Bone Cities, Ash Towers, and 4 Other Futuristic Buildings

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to learn more. [♪ INTRO] Right now, the construction industry heavily
relies on concrete. And for some good reasons. Concrete is cheap, and it is a highly efficient
way to build safe and secure buildings. But it’s also so bad for the Earth. It takes huge amounts of energy to produce
and ship this stuff, and these days, concrete alone produces about 8%
of global carbon emissions. In 2018, that translated to almost 3 billion
metric tons of carbon dioxide. So while concrete is convenient and all, it
would be great if we could find an alternative and start making our buildings out of something else. Well, maybe shockingly, we’re not actually
the first people to have had this thought! Many scientists are already conducting research
into the materials of the future, and some of their ideas are so off the wall that they
just might work. Here are six of them. Let’s kick things off with one of the weirder
examples: synthetic bone. Because, you know. Living in a building made
of real bones, that would just be too upsetting. Scientists at Cambridge have been working
on this project since around 2011, and although it may seem odd, there are several good reasons for using bone-like materials in construction. For one, bones are incredibly strong for their
size and weight. A bone fragment the size of a sugar cube can
support over 1500 kilograms, more than some types of concrete. Also, thanks to their structure and composition, bones are very elastic and resistant
to fracture and breaking. They’re made of minerals like calcium and
phosphate, along with the protein collagen. That collagen clusters into long fibers, and
it combines with the mineral in just the right way to create a strong, flexible matrix. Your body made this kind of matrix over years
of development, but to make synthetic bones, scientists have found ways to speed up that
process. To make their material, they dip a small template
into a solution of calcium and collagen proteins. Then, they dip that into a solution of phosphate
and collagen proteins. And back again. This process is repeated over and over,
layer after layer, until it creates a sample that mimics the strength and structure of natural bone. This method is great, and if we could get
it going on a large scale, it seems like it could be a cool alternative to concrete. But it does have its downsides. Right now, the biggest problem is that the
only good place to get collagen is from animals. This protein is super hard to replicate in
the lab, so if we wanted to build something from synthetic bone, we would need a lot of animal parts. And while we could use waste from the meat
industry, even that might not be enough. So until we figure out synthetic collage, don’t expect to see super goth, bone cities any time soon. But, that doesn’t mean they’re off the
table. So I want to see it in your scifi short stories! Next, the magic of mushrooms is at it again. While some teams are looking for materials
that outperform concrete, others are just looking for things
that are safe for the environment. And that’s led them down some weird paths. Take the work of an architectural team known
as The Living. In 2014, they designed and built a 12 meter-tall
castle, the first and only building to be made of nothing but fungi. The bricks in this tower were made of recycled
mycelium, which are thin, branching structures
that look similar to roots. The mycelium was collected from fungi that
grew on agricultural waste, like corn and wheat crops, so it was a totally sustainable
and renewable material. And the bricks weren’t that hard to make, either. To create them, researchers placed organic
materials, anything from dirt to nut shells, full of mushroom spores into a brick mold. And in only 5 days, the mycelium had grown
dense enough to make a brick. As a bonus, because these blocks are made
from fungi, they’re totally compostable. If you throw them in a compost heap, they
would be dirt again within sixty days. Still, just because these bricks are eco-friendly
doesn’t mean they’re strong. They can withstand only about 0.2 megapascals
of pressure, which is less than 1% of what concrete can handle. Realistically, that means we will not be building
mycelium cities. Instead, researchers have suggested that we
could combine the mycelium with other things to make more stable structures. So, it’s a start! Both synthetic bone and mycelium are pretty
futuristic materials, and it’s going to take a lot of work to figure out how they
might fit into our world. But this next example might be pretty easy
to adopt. In 2013, scientists at MIT developed 3-D-printed,
reusable bricks that function a lot like LEGO bricks. Except, instead of being made of regular plastic,
they’re made from a carbon-reinforced epoxy resin. Epoxy resins are a group of materials that
easily form strong bonds with other materials, like glass or carbon. They’re exceptionally strong and very resistant
to erosion or damage. And in this case, since they’re being 3-D
printed, they’re customizable, too. Engineers can make structures stronger or more elastic by assembling the resin bricks into different shapes. Now, to be clear, most epoxy resins aren’t
that environmentally friendly. They’re basically a type of plastic, and
plastic is, you know, terrible for the environment. It requires a lot of natural resources to
make and takes forever to disintegrate. But these bricks try to make up for that by
being extremely reusable. They’re easy to retrieve when a building
needs to be taken down, and they can be used again and again for new buildings. Also, these things are surprisingly strong. Structures made from them can withstand 12.3
megapascals of pressure, which is incredible for such small and light materials. For comparison, average concrete can withstand
17 to 28 megapascals of pressure. And it’s much heavier and worse for the
planet. Researchers believe these blocks might not
be strong enough for skyscrapers, but they could be used in much smaller buildings, like
houses. And it’s not hard to imagine a future where
a crew shows up, stacks a bunch of blocks together, and creates the shell of a house. So again, if these bricks can be mass-produced,
it could mean great things for construction. The last 3 examples have been pretty innovative, but they’ve almost entirely ditched traditional building materials and gone in new directions. That’s great, because new ideas can lead
to big places. But it also means that it might be a while
before these things hit the primetime. These next examples, though, are a bit different: They’re more practical, and probably wouldn’t
be as expensive to implement on a larger scale. So you might be seeing them enter the market
a bit sooner. One option like this is called AshCrete, and
it’s a modified version of concrete. Standard concrete is made by using cement
to bind together small aggregates like sand, gravel, or crushed stone. This makes it heavy and hard to transport,
but also, those aggregates aren’t sustainable. We only have so much sand and stone to throw
around. Enter AshCrete. It’s an alternative concrete made using ash from waste-incineration facilities as the aggregate particles. It can be used in many of the same places
as traditional concrete, and it allows those waste facilities to recycle some of their ash. So, win-win. Unfortunately, although it can solve some
of concrete’s problems, it’s not perfect. Most notably, making and transporting AshCrete
requires the same amount of energy as concrete, and this new material isn’t great for all
climates. Compared to regular concrete, AshCrete can
take longer to solidify, and it’s more susceptible to cracking from freeze/thaw cycles, since it doesn’t trap as many insulating air particles. So it has its flaws. But if we want to start rolling out better
materials for the planet soon, it might be a good place to begin. And besides Ashcrete, there’s also a number of other materials that try and improve upon things we have now. For instance, scientists have also thought
about trying to reinforce clay bricks with 2 of the most renewable substances we’ve
got: wool and seaweed. Which sounds weird, but would work surprisingly
well. Although they don’t get as much attention
as concrete, regular clay bricks are a huge pollution problem because they require a ton of energy and natural resources to make. Like, not only do you need things like soil,
sawdust, sand, and lime to make the brick, but then you have to fire it. And that means you have to burn things like
wood or coal, and that results in a bunch of carbon emissions. One way companies try and clean up this process
is by making what’s called a non-fired brick, where you use machines to smash a bunch of
clay together and then let it dry in the sun. The problem here is that the final product
typically isn’t as durable as a fired brick, but there might be a way to change that. At least, according to a 2010 paper published
in the journal Construction and Building Materials. In that paper, two architects suggested using
wool and seaweed to make these bricks even stronger. In these blocks, wool fibers are mixed with
a natural compound from seaweed called alginate. Then, that’s mixed into traditional, non-fired
clay bricks. The alginate acts as a binder instead of sawdust, and the wool fibers increase the strength and structure of the bricks. By a lot, actually! Traditional non-fired bricks have an average
strength of around 2.3 megapascals. But in a test, scientists demonstrated that
when both alginate and wool are added to the blocks, the strength increased to around 4.4
megapascal, almost double! That would make them great for things like
walls, small houses, or decorating. And with much less of an impact on the planet. Finally, our last and most practical example! Because, look, sometimes the future starts
small, and that’s okay. Say hello to the pollution-absorbing brick. These bricks were developed in 2013, and admittedly,
they are made of traditional concrete, since that allows them to be competitive with current
materials. But they’re trying really hard to make up
for that. These blocks take in pollution from the outside
air, and then release clean air into your building through a traditional ventilation system. So these things have two main components. The first is, of course, the brick itself,
which faces the exterior of the building. Each brick has a cyclone air filtration system
in it, which creates a super fast spiral vortex inside the brick, sort of like a mini hurricane or a centrifuge. As the vortex spins, the heavy pollutant particles
drop to the bottom of the vortex and are deposited into a collection hopper at the bottom of the wall. The second component is the recycled plastic
couplers, which go between each of the bricks. These couplers both help align the bricks and allow air to get into the center of the bricks and the filtration system. The blocks can trap about 30% of pollutants
from the air the touch, as well as 100% of coarse particles like dust. This makes them a great potential way to passively
clean up the air in our cities. So even though it won’t solve our concrete
problem, it is a start. And it could likely help us with at least
some of our environmental woes. There’s a ton of cool research being done
into alternative construction methods, and the list goes way beyond these six examples. That’s important to keep in mind, because
any one of these solutions probably can’t make construction eco-friendly all by itself. We’re likely going to need tons of alternative
options, so the more ideas there are, the better we might be. And things seem to be moving in the right
direction, at least, based on these projects. And one way or another, it’s cool to see
what kinds of solutions engineers are coming up with. Even if I never get to live in like, a sweet
bone building. If you enjoyed this episode of SciShow, there’s
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of the Internet, and it has a really futuristic vibe, kind of like this episode of SciShow. It’s hosted by Veritasium’s Derek Muller,
and it talks about how the Internet got here and where it’s headed. If you want to give it a watch, you can get
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you’re also supporting SciShow and helping us make more content like this. So thanks for considering it. And we hope you learn something cool. [♪ OUTRO]