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The earliest glass item from the Indus Valley civilization is a brown glass bead found at Harappa, dating to 1700 BCE. This makes it the earliest evidence of glass in South Asia. [3] [20] Glass discovered from later sites dating from 600 to 300 BCE displays common colors. [3]
The study found that the room temperature viscosity of this glass was roughly 10 24 Pa·s which is about 10 16 times less viscous than a previous estimate made in 1998, which focused on soda-lime silicate glass.
The deuterium to hydrogen ratio for ocean water on Earth is known very precisely to be (1.5576 ± 0.0005) × 10 −4. [35] This value represents a mixture of all of the sources that contributed to Earth's reservoirs, and is used to identify the source or sources of Earth's water.
The first eon in Earth's history, the Hadean, begins with the Earth's formation and is followed by the Archean eon at 3.8 Ga. [2]: 145 The oldest rocks found on Earth date to about 4.0 Ga, and the oldest detrital zircon crystals in rocks to about 4.4 Ga, [34] [35] [36] soon after the formation of the Earth's crust and the Earth
The 300-plus-year-old glass onion bottles were discovered from the 1715 Treasure ... of the shop and then being submerged under water for (more than) 300 years where they were subject to tidal ...
The structural theories of glass formation only consider the relative ease of glass formation. Materials which form glasses under a moderate cooling rate are called good glass formers, those that require a rapid cooling rate are called poor glass formers and those that require extreme cooling rates are referred to a non-glass formers.
Around 420 BC, Empedocles stated that all matter is made up of four elemental substances: earth, fire, air and water. The early theory of atomism can be traced back to ancient Greece . Greek atomism was made popular by the Greek philosopher Democritus , who declared that matter is composed of indivisible and indestructible particles called ...
It has been proposed that glass eye covers in hieroglyphs from the Old Kingdom of Egypt (c. 2686–2181 BCE) were functional simple glass meniscus lenses. [40] The so-called Nimrud lens, a rock crystal artifact dated to the 7th century BCE, might have been used as a magnifying glass, although it could have simply been a decoration. [41] [42 ...