Cosmological decade

A cosmological decade ( CÐ ) is a division of the lifetime of the cosmos. The divisions are logarithmic in size, on base 10.

As expressed in log( Seconds per Ðecade )

When CÐ is measured in log( seconds/Ð ), the epoch CÐ -43.2683307 was 10**(-43.2683307) seconds, the Planck time since the big bang. CÐ 7.3230203 is 1 year = 365.2564 mean solar days. The epoch CÐ 17.6355 has lasted 10**(17.6355) seconds = 13.7 billion years since the big bang. There have been 60.9 cosmological decades between the Planck epoch, CÐ -43.2683307, and the current epoch, CÐ 17.6355.

• CÐ 1 lasts 10 seconds
• CÐ 100 lasts 10¹⁰⁰ seconds.

The 100th cosmological decade lasts from 10¹⁰⁰ to 10¹⁰¹ seconds after Time Zero (Big Bang event). CÐ - is Time Zero.

As expressed in log( Years per Ðecade )

Fred Adams & Greg Laughlin, (1997), in The Five Ages of the Universe first defined the cosmological decade as expressed in log years per decade. To convert to this format, simply divide by seconds per year; in logarithmic terms, simply subtract 7.3230203 from the values listed above. Thus when CÐ is expressed in log(years/Ð), the Planck time could also be expressed as 10**(-43.2683307 - 7.3230203) years = 10**( -50.5913510 ) years.

In this definition, the current epoch is CÐ 17.6355 - 7.3230203 = 10.3125 cosmological decades. As before, there have been 60.9 cosmological decades between the Planck epoch and the current epoch. In this definition, in the 100th cosmological decade, there are 10**100 years.

In their view, the history of the universe can be segmented into 5 Ages: