Now you ask, how did he get the year 4004 BC?
Answer: He took the chronologies in Genesis 5 and 11, together with some other Bible passages which we will look at. To simplify the calculations, we will tie the chronology to the fall of Jerusalem in 588 BC. The detailed calculations cover over 100 pages in the original document!
From Genesis 5 we get the following:
First Genealogy-Genesis 5
Verse Event Age of the Earth
1:1-31 Creation 0
5:3 Seth born when Adam, 130 130
5:6 Enos born when Seth, 105 235
5:9 Cainan born when Enos, 90 325
5:12 Mahalaleel born when Cainan, 70 395
5:15 Jared born when Mahalaleel, 65 460
5:18 Enoch born when Jared, 162 622
5:21 Methuselah born when Enoch, 65 687
5:25 Lamech born when Methuselah, 187 874
5:28 Noah born when Lamech, 182 1056
11:10 Shem born when Noah, 502 1558
7:6 Flood when Noah, 600 1656
From Genesis 11 we get:
11:10 Arphaxad born when Shem, 100 1658
11:12 Salah born when Arphad, 35 1693
11:14 Eber born when Salah, 30 1723
11:16 Peleg born when Eber, 34 1757
11:18 Reu born when Peleg, 30 1787
11:20 Serug born when Reu, 32 1819
11:22 Nahor born when Serug, 30 1849
11:24 Terah born when Nahor, 29 1878
11:32, 12:4 Abraham born when Terah, 130 2008
12:4 Abraham enters Canaan, 75 2083
In the Bible there are some large time periods given. These enable us to do the same calculations as Ussher, without going into all the intermediate details as he did.
Golden Arches of Time
Abraham left Haran until the Exodus exactly 430 years to the day.
-( Ge 12:10, Ex 12:40, Gal 3:17)
2513
Exodus to start of Temple, 479 years
-( 1 Ki 6:1, in the 480th year or after 479 years)
2992
Start of Temple to division of the Kingdom, 37
-( Solomon reigned 40 years, 1Ki 11:42, temple started in his 4th year)
3029
Division of the Kingdom to final deportation about four years after Jerusalem fell,
390 whole years plus part of one year
(Eze 4:4-6)
Final deportation in 584 BC
3421
Hence date creation = 584 + 3421-1 = 4004 BC
Now you have a rough idea of how Ussher did his calculations.
Hoops says, in her usual throw-away style:
Hoops wrote:Second: does the Biblical record allow for an older earth and still maintain the accuracy of the genealogies? Quite possible.
Show us how it is possible, given that Adam was created in the same week as the rest of the work of creation was accomplished.
(It is of course irrelevant WHY the genealogies are there - what matters is that they are there, that you believe them to be true, and that has certain obvious mathematical consequences about the length of time that has elapsed since the creation, making it about 6,000 years.)