欢迎来到“压缩饼干”城市 / Welcome to the World's Most Compressed City

想象一下，如果有人告诉你，整个香港的人口——750万人——可以被塞进一个房间里。你会怎么想？

可能你的第一反应是：这怎么可能？香港有那么多摩天大楼、那么多街道、那么多商场，怎么可能只用一个房间就装下？

让我带你做一个思想实验。

首先，我们需要一个足够大的房间。假设这个房间是一个完美的立方体，长、宽、高都是100米。这样的房间有多大？想象一下一个足球场的宽度，一个足球场长度的四分之一，再加上一座十层楼的高度。差不多就是这么大。

现在，让我们开始往里面装人。

如果按照香港真实的居住密度——每平方公里大约66,000人——我们需要重新思考这个实验。香港不是把所有人平铺在地上，而是垂直堆叠。想象一下把750万人均匀分布在，香港总面积1107平方公里的土地上，然后垂直压缩……

等等，这个比喻还不够震撼。让我换一个。

你知道香港人的居住空间有多小吗？香港的人均居住面积大约只有15平方米。这是什么概念？美国的人均居住面积大约是67平方米，新加坡大约是35平方米，北京大约是33平方米，深圳大约是27平方米。香港，是这些城市中居住空间最小的。

15平方米，相当于一个普通停车位的面积，或者一间小型卧室的大小。在这15平方米里，你需要放下床、衣柜、书桌、厨房、卫生间——可能还要和家人共享。

现在，回到我们最初的房间实验。如果把香港750万人按照人均15平方米居住，计算一下需要多少空间？答案是一个长约3.4公里、宽3.4公里的正方形区域，大约12平方公里。相当于一个中等规模的大学校园。

这听起来好像也不少？但别忘了，香港不是一片平坦的空地。这750万人，实际上挤在不到30%的可开发土地上。其余的70%，是山地、郊野公园、受保护的原生态地区。

香港有400多个摩天大楼，高度超过150米。深圳福田CBD有20多栋写字楼，香港中环和西九龙一带则更多。密集的轨道交通网络覆盖全城，每天运送超过500万人次。街道上永远人头攒动，商场里永远熙熙攘攘。

这就是香港——世界上人口密度最高的城市之一。

Imagine this: someone tells you that all of Hong Kong's population—7.5 million people—could fit into a single room. What would be your first reaction?

Perhaps you think: How is that possible? Hong Kong has so many skyscrapers, so many streets, so many shopping malls. How could it possibly fit into just one room?

Let me take you through a thought experiment.

First, we need a large enough room. Suppose this room is a perfect cube, 100 meters long, 100 meters wide, and 100 meters high. How big is that? Imagine the width of a soccer field, a quarter of its length, plus the height of a ten-story building. That's roughly the size.

Now, let's start packing people into it.

If we go by Hong Kong's actual population density—approximately 66,000 people per square kilometer—we need to rethink this experiment. Hong Kong doesn't spread everyone flat on the ground; it stacks them vertically. Imagine distributing 7.5 million people evenly across Hong Kong's total area of 1,107 square kilometers, then compressing everything vertically...

Wait, this metaphor still isn't shocking enough. Let me try another.

Do you know how small Hong Kongers' living spaces are? The per capita living space in Hong Kong is approximately 15 square meters. What does that mean? In the United States, it's about 67 square meters per person; Singapore, about 35 square meters; Beijing, about 33 square meters; Shenzhen, about 27 square meters. Hong Kong has the smallest living space among these cities.

15 square meters is roughly the size of a standard parking space, or a small bedroom. Within these 15 square meters, you need to fit a bed, wardrobe, desk, kitchen, bathroom—and you might have to share all of this with family members.

Now, back to our initial room experiment. If we fit Hong Kong's 7.5 million people at 15 square meters per person, how much space would we need? The answer: a square approximately 3.4 kilometers long and 3.4 kilometers wide, about 12 square kilometers. That's roughly the size of a medium-sized university campus.

That doesn't sound too bad, does it? But remember, Hong Kong isn't a flat empty space. These 7.5 million people actually crowd into less than 30% of its developable land. The remaining 70% is mountains, country parks, and protected natural areas.

Hong Kong has over 400 supertall buildings exceeding 150 meters. Shenzhen's Futian CBD has more than 20 office towers, and Hong Kong's Central and West Kowloon areas have even more. A dense rail network covers the entire city, transporting more than 5 million passengers daily. The streets are always bustling with people, and the shopping malls are always crowded.

This is Hong Kong—one of the most densely populated cities in the world.

什么是密度？密度背后的数学

在继续深入之前，让我们先搞清楚几个概念。

人口密度（Population Density）是指单位面积内的人口数量，通常用“每平方公里多少人”来表示。比如，香港的人口密度是66,000人/平方公里，意味着每平方公里的土地上，生活着大约66,000人。

但是，单纯看人口密度有时候会误导我们。因为城市不是均匀分布的。

想象一下，你站在香港中环的街头，放眼望去全是高楼大厦。但如果你开车去大屿山，那里大片大片的区域可能几个小时都见不到一个人。所以，我们还需要理解另一个概念——市区密度（Urban Density）。

市区密度是指城市核心区域的人口密度。在这方面，香港更是惊人。根据不同的统计口径，香港核心城区的人口密度可以达到每平方公里20万甚至30万人。

这是什么概念？纽约曼哈顿的人口密度大约是每平方公里26,000人，东京大约是6,000人。香港核心区的密度是曼哈顿的8到12倍。

当然，香港也有自己的“呼吸空间”。香港的郊野公园面积占土地总面积的40%以上，全港有超过260公里的远足径。如果你喜欢爬山、徒步，香港可能是全世界最方便的大都市之一。但这并不能掩盖核心城区面临的巨大压力。

现在，让我们用一些更直观的方式来理解这个数字。

如果把香港的750万人想象成沙子，均匀铺开，大约可以覆盖一个标准足球场的表面，厚度大约是……15米。

或者这样想：如果把全球80亿人全部聚集在一起，每个人占据0.5平方米的空间（相当于一个人站立所需的最小面积），那么所有人加起来的面积大约是400平方公里。这个面积大约相当于香港陆地面积的36%。也就是说，地球上的全部人口可以舒服地站在香港的土地上，还有大量剩余空间。

当然，这种计算方式过于理想化。它忽略了地形、建筑、交通等所有现实因素。但它确实给我们提供了一个参照系，让我们理解香港的“高密度”究竟意味着什么。

What is Density? The Mathematics Behind It

Before we go further, let's clarify a few concepts.

Population density refers to the number of people per unit area, usually expressed as "people per square kilometer." For example, Hong Kong's population density is 66,000 people per square kilometer, meaning approximately 66,000 people live on each square kilometer of land.

However, looking at population density alone can sometimes be misleading. Cities aren't evenly distributed.

Imagine standing on the streets of Central, Hong Kong—skyscrapers everywhere you look. But if you drive to Lantau Island, you might go hours without seeing another person. So we also need to understand another concept—urban density.

Urban density refers to the population density of a city's core areas. In this regard, Hong Kong is even more staggering. Depending on different statistical methods, Hong Kong's core urban density can reach 200,000 or even 300,000 people per square kilometer.

What does that mean? Manhattan in New York has a population density of about 26,000 people per square kilometer; Tokyo, about 6,000. Hong Kong's core area is 8 to 12 times denser than Manhattan.

Of course, Hong Kong has its own "breathing spaces." Country parks in Hong Kong cover more than 40% of the total land area, and there are over 260 kilometers of hiking trails across the territory. If you enjoy hiking and outdoor activities, Hong Kong might be one of the most convenient megacities in the world. But this doesn't negate the tremendous pressure faced by the core urban areas.

Now, let's understand this number through some more intuitive ways.

If we imagine Hong Kong's 7.5 million people as sand, spread evenly, it would cover the surface of a standard soccer field to a thickness of... 15 meters.

Or think about it this way: If all 8 billion people on Earth gathered together, with each person occupying 0.5 square meters (roughly the minimum space a standing person needs), the total area would be about 400 square kilometers. This area is approximately 36% of Hong Kong's land area. In other words, the entire global population could comfortably stand on Hong Kong's land, with plenty of room to spare.

Of course, this calculation is overly idealized. It ignores terrain, buildings, transportation, and all other real-world factors. But it does provide us with a reference point to understand what Hong Kong's "high density" truly means.

和全世界比一比：香港排第几？

香港到底有多挤？让我们和世界上其他著名的大城市做一个比较。

东京——日本首都，常住人口约1400万，是全球最大的都市圈之一。东京的人口密度约为每平方公里6,000人，整个都市圈的人口密度约为2,700人/平方公里。东京都23区的密度较高，大约是15,000人/平方公里，但仍然不到香港的一半。

新加坡——花园城市，以高效的城市规划和清洁的环境著称。总人口约600万，人口密度约为每平方公里8,400人。虽然密度也不低，但大约只有香港的八分之一。新加坡近年来通过填海造地来增加可用土地面积，缓解了一部分压力。

纽约——美国最大的城市，曼哈顿是著名的金融和文化中心。曼哈顿的人口密度约为每平方公里26,000人，整个纽约市的密度约为10,000人/平方公里。纽约的“密度”很大程度上是由曼哈顿这个超级核心贡献的。

伦敦——英国首都，欧洲最大的城市之一。伦敦的人口密度约为每平方公里5,700人，整个大伦敦地区的密度更低，大约是800人/平方公里。

上海——中国最大的城市，浦东新区的摩天大楼群举世闻名。上海的人口密度约为每平方公里3,800人，市中心的密度会更高一些。

北京——中国首都，故宫和长城所在地。北京的人口密度约为每平方公里1,300人，但由于城市面积巨大，人口总数超过2000万。

深圳——毗邻香港的中国科技之城。深圳的人口密度约为每平方公里9,000人，是中国密度最高的城市之一。

孟买——印度商业中心，宝莱坞的所在地。孟买的人口密度约为每平方公里32,000人，是全球密度最高的城市之一。孟买和香港经常被拿来比较，因为两座城市都有极高的密度，同时都有大片贫民窟区域。

如果把香港放在全球背景下，它的总体人口密度可以排进世界前五。但如果只看城市核心区，香港几乎是无可争议的冠军。

但数字只是数字。真正重要的是，这些数字背后意味着什么？香港人是如何在这片“压缩饼干”上生活的？

Comparing with the World: Where Does Hong Kong Rank?

How crowded is Hong Kong exactly? Let's compare it with other famous cities around the world.

Tokyo—The capital of Japan, with a permanent population of about 14 million, is one of the largest metropolitan areas globally. Tokyo's popul