The Yird is whaur we, Jock Tamson’s bairns, aw bides, alang wi the hail beasts. The Yird is oor hame, an oor only hame. Sae faur oor warld alane is the ae warld that we ken haes life on it. The word Yird haes its oreeginal in the auld Germanic *erþÅ. In the Auld-Angles leid it wis eorðe an in Auld Norse jÇ«rð.

The Yird taks 365.256 days tae gang-roond the Sun an taks 24 houres tae birl aboot itsel. At the hert o oor planet sits a muckle globe o hard iron surroondit wi liquid iron that kirns an turns an maks the magnetic fields that haps the planet ootwardly. Atween the iron hert an the crust the’r a layer cryed the mantle that’s driven wi heat an gars volcanoes an plates flist an gang, flit an lift. Ower millions o year thir plates flits an chenges the wey the continents is shaped while the atmosphere – ever fykie – weirs doun rock an stane. As ae side o the warld faces awa fae the Sun we hae nicht an the pairt taewards the Sun haes its day. Aboot 29% o this warld is made fae land while the lave – 71% - is watter. At the twa ends o this globe the’r north an sooth poles that’s maistly happit in ice. Ower lang ages the ice keps haes grown an dwyned mony times ower giein us oor antrin ice ages.

Aboot 12,000 year syne the war some 5 million humans on the Yird – that’s as mony fowk as is in Scotland thir days – but bi 1800 this haed risen tae 1 billion. In the last twa hunner year alane this haes risen fae 1 billion tae 7.7 billion, an growin yet. As this grows we weir throu mair an mair resources, an mak life for ither speshie unchancy.

But a human life is naething but a gliff in compare wi geologic time. In fact, Jock Tamson’s bairns haes haurdly been here ava. Oor minds maun warsle wi the undemous lang ages. The Yird wabbles back an forrit as it birls aboot the Sun an the hail gird aboot the Sun gaes up an doun like cosmic cuddies at rides in the shaws – only this gaes on ower hunners o thoosands an millions o year, appearinly athoot end. But it wisna that lang syne that we war blin tae sic lengths o time.

A puckle o the auld Greek screivars an thinkers pit forrit ideas anent time – the god o time wis Chronos (whiles confoondit wi the Titan Cronus) an it is fae him that oor Clessical word chronology springs. Here in Scotland in the days lang afore recordit history oor forebears biggit stane circles an ither monumental warks that markit the comin an gauin o the seasons, the hecht an dwyne o the Moon an the Sun. It is jaloused that the auldest stane circles is at Stenness in Orkney (cryed Stane-is in the Orkney byleid) biggit aboot 3,100 year Afore Christ, an Callanish on Lewis biggit atween 2,900 an 2,600 AC. Fae thir warks it is weel seen that oor forebears haed a notion o lang time that gaed weel ayont thair ain lifespans. But hoo lang?

The Christian monks that wrate the gospels whiles eikit the fechts an the deiths o kings tae the margins o thair buiks an fae this oor auldest wrutten fernyears first springs. An aboot AD 500 the monk Dionysius Exigus in Rome cam awa wi the anno domini calcul (‘in the year o the Lord’) syne used for makkin linear history.  In 1650 Jeems Usher airchbishop o Armagh, in Irland, took the Auld Testament an even cam awa wi a date for the makkin o the warld: 23 October 4004 AC. Sae, mony Christian fowk that lippent on the Bible gaed wi this date.

Hooanever, in 1788 fowk wirkin aboot the fields an gaits o Siccar Pynt at Pease Bey in Berrickshire wad’a seen twa curious cheils scrammlin aboot an pyntin doun at the rocks.  Twa weel buskit bodies that haed nae business in amang the rocks an seabraes, at least no for ordnar. Ane wis Jeems Hutton (1726-1797), the faither o geology, an the ither, John Playfair (1748-1819) the kirk meenister an scientific speirar. Thay haed come for tae tak the swatch o the upthrew rocks that Hutton jaloused wad prove the Yird wis faur aulder nor Usher’s 6,000 year.  As thay baith vizzied the appearinly nummerless strata it maun’a been a clearance as the facts an the theory cam thegither.

In his wark Theory of the Earth (1788) Hutton wrate “The result, therefore, of our present enquiry is, that we find no vestige of a beginning, - no prospect of an end.” But aiblins it is the lines fae Playfair’s 1805 wark Illustrations of the Huttonian Theory of the Earth that gars a body’s backbane chitter the maist. Playfair wrate “The mind seemed to grow giddy by looking so far back into the abyss of time.” Hutton an Playfair’s new uptak o geologic time wad come tae chenge oor unnerstaunin o the warld an its place amang the lave o the planets. Grundit on thir scientific speirings it is noo acceptit bi aw thaim that’s in the fay o science that the Yird is 4.543 billion year auld.