Telescopes
Telescopes
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation such as visible light. The first known practical telescopes were invented in the Netherlands at the beginning of the 17th century, using glass lenses. They found use in terrestrial applications and astronomy.
Telescopes come in all shapes and sizes, from a little plastic tube you buy at a toy store for $2, to the the Hubble telescope which weighs several tons. Amateur telescopes fit somewhere in between, and even though the are not nearly as owerful as the space telescopes, the can do some incredible things. For example, a small 6-inch (15 centimeter ) scope lets you read the writing on a dime from 150 feet (55 meters) away!
Within a few decades, the reflecting telescope was invented, which used mirrors. In the 20th century many new types of telescopes were invented, including the radio telescopes in the 1930s and infrared in the 1960s. The word "telescope"(derived for the Greek language tele "far" and skopein "to see or look" i.e. teleskopos "far-seeing) was coined in 1611 by the Greek mathematician Giovanni Demisiani for one of Galileo Galilei's instruments presented at a banquet at the Accademia dei Lincei in the Starry Messenger, Galileo had used the term "perspicillum".
History
The earliest recorded working telescopes were the refracting telescopes that appeared in the Netherlands in 1608. Their development is credited to three individuals: Hans Lippershey and Zacharias Janssen, who were spectacle makers in Middelburg, and Jacob Metius of Alkmaar.[4] Galileo heard about the Dutch telescope in June 1609, built his own within a month,[5] and greatly improved upon the design in the following year.
The purpose of a telescope is not to magnify, as commonly thought, but to collect light. The larger the telescope's main light-collecting element, whether lens or mirror, the more light is collected. Importantly, it is the total amount
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation such as visible light. The first known practical telescopes were invented in the Netherlands at the beginning of the 17th century, using glass lenses. They found use in terrestrial applications and astronomy.
Telescopes come in all shapes and sizes, from a little plastic tube you buy at a toy store for $2, to the the Hubble telescope which weighs several tons. Amateur telescopes fit somewhere in between, and even though the are not nearly as owerful as the space telescopes, the can do some incredible things. For example, a small 6-inch (15 centimeter ) scope lets you read the writing on a dime from 150 feet (55 meters) away!
Within a few decades, the reflecting telescope was invented, which used mirrors. In the 20th century many new types of telescopes were invented, including the radio telescopes in the 1930s and infrared in the 1960s. The word "telescope"(derived for the Greek language tele "far" and skopein "to see or look" i.e. teleskopos "far-seeing) was coined in 1611 by the Greek mathematician Giovanni Demisiani for one of Galileo Galilei's instruments presented at a banquet at the Accademia dei Lincei in the Starry Messenger, Galileo had used the term "perspicillum".
History
The earliest recorded working telescopes were the refracting telescopes that appeared in the Netherlands in 1608. Their development is credited to three individuals: Hans Lippershey and Zacharias Janssen, who were spectacle makers in Middelburg, and Jacob Metius of Alkmaar.[4] Galileo heard about the Dutch telescope in June 1609, built his own within a month,[5] and greatly improved upon the design in the following year.
The purpose of a telescope is not to magnify, as commonly thought, but to collect light. The larger the telescope's main light-collecting element, whether lens or mirror, the more light is collected. Importantly, it is the total amount