Today’s Illustration: Distortion Free

clear reflections  Clear Reflections!

On This Day: November 11, 2015

Groundbreaking for the building of the world’s largest optical telescope was held on Wednesday, November 11, 2015.

“With today’s groundbreaking, we take a crucial step forward in our mission to build the first in a new generation of extremely large telescopes. The GMT will usher in a new era of discovery and help us to answer some of our most profound questions about the universe,” says GMTO Board Member and Director of the Harvard-Smithsonian Center for Astrophysics Dr. Charles Alcock. “We are pleased to celebrate this momentous milestone with our Chilean colleagues, our international partners, and the astronomical community.” — https://scitechdaily.com/on-site-construction-begins-on-the-giant-magellan-telescope/

The History:

Presently, three of the top four telescope in the world are all located in the United States.  The fourth and greatest one is co-owned by the United States — The Gran Telescopio. . . .

#1) The Gran Telescopio Canarias located on the Canary Islands was a joint effort by Spain, Mexico, and the United States. 2006-2009 — Mirror Size — 10.4 m / 34.12 feet

#2) The Hobby-Eberly Telescope located in McDonald, Texas as a joint effort by The United States and Germany — 1997 — Mirror Size– 10.0 m / 32.80 feet

#3) Keck 1 located in Mauna Kea, Hawaii — 1993  — Mirror Size — 10 m / 32.80 feet

#4) Keck 2 located in Mauna Kea, Hawaii — 1996 — Mirror Size — 10m / 32.80 feet

 

•  A new round of giant telescopes was marked by the planning and development of the “Giant Magellan Telescope.”

•  This new class of giant telescopes was inaugurated on November 11, 2015

•  It is a joint venture by the United States, along with Australia, Brazil, South Korea, and Chile.

•  The “Giant Magellan” is situated in the country of Chile.

•  The final mirror will be composed of seven identical separately manufactured and integrated mirror surfaces which will all be ground and polished.

•  The grinding and polishing of the first mirror took 6 1/2 years.  The first one had to be made before the second one could be started because they were not sure the first one could even be made.

•  Each of the seven combined mirrors will weight 17 tons and cost $20 million.  The completed mirror alone will weight approximately 120 tons!

•  It will be located in “one of the highest and driest locations on earth, Chile’s Atacama Desert.”

•  The actual location is on the mountain peak called —  “Las Campanas Peak,” Chile.

•  Las Campanas Peak is approximately 8,500 feet above sea level.

•  The building which houses the telescope is 22 stories high.

•  This location is expected to allow for at least 300 nights of clear conditions for viewing the universe.

•  Only the University of Arizona is capable of manufacturing and polishing such large mirrors.

“They are a marvel of modern engineering and glassmaking; each segment is curved to a very precise shape and polished to within a wavelength of light—approximately one-millionth of an inch.”

•  The project which involves producing seven integrated mirrors began in November of 2005.

“They kicked the oven temperature up to 2,129 degrees. The high temperature melted nearly 20 tons of jagged glass that had been shipped in from Japan. The glass melted and flowed into the nooks and crannies of a specially built mold.”

•  On November 2017 the fifth mirror was begun.

 

•  The mirrors’ shapes are described as a “potato chip.”

Polishing Potato Chips

“We had to make the first one before they let us make the second,” says Dae Wook Kim, “because they didn’t think it was possible to make such a potato chip.”

•  The observatory anticipates viewing images by 2023 when the first four-member mirrors should be installed . . . .

“With four mirrors, we’ll still be the largest telescope in the world by a factor of two.  “In many respects, we’ll have a good fraction of our full capability.”

•  The first images from the finished telescope, with the full complement of seven integrated mirrors in place, should begin in 2025.

•  Its useful life is expected to be around 50 years.

 

Two of the key elements of these giant telescopes, which make them so scientifically productive are . . . .

#1) Size: The greater the size of the final mirrored surfaces, the more light it can capture. Capturing more light gives a telescope both greater clarity and further distances!

•  The “Giant Magellan” will have a final 24.5-meter diameter reflective mirror (80 feet in diameter).  The largest ever manufactured!

 

#2) Free From Distortion: Steps are also taken to prevent and avoid any possible distortion of the final images.

√ The actual location of a telescope is vital.  The further removed the telescope from both air and light pollution, the better the images.

For instance, the Hubble Space Telescope has produced some of the greatest images of the universe to date and only has a mirror 7.9 feet in diameter.  However, it was launched into outer space and is located approximately 335 miles above the earth “outside the distortion of Earth’s atmosphere” which “allows it to take extremely high-resolution images, with substantially lower background light than ground-based telescopes.”

 

√ The production and installation of distortion-free mirrors.

One of the marks of expensive glass, or a costly mirror, and even quality eyeglasses is the absence of distortion.  Such quality glass is spoken of as being homogeneous with no strain, striations, or discolorations.  

•  Each of the seven mirrors uses twenty tons of glass and takes six months to cool at a controlled cooling rate to prevent distortion.

•  The weight of the mirror will also pose another problem of distortion since they can begin to bend under their own weight.  The weight of the mirrors (still a final weight of 17 tons each and are 80% hollow) was significantly mitigated by its unique design.

“This is accomplished by using a honeycomb mold, whereby the finished glass is mostly hollow.”

•  The mirrors are ground and then polished by a process which takes years!

Hubble’s main mirror was found to have been ground incorrectly, compromising the telescope’s capabilities. The optics were corrected to their intended quality by a servicing mission in 1993

•  After installation, the mirrors are also cooled with fans to prevent heat distortion.

“Finally, since the giant mirrors are essentially hollow, they can be cooled with fans to help equalize them to the night air temperature, thus minimizing distortion from heat.”

•  The Giant Magellan will be able to produce images “10 times sharper than the Hubble Space Telescope.”

 

Light Gathering Ability & Preventing Image Distortion!

Both are critical to receiving clear and precise images of the universe!

 

Key Illustrative Thoughts:

Jesus is the expressed image of the Father — Distortion Free

God’s people are designed to reflect our Lord.

Image distortion

Light Gathering Ability

How to minimize distortion in our lives.

One day, distortion free

It takes years to polish.

Useful life – maybe 70 years

Only one place it can be “manufactured.”

How many nights a year?

Thirty-three years, 365 days a year — Jesus reflected the Father

Kinds of pollution which cloud the image

A unique design which makes it possible.

 

 



Other Information and Links:

 

https://www.gmto.org/overview/
https://en.wikipedia.org/wiki/Giant_Magellan_Telescope
https://www.space.com/38652-giant-magellan-telescope-fifth-mirror-casting.html
https://www.popularmechanics.com/space/telescopes/a13978782/giant-magellan-telescope-chile-atacama/
http://www.industrytap.com/giant-magellan-telescope-building-mirror-largest-telescope-world/44942
https://www.engadget.com/2015/11/12/giant-magellan-telescope-begins-construction/
https://scitechdaily.com/on-site-construction-begins-on-the-giant-magellan-telescope/
https://www.space.com/31645-putting-the-polish-on-epic-scale-telescope-mirrors.html

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