Tuesday, March 27, 2007

Classical Science: Telling Time with the Sun


Time to run outside in the sun!

For a simple animation of how shadows vary with time and position of the sun, click here. The animation here shows you how to estimate the size of a very large object (like the Statue of Liberty or T Rex) by comparing shadows.

When Isaac Newton was a boy, he was interested in studying the patterns of how shadows moved. He eventually constructed many sundials around his house and could tell the time just by looking at the placement of shadows.

For a good background on telling the time by the sun, and a print-out template for one to make yourself, click on this NASA site. You'll have to determine your latitude before you can use the sundial accurately so that you can factor in the tilt of the earth and its curvature. There are many beautiful sundial pictures at Wikipedia.

Another device an ancient Roman could use was an horologium ex aqua, or water clock - that displayed the month and hour on a column of water. For more on how ancient Romans kept time, check here.

If you're wondering how a person in the Middle Ages might have been able to tell the time at night, they could have used a Star Clock that uses the pointers of the Big Dipper.

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Previous Latin Sayings of the Week

"Soli deo gloria." - For the glory of God alone.


Christus resurrexit! Vere resurrexit! - Christ is Risen! He is risen, indeed!



"Lex malla, lex nulla." - St. Thomas Aquinas
(A bad law is no law.)


"Cantantes licet usque (minus via laedit) eamus. " - Let us go singing as far as we go: the road will be less tedious.


"Caelitus mihi vires." - My strength is from heaven.

"Magnificat anima mea Dominum, et exsultavit spiritus meus in Deo Salvatore meo" - My soul doth magnify the Lord, and my spirit hath rejoiced in God my Savior (Luke 1:45)

In Omnibus Ipse Primatum Tenens “That in all things He (Christ) might have the preeminence.” (Colossians 1:16-18)


"Qui bene cantat bis orat." - He who sings well, prays twice - (St Augustine)

"Nos fecisti ad te et inquietum est cor nostrum donec requiescat in te." -
Thou hast made us for Thyself, O Lord, and our hearts are restless until they rest in Thee. (St Augustine)

"Caelitus mihi vires
." - My strength is from heaven.

"Ubi caritas et amor Deus ibi est." - Where there is charity and love, God is there.

"Nisi credideritis, non intelligetis ."

Unless you will have believed, you will not understand. - St Augustine

"Deo vindice" - With God as Protector


"Credite amori vera dicenti." - Believe love speaking the truth. (St. Jerome)


De vitiis nostris scalam nobis facimus, si vitia ipsa calcamus." - If we tread our vices under feet, we make them a ladder to rise to higher things. (St. Augustine)

Dei gratia - By the grace of God

Verbum Domini Manet in Aeternum. - The Word of the Lord Endures Forever.

"Est autem fides credere quod nondum vides; cuius fidei merces est videre quod credis." - Faith is to believe what you do not see; the reward of this faith is to see what you believe. (St. Augustine)

"Deo iuvante" - with God's help

"Ut In Omnibus Glorificetur Deus." - That God may be glorified in all things

"Pax vobiscum." Peace be with you.

"Jubilate Deo." Be joyful in the Lord.

"Ille vir, haud magna cum re, sed plenus fidei." He is a man, not of ample means, but full of good faith.

"Facit enim mihi magna qui potens est." - For He that is mighty does to me great things.

"Oremus semper pro invicem." - Let us ever pray for each other.

"Distrahit animum librorum multitudo." - Seneca
A multitude of books distracts the mind.

"Nullam est nunc dictum, quod sit non dictum prius." - Terence
There is nothing said now, that has not been said before.

"Nosce te ipsum." - Plato
Know thyself.

"Non mihi, non tibi, sed nobis" - Not for you, not for me, but for us.

"Primum non nocere." - First, do no harm (Hippocrates)

"Est autem fides credere quod nondum vides; cuius fidei merces est videre quod credis." - Faith is to believe what you do not see; the reward of this faith is to see what you believe. (St. Augustine)

"Deo iuvante" - with God's help

"Ut In Omnibus Glorificetur Deus." - That God may be glorified in all things

"Pax vobiscum." Peace be with you.

"Jubilate Deo." Be joyful in the Lord.

"Ille vir, haud magna cum re, sed plenus fidei." He is a man, not of ample means, but full of good faith.

"Facit enim mihi magna qui potens est." - For He that is mighty does to me great things.

"Oremus semper pro invicem." - Let us ever pray for each other.

"Distrahit animum librorum multitudo." - Seneca
A multitude of books distracts the mind.

"Nullam est nunc dictum, quod sit non dictum prius." - Terence
There is nothing said now, that has not been said before.

"Nosce te ipsum." - Plato
Know thyself.

"Non mihi, non tibi, sed nobis" - Not for you, not for me, but for us.

"Primum non nocere." - First, do no harm (Hippocrates)

"Dei plena sunt omnia." - Cicero (All things are full of God.)