are extremely strong
and encase all of the animal's vital organs.
From this cross section, we can see how the shell
is essentially an extension of the ribcage.
The stronger outer layer is fused to the ribcage
and connected to the tortoise's vertebrae.
This is why you should never pick up a tortoise
or turtle by the sides or top of the shell.
Only ever underneath to support its skeleton.
Number 10: Stem.
This time, we have a microscopic cross section,
incredibly details and colorful,
it reveals the complexity of plant stem,
the main component of plant, which supports it
and brings nutrients up from the ground.
There are a few different cells in a plant stem,
but there are two main ones, which
you may recollect from school, named xylem and phloem.
They both bring up nutrients from the stem,
but xylem are actually primarily dead cells
that form the hard core of an adult stem,
whereas phloem are still living, flexible tubes.
Number 9: Plane.
It's not just small things that humans have cut in half.
This cross section reveals just how much storage
there is beneath your feet as you're flying on an airplane.
Some of us love flying and some of us hate it.
Whichever camp you're in, this cross section
may or may not help you appreciate
the structural integrity of a plane.
There really isn't much metal separating you
and the outside, but don't worry.
Plane testing these days is absolutely brutal.
For example, most wings can flex an amazing 90 degrees.
Number 8: Lock and Key.
An every day item that we never see the inside of,
a lock and key is a surprisingly complex bit of engineering.
We take them for granted, but they do so much work for us,
securing our houses day and night, our cars,
our school lockers, and our luggage, but how do they work?
This cross section reveals
the lock's barrels, with several pins.
When the key is pushed in, the pins are pushed down
until they become flush with the barrel,
which will allow the lock to turn.
If the wrong key is inserted, some or
all of the pins will still lock
the door's barrel, preventing it from turning.
Number 7: Toothpaste.
Ever wondered how the stripes in
your toothpaste don't get mashed up?
This cross section reveals all.
Well, most of it anyway.
It reveals that, firstly, the stripes aren't coiled up
inside the tube, but instead, the tube contains
one big core of striped gel and paste.
When you squeeze the tube, this large cylinder of paste
gets forced through a smaller tube, and compacts.
This is based on a branch of physical called rheology,
which deals with the complex flow of liquids, like gels.
The different gels in toothpaste
have identical flow characteristics,
which means the whole tube flows as one,
even though it's forced through a hole.
Number 6: Cruise Ship.
Ships are sometimes lengthened
by cutting them in half and adding a cross section
into the middle of the boat, and then they're,
of course, welded back up to be water tight and strong.
This is what you're seeing here.
They're incredibly large, densely packed vehicles,
that can weigh hundreds of thousands of tons.
This particular fairy was lengthened a huge 75 feet
by adding a cross section into the middle of it.
It might've been a lot of work,
but it's still cheaper than a new boat.
Number 5: Grey Owl.
Owls are big birds.
Their feathers are very thick, and densely layered,
and they have big, round heads with big eyes.
Shed all of the feathers, though,
and an owl may not look so majestic and wise,
but, instead, small and scrawny, resembling a chick.
To be fair, though, all birds would look similar to this
if they didn't have feathers, and you can really see
the dinosaur in them, from which they originally evolved.
An owl's plumage is dense and well-layered.
It definitely looks warm.
It's like having a coat a couple times thicker
than your actual body.
Number 4: Gas Station.
Okay, okay, they didn't get some giant excavators
and diggers to cut up a real gas station.
This is just a model, but an interesting one at that,
and I bet you've never considered just how much gas
lies beneath our gas stations.
Beneath where you stand at the pump,
lies an enormous reservoir.
Now that explains why these things cause
such massive explosions in movies.
Number 3: Fireworks.
Fireworks are just primitively built explosives,
but they do feature a host of chambers
that are filled with different chemicals,
which produce different color explosions.
A fuse delays the takeoff long enough
to get away from the firework,
and then it's propelled into the air.
Number 2: Grenade.
Precision engineered to work reliably,
just the way you need them to,
a grenade is formed from many mechanical components
exposed by its cross section.
They work similar to bullets.
There are explosives held in a reservoir
that is triggered by a chain reaction.
There are actually three small explosions
that happen in series.
If you look at the components from
the top to the bottom, you can trace this reaction.
A grenade is triggered by a striker
that lies inside the grenade.
When the grenade is inactive,
the striker is held in place by the pin
on the outside of the grenade,
but once you pull the pin, the spring is released,
and the striker creates a small spark,
which lights the fuse.
The fuse material delays the explosion.
It has to burn all the way through,
and when it does, it sets off the detonator explosives,
which then cause the larger amount of material
in the outside of the grenade to explode.
Number 1: Visa cards.
This is something that is well and truly taken for granted
until you run out of money and really appreciate
the power this small card has over you.
They sit in our wallet day in, day out.
It might seem like they just contain a chip,
but don't forget the card strip too.
That lies below the chip, within the card's slim interior.
There's more metallic circuitry here than you would guess,
as Visa cards aren't just plastic after all.
There's certainly some extremely cool cross sections here.
Which cross section did you think was the most interesting?
Leave comment down below to let me know.
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