Crash Course Computer Science1

Hello world! I am Carrie Anne. Also are looking forward to joining Crash Course Computer Science. Hello world！I am Carrie Anne. Are excited about joining the computer science speed-up course!

在整个系列中, 我们将深入探讨 bit（比特）、byte（字节）、transistors（晶体管）以及 logic gates（逻辑电路）。

until reaching the domains of Operating Systems, Virtual Reality, and Robotics.

We're planning to discuss a significant number of topics, but first we must outline the plan. 我们计划讨论许多主题，并且必须先制定一个详细的计划。

we ARE NOT going to teach you how to program.
我们 不会 教你怎么编程

Instead, we're going to explore a range of computing topics as a discipline and a technology.
我们会从高层次上纵览一系列计算机话题

Computers are the lifeblood of today's world.
计算机是当今世界的命脉

If they were to suddenly turn off, all at once,
如果突然关掉所有的计算机

The power grid might shut down, automobiles might crash, and aircraft might collide.

water pollution control facilities will be shut down, stock markets will temporarily halt trading, 水污染控制设施将被关停, 股票市场将暂时停市

Trucks loaded with food couldn't figure out their destinations, while employees would fail to receive their dues.

然而计算机以外的许多事物也具有这种特性 例如DFTBA品牌T恤以及我现在所坐的椅子

by computer-managed factories, they are produced

Computer Science has revolutionized all areas of our lives.

This phenomenon isn't the first instance of technology-driven global change we've encountered. 我们也不是第一次见证推动全球发展的科技现象。

Progress in manufacturing techniques during the Industrial Revolution saw significant advancements.

introduced a new dimension to humanity’s progress in agriculture, industry, and domestic spheres.

Mechanization led to improved agricultural yields and a greater food supply, as well as the industrialized production of goods in batches.

more affordable and quicker transportation and communication, generally leads to an enhanced standard of living.

当前的计算技术与工业革命的影响程度相同

Our systems rely on autonomous farming technologies and advanced medical equipment.

The focus is toward globally advancing communication networks as well as providing accessible educational opportunities available.

除了包括虚拟现实和无人驾驶汽车之外，并涉及诸如这些前沿领域

We may live in an era that will be regarded as the Digital Age, likely to be remembered for its technological advancements.

Equipped with billions of transistors, computers may appear quite intricate within your smartphones.

but really, they're just simple machines
但实际上它是很简单的机器

该方法通过多层抽象来执行复杂的动作。 多层抽象下完成复杂操作。

Within this series, we will systematically dismantle the various layers. Within this series, we will elucidate each layer step by step.

From the simplest of binary digits (bits), known as bits in computing, through the creation of logic circuits, integrated circuits (ICs), we can understand how modern computers process information.

操作系统、整个互联网以及以上

When shopping for t-shirts online, people don’t need to know how the website operates. As for not understanding how the website is built, it’s unnecessary knowledge for purchasing t-shirts online.

无需了解该网页是如何编写的，
不必担心,就像购买T恤的顾客无需了解网站代码编写方式一样

or the web designer don’t have to figure out how data packets move,
don’t have to understand how data packets move

or router engineers do not require knowledge of transistor logic,
设计师无需掌握晶体管的工作原理。

该系列将基于先前节目的发展而进步，并非完全依赖它们。在本系列中每个视频将延续上一集的内容进行深入讲解，并非完全受限于前面的视频内容。

By the end of this series,
等这个系列结束后

I believe that you can better grasp the significance of computing not only in your personal life but also within our broader community.

and in what way (arguably) humanity's most remarkable creation is still in its early stages,

with its biggest impacts yet to come.
它对未来还会有更大的影响

However, prior to delving into such matters, it is imperative to begin our discussion with an examination of the origins of computing.

虽然电子计算机仅在近期才发展起来，在此之前人类对计算的需求就已经长期存在。

Computing's earliest recognized device was the abacus. 在历史上最先被认可的计算工具是算盘。

invented in Mesopotamia around 2500 BCE.
发明于"美索不达米亚"，大约公元前 2500 年

Essentially, it is a manual operated calculator. It is designed to perform basic arithmetic operations, particularly addition and subtraction. This device is specifically crafted for assisting in simple numerical computations. The primary function of this calculator is to facilitate easy and efficient computation of numerical values through manual operation.

it facilitates the performance of addition and subtraction on numerous numbers. It is a manual calculator designed to perform addition and subtraction operations.

It not only maintains a record of the computational state but also ensures its integrity through advanced algorithms. Similarly, your modern hard drive is designed to preserve data efficiently.

The abacus was created because,
人们制造算盘是因为

The magnitude of society has surpassed the calculating ability of an individual.

What is capable of a single person to retain and manage within their mind?
The scope of society has exceeded the individual mental capacity of human beings, resulting in an inability to handle vast amounts of information.

在一个村庄里可能存在数千至数万人，在牛的数量方面则可能存在数十万头

There are many variants of the abacus,
算盘有很多变种

让我们看看一个简单的版本，在每一行中代表的是不同的10次方。

每一颗位于最底端行的珠子代表单一单位，
底部一行的一个珠子表示十的零次幂，
等于1。

In the subsequent line, they correspond to 10; the one above that is 100, continuing in this manner. The line above that is ten to the power of one (which is simply ten). The following line is ten squared (proceeding in this fashion).

Let's suppose that we represent 3 head of cattle with 3 beads in the bottom row on the right side.

If we were purchasing additional cows, it could potentially increase our livestock count by four additional cows. By moving four beads toward the right end, we can accurately represent a total of seven animals in this scenario.

Although adding five more after the initial three would deplete our bead stock, purchasing five more after the initial three would result in a shortage.

so we would slide everything back to the left,
所以把所有珠子移回左边

move one bead on the second row to the right, representing ten, 在第二排把 1 颗珠子向右移动，代表 10

and then insert the final two beads into the bottom row to make a total of 12. 然后The following row, shift the last two beads to signify 12.

This method proves to be significantly effective when dealing with large numbers. This approach proves to be effectively managing large numerical figures.

So if we were to add 1,251
假设要表示 1251

We would only require adding a single unit to the bottom line, five units to the second line, two units to the third line, and a single unit to the fourth line. From the bottom up: ———— First line shifted by ———— Second line shifted by ———— Third line shifted by ———— Fourth line shifted by.

we don't need to be required to keep the sum in our heads and the abacus will store the running total.

In the upcoming 4,000 years, humans will create various types of ingenious computing machinery.

like the astrolabe, which allowed ships to precisely determine their latitude at sea. 比如星盘，在海上它能够让船只精确地测定他们的纬度.

A slide rule is often employed for performing arithmetic operations involving multiplication and division. It is a tool used to calculate arithmetic operations such as multiplication and division.

There were several hundred types of clocks created in the past.

this device has the capability to determine sunrise times, tidal patterns, positions of celestial objects, and can also serve as a simple timer for daily use.

这些设备使过去需要大量时间和精力才能完成的任务变得快速而高效。它们让过去繁琐耗时的事情变得更加简便、快捷且精确。

These设备使得那些耗时较多的任务变得更加容易、更快捷，并且更加精确。

- it lowered the barrier to entry,
降低了门槛

and at the same time, amplified our mental abilities -
加强了我们的能力

Take note: this is a theme we will explore extensively in this series. Note well: This series will delve into this topic repeatedly.

As one of the most influential figures in the history of computing, Charles Babbage is known for his work as the father of the digital age.

With each accumulation of knowledge and the introduction or development of every new tool,
人工劳力将逐渐减少.

The use of manpower will turn into abridgement. With the advancement of knowledge and the invention of new tools, man power will become fewer.

然而，并非所有的这些设备都被称作"计算机"。

The first known instance of the term "computer" was recorded in 1613 within a publication by Richard Braithwait. 最早使用 "计算机" 这个词的文献来自 1613 年出版的一本书籍《The work of Richard Braithwait》.

And it wasn't a machine at all; instead, it was a job title.

Braithwait said,
Braithwait 说：

Upon reading numerous computers throughout history, I was astounded at the ingenuity. Among all computers I've heard about, this one stands out for its unparalleled capability. It could significantly reduce several days' worth of workload.

and the best mathematician that ever lived, he condenses days of labor into a concise figure.
在我所了解的历史中被公认为最杰出的数学家,他将许多天的工作简化为简洁的时间数值.

In those days, calculations were carried out by a person referred to as the computer. 在那个时候, "Computer" 指的是执行计算任务的人.

Occasionally, computers occasionally employ machines to assist them, but typically operate independently.
"Computer" occassionally employs machines for assistance, but typically operates independently.

This job title persisted until the late 1800s,
这个职位一直到 1800 年代还存在

With the shift in computer's meaning, it eventually began to represent machines.

在这些装置中 standout的是the Step Reckoner. 其中most famous is theStep Reckoner.

built by the distinguished German polymath Gottfried Wilhelm Leibniz in the year 1694.
由著名的德国博学者 戈特弗里德·莱布尼茨 在公元1694年建造

Leibniz expressed his view that "...the calculation wasted by excellent individuals is considered beneath the intellectual level." It is a regrettable reflection on the intelligence of humanity that Leibniz expressed such an opinion.

As long as any peasant could perform the task with equal precision, they were provided with machines' aid.

It functioned similarly to an automobile's mileage indicator.
The step-by-step calculator has a design reminiscent of an automobile's mileage indicator. It continuously accumulates the total distance.

它本质上只是一个累加里程的装置。
"步进计算器"模拟汽车里的里程表，并持续累加里程数。

The device had a series of gears that turned;
它有一连串可以转动的齿轮

该种机械设计用于象征数字从零到九的变化

Each time a gear passed through nine teeth, it returned to position zero and pushed the neighboring gear forward by one tooth.

Kind of like when hitting 10 on that basic abacus.
就像算盘超过 10 一样.

This machine operated in the opposite direction when performing subtraction operations, as well.

With some clever mechanical tricks,
利用一些巧妙的机械结构

The Step Reckoner is capable of multiplying and dividing numbers as well.

Multiplication and division consistently represent a series of additions and subtractions.

For instance, when attempting to compute the division of seventeen by five, one could perform the operation as follows: subtract five from seventeen to obtain twelve; subsequently subtract five again from twelve to arrive at seven; and finally subtract five once more from seven to attain two. This method effectively demonstrates the step-by-step process of dividing seventeen by five through repeated subtraction.

Until we can no longer subtract any more fives... we know that 17 equals five multiplied by three plus a remainder of two.
一直到不能再从被除数中减去五为止,我们知道了17等于五乘以三再加上余数二

The Step Reckoner machine could perform calculations with high precision, and the machine can execute the operation automatically.

this machine is the earliest capable of executing all four arithmetic operations.

该设计极为成功，并因此被用于计算器设计的接下来三个世纪。

Unfortunately, without the help of mechanical calculators,

许多现实问题仍需经过多个计算阶段才能得出解答

整个过程可能需要几个小时到几天的时间

Moreover, these hand-crafted machines were very expensive, and unaffordable for most people in the population.

So, before 20th century,
所以在 20 世纪以前

The majority of individuals are accustomed to using predesigned calculation reference tables for computing.

these calculation tables were compiled by those outstanding 'mechanical calculators'. 我们曾提到过这些‘人力计算器’.

If you were to require knowledge of the square root of 8 million 6 hundred and 75 thousand 3 hundred and 9,

而不是每天花费一整天手动操作"步进计算器"

It would only take you a minute or so to look it up in a huge book filled with square root tables.

The speed and accuracy of actions are crucial in battle situations.

military earliest adopters of using computation or calculating techniques in solving complex challenges.

The task of precisely targeting missile rounds is highly challenging

by the late 19th century, projectiles could traverse several kilometers. In the 19th century, projectiles had ranges exceeding approximately half a mile.

Wind force, temperature, and atmospheric pressure will be continually changing as a result of these conditions.

even aiming at vast objects proved to be a challenge.

Range tables were established to enable gunners to access weather conditions and shooting distances. Consequently, a system of range tables emerged, allowing shooters to reference weather conditions and shooting distances for improved accuracy.

they aimed at a certain distance, 于是出现了射程表, allowing gunners to consult environmental conditions and shooting distances.

and the table would indicate the angle at which to set the cannon.

These Range Tables achieved remarkable success, bringing them into extensive use during World War Two.

问题出在如果你更改了大炮或炮弹的设计，
那就必须编纂一套新的表格

a new table must be calculated,
问题是什么？当改变大炮或炮弹设计时，则必须计算一张新的表格。

this method proved to be highly time-consuming and inevitably resulted in errors.

Charles Babbage 在 1822 年注意到这个问题。
在 1822 年，查尔斯·巴贝奇发表了一篇关于这个问题的文章。

as a paper submitted to the journal of the Royal Astronomical Society, titled:
this issue was brought to the Royal Astronomical Society's attention.

Title: Report on the use of machinery in celestial and mathematical computations

Let's go to the thought bubble.
让我们进入思想泡泡

Charles Babbage invented a novel mechanical invention, which was referred to as the Difference Engine. Charles Babbage was noted for developing a novel mechanical contrivance, which was also known as the Difference Engine.

A significantly advanced machine is capable of approximating polynomial functions.

Polynomial expressions can represent the interconnection among multiple variables.

similarly, such as the distance range and atmospheric pressure, or the quantity of pizza that Carrie Anne consumes and happiness level.

多项式也可以用来估计对数函数和三角函数

which are a real hassle to calculate by hand.
这些函数手算相当麻烦

Babbage started construction in 1823,
Charles Babbage 在 1823 年开始建造差分机

此外，在接下来的二十年内也试图制造与安装这25,000个零件

collectively weighing around 15 tons.
总重接近 15 吨

Unfortunately, the project came to an unfortunate end.

But, in 1991,
但在 1991 年

History experts completed constructing the Difference Engine by referencing Babbage's original drafts, hand稿s, and notes.

- and it worked!
而且它还管用！

Especially significant is the process of constructing the difference machine during its construction period.

The Analytical Engine was conceived as an exceptionally intricate device by Charles Babbage.

与差分机相比而言，在过去其他计算设备中没有像步进计算器这样先进

The Leibniz stepped reckoner and all other computational devices prior to its introduction differ significantly from the differential analyser. Unlike the differential analyser, mechanical calculators such as the stepped reckoner prior to their time exhibit distinct characteristics.

Analytical Engine is known as a general-purpose computer.

It is applicable to various purposes, not merely a specific calculation;

the system can receive data and perform a series of operations in a sequential manner;
even the system is capable of receiving data and processing a sequence of tasks in an orderly fashion.

it had memory, but even more minimally equipped with an rudimentary printing device.

like the difference engine, it was a marvel that fell short of completion.

However, the idea of an "automatic computer"
然而，这种 "自动计算机" 的概念

- A self-operating system capable of executing a sequence of processes without external intervention.

• A self-operating computer system is capable of efficiently performing a series of processes.

这个概念是一个重要的里程碑，并预示着计算机程序的诞生。

这个概念是里程碑式的思想，并暗示了计算机程序的出现。

The English mathematician Ada Lovelace developed imaginary programs for the Analytical Engine, stating that she believed.

未来将会发展出一门全新的、强大且专用于分析的语言

因此 Ada 被认为是第一位在世界范围内工作的程序员。

分析机将激励（可以说）第一代计算机科学家

这些计算机科学家将许多查尔斯·巴贝奇的想法融入到他们的机器中

Due to his pioneering work, Charles Babbage has earned the title of the "father of computing". The recognition of Charles Babbage as the "father of computing" stems from his groundbreaking achievements.

Thanks! Thought Bubble
谢啦！思想泡泡

So by the end of the 19th century,
到了 19 世纪末

在科学与工程领域中设置了特定用途的任务使用了计算设备，在数学与技术研究中应用广泛

但公司、政府机构及家庭环境中很少见到计算设备

However, the US government encountered significant challenges in conducting the 1890 census.

That required a highly efficient approach, only computers can achieve.

The United States Constitution mandates a population census to be carried out every ten years,
The United States Constitution mandates a population census to be conducted each ten-year period.

with the aim of allocating federal funds resources, ensuring congressional representation, and including valuable items such as

The U.S. population, by the 1880s, was on the rise, largely due to an influx of immigrants.

完成人口普查需要耗费七年的时间来进行人工记录工作。等到完成全部的人口普查工作之后就会过时。

when it had just been finished, it had become outdated.

• and it had been anticipated that the United States Census Bureau's system would require thirteen years for completion.
• Additionally, it was predicted that the United States Census of 1890 would be completed in a span of thirteen years.

This approach is quite challenging, as it occurs every decade. Yet the census is conducted every ten years.

人口普查局委托Herman Hollerith为其发明了一种打孔卡片制表机提供了技术支持

His machine was "electro-mechanical"
他的机器是 "电动机械的"

• they employed traditional mechanical systems to perform counting operations,
• 采用了传统机械系统进行计数。

采用了莱布尼茨式的机械设计，并配备了电动驱动系统以整合多种辅助组件

Hollerith's machine used punch cards
Hollerith 的机器用打孔卡

这些纸卡片上印有网格图案，在被刺孔的位置插入标记物即可记录数据。

For instance, there was a series of holes representing marital status.

If a person got married, they would drill a hole at the marriage location, which is an indicator of their marital status.

Upon inserting the bill into Hollerith's machine, small metal needles would drop onto it.
当一张卡片被插入霍勒金斯机器时, 小金属针会掉在卡片上.

if a spot was punched out, the pin would pass through the hole in the paper

into a small amount of mercury, thus completing the electrical circuit.

This now completed circuit powered an electric motor,
电路会驱动电机

将一个齿轮的齿数增加了一个单位，在这种情况下，则总齿数达到了已婚状态的状态数值。随后为处于"已婚"状态的齿轮增加了一个齿

Hollerith's machine achieved approximately 10 times the speed of manual data processing.

The population census was finished in only two and a half years.

The program has successfully reduced costs for the census office, conserving numerous amounts of money.

businesses have been acknowledging the importance of computational power,

可以看到该方法能够通过优化劳动力以及数据密集型任务来提升利润

如上所述所示所示所示所示所示所示所示所示所示所示所示所示所示所示如上所述如上所述如上所述如上所述如上所述如上所述如上所述如上所述

为了满足这个需求,Hollerith 建立了制表机器公司

this company subsequently integrated with other major machine manufacturers in 1924

Became known as IBM, the company originally established as the International Business Machines Corporation (IBM) began to be referred to as IBM.

- which you've probably heard of.
-你可能听过 IBM

Electro-mechanical business machines achieved significant results. The transformation of these electronic and mechanical business machines had a profound impact on both sectors.

and by late 1800s, a dramatic surge in global population numbers and the emergence of a robust globalization-driven trade system.

required increasingly fast and more adaptable processing tools to handle data.

Laying the groundwork for digital computers, constituted the foundation for their development.

which we'll talk about next week.
我们下周讨论