- #36
- 24,775
- 792
Fra, Amazon does not provide figures on the numbers of copies sold. They only give a sales rank. The book that sells the most copies is #1, the next most copies sold gets rank #2.
Also publishers tend to be reticent about actual numbers sold. So all we have to go on are the ranks. I calculate the ratios myself because the rank of a physics book is hard to interpret, I like to know the rank compared with something.
So for example the ratio at noon today was 1.67. Trouble was doing a bit more than one and a half times better than the stringy benchmark I compare with. The way it works is this:
At noon TwP rank was 2907.
The five most popular stringy books today were elegant, fabric, parallel, idiot guide, hyperspace and their ranks were 2620, 2871, 4090, 5257, 9431.
This makes an average of 4853.8. One just adds up the five ranks and divides by 5.
So the average stringy rank, for books in the top five, was 4853.8.
Smolin's rank of 2907 was 1.67 times better than that. That is the ratio 4853.8/2907.
So I record this for today:
17 July 1.67Another example was the ratio for 6 July, as described here:
On that day the most popular string books (and their ranks) were Brian Greene's Fabric (#1507) and Elegant (#1782), Michio Kaku's Parallel Worlds (#5330) and Hyperspace (#7309) and Lisa Randall's Warped Passages (#15503). Among the top five, the average salesrank was 6286.2. The Smolin book's salesrank was 15.81 times better than this stringy benchmark. Since that day it happened to be #395 among all books that Amazon sells.
The point of such an index is that it should be quick to calculate, and one should calculate it consistently always the same way. And one then watches it over time. Only the change over time, if there is any change, can mean something. By itself one cannot say what the number means.
The stringy benchmark to some extent measures the size of the problem (the over-hyping and over-selling of string to the public) and so the ratio has a connection with how well Smolin's initiative is doing relative to the size of the mountainous problem it addresses. But there is no rigorous meaning---one can learn what it means only by watching it over time and seeing what it correlates with. Like any other numerical indicator that one tracks.
Also publishers tend to be reticent about actual numbers sold. So all we have to go on are the ranks. I calculate the ratios myself because the rank of a physics book is hard to interpret, I like to know the rank compared with something.
So for example the ratio at noon today was 1.67. Trouble was doing a bit more than one and a half times better than the stringy benchmark I compare with. The way it works is this:
At noon TwP rank was 2907.
The five most popular stringy books today were elegant, fabric, parallel, idiot guide, hyperspace and their ranks were 2620, 2871, 4090, 5257, 9431.
This makes an average of 4853.8. One just adds up the five ranks and divides by 5.
So the average stringy rank, for books in the top five, was 4853.8.
Smolin's rank of 2907 was 1.67 times better than that. That is the ratio 4853.8/2907.
So I record this for today:
17 July 1.67Another example was the ratio for 6 July, as described here:
marcus said:...
To continue recording the noon readings for this interesting spike in sales of Smolin's book:
2 July 3.78
3 July 5.88
4 July 5.11
5 July 16.10
6 July 15.81
Trouble with Physics was number one on the Amazon list of physics books (ahead of Hawking, Greene, whoever). At noon on 6 July it ranked 395 and the string topfive average was 6286.2, making the ratio 15.81.
The five most popular string books that day (fabric, elegant, parallel, hyperspace, warped) ranked 1507, 1782, 5330, 7309, 15503.
On that day the most popular string books (and their ranks) were Brian Greene's Fabric (#1507) and Elegant (#1782), Michio Kaku's Parallel Worlds (#5330) and Hyperspace (#7309) and Lisa Randall's Warped Passages (#15503). Among the top five, the average salesrank was 6286.2. The Smolin book's salesrank was 15.81 times better than this stringy benchmark. Since that day it happened to be #395 among all books that Amazon sells.
The point of such an index is that it should be quick to calculate, and one should calculate it consistently always the same way. And one then watches it over time. Only the change over time, if there is any change, can mean something. By itself one cannot say what the number means.
The stringy benchmark to some extent measures the size of the problem (the over-hyping and over-selling of string to the public) and so the ratio has a connection with how well Smolin's initiative is doing relative to the size of the mountainous problem it addresses. But there is no rigorous meaning---one can learn what it means only by watching it over time and seeing what it correlates with. Like any other numerical indicator that one tracks.
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