I recently read a few statements that were being used to illustrate the passage of time and to put past events into context. I thought they were all interesting in a "oh yes, how true" sort of way:

As much time separates the building of the Great Pyramid and the life of Cleopatra … as separates Cleopatra from ourselves.
As much time separates the first trans-Atlantic flight and the first moon landing ... as separates the moon landing and ourselves.
As much time separates the dinosaurs Brontosaurus and Tyrannosaurus … as separates Tyrannosaurus from ourselves.

Another old chestnut is that if the age of the earth is represented as a 24hour day then all human history would only occupy the very last second before midnight.

Can anyone suggest any other similar facts or analogies that serve to illustrate just how close, or how remote, are other historical events, or that similarly work to make the passage of time more comprehensible?

More a case of time putting man into context, but ...

From approximately 23 million years ago (start of the Neogene period) up to 1598 - the length of time the evolved dodo existed prior to being noticed by Europeans, according to recent DNA research

64 years later - extinct

Here's one for genealogists.

Take a normal A4 pad of double-sided ruled paper. On the first line of the top sheet you write your name. On the line below you write your mother's name; below that her mother's name (your grand-mother); below that her mother's name (your great-grandmother); ... and so on down the page.

About half way down the first page you'll probably be writing the name, assuming you know it, of someone alive during Elizabeth I's reign. As you get to the bottom of the reverse side of the first sheet it'll be someone born well before Christ. And when you complete the last line of the last page of the pad it'll be the name of someone that isn't even of your own species, as she'll be a Homo erectus.


(This is just a rough back of envelope calculation ... I'm assuming a 60 sheet pad with 30 ruled lines on each page, and I took the average age for each generation as 25 years for the first couple of thousand years, and then before that to be 20 years as the average age of each mother at the birth of her daughter (who of course may not have been the first nor last child).

And there is a hypothesis that, around half way down page 7, we could all be writing the same name.

Sirius - the "Dog Star" - is the brightest star (actually an entire star system) in the night sky.



If you take a peek at it this evening you can reflect (in its rays) on the fact that as the light you are experiencing originally left its source Gerry Adams and Ian Paisley had just shaken each other by the hand, the final Harry Potter film had just hit the cinemas, 20 million Barbies had been recalled due to the Chinese factories they were moulded in having used lead and other nasties in her make-up, and the first iPhone had just been unveiled by Steve Jobs (it broke).

Its nearest bright neighbour, Adhara (which features on the Brazilian flag) twinkles merrily beside it, though as the twinkle you see now started out on its journey chocolate had just arrived for the first time in Europe, Queen Elizabeth of England's ships in Spanish ports had been seized by order of Philip (leading to later armadillos etc), a very young Billy Shakespeare was settling in in the big smoke of London with (we assume) plans to become a scribbler of renown, Walter Raleigh had just established the doomed Roanoake colony in the Americas, and the Chinese - yet to embark on a Barbie industry - contented themselves with introducing soya beans to Mexico.

The light from the third brightest star in the group, Delta Canis Majoris (or Wezen to closer acquaintances), started out when the Visigoths had just invaded Spain, the Eustathian schism in Antioch had just been healed (much to the relief of Eusebius who had chickened out at the last minute when offered the Eustathian bishopric, presumably since he didn't want people to think he had a lisp), in Alexandria his fellow Christians were busy murdering Hypatia the Librarian (a form of extreme literary censorship much refined by later Christians but with equal effect), while further up the coast one of their number "Augustine the Hippo" had started a book of his own - most likely a children's story.

Sandwiched between the above two lies Aludra (or Eta Canis Majoris to stuffy sods). The light from it in which you bask, it should be noted, started out just as the nasty Philistines were setting the Indiana Jones franchise in motion by capturing the Ark of the Covenant from the good guys and then suffering from "mice and haemorrhoids" (a much better end to the movie, I reckon), a bunch of nomads with a name that spelled terror in the hearts of generations of schoolchildren called "the Latins" had just arrived in the Italian peninsula (and we all know what THAT declined and fell into), the Phoenicians - presumably upon hearing of the Latin advance - decided it was high time to invent an alphabet of actual letters that everyone could copy afterwards (it was a bad year for schoolchildren), a young lad in Israel called David when not throwing stones decided it was now his destiny to stow thrones, and the Japanese - seemingly the only really practical people around at the time - invented rice.

Blink and you'd miss all that.

The trouble with geologic time (along with the national debt, and astronomy) is that it uses really, really big numbers. So while many a school child (at least one of non Young Earth Creationist parents) might be able to tell you that dinosaurs died out about 65 million years ago, very few people have much of a grasp just how big a number that is.

A million is 1,000,000 but how big is that really?

Today I’ve been cleaning out my swimming pool ready for the summer. It’s an average-sized domestic pool, lined with standard little one inch square ceramic tiles (they usually come in flexible 50cm x 50m sheets supported on an  open nylon mesh - you don't have to cement each tiny tile in place individually). There are obviously a great many of them. Might there in fact be as many as a million of them?

Without counting/calculating, at a quick glance I wonder how many people would be able to say how many, or how few, a typical swimming pool contains.

Are there a million tiles here?



In fact there are just over ten thousand tiles in my pool ... so you'd need about a hundred similar-sized swimming pools before you got to a million. If an individual tile was taken to represent a single year, one and a half square metres would roughly equate to the time back to Christ, but the time back to the extinction of the dinos would need all the tiles in about sixty swimming pools .... and something like three hundred pools to get back to the extinction of trilobites at the end of the Permian.

It puts many costs and debts in perspective too ... say the nine billion pounds cost of the 2012 London Olympics (at £1 a tile that would be equivalent to nearly a million swimming pools).

Fulten McKay and Burt Lancaster on the beach. As opposed to "On The Beach". Love it!

That stumped me for a minute - but then it dawned.




A million ain't what it used to be, not in monetary terms anyway. £1,000,000 used to seem an unimaginable amount of cash but not any more, now it would only buy you a nice house and a fancy car or in London, a small flat.

I got it wrong - it was Fulton Mackay and Peter Riegert, not Burt Lancaster. Up there with Time Bandits and Life of Brian among the all-time great films ...



Here's an interesting slice of time also. The pie chart illustrates the most common media people used to listen to music between 1981 and 2010. In the six years since this graphic was produced the red has shrunk even further ...

There are whales alive today who were around before Moby Dick was written. Alaskan Bowhead whales (which may have inspired the 1851 novel) can live for over 200 years.

Also here's a graphic from the XKCD comic called "Frequency" which illustrates real-time events as they are happening:



Great comic to browse. Their site contains this piece of advice: Warning: this comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors).

Meles meles wrote:

Take a normal A4 pad of double-sided ruled paper. On the first line of the top sheet you write your name. On the line below you write your mother's name; below that her mother's name (your grand-mother); below that her mother's name (your great-grandmother); ... and so on down the page.

About half way down the first page you'll probably be writing the name, assuming you know it, of someone alive during Elizabeth I's reign. As you get to the bottom of the reverse side of the first sheet it'll be someone born well before Christ.

This is evidenced (coincidently with the James Garner and others thread) by the fact that the lifespan of the last surviving former permanent resident of St Kilda is about 1/29th of the entire known history of the human habitation of that island. Put that way it sounds a lot less daunting than 2,500 years.