Corridor Story

THE REVOLUTIONARY LAMPS

Lamps

1. The word lamp is derived from Greek word ‘lampos’ which means torch.

2. The first lamp was created in 70000BC.

3. It was made from hollow rocks or shell filled with moss that was soaked in animal fats and ignited.

4. Around 7th century BC, the Greeks began making terracotta lamps to replace hand-held torches.

Ami Argand was the innovator of these lamps. It was developed in 1783. It consisted of central burner. The fuel was enclosed in metal and a metal tube was added to control the intensity of the light and the amount of the fuel burning.

Oil Lamp

Gas lamp

In 1792, William Murdoch used coal gas to heat his house in Redruth, Cornwall. German inventor Friedrich Winzer was the first person to patent coal gas lighting in 1804. David Melville received the first US gas light patent in 1810. In early 19th century, most cities in US & Europe had street that were using gas lighting.

Sir Humphrey Davy of England invented the first ‘Electric Carbon Lamp’ in 1801. Working A carbon arc lamp works by hooking two carbon rod to a sources of electricity. The end of the rods are spaced at right distance so that the current will flow through an ‘arc’ creating an intense white light. A.E. Becquerel of France theorized about the fluorescent lamp in 1857.

Electric arc lamp

Electric Incandescent

The inventor of electric incandescent lamp was Sir Joseph Swan. Thomas Edison simply improved upon sir Joseph’s 50 year old idea.

Electricity flows through the filament while the filament resist the electricity. The resistance causes the filament to heat up. On further heating it radiates light.

Halogen lamp is an innovation upon the electric incandescent lamp to improve its lifetime. The first commercial lamp to use halogen gas (Iodine) was patented in 1959 by General Electric company. It was developed by Elmer Friedrich and Emmet Wiley, who worked in General Electric in 1955.

Halogen Lamp

LED

LED Corridor Stories Nick Holonyak employed in General Electric developed first LED that emitted light in visible spectra in 1962. It was red LED. In 1972, George Craford- student of Holonyak invented first yellow LED, which was brighter than the red LED. Thomas Pearsal developed high brightness LED in 1976 which was used in telecommunication. Shuji Nakamura of Nichia Corporation made first blue LED in 1979, but it was hundred times more expensive for commercial use.

CFL Lamp CFL lamp was invented in 1976 by Edward E. Hammer, an engineer of ‘General Electric’, in response to 1973 oil crisis. Compared to general incandescent lamps giving same amount of visible light, CFLs consumes 20% to 33% of the electric power and lasts 8 to 15 times longer.

CFL Lamp

Helium Discovery

YELLOW YELLOW MYSTERIOUS FELLOW

The bright yellow spectral line he observed was believed to be sodium but on further study he found the wavelength of this yellow band(λ=587.49nm) didn’t match with the wavelength of sodium nor with any of the known elements.

Wavelength : The distance between two consecutive particles in a wave which are in same phase

HELLIOSCOPE

Brightness of this yellow band was high, so he was sure that he could obtain its spectrum in normal daylight. For proper observation, he then started constructing a new spectroscope called a spectrohellioscope. It was specially designed for observing the sun’s spectrum.

INCIDENCE OF CO-INCIDENCE

(Pierre Janssen)

While Janssen was working with Spectrohelioscope in India at the same time another person named Norman Lockyer in England was also working towards the (Pierre Janssen) discovery of this unknown spectral line and both arrived at the same result. They documented their respective result and sent it to French Academy of Science on Oct 26 1868. But coincidently their paper arrived there on the same day and hence, both of them were credited for this discovery.



(Norman Lockyer)

French Academyof Science : The French Academy of Science is a learned society founded in 1666 to encourage and protect the spirit of French Scientific research.

THE NAMING CEREMONY

THE PERIOD OF DISAPPROVAL

Norman coined the name Helium, to the new element who’s yellow band was observed in his Spectrum. The name helium was given because in Greek sun means Helios.

Many scientists doubted this discovery of Helium. Some of them said that helium was only present on sun, while others disregarded the whole discovery.

SORPRESA HO TROVATS T’ELIS SULLA TERA (I FOUND HELIUM ON EARTH)

(Luigi Palmieri)

In 1882, on Italian physicist Luigi Palmieri analysed lava spectrum from Mount Vesuvius. He observed the same yellow spectral lines in his data.

(Mount Vesuvius Erupting)

#THE He ISOLATED

After 1994, Scottish geologist William Ramsey started working with uranium ore. He was trying to isolate argon by treating uranium ore with mineral acid. Instead he noticed some unusual gas locked inside the specimen. He sent the specimen to Norman. It was the same bright yellow band and it's properties matched with Helium. And hence, in this way, the existence of Helium on earth was confirmed.