1.
Quantum computing is the technology
based on the principle of quantum mechanics
quantum computer is the hardware system
used for quantum computing.
We use electronic computers every day.
There is a vast difference between them.
If we make an analogy,
the difference is not
"changed from burning coal
to burning gasoline",
but to using nuclear energy.
How big is the difference?
If all the material in our sun is coal,
burning at this level,
it can only last for thousands of years.
But the real sun uses nuclear energy,
it can burn for tens of billions of years.
Quantum computing brings
a nuclear-weapon-level upgrade
to computer capabilities.
Let me introduce you
to the nature of computing.
2.
computation is
"input + operation + output"
Imagine, how do children in kindergarten
calculate 1 plus 2?
First, open 1 finger of the left hand for
1,
then,
open the 2 fingers of the right hand for 2,
and put the 2 hands together,
and then count,
"there are 3 fingers,
so the result is 3."
Even though this process is simple,
it is a complete calculation process,
which is essentially
the same as an electronic computer.
It's just that children use their fingers
as hardware,
while electronic computers use
all kinds of electronic circuits.
We can also see
"what is the nature of computing".
One hand opens one finger,
and the other opens two fingers,
which inputs "what you want to calculate".
Then, put the two hands together,
and this is the operation.
Finally, read out the numbers
represented by the three fingers,
and this is the output.
Whether a complex electronic computer
or a simple finger,
calculation can be seen as a process:
first input,
then,
processing according to specific rules,
and finally, output results.
This is the essence of computing.
The nature is easy to understand,
but if you want to know
the nature of quantum computing,
we need to continue to dig into
the meaning behind it.
3. in physical systems,
"Input, operation and output" is .
the "initial state, evolution and final state"
.
Whether it is an electronic computer
or counting fingers,
it is easy for us to understand that .
this is a computational process.
So, next, you have to judge
whether the process I'm talking about
is still a computation:
Let's talk about building airplanes.
Plane is tested in the wind tunnel
before it takes off.
Wind tunnel
is sizeable human-made equipment that
simulates the influence of airflow on an aircraft.
It can help us check
the aircraft's structural design,
material strength,
and control system,
whether they are perfect.
Do you think this process is computation?
Is it more like a physical experiment?
But I want to tell you that .
the wind tunnel is also a computer.
We put the aircraft into the wind tunnel
and set up the airflow,
which is the "input".
The aircraft flies in the wind tunnel,
according to the law of .aerodynamics, .
it moves, fluctuates up and down,
which is the "process of calculation".
At the end of the experiment,
whether the state is in line with the design,
and where is a deviation,
these are the "final results".
Not only those which deal with data
are called "computing",
but the meaning of computing
is much greater.
Wind tunnel is designed by us,
while nature itself
can compute something.
Between multiple cities,
finding the best road
is an intricate problem,
Even with our current computers,
it is challenging to deal with.
However, in some cases,
it is easy to solve
if we make use of the power of nature.
Japanese researchers experimented
with slime moulds.
Slime molds are microbes.
They have the habit of
building networks between foods
in different locations.
So the experimenters put food
in a petri dish of the same shape as
the Kanto region of Japan,
and used the food to simulate the station.
Among them, the largest piece of food
is regarded as Tokyo Station,
and the other smaller food
is regarded as some other station.
They also take advantage of the fact
that slime molds do not like light,
using light spots to simulate
mountains and lakes in real life.
After a period of free evolution,
the food network formed by slime molds
is similar to the real Kanto railway network.
Slime molds, food and light spots.
Their initial position
are the input.
The evolution of slime molds
is the process.
In the end,
the food network they form
is the result.
This is a biological experiment, yes,
but it is also a computer.
Wind tunnels and slime molds…
Through these examples,
I just want to push
the nature of computing
to a deeper level.
Computing must be
based on a physical system.
Slime molds are biological
but still physical.
So, essentially, computing is
evolution process of physical system,
input is the state at the beginning,
and output is the state at the end.
Abstractly, computing is
input, operation and output.
corresponding to the physical system,
they are specific initial state,
evolution and final state.
Whether we can
use some system for calculation,
depends on whether we can use
the corresponding rules
to manipulate the initial state,
evolution and final state.
In other words,
the ability of a computing system
depends on
what kind of physical system it is,
and how much we control its rules.
Wind tunnels and slime molds,
it's easy
to use them to solve specific problems,
but it is too troublesome
to get them to calculate "1+ 1".
But the electronic computer is different,
it follows the electromagnetic law,
through controls the electron
to realize the calculation
input, the operation and the output.
We have a powerful ability
to control the laws of electromagnetism,
so almost all computing problems
can be projected into
physical system of electronic computer,
and the processing speed is fast.
This is why electronic computer
has been so successful.
Since electronic computers are so good,
why do we need quantum computers?
4.
Quantum computer can breakthrough
the bottleneck of electronic computer.
Because we have almost reached the limit of
our control over the laws of electromagnetism,
it also represents that
the ability of electronic computers
has encountered a bottleneck.
However,
the problems we face have not diminished.
The first photo of a black hole
was taken in April 2019,
for the best electronic computer
it takes two years to develop the films.
Such computers limit
our exploration of the larger universe.
The same situation also happens in many fields,
such as drug discovery,
Pharmaceutical Development,
biotechnology, energy technology, etc.
So, finding a better computer
is our rigid requirement.
To breakthrough the bottleneck of computing
power,
we must think from the bottom,
"what other laws can we control?"
That's when quantum computing technology
came on the scene.
Our mastery of quantum mechanics
has enabled us to use it
to achieve general-purpose computing
like electronic computers do.
In our ability to use energy,
why is there a significant improvement?
Because we have changed
"the chemical rules for the use of coal and
oil".
to the nuclear rule.
The same is true of computing,
switching from classical electromagnetic
to quantum rules,
will certainly bring about
an explosion of computing power!
In breaking through
the bottleneck of electronic computers,
we have not only quantum computing,
but also biological computing,
brain-like computing,
and other possibilities.
But from our mastery of the rules,
quantum computing
is the most promising solution!
It has been strictly proven
in the principles of mathematics and physics,
but what excites us is that
a small-scale experimental prototype
has been realized in recent years.
Major technology companies
have invested in this field,
which also shows
"people's confidence in quantum computing."
