Connect with us

Science

Researchers find that laser light has the ability to cast shadows

Published

on

A blue laser was used to illuminate the ruby cube from the side while a high-power green laser was focused through it for the experiment. In order to produce a matched region in the illuminating light and a darker area that looks as a shadow of the green laser beam, the green laser increases the optical absorption of the blue illuminating laser beam.

Is it possible for light to cast a shadow? Researchers have discovered that, in some circumstances, a laser beam can behave like an opaque object and cast a shadow, which may sound like a philosophical conundrum. The finding casts doubt on the conventional wisdom regarding shadows and creates new opportunities for devices that could manipulate another laser beam with a laser beam.

“Laser light casting a shadow was previously thought impossible since light usually passes through other light without interacting,” said Raphael A. Abrahao, the leader of the study team from Brookhaven National Laboratory, formerly at the University of Ottawa. “Our demonstration of a very counter-intuitive optical effect invites us to reconsider our notion of shadow.”

In Optica, scientists explain how they demonstrated that a laser beam could block light and produce a visible shadow because of a nonlinear optical process using a ruby crystal and particular laser wavelengths. Light can affect another optical field when it interacts with a material in an intensity-dependent manner.

“Our understanding of shadows has developed hand-in-hand with our understanding of light and optics,” Abrahao stated. “This new finding could prove useful in various applications such as optical switching, devices in which light controls the presence of another light, or technologies that require precise control of light transmission, like high-power lasers.”

The new study is a part of a broader investigation of nonlinear optical processes and the interaction of two light beams under specific conditions.

Some experimental drawings created with 3D visualization software portray the shadow of a laser beam because they interpret it as a cylinder without taking into account the physics of a laser beam. This idea was first raised during a lunch chat. Could this be done in a lab? asked some of the scientists.

“What started as a funny discussion over lunch led to a conversation on the physics of lasers and the nonlinear optical response of materials,” Abrahao remarked. “From there, we decided to conduct an experiment to demonstrate the shadow of a laser beam.”

The researchers accomplished this by shining a blue laser sideways on a cube of regular ruby crystal and passing a high-power green laser through it. The material’s reaction to the blue wavelength is locally altered when the green laser enters the ruby. Whereas the blue laser behaves like illumination, the green laser behaves like a regular object.

On a screen, the interaction of the two light sources produced a shadow that could be seen as a dark spot where the blue light was blocked by the green laser. Because it was visible to the unaided eye, followed the outlines of the surface it fell on, and followed the location and form of the laser beam, which functioned as an object, it satisfied all the requirements for a shadow.

The ruby’s optical nonlinear absorption is what causes the laser shadow effect. The green laser produces a corresponding region in the illuminating light with reduced optical intensity by increasing the blue illuminating laser beam’s optical absorption. As a result, the green laser beam appears as a shadow in a darker area.

Continue Reading
Advertisement

Science

NASA postpones the next Artemis flights much more

Published

on

NASA has postponed the first crewed landing of the program until mid-2027, delaying the following two Artemis trips to the moon.

After identifying the primary cause of Orion heat shield erosion on the Artemis 1 mission two years ago, NASA leadership announced at a news conference on December 5 that they were postponing the Artemis 2 and 3 flights.

Artemis 2, which was originally planned to launch in September 2025, would now debut in April 2026 under the updated schedule. It will be the first crewed voyage of Orion to take four astronauts from the United States and Canada around the moon.

As a result, Artemis 3, which will use SpaceX’s Starship vehicle for the first crewed landing of the entire exploration effort, will be delayed. Originally scheduled for September 2026, that mission is now anticipated to occur in mid-2027.

Following an examination of Artemis 1’s heat shield deterioration, NASA changed that timeline. In October, agency representatives claimed to have identified the cause of the heat shield material’s release, but they did not elaborate on the cause or NASA’s plans to fix it.

NASA Deputy Administrator Pam Melroy said the issue was related to Orion’s “skip” reentry, in which the capsule enters and exits the atmosphere to release energy. In the outer layers of the heat shield, more heat was retained than anticipated, resulting in trapped gases. “This caused internal pressure to build up and led to cracking and uneven shedding of that outer layer,”  she said.

This judgment was confirmed by an independent review panel after a thorough study. “There were a lot of links in the error chain that accumulated over time that led to our inability to predict this in ground tests,” stated Amit Kshatriya, deputy assistant administrator of NASA’s Moon to Mars Program Office. This included modifications to the shape of the material blocks and modifications to the manufacturing process of the heat shield material, known as Avcoat.

He said that in areas of the Avcoat material with the required greater permeability to let the gasses out, that was verified. “In those places, we did not witness in-flight cracking, and that was the key clue for us.”

NASA will alter the reentry profile, including shortening the skip phase of the reentry, rather than replacing the entire heat shield for the Artemis 2 mission. According to ground tests, those adjustments should be enough to prevent material from breaking off as a result of cracking.

The agency has been working on a number of other Orion issues while looking into the heat shield issue, such as a battery issue that was reported in January but was reportedly fixed, according to Kshatriya.

Despite an upcoming presidential transition that would probably rethink the entire Artemis design, agency chiefs said they made the decision immediately to prevent future delays. “We’re on a day-for-day slip. We had to make this decision,” Melroy stated. “If you’re waiting for a new admininstrator to be confirmed and a team to come up to speed on all this technical work we’ve all been tracking very closely, I think that would be actually far worse.”

Shortly after President-elect Donald Trump stated on December 4 that he would select Jared Isaacman to oversee the agency, NASA Administrator Bill Nelson claimed he spoke with Isaacman. He did, however, add that he and other authorities had a discussion prior to the meetings in which they confirmed the revised plan for Artemis 2 and 3. Melroy went on to say that NASA could have been consulted on the decision, but the incoming administration has not dispatched a transition team there.

Nelson, however, maintained that the present architecture was still the most effective way to send humans back to the moon in spite of the problems and delays, pointing out that even with the most recent postponement, NASA would still make a lunar landing before China’s projected 2030 lunar mission.

“Are they going to axe Artemis and insert Starship?” In reference to the impending Trump administration, Nelson stated. Only Orion is rated for human spaceflight outside of Earth’s orbit, he said. “I expect that this is going to continue.”

Continue Reading

Science

Firefly plans to launch its first lunar lander mission in January

Published

on

The first lunar lander mission is scheduled to launch in January, according to Firefly Aerospace. This means that none of the three commercial lander missions that were originally scheduled to launch in the fourth quarter of this year will actually launch.

On Nov. 25, Firefly said that it would launch its Blue Ghost 1 lander mission over the course of six days in mid-January. A SpaceX Falcon 9 will take out from Florida with the spacecraft.

After the spacecraft finished testing at NASA’s Jet Propulsion Laboratory in October, the launch date was announced. In the release confirming the launch date, Firefly CEO Jason Kim remarked, “Blue Ghost aced environmental testing and proved the lander is performing 100% as expected.” “While we know there will be more challenges ahead, I’m confident this team has what it takes to softly touch down on the lunar surface and nail this mission.”

The spacecraft’s launch was initially scheduled for the fourth quarter of 2024, but the corporation did not provide a precise date. Joseph Marlin, the principal engineer of Firefly’s Elytra Dark spacecraft, again suggested a fourth-quarter launch date during a Lunar Exploration Analysis Group (LEAG) conference on October 29. However, he stated that he was unable to provide more precise details, implying that it depended on the availability of launch vehicles. At that time, he stated, “SpaceX is still sorting out its schedule,”

The company’s first lunar lander mission is called Blue Ghost. Through the Commercial Lunar Payload Services (CLPS) program, the spacecraft will transport ten NASA payloads. In February 2021, Firefly received a $93.3 million task order from NASA for the mission, which was initially scheduled for launch in 2023. Whether the spacecraft is carrying any non-NASA payloads has not been disclosed by Firefly.

The corporation has named the mission “Ghost Riders in the Sky,” and it will run for roughly 60 days. The spacecraft will first operate in phasing orbits around the Earth for 45 days before traveling to the moon and putting into orbit. The spacecraft will land close to Mons Latreille, a volcanic formation in Mare Crisium on the moon’s northeastern near side. The lander is intended to stay in operation for several hours into the lunar night and throughout the whole two-week lunar day.

Up to three commercial lunar lander missions were originally scheduled to launch in the fourth quarter of this year, but none of them will now. In a financial announcement for its fiscal second quarter, the Japanese company iSpace said on November 12 that its Mission 2 lunar lander, which was previously scheduled to launch in December, will instead launch no early than January. The lander will launch on a SpaceX Falcon 9, just as Firefly.

During a Nov. 14 earnings call, Intuitive Machines revealed that its IM-2 mission, which had been aiming for a December or early January launch, will now launch on a Falcon 9 no earlier than February. The business did not provide an explanation for the slip.

However, Firefly might still be beaten to the moon’s surface by Intuitive Machines. The IM-2 mission will land around a week after launch, following a more direct path to the moon than the IM-1 mission, which launched in February 2024. According to Firefly’s Marlin, who spoke at the LEAG meeting, the two businesses have been talking about ways to deconflict their landings, such as making sure that communications don’t conflict.Firefly plans to launch its first lunar lander mission in January.

Continue Reading

Science

Human Activity is Solely to Blame for the 31.5-inch Tilt in the Earth’s Rotation

Published

on

As a dynamic creature, our earth is always changing and adapting. Unbelievably, even something as seemingly trivial as how much water we use might alter Earth’s physical orientation.

Our groundwater pumping has caused the Earth to tilt 31.5 inches in less than 20 years. For comparison, this water redistribution corresponds to about 0.24 inches of sea level increase.

According to Ki-Weon Seo, a geophysicist at Seoul National University, “our study demonstrates that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole.”

Therefore, keep in mind that even the tiniest actions have consequences before you discount the importance of your water usage.

What is groundwater, exactly?

The water that fills the voids left by soil, sand, and rock formations beneath the Earth’s surface is known as groundwater.

It originates from rain and other precipitation that seeps into the earth and slowly descends to subterranean reservoirs known as aquifers.

Groundwater is hidden away, functioning as nature’s covert water bank, in contrast to the water found in rivers and lakes.

It is essential to the water cycle because it supplies a consistent amount of water, even in dry seasons when surface water may be in short supply.

Groundwater is vital to many aspects of human life. It is the main supply of drinking water for many people, particularly in rural areas where surface water is scarce.

In order to irrigate crops and ensure that food production can continue even in the absence of sufficient rainfall, farmers rely on groundwater. Groundwater is also used by enterprises for cooling systems and manufacturing procedures.

Earth’s tilt and the role of groundwater

With data spanning from 1993 to 2010, the study demonstrated that the tilt of the Earth had shifted as a result of pumping up to 2,150 gigatons of groundwater.

Although it’s difficult to understand, these numbers show how much water we use for human consumption and irrigation.

The majority of our water is ultimately carried to the oceans, even though we may not consider its destination after use.

According to Seo, “Observing changes in Earth’s rotational pole is useful for understanding continent-scale water storage variations,” 

Connecting these differences to water movement, especially from northwest India and western North America, demonstrates how our daily activities can have a global impact on the planet.

Pole drift in rotation

Groundwater pumping not only affects the tilt and rotation of our earth, but it also presents a concerning image of the effects of climate change.

“I’m very glad to find the unexplained cause of the rotation pole drift. On the other hand, as a resident of Earth and a father, I’m concerned and surprised that pumping groundwater is another source of sea-level rise,” Seo added.

Given the difficulties we are already facing in the fight against climate change, these findings may seem overwhelming.

Nonetheless, knowing how groundwater pumping affects Earth’s tilt and climate is a positive start.

This information may help conservationists develop practical plans to slow down future sea level rise and other climate-related problems.

Pumping groundwater and polar motion

Our comprehension of climate change and our ability to take action are expanded by the recent discoveries on groundwater pumping.

“They’ve quantified the role of groundwater pumping on polar motion, and it’s pretty significant,” stated Surendra Adhikari, a research scientist at NASA’s Jet Propulsion Laboratory (JPL).

This knowledge of the worldwide effects of groundwater pumping ought to encourage us to reevaluate how much water we use on a daily basis.

Upcoming studies and policy projects

In light of the study’s important conclusions, sustainable groundwater management must be given top priority in future research and policy activities in order to lessen its negative effects on climate change and Earth’s rotation.

Innovative approaches to water use, such improved irrigation systems, rainwater collecting, and better municipal water management, are necessary to strike a balance between human requirements and environmental conservation.

Furthermore, in order to develop comprehensive policies that address the fair distribution and usage of water resources, international collaboration among nations is crucial.

We can create a strong foundation for more sustainable water management techniques by promoting interdisciplinary cooperation between geophysicists, climate scientists, decision-makers, and the general public.

Such programs support larger efforts to mitigate climate change in addition to having the potential to preserve Earth’s rotational stability.

Earth tilting due to water taps

The process of comprehending and addressing climate change is a protracted and intricate one. However, in this conflict, information is power.

Comprehending the effects of groundwater pumping is a crucial weapon in our toolbox.

Let’s use this information to our advantage as we look to the future and work toward a more sustainable world.

Continue Reading

Trending

error: Content is protected !!