4 ms·
In the numberfile video he doesn't explain the way he calculates 2・S_2. He says he shift it, but doesn't explain why that is valid. Shifted version:
by olsgaard 10y ago
In the numberfile video he doesn't explain the way he calculates 2・S_2. He says he shift it, but doesn't explain why that is valid.
Shifted version:
1-2+3-4+5-6 ...
1-2+3-4+5 ...
sum: 1-1+1-1+1-1 ...
Multiplied version:
2-4+6-8+10-12 ...
The multiplied version shifts between +(2n) and -(2n). Following the logic that S_1 = 0.5, because that is the average between 0 and 1, I would argue that the multiplied version of S2 should equal 0, as that is the average between a postitive constant and its negative (but the variance is going to be infinite. Doesn't that have a say?).
What if we triple shift?
Triple shifted version:
1-2+3-4+5-6+7-8+9 ...
1-2+3-4+5-6 ...
sum: 2-3+3-3+3-3+3 ...
Look! now 2・S2 is equal to 2!
- diogofranco 10y agoI don't think your math adds up. Your triple shifted version would be between -1 or 2 depending on the cut right? So, still 1/2.
- olsgaard 10y agoYeah, that was a brainfart on my end. What about the multiplied version? That is how I would intuitively understand 2S_2, and I still don't accept that shifting is the same.