

Two thousand years in one chart - davi
http://www.economist.com/blogs/dailychart/2011/06/quantifying-history

======
resdirector
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!"

------
joshuamerrill
"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.

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

------
_delirium
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!

~~~
janzer
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.

------
shoham
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.

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

~~~
shoham
OK, thanks.

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

~~~
wcoenen
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.

------
ars
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.

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

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

~~~
ars
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.

~~~
GavinB
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.

~~~
doyoulikeworms
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.

