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Gaussians everywhere. Central limit theorem. Gaussians in physics. Slightly-disguised Gaussians in biology. 0. 1. -1. 0. Central limit theorem. H. T. -3. -2. -1. 0. 1. 2. 3. Gaussians everywhere. Central limit theorem. Gaussians in physics. - PowerPoint PPT Presentation
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๐ฟ ๐ฅ๐
๐ (๐ฟ ๐ฅ )
0 1-1
Central limit theorem
Gaussians everywhere
Gaussians in physics
Slightly-disguised Gaussians in biology
๐ (๐ฆ๐๐ )
0๐ฆ ๐๐
๐ฟ ๐ฆโ ๐ (๐ฟ ๐ฆ )๐ (๐ฟ๐ฅ1 )|๐ด๐๐ธ ๐ฟ๐ฅ1+โฏ
2
Central limit theorem
๐ (๐ฅ )= 1๐ โ2๐
๐โ 12 ( ๐ฅโ๐๐ )
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HT
๐ฟ ๐ฅ๐
๐ (๐ฟ ๐ฅ )
0 1 2 3-1-2-3
3
๐ฟ ๐ฅ๐
๐ (๐ฟ ๐ฅ )
0 1-1
Central limit theorem
Gaussians everywhere
Gaussians in physics
Slightly-disguised Gaussians in biology
๐ (๐ฆ๐๐ )
0๐ฆ ๐๐
๐ฟ ๐ฆโ ๐ (๐ฟ ๐ฆ )๐ (๐ฟ๐ฅ1 )|๐ด๐๐ธ ๐ฟ๐ฅ1+โฏ
4
Physics lab: Engineered for tightly-controlled noise
5
Physics lab: Engineered for tightly-controlled noise
6
Physics lab: Engineered for tightly-controlled noise
t
V
x1
x2
x3
x5
x4
Hook vibration
Uneven air flow
Thermal expansion
Laser pointer vibration
Twisting
y
๐ฟ ๐ฆ=๐ฟ ๐ฆ (๐ฟ๐ฅ1 , ๐ฟ๐ฅ2 , ๐ฟ๐ฅ3 ,โฏ )
๐ฟ ๐ฆโ ๐ฟ ๐ฆ ๐ด๐๐ธ+๐ (๐ฟ ๐ฆ )๐ (๐ฟ ๐ฅ1 )|๐ด๐๐ธ๐ฟ๐ฅ1+ ๐ (๐ฟ ๐ฆ )
๐ (๐ฟ๐ฅ2 )|๐ด๐๐ธ๐ฟ๐ฅ2+โฏ๐
๐ 1 ๐ 2
โSmallโ noise: Neglect quadratic terms in Taylor expansion
0
7
๐ฟ ๐ฅ๐
๐ (๐ฟ ๐ฅ )
0 1-1
Central limit theorem
Gaussians everywhere
Gaussians in physics
Slightly-disguised Gaussians in biology
๐ (๐ฆ๐๐ )
0๐ฆ ๐๐
๐ฟ ๐ฆโ ๐ (๐ฟ ๐ฆ )๐ (๐ฟ๐ฅ1 )|๐ด๐๐ธ ๐ฟ๐ฅ1+โฏ
๐ ๐ฆ๐๐ก
=๐ ๐ฆ
๐๐ +ยฟ๐๐ +ยฟ
๐๐ก+ ๐ ๐ฆ๐๐ โ
๐ ๐ โ
๐๐กยฟยฟ
8
Biology: Law of mass action and logarithms
yx2x1 x3
y
y yy
y yy y y
๐+ยฟ ยฟ ๐โ๐ +ยฟยฟ ๐ โ
๐+ยฟ ๐ฅ1๐ฅ2๐ฅ3โฏ ยฟ ๐โ๐ฆ+1 -1
0=๐+ยฟ ๐ฅ1๐ฅ2 ๐ฅ3โฏโ๐โ ๐ฆ๐๐ ยฟ
๐โ๐ฆ ๐๐=๐+ยฟ๐ฅ1๐ฅ2 ๐ฅ3โฏ ยฟ
ln ( ๐ฆ๐๐ )=ln ยฟยฟFluctuations in x1, x2, x3, etc. are not necessarily engineered to be small. First-order Taylor-expansion might be inaccurate.
ln ( ๐ฆ๐๐ )=ln ยฟยฟln ( ๐ฆ๐๐ )โ ln ยฟยฟ
๐ ๐ 2๐ 1
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Biology: Law of mass action and logarithms
ln ( ๐ฆ๐๐ )โ ln ยฟยฟ๐ ๐ 2๐ 1
A histogram of the logarithm of the concentration of y displays a normal distribution
30001507 3001500
๐ [ln ( ๐ฆ๐๐ ) ]
5 6 7 82 3 4ln ( ๐ฆ๐๐ )
๐ (๐ฆ๐๐ )
200 3001000 ๐ฆ ๐๐
yST = e4 = 55
e5 = 150
e6 = 400