Nanoporous polyethylene achieves its goal when the external temperature is lower than your body's. If this material is sandwiched between cotton cloth pocked with tiny holes for airflow and treated with a chemical to wick away water, you get the perfect workout outfit. Researchers are studying how flexible it can be made and how it works on human skin.
Don't worry, material engineers haven't forgotten their roots. It makes perfect sense for them to look to the animal kingdom for inspiration, just as their Stone Age ancestors did. Small animals such as beavers evolved fur that traps air. This air provides a layer of insulation whenever the animal enters water.
Now the spacing between hairs and the length of the hairs on artificial pelts keep the air level intact. In water, it maintains the air layer. Scientists are modeling small animal pelts so they can create swim gear for cold-water divers.4
IT'S ELEMENTARY
An element is something made of a single atom. For example, hydrogen is an atom made up of one proton. If you add a proton (think fusion) to hydrogen, it becomes a helium atom once. The elements have been good to us inside and out. Your body and everything you can ever interact with are made up of elements.
Scientists have done a lot with the known ingredients they've found, all of which are listed in the periodic table of elements. After the addition of nihonium, moscovium, tennessine, and oganesson in 2016, the tally stands at 118.5 Granted, these newbies are stable for only a fraction of a second and therefore not very practical for making new materials, but they do add to our understanding of the earliest moments after the big bang when these higher-order elements might have existed.
Even with the 118 that have been found, there might not be enough elements on the periodic table to meet the demands (or dreams) material engineers have for the next generation of synthetic materials. The solution is simple. Just make a bigger table with more elements. Add a little bit to nature. This is where superatoms come in.
Superatoms occur when a group of regular atoms are combined to act like a single element, one not found on the periodic table. A superatom can have properties that don't exist when the mundane elements are combined. Chemists are working out the rules for linking them into molecules.6 Once they do, they'll be able to create synthetic structures that can be tweaked to serve specific purposes in exotic materials.
These superatoms might be why Tony Stark can make his Iron Man uniform. Otherwise, how could it be so light and flexible? At face value, it defies the properties of non-synthetic elements. Iron and titanium are too heavy for his movements or for flight.
As long as we are talking about members of the Avengers, Captain America's shield is made from vibranium, a metal/material I challenge you to find the elements for. In the Avengers movie, the shield is somehow able to displace the kinetic energy of blows from Thor's hammer (whatever that is made of). Following the rules of physics, my math kung fu cannot begin to work out the displacement that makes that possible. Unless Thor's hammer isn't all that powerful. And yet, it is.
WHAT IS A SUPERCONDUCTOR?
Superconductors are a type of material in which electrons are liberated and therefore free to flow between atoms without resistance. And as a perk, no heat or stray energy is released from their motion. On a superconducting material, an electric current could flow endlessly without needing a power source to give it a swift kick in the rear to keep it moving.
It sounds like the perfect material, and it would be if it didn't have one tiny (almost not worth mentioning) problem. The electrons are only free when the material is unenergetic, meaning it has to be very, very cold, near absolute zero cold (-273 degrees Celsius/460 Fahrenheit).7 It takes a lot of energy to cool a material enough to make it superconductive. In Star Trek, if Spock were an economist, he might tell Kirk that the cost of superconducting outweighs the benefits.
The holy grail for material scientists is to discover a material that acts as a superconductor at room temperature.
ANY WAY AROUND THAT FREEZING PROBLEM FOR SUPERCONDUCTORS?
The answer is a work in progress. Perhaps the solution will be found with the most basic of the elements, hydrogen. Rival teams of scientists are racing to turn the simplest, most common, and first among all elements in our universe into a metallic room-temperature superconducting material.8
The record for warmest superconductivity is held by hydrogen sulfate at -70 degrees Celsius.9 I bet you knew that hydrogen sulfate contains hydrogen. If hydrogen can successfully be made into a metallic material, it could replace copper in electrical wiring, reducing the loss of energy that comes with copper. Best of all, that efficiency would decrease the demand for power.
As is true for most matter, depending on temperature and pressure, hydrogen comes in different flavors or, rather, different phases called states. The third interlude includes details for the different states of matter. At room temperature and earthly atmospheric pressure, hydrogen is a gas. As pressure increases, it will transition into a solid. Mix in more heat to have it transition from a solid into a liquid. Under extreme pressure, the electrons begin to dislodge. The hydrogen changes into either a liquid or solid metal. If it becomes a solid and is able to maintain that state after the pressure is released, we can have our superconducting wiring.
A CARBON SOLUTION FOR MATERIALS
Carbon is the sexy hero element of the day and not just because it's the element that makes you organic. When it pulls off its glasses, it goes from mild-mannered element to the superhero of exotic materials. One is graphene. It's such a fantastic material that Andre Geim and Kostya Novoselvo won the 2010 Nobel Prize in Physics for isolating the material in 2004 at the University of Manchester.10
Graphene is the thinnest of carbon materials, the width of a single carbon atom, and it is flexible. That's not all. Additional benefits are that it's stronger than steel, flexible, transparent, and unreactive. Although it might not be a superconductor, it is the most conductive of the current materials. Due to its slenderness and flexibility, it is the material of choice for nanotechnology.
At the Tsinghua University in China, researchers discovered that spiking the mulberry leaves they feed silkworms with a graphene solution makes the little critters spin silk that is 50 percent stronger.11 This super silk also has the ability to conduct electricity. This new material could someday be used to make wearable electronics.
Carbon knows another cool trick. If we arrange the atoms a bit differently, we form a carbon-based material called Q-carbon. It gets the “Q” designation because forming the material involves heating and rapidly cooling the atoms in a process called quenching. Besides the cool name, it is both magnetic and stronger than a diamond. And, believe it or not, it glows in the dark!12
This material is perfect for many applications like electronic displays or abrasive coatings for biomedical sensors. Not that it matters much, but the Q can be used as a quick way to make diamonds. Carbon has many structural forms (graphene, graphite, nanotubes, buckyballs, diamonds, etc.), but none are magnetic. This property makes the Q-carbon structure so exciting.
By the way, a nanotube is rolled-up graphene, and buckyballs are hollow balls made of carbon atoms that can be used as medical delivery systems.
CAN ANY MATERIALS HARVEST LIGHT?
A polymer-based photovoltaic material can be used to harness not just the sun's visible light but also the infrared rays.13 The new plastic material uses quantum dots mixed with a conducting polymer to absorb infrared. Quantum dots are tiny semiconductor particles made up of cadmium telluride that react to electricity or light. The switch from silicon to plastic solar cells could make it easier and cheaper to soak up the sun's rays for energy.
Previously, plastic solar cells relied solely on visible light. They were only able to convert an anemic 6 percent of the sun's energy into electricity.14 Using this new material, plastic solar cells might be able to achieve up to 30 percent efficiency.15 Want more? Okay. This material can also be used to detect infrared light for night vision came
ras. The current cameras rely on semiconductor crystals. Imagine swapping out expensive crystals with plastic.
NOW YOU SAW IT, AND NOW YOU DIDN'T
What do you think about people seeing through you (optically, that is)? Or, how about cloaking your starship as you sneak past an enemy armada? If you have thought about these things, then read on. But beware: the methods of invisibility I'm going to describe are more Klingon than Harry Potter. This is invisibility of the science kind.
Two scientific methods can render an object invisible: spatial cloaking (making something invisible in space) and temporal cloaking (making something invisible in time). These theories are straightforward and easy to understand; however, the methods of their application are very complex. In science fiction, the opposite is usually true: the theories are based on a lot of fantastical elements of the novel's world, and application is simple—we push a button, or drink a formula, or wave a magic wand that is sometimes called a sonic screwdriver, and presto chango! We're invisible.
The key to invisibility is light manipulation. As light reflects off an object, it carries information about the object (such as its size and shape) to our eyes or to mechanical detectors. So, the goal of invisibility is to prevent tattletale light from passing on these details.
Spatial Cloaking Using this nifty trick, light flows around an object and recombines on the other side, leaving no evidence of its detour. If you were to look at the object, you would only see what's on the other side. The physics behind this isn't much different than how refraction makes a straw appear bent in water.
As usual, the difficulty (not so difficult in science fiction) is in the how of building the cloak. It all comes down to the construction of metamaterials, materials that have properties not found in nature. In spatial cloaking, optical metamaterials made from nanotechnology surround the object to bend light.
Think back to your last vacation when you were getting your Zen on. You might have watched water flowing evenly around a stone in a river. This is what metamaterials do. They flow light around an object. Of course, the low-tech option uses mirrors to direct light around what you are trying to hide. Although this is magician simple, it isn't as efficient because it's a stationary form of invisibility. With a metamaterial cloak, you (might) be able to walk around unseen.
Fig. 18.1. Illustration of spatial cloaking.
Temporal Cloaking Instead of cloaking an object, why not cloak an event? Whenever light illuminates an event, it marks that event in time. If an event somehow managed to leave light unperturbed, then the event would remain hidden. How can this be done? Easily, when you exploit a characteristic of light: speed.
General relativity shows that time can be slowed, or at least its appearance relative to a different frame of reference can be slowed. A time lens takes advantage of this time-bending property. As light passes through a time lens, it will split; that is, the light scatters. Some of the light will speed up, and some will slow down as the lens changes their frequency and wavelength, creating a zone of darkness.
These separate pieces of light pass through a second lens that recombines the streams. Any event that occurred inside that dark gap won't have scattered any light. It will appear as if it never happened. There will be nothing to be seen. This is a time gap. This is not science fiction. In a study that appeared in the journal Nature, a group of Cornell University scientists created a time gap forty trillionths of a second long.16 Yeah, I know. Not much time. Still, it is proof of concept.
In science fiction, a nefarious villain could hold the technology needed to lengthen the time gap. Then, during the gap, the fiend could attempt to commit the perfect crime, one that appeared to never have happened. (Except for the criminal consequences, of course.)
No matter how it ends up being used, for now, the science of temporal cloaking offers science fiction a lot of cool phrases like manipulating the perception of time, time lens, and time gap, all of which are actual concepts in real science.
Now for the difficult question: how can we get it to work? Once again, this isn't as difficult for a science fiction writer as it would be for a physicist. Temporal cloaking requires special lasers and optical fiber metamaterials to disperse and reconstitute light. We might need a few more years for this one.
PARTING COMMENTS
The title of this chapter asks, why are we so materialistic? The answer is, because we have to be. After all, things need to be made of things. Warfare, clothing, and food production are the great motivators for material discovery. The different types of materials humans have used over the centuries include stone, wood, bronze, iron, steel, cotton, and wool.
Material science emerged during the nineteenth century as the study of the structure of the elements within substances. Modern material engineers are developing new materials, for products that function better, and new technologies. This includes metamaterials, materials with properties beyond what is available in naturally occurring materials.
One such property might be invisibility. Two scientific ways to render an object invisible are spatial cloaking, which disguises an object in space; and temporal cloaking, which disguises an event in time.
We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run.
—Roy Amara, researcher and futurist
We wanted flying cars, instead we got 140 characters.
—Peter Thiel, entrepreneur
1. Anything that is in the world when you're born is normal and ordinary and is just a natural part of the way the world works.
2. Anything that's invented between when you're fifteen and thirty-five is new and exciting and revolutionary and you can probably get a career in it.
3. Anything invented after you're thirty-five is against the natural order of things.
—Douglas Adams, The Salmon of Doubt
This chapter is gadget-driven. It is completely free from mind-staggering questions of existence or galactic origins. Here it's just cool technology. We might not have flying cars, but as you've seen from the examples throughout this book, we aren't doing too shabby. Yes, instead of flying cars, the wish of the 1950s, we got the internet. I can live with that.
THE LASER
Before becoming a plaything of scientists and either tools or weapons in endless science fiction stories, it was an acronym: Light Amplification by Stimulated Emission of Radiation. A laser spits out energetic coherent photons (quantum light particles) focused on a tight spot.
Think of it as light amplified via a crystal and focused rather than scattered. Remember that light is also a wave, and the term coherent is a fancy way to say that all the peaks and valleys of light waves are lined up. This also means they are all the same color. If they were solid, they could be nicely stacked on top of each other. This is called being in-phase.
The first lasers were built in the 1960s. They are used in computers (in optical disk drives), printers, surgery, cutting tools, tools to measure distances between objects in carpentry, and really destructive weapons in science fiction.
POPULAR NAMES FOR LIGHT-ENERGY WEAPONS IN SCIENCE FICTION
Laser (go with what you know)
Heat ray (The War of the Worlds)
Ray gun (used in early science fiction, generally before lasers were invented)
Death Ray (the 1930s’ Nikola Tesla idea for directed energy weapons)
Phaser (short for phased array pulsed energy projectile weapon in the Star Trek universe)
Pulse rifle (science fiction outside of the Star Trek universe)
Blaster (Star Wars)
Lasgun (Warhammer 40,000)
Plasma gun (not a laser; learn all about plasma in the third interlude to find out why)
3-D PRINTING
Although not quite a Federation replicator from the Star Trek universe, the nonfiction 3-D printer comes close. It is capable of printing out physical objects from an inputted digital model. The printing is an additive process that creates copies by
laying down successive layers of material.
I'll let you
I'll let you know
I'll let you know when I have
I'll let you know when I have finished
I'll let you know when I have finished making a
I'll let you know when I have finished making a 3-D-printing joke.
If you have the necessary materials, the only limit on what you can print is your imagination. Of course, you need the correct materials to load your printer. I'm pretty sure plastic polymers might not make the best mug of beer.
One of the most fascinating and practical things about 3D printing is medical applications. Print up some organs for drug testing. No more mice needed. All you have to do is take a scan of the patient, which creates instructions (a digital model) for the printer. These instructions are sent to the printer's nozzles, which spew out a gel-like mixture composed of mature tissue cells, stem cells, and polymers designed to mimic real tissue consistency. The organ is printed in a layered lattice, leavings channels throughout that will act as blood vessels so that nutrients can circulate.1
3-D-printed body parts have been implanted in test animals.2 The Integrated Tissue and Organ Printing (ITOP) system begins by printing layers of biodegradable materials into the form of the desired tissue. This scaffolding is then filled with gels containing living cells that develop into functional tissue. Implanted materials in the scaffolding can encourage bone growth so that the scaffold can be removed.
Although it will be a while before personalized organs are available for transplants, biologists are getting closer. In 2001, the human bladder became the first bioprinted organ successfully implanted into a human.3
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