quantum computers have the potential to be the most important the most dangerous and the most unpredictable invention of our lifetime they can even become all three of those things all at the same time we hear this term come up every now and again it sounds very futuristic and speculative but quantum computers are very real they exist right now and they are on the verge of becoming a big part of our daily lives you don't need to be a physicist to understand the role that these Quantum machines could play in changing the world as we know
it and I'm here to guide you into the quantum realm let's go okay Marvel's Ant-Man has some questionable physics at best but one thing that Professor Pim does have right is that the smaller things get the stranger the laws of physics that govern them will become this is important to keep in mind as we go along you've probably seen a quantum computer before it looks pretty weird more like some kind of a cross between a golden Chandelier and a giant squid than anything we traditionally associate with a computer but that's largely because our current Viewpoint
is a little too narrow this thing is also a computer the first computer actually as in the first ever it was found at the bottom of the Mediterranean Sea and dates back to ancient Greece it is known as the anti theera mechanism it was used to predict the movements of the Sun the Moon and the Earth it could have forecasted a solar eclipse decades in advance the same as we can today and this computer also looks pretty weird although these shiny golden mechanisms you're seeing are just artistic Recreations the real artifact is actually a bunch
of fragments encrusted with thousands of years worth of ocean Gunk calculating machines have taken many forms over this centuries that they've been used by humankind so in many ways the quantum computer is just a next phase of evolution but in many other ways it's not that at all modern computers as we know them are defined by bits a bit is the smallest unit of data that a computer can process and store bits are the building blocks of every piece of digital information you have ever experienced a bit is always existing in one of two states
kind of like a switch this is why we say that computer speak a binary language the state of each bit is typically represented by either a one or a zero but it can also be represented by on or off up or down left or right as long as each bit is holding one of two potential values this is binary Computing the physical manifestation of a bit is called a transistor this is like an electronic switch and again it can exist in one of two potential States on and off so the more physical transistors you have
the more bits of information you can process at one time which is an oversimplification but it gets the point across so we've been constantly trying to make these transistors smaller and smaller over time so that we can fit more transistors into increasingly smaller devices this old desktop calculator from the 1960s used 250 transistors a current model iPhone has 19 billion transistors in its main processor chip of alone to accomplish this we have reduced the size of the transistor down to a width of just 3 nanom this is too small for the mind to truly comprehend
it's only slightly wider than a strand of human DNA which is 2 and a half nanometers it's possible the transistors could be reduced to the size of 1 nanometer by the end of this decade there is a physical limitation on how small they can be but regardless of how small you make a transistor it is still limited by the binary nature of the bit it can only ever be in one of two states and this is where quantum computers come into play a quantum computer uses its own unit of data measurement which is the Cubit
and these things can get pretty weird because cubits also represent ones and zeros just like traditional bits but cubits can also represent both one and zero at the same time they are nonbinary and this ENT potentially gives cubits the potential to hold vastly more information than traditional bits and the physical manifestation of a cubit is achieved by manipulating the spin state of subatomic particles either protons or electrons causing them to spin up and down or left and right creating two distinct States your one and zero except quantum mechanics allows these subatomic particles to exist in
multiple States simultaneously so they can potentially be spit in all directions all at once remember the smaller things get the stranger the laws that govern them here's what that looks like if you put two bits together we know that each bit will represent either a one or a zero so regardless of the combination you have two bits of information but when you put two cubits together you end up with the equivalent of four bits of information this is because there are now four possible combinations of one and zero because each Cubit has the potential to
be both values at the same time so instead of just being one and zero the pair could also be zero and one or one and one or zero and zero all at the same time if this is starting to sound familiar then that's probably because you're already a Quantum physicist or you've heard about a thought experiment called Schrodinger's Cat the basic explanation of Schrodinger's idea is that you could take a cat and put it in a box then put something else in the box that could potentially kill the cat like like a cup of poison
then you seal the Box again thought experiment no one put a cat in a box with poison at least not that we know of now as long as there is no way for us on the outside to know what's happened inside the box then we have no evidence to suggest that the cat is dead or alive maybe it drank the poison maybe it didn't my cat eats plastic but refuses to eat chicken they're unpredictable creatures and as long as we have no observable method to predict the fate of the cat then it may be considered
simultaneously to be both dead and alive at the same time this is referred to in quantum physics as a super position and it is a state in which our cubits are able to reside they are two potential outcomes occurring simultaneously now the trick here is that the moment you open the box and check on the well-being of the cat that superp position collapses back into a binary the cat will either be dead or alive and the same applies to cubits they eventually have to pick a side and resolve as either a one or a zero
but that time spent in a super position allows the quantum computer to explore a vast network of potential combinations before arriving at a final answer this super position is where the quantum computer gets its power when you start adding up all of the potential values from the superp positions of multiple cubits working together then you start to get some pretty staggering numbers remember when we said that two cubits were able to store four possible values making them equivalent to four standard bits well combining just 20 cubits together will produce more than 1 million potential values
the largest quantum computer that exists today that we know of was built by IBM and has over 1,000 cubits of processing power in one decade from now IBM expects that will increase to 100,000 cubits now now what does that mean for you and me the first thing that we should establish is that quantum computers are not just a better version of our existing computers they are less of an evolution and more like an alternative mode of transportation quantum computers can take us to places that we have never been before in the same way that your
boat can take you places that your car can't drive but a boat is not an improvement on a car or a substitute so Quantum Computing will not be replaced 99% of the jobs that are currently done by existing supercomputers and you definitely won't be adding one to your existing lineup of personal Tech the most simple reason for this is that in order for a Quantum chip full of cubits to actually function it needs to be held at a temperature as close to absolute zero as physically possible this is as cold as cold can be it's
colder than the vacuum of space so in order to even operate a quantum computer you first need need to obtain the world's most powerful freezer oh and even with the necessary cooling system existing quantum computers can only operate for around 1 second at a time before the cubits lose their superposition State the second problem is a bit more difficult to wrap your head around but in simple terms quantum computers are actually able to make mistakes and they do it fairly often this is a bit of a weird one because most of us are not really
familiar with computers that make mistakes imagine if your calculator just occasionally gave you the wrong answer and existing quantum computers tend to have error rates that sit between 1 and 100 at worst and 1 in 1,000 at best it's been speculated that in order for a quantum computer to be truly practical the error rate needs to be reduced to at least 1 in 1 million this comes down to the nature of cubits and their superpositions each Cubit on its own is inherently unstable and when you begin combining multiple cubits together that instability will only multiply
essentially meaning that the more capable your quantum computer is the more likely it will be to make an error with great power comes great instability but even with this factor of unpredictability taken into account it is still more than possible for existing quantum computers to solve math problems in a matter of seconds that would take a conventional computer thousands of years to complete this actually has the potential to become a really big problem but is it one that you should be worried about most iPhone users probably missed this announcement but in February 2024 Apple revealed
that iMessage had been cryptographically upgraded with postquantum security meaning that even a sophisticated quantum computer attack would not be able to Brute Force hack your iMessage account which is good news but it also demonstrates that Apple has enough concern about the potential Quantum of hacking to take it seriously and apple is one of the leaders in this current move towards Quantum safe encryption which means that there are still plenty of online services that you probably use that have not taken the same measure that includes emails bank accounts cloud storage even cryptocurrency wallets like Bitcoin that
are literally built on cryptography it's in the name these private keys can be Brute Force hacked by quantum computers one of the biggest problems we have right now is that the arms race towards Quantum Supremacy is not being won by the United States this is an area where China has taken the early lead they have the largest quantity of powerful and stable quantum computers in 2020 then president Donald Trump announced that the US government would be spending $1 billion per year on Quantum Computing in America by 2022 the Chinese Communist Party had committed $15 billion
per year for their own Quantum development so that is a bit scary but is there anything that any of us normal people can really do about it well not really but it's maybe worth keeping an eye on which Services you use that are upgrading to postquantum encryption and if it's something that you're concerned about then maybe consider switching to services with higher levels of encryption it's not a fun thing to think about but this is the world we live in now I want to leave you with something fun to think about the potential importance of
quantum computers for doing good things things so immeasurably good that they will change the course of human history towards the science fiction Star Trek utopian future that has so far only been dreamed about if there's one thing that our existing computer systems are really lacking it would be an ability to understand nature and the physical world traditionally computers have been pretty bad at grasping very important Concepts like biology and weather for example we can't cure cancer because we still do not understand cancer 20 years ago scientists were able to map the human genome with help
from supercomputers of the time it was an amazing accomplishment but even with vastly more powerful machines available in the modern day we are failing to make meaningful breakthroughs in medical science one of the biggest problems here is that forces of nature like diseases and viruses also operate on the quantum level just like the cubits and that means that they have their own superpositions where subatomic particles within the virus are existing in multiple States simultaneously meaning that just like schroedinger's cat there is no right answer until we open the box and when it comes to opening
the box on the nature of life the universe and everything we need to be able to meet nature on its own level which goes all the way down to the foundation of the atoms that make up the universe nature is operating at the quantum scale and that's where we need to go in order to finally understand it we're not there yet it might happen in my lifetime or yours it might not but for the first time in the three billion year history of life on Earth we are pretty close to figuring it all out and
that in itself is a pretty amazing thing to be around for
