About Time Scale In The Standard Model

The linked video is a powerful illustration of the notion of different orders of magnitude of scale from the human scale on up.

It doesn't go the other direction and only looks at distance, however.

Since I am often guilty of lumping all small time intervals into the tiny "ephemeral" category, I'll do penance by touching on the remarkable orders of magnitude differences is decay rates in particle physics.

There are actually huge disparities of scale between the mean lifetimes of various fundamental particles and hadrons (27 orders of magnitude from the shortest lived to the longest lived unstable particle to be exact). It is hard to get you head around numbers like that. It is particularly hard to do when humans have no ability to consciously distinguish between all but the two or three longest time periods involved.

To help you do so, let's look at all of mean lifetimes for fundamental particles and hadrons that have been measured experimentally, from longest to shortest in mean lifetimes (all data via Wikipedia) in terms of a scale where the mean lifetime of a W boson (the shortest lived particle, tied with the Z boson) is set arbitrarily at 1 W second, which can make this easier to understand (below the break).

Particle name	Symbol	Quark content	Mean lifetime (s)	Multiples of W Boson Lifetime = 1 W second
Nucleon/proton	p  /  p+  /  N+	u u d	Stable	Not Applicable
Nucleon/neutron	n  /  n0  /  N0	u d d	8.800×10+2	92 sextillion W years
Muon	μ−	not applicable	2.1969811×10−6	232 billion W years
K-Long	K0 L	complex{\displaystyle \mathrm {\tfrac {d{\bar {s}}+s{\bar {d}}}{\sqrt {2}}} \,}Coocomplc	5.116×10−8	5 billion W years
Pion	π+	u d	2.6033×10−8	3 billion W years
Kaon	K+	u s	1.2380×10−8	1 billion W years
K-Short	K0 S	complex{\displaystyle \mathrm {\tfrac {d{\bar {s}}-s{\bar {d}}}{\sqrt {2}}} \,}	8.954×10−11	10 million W years
Omega	Ω−	s s s	8.21×10−11	9 million W years
B meson	B+	u b	1.638×10−12	173,022 W years
B meson	B0	d b	1.519×10−12	160,452 W years
Strange B meson	B0 s	s b	1.512×10−12	159,712 W years
bottom Omega	Ω− b	s s b	1.13×10−12	119,362 W years
D meson	D+	c d	1.04×10−12	109,855 W years
strange D meson	D+ s	c s	5.00×10−13	52,815 W years
Charmed B meson	B+ c	c b	4.52×10−13	47,745 W years
D meson	D0	c u	4.101×10−13	43,319 W years
Tau lepton	τ−	not applicable	2.906×10−13	30,696 W years
double charmed Xi	Ξ+ cc	d c c	3.3×10−14	3,486 W years
Pion	π0	complex	8.52×10−17	9 W years
Eta meson	η	complex{\displaystyle \mathrm {\tfrac {u{\bar {u}}+d{\bar {d}}-2s{\bar {s}}}{\sqrt {6}}} \,}	5.02×10−19	19 W days
Sigma	Σ0	u d s	7.4×10−20	69 W hours
Upsilon meson	ϒ (1S)	b b	1.22×10−20	11 W hours
D meson	D∗+ (2010)	c d	7.89×10−21	7 W hours
J/Psi	J/ψ	c c	7.09×10−21	7 W hours
Eta prime meson	η′ (958)	complex{\displaystyle \mathrm {\tfrac {u{\bar {u}}+d{\bar {d}}+s{\bar {s}}}{\sqrt {3}}} \,}complex	3.32×10−21	3 W hours
Strange D meson	D∗+ s	c s	3.4×10−22	18 W minutes
bottom Xi	Ξ∗0 b	u s b	3.1×10−22	17 W Minutes
D meson	D∗0 (2007)	c u	3.1×10−22	17 W minutes
charmed Xi	Ξ∗+ c(2645)	u s c	2.1×10−22	11 W minutes
Phi meson	ϕ (1020)	s s	1.54×10−22	8 W minutes
charmed Sigma	Σ0 c	d d c	3.05×10−22	17 W minutes
charmed Sigma	Σ++ c	u u c	2.91×10−22	16 W minutes
charmed Sigma	Σ+ c	u d c	1.43×10−22	8 W minutes
bottom Sigma	Σ− b	d d b	1.34×10−22	7 W minutes
charmed Xi	Ξ∗0 c(2645)	d s c	1.2×10−22	7 W minutes
bottom Sigma	Σ∗− b	d d b	8.8×10−23	5 W minutes
Omega meson	ω (782)	{\displaystyle \mathrm {\tfrac {u{\bar {u}}+d{\bar {d}}}{\sqrt {2}}} \,}complex	7.75×10−23	4 W minutes
Xi	Ξ∗0 (1530)	u s s	7.23×10−23	4 W minutes
bottom Sigma	Σ+ b	u u b	6.8×10−23	4 W minutes
Xi	Ξ∗− (1530)	d s s	6.6×10−23	4 W minutes
bottom Sigma	Σ∗+ b	u u b	5.7×10−23	3 W minutes
charmed Sigma	Σ∗0 c(2520)	d d c	4.54×10−23	3 W minutes
charmed Sigma	Σ∗++ c(2520)	u u c	4.42×10−23	148 W seconds
charmed Sigma	Σ∗+ c(2520)	u d c	3.87×10−23	129 W seconds
Kaon	K∗+	u s	3.26×10−23	110 W seconds
Charmed eta meson	η c(1S)	c c	2.04×10−23	68 W seconds
Sigma	Σ∗+ (1385)	u u s	1.839×10−23	61 W seconds
Sigma	Σ∗0 (1385)	u d s	1.83×10−23	61 W seconds
Sigma	Σ∗− (1385)	d d s	1.671×10−23	56 W seconds
Kaon	K∗0	d s	1.39×10−23	46 W seconds
Delta	Δ++ (1232)	u u u	5.63×10−24	19 W seconds
Delta	Δ+ (1232)	u u d	5.63×10−24	19 W seconds
Delta	Δ0 (1232)	u d d	5.63×10−24	19 W seconds
Delta	Δ− (1232)	d d d	5.63×10−24	19 W seconds
Neutral rho meson	ρ0 (770)	complex{\displaystyle \mathrm {\tfrac {u{\bar {u}}-d{\bar {d}}}{\sqrt {2}}} \,}	4.45×10−24	15 W seconds
Charged rho meson	ρ+ (770)	u d	4.41×10−24	14 W seconds
Top quark	t	t	5×10−25	2 W seconds
W+/- boson	W+/W-	not applicable	3×10−25	1 W second
Z boson	Z	not applicable	3×10−25	1 W second

Notes on The Table

1. For these purposes, I have disregarded experimental uncertainties (which generally do not change the order of magnitude of the time frame involved).

2. When a particle has a mean lifetime less than a given value have used the maximum value for that particle without annotation.

3. The W second based times in the table were rounded to remove all decimal quantities, after the mean lifetime in seconds shown in the table for each entry was converted to W second units.

4. Mesons with complex quark content are blends of mesons with different quark contents or with different kinds of blending.

5. The term "not applicable" in the fundamental particle column applies to particles treated as fundamental in the Standard Model.

6. The common names of the hadrons given is sometimes ambiguous because they omit designations of electric charge and spin, but the symbols are generally unambiguous.

7. Anti-mesons of the types shown (which are identical for electrically neutral mesons) have been omitted because they have the same mean lifetimes as the meson shown.

8. The table inadvertently omitted the Higgs boson which has a mean lifetime of 1.56×10⁻²² seconds, which is about 9 W minutes.

9. The table also omits electrons, photons, gluons and neutrinos. Electrons, photons and gluons are "stable" in the Standard Model, although in practice, gluons are short lived because they tend to interact with other particles at very short ranges and travel at the speed of light (apart from dynamically acquired mass). Neutrinos in the Standard Model oscillate but do not decay in the sense relevant to determining a mean lifetime.

10. Mean lifetime can be converted to half-life by dividing the mean lifetime by approximately 1.44 (more precisely the natural logarithm of 2).

Incidentally, don't assume that you can advance science by decoding the patterns in this chart, because that is a problem that has already been solved by the Standard Model of Particle Physics. Mean lifetimes are derived quantities in the Standard Model (even in the case of fundamental particles like the Higgs boson) that can be calculated from first principles without too much difficulty. Essentially, you just add up the decay times of every possible path of decay in the appropriate way.

Composite particles with decay products that can be formed without W boson interactions are generally much shorter lived than those that can only be formed with a W boson flavor changing interaction.  The weak force and strong force coupling constants drive the speed of the respective decay paths.