Two thousand years in one chart | Hacker News Reader

Two thousand years in one chart

economist.com

96 pointsdavi21 comments

I'd like to see a similar graph ending in 1900, 1800, etc. How different do those graphs look to this one? (EDIT: obviously you can just block out the last column(s), but the resolution isn't that good.)

In other words, is there anything special about this point in time?

Would a log graph better show if there has been other explosive growths like the 20th and the start of the 21st centuries? Maybe I'm incredibly naive, but it seems like they've plotted exponential growth and said, "hey, it looks exponential!"

"If people do make history, as this democratic view suggests, then two people make twice as much history as one."

If those people are isolated, this may be true, but if they are able to communicate, interact, and cooperate, to me it follows that the whole would be greater than the sum of the parts.

Only if you don't count the communication/interaction/cooperation networks as being a part of the whole.

It's not clear to me that you gain much understanding by comparing economic output across time in this way. A lot of "economic output" is not objective production, but just people trading amongst themselves. More people, more churn, so a higher number. But not necessarily more production or scientific discoveries or technological advances. A group of 500 people cutting each other's hair has more economic output than 50 people doing so!

Thankfully since the chart also shows years-lived per century, it is quite easy to grasp the change in economic output per year-lived as well. The 20th century was the first to surpass a 1:1 ratio and did it quite impressively with almost 2:1. While so far this century it is around 4:1 already.

Interesting chart. Can someone explain 'years lived' to me? Is this the percentage of all years all people combined to live in each respective Century?

Thanks.

Yup, it ought to be the population integrated over time, and then normalized to add up to 100%.

OK, thanks.

Cheap hydrocarbons made all the difference in the 20th century. Whether this growth will flatten or slow down, we will wait and see.

As Moore said about exponentials: "It can't continue forever. The nature of exponentials is that you push them out and eventually disaster happens."

Global energy consumption in 2008 was estimated to be 474 exajoules. The energy received by the earth from the sun is 5 million exajoules. So the difference is about a factor 10,000.

Assuming that we find a replacement for hydrocarbons (fusion, thorium?) and a modest 2% growth rate, that means we're only log(10000) / log(1.02) = 465 years away from having to deal with an amount of industrial waste heat equivalent to a second sun shining onto our planet. This is obviously absurd. We'll run into serious problems that will stop our growth long before that.

And yet another non logarithmic graph of money.

I'm really surprised to see such ignorance on The Economist. People who write about money for a living should know better.

The scale is % of economic output and years lived. Assuming the output is inflation adjusted, why would you prefer the scale to be logarithmic?

Agreed, since economic output is measured in 1990 Dollars, there's no need for a logarithmic scale here.

Because economic output always builds on previous output. That is the definition of an exponential function, and to reverse those effects you need to take the log.

It's easy to see this - just look at the early years, and notice the curve - it's an almost exact exponential curve. Graphing an exponential curve teaches you very little about the underlying data.

A logarithmic view would be great for showing when the population and output stalled or increased faster, but the purpose of this graph is to show that the fact that the increase is dramatically exponential, and at what point in the curve we are right now.

Ideally both would be shown--but just showing the log graph would be misleading in this context.

I agree. I think that the point of this graph is to convey exponential growth, and simply that. It's not meant to be used "seriously," which'd make a logarithmic graph more suitable.

Ars is correct on this one (and also resdirector, the topvoted comment right now)- the issue is not money inflation, it's the simple fact that compounding growth will be exponential, always. So if your point is to show that growth rates increased in recent centuries, then you need to show growth rates, or show this but using a log scale.

Why should it be logarithmic?

Logarithmic scale would better show the percent change of population in the early years. Using linear scale hides the movement of the early years because the 20th century's magnitude is so great that the previous centuries look identical to each other. It's more dramatic this way, but perhaps misleading.

But that is the point of the graph - to show the ratio of history that has happened has happened recently. Or in other words, the point is not to show the growth patterns, but to show the nominal value.

I think that's where it's wrong, though; imo, "history" is better identified with the percent change, not with the nominal value. If someone improved some technology by 10% in 1850, and someone else improved it by another 10% in 1950, I'd call those historically equivalent contributions.

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