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3D Printing in Smart Construction and Prototyping

  Revolutionizing the Building Industry Introduction The integration of 3D printing technology into the construction industry has sparked a revolution in the way buildings are designed, prototyped, and constructed. With its ability to fabricate complex structures layer by layer, 3D printing offers unparalleled flexibility, efficiency, and sustainability in construction processes. In this article, we explore the transformative impact of 3D printing in smart construction and prototyping, examining its applications, benefits, and future prospects in reshaping the built environment. Understanding 3D Printing in Construction: 3D printing, also known as additive manufacturing, involves the layer-by-layer deposition of materials to create three-dimensional objects from digital models or CAD (Computer-Aided Design) files. In the context of construction, 3D printing enables the fabrication of building components, structures, and even entire buildings usin
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How Do You Solve a Moon Mystery? Fire a Laser at It

 

The moon moves away. Every year it moves about an inch and a half away from us. Hundreds of millions of years from now, our companion in the sky will be far enough away that there will be no more total solar eclipses.

For decades, scientists have measured the moon's recoil by firing a laser at light-reflecting panels, called retroreflectors, left on the lunar surface, then timing the light's round trip. But the moon's five retroreflectors are old and now much less efficient at reflecting light. To determine whether a layer of lunar dust might be to blame, the researchers devised a bold plan: They bounced laser light off a much smaller but newer retroreflector mounted aboard a NASA spacecraft flying over the surface of the Earth. moon at thousands of miles per hour. And it worked.

These results were published this month in the journal Earth, Planets and Space.

Of all the things humans have left on the moon, the five retroreflectors, which were delivered by Apollo astronauts and two Soviet robotic rovers, are among the most scientifically significant. They are similar to very long criteria: By precisely timing how long it takes for laser light to travel to the moon, bounce off a retroreflector, and return to Earth (about 2.5 seconds, give or take), scientists can calculate the distance between the moon and the earth

Arrays of glass cube corner prisms make this cosmic bounce possible. These optical devices reflect incoming light exactly where it came from, ensuring that the retroreflectors send photons out in a tight, neat curve.

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Making repeated measurements over time allows researchers to put together a better picture of the moon's orbit, its precise orientation in space, and even its interior structure.

But the suitcase-sized moon retroreflectors, delivered between 1969 and 1973, are now showing their age. In some cases, they are only a tenth of what is expected, said Tom Murphy, a physicist at the University of California, San Diego, who was not involved in the research. "Yields are severely depressed."

A laser aimed at the Lunar Reconnaissance Orbiter from the Goddard Space Flight Center Laser Ranging Facility in Greenbelt, Maryland in 2010.

A laser aimed at the Lunar Reconnaissance Orbiter from Goddard Space Flight Center's Laser Ranging Facility in Greenbelt, Maryland, in 2010.Credit...NASA/Goddard

An obvious culprit is moondust that has collected on retroreflectors. The dust can be kicked up by meteors hitting the moon's surface. It has stained astronauts' lunar suits during their visits, and this is expected to be a major problem if humans ever colonize the moon.

While it has been nearly 50 years since a retroreflector was placed on the moon's surface, a NASA spacecraft launched in 2009 carries a retroreflector the size of a paperback. This spacecraft, the Lunar Reconnaissance Orbiter, orbits the moon every two hours and has transmitted millions of high-resolution images of the lunar surface.

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The Lunar Reconnaissance Orbiter "offers a pristine target," said Erwan Mazarico, a planetary scientist at NASA's Goddard Space Flight Center, who, along with colleagues, tested the hypothesis that lunar dust could affect the moon's retroreflectors. .

But it is also a moving target. The orbiter flies over the surface of the moon at 3,600 mph. "It's hard enough hitting a stationary target," said Dr. Murphy, who heads Apache Point Observatory's Lunar Laser Ranging Operation, or APOLLO, a project that uses retroreflectors on the Moon's surface. "We're going to give you a smaller board and have it move on you."

In 2017, Dr. Mazarico and his collaborators began firing an infrared laser from a station near Grasse, France, about a half-hour drive from Cannes, at the orbiter's retroreflector. Around 3 a.m. m. on September 4, 2018, they recorded their first success: a detection of 25 round-trip photons.

The researchers obtained three more results in the fall of 2019. After accounting for the smaller size of the orbiter's retroreflector, Dr. Mazarico and his colleagues found that it often returned photons more efficiently than the Apollo retroreflectors. .