In­ven­tive Ge­nius: The Mi­cro­scope

ZACHARIAS JANSSEN

The Borneo Post - Good English - - Front Page -

In 1590, the Dutch fa­ther and son duo of Zacharias and Hans Janssen, eye-glass makers by pro­fes­sion, pieced to­gether a con­trap­tion of a tube with mul­ti­ple lenses placed in it, and dis­cov­ered that one can see ob­jects in a much larger size if viewed through their con­trap­tion. This is per­haps the first recorded in­stance of a mi­cro­scope (and, prob­a­bly a tele­scope too).

The dis­cov­erer of the cell, Robert Hooke also made his own ver­sion of the mi­cro­scope, prob­a­bly the first com­pound mi­cro­scope, in 1655 AD. He pub­lished a book ti­tled ‘Mi­cro­graphia’ ten years later, de­scrib­ing the won­der­ful world he ob­served through his in­ven­tion.

Also given credit is An­tonie van Leeuwen­hoek. Leeuwen­hoek was a trader by pro­fes­sion and an ama­teur lens grinder. It was he who in­vented the mi­cro­scope as we know it to­day, re­plete with small glass lenses mounted in brass, and screws and pins to fo­cus the sam­ple un­der ob­ser­va­tion.

Leeuwen­hoek was a mas­ter in grind­ing lenses and cre­ated pow­er­ful lenses to the or­der of 270X-300X, that could mag­nify much more than what was ever pos­si­ble ear­lier. His mi­cro­scopes were in­stru­men­tal in his dis­cov­ery of blood cells, bac­te­ria and sperms. Leeuwen­hoek’s mi­cro­scope de­sign was copied and/or im­proved upon by many in­clud­ing Robert Hooke.

Mi­cro­scopes opened up a to­tally new world - that of struc­tures too small to be seen by the hu­man eye. And from the ba­sic mi­cro­scopes of the 16th and 17th cen­turies to the ad­vanced elec­tron and con­fo­cal mi­cro­scopes of to­day, the jour­ney has been noth­ing short of mirac­u­lous.

In the 1870s, mi­nor im­prove­ments in op­tics and de­sign were made, but there was a gen­eral pe­riod of lull for the fol­low­ing two cen­turies. The next ma­jor mile­stone was Joseph Lis­ter’s ef­fort in 1830 which lead to lenses hav­ing re­duced chro­matic ef­fect. Lis­ter showed that com­bin­ing mul­ti­ple weak lenses at spe­cific dis­tances re­duced blur­ring and spher­i­cal aber­ra­tion due to re­frac­tion of light. And thus was born the ‘achro­matic lens’ as we know it to­day. Achro­matic lenses could re­solve up to one mi­cron.

Mak­ing lenses and mi­cro­scopes had now be­come a flour­ish­ing busi­ness, and Carl Zeiss in 1847 started mak­ing mi­cro­scopes in the town of Jena in Ger­many.

It was soon es­tab­lished that us­ing white light, one can­not re­solve ob­jects that are sit­u­ated closer than half the wave­length of the light. As white light has a wave­length of 550 nm, no two ob­jects sit­u­ated 275 nm or lesser apart can be re­solved. The so­lu­tion was to use light of a shorter wave­length for il­lu­mi­na­tion, and Richard Zsig­mondy was the first to ac­tu­ally do it, cre­at­ing the first ever Ul­trami­cro­scope. This achieve­ment fetched him the No­bel Prize in Chem­istry in 1925.

The next two No­bel Prize win­ning ef­forts for im­proved mi­cro­scopes were for the Phase Con­trast mi­cro­scope and the Elec­tron mi­cro­scope, which were dis­cov­ered in 1932 and 1931 re­spec­tively. The 1953 No­bel Prize in Physics was given to Frits Zernike, who in­vented the phase con­trast mi­cro­scope. Us­ing phase con­trast, one could study even color­less trans­par­ent ob­jects.

The 1985 No­bel Prize in physics was awarded to Ernst Ruska, co-inventor of the elec­tron mi­cro­scope, which went a step ahead of the orig­i­nal ul­trami­cro­scope and used elec­trons as a source of light, en­abling atomic-scale res­o­lu­tions and mag­ni­fi­ca­tion up to 1,000,000X.Red White Blood cells

In­deed, one can view in three di­men­sions, us­ing the scan­ning elec­tron mi­cro­scope, sub-cel­lu­lar ul­tra­struc­tures in tremen­dous de­tail. The in­ven­tors of the scan­ning elec­tron tun­nelling mi­cro­scope, Gerd Bin­nig and Hein­rich Rohrer were the re­cip­i­ents of the No­bel Prize for Physics in the sub­se­quent year, 1986. 1. A periscope is an in­stru­ment for ob­ser­va­tion usu­ally used in­___. a) a ship b) a sub­ma­rine c) an air­craft

2. Who usu­ally uses a stetho­scope? a) a plumber b) a me­chanic c) a doc­tor

3. The largest tele­scope in the world is lo­cated in­____. a) Ca­nary is­lands b) Texas c) Hawaii

4. What is used to ex­am­ine a ship’s hull while it is un­der­wa­ter? a) periscope b) mi­cro­scope c) aquas­cope

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