"Stage Evaluation" of Outstanding Young Projects: 41 Projects Doubled Grants, 9 Projects Received "Bad Evaluations"

Quick Facts

1. "Stage Evaluation" of Outstanding Youth Projects: 41 projects were doubled, and 9 projects received "bad evaluations"
2. The prophecy of 90 years ago came true: the mysterious Vigner crystallized itself
3. The Earth's orbit is becoming increasingly congested, and potential impact events need to be vigilant
4. The highest-resolution telescope camera ever built is about to go live
5. Another explanation for dark matter: a large number of miniature black holes

Academic headlines

1. "Stage Evaluation" of Outstanding Young Projects: 41 projects were doubled, and 9 projects received "negative evaluations"

On April 16, the first final grading evaluation and continuation of the funding review meeting of the outstanding young projects ended, and the assessment and evaluation of the 199 outstanding young projects that expired at the end of 2023 were completed. After rigorous evaluation by experts, 41 projects have made significant progress and received renewed funding for the next five years, and 9 projects were rated as "poor" in implementation. The Natural Science Foundation of China will truthfully feedback the assessment and evaluation results to the supporting units, and suggest that the project supporting units provide good support and guarantee conditions for the project leaders who have received the continuation of funding, and strengthen supervision and guidance for the project leaders with poor implementation.

Source: National Natural Science Foundation of China

2. The prophecy of 90 years ago came true: Physicists capture the mysterious Wigner crystal

尤金·维格纳(Eugene Wigner)

Recently, physicists have finally captured the mysterious Vigner crystal, fulfilling Eugene Wigner's prediction 90 years ago. A Wigner crystal is a solid-state form in which electrons are arranged in a regular lattice, usually at low temperatures and low electron densities. This discovery not only verifies Wigner's theory, but also provides a new research direction for condensed matter physics.

In 1934, Wigner predicted that in a uniform positive electric background field, three-dimensional low-density electron gases could be arranged into lattices at low temperatures to form a Wigner lattice. In recent years, scientists have observed signs of Wigner lattices in two-dimensional electronic systems, but directly capturing this crystal structure has been a challenge. The latest experiments used scanning tunneling microscopy (STM) techniques to observe the honeycomb arrangement of electrons under specific conditions at very low temperatures. This arrangement minimizes the Coulomb repulsion between the electrons, thus stabilizing the structure of the Wigner crystal.

Triangular Vigner crystals

Picture: Yen-Chen Tsui, Princeton University

The success of this experiment not only confirms the existence of Wigner crystals, but also demonstrates the progress of modern technology in observing and manipulating microscopic particles. This milestone will contribute to a deeper understanding of the properties of quantum materials, paving the way for future technological innovations. The paper was published in Nature.

Reference Sources:

https://www.nature.com/articles/s41586-024-07212-7

Astronomical Passage

3.

As the number of artificial satellites proliferates, so does the risk of space collisions. There are currently more than 10,000 artificial satellites orbiting the Earth, a number that has quadrupled since 2019. The number of low-Earth orbit satellites approved for launch worldwide is expected to reach a staggering 400,000. This trend bodes well for the future of increased space activity that will bring unprecedented challenges. According to NASA Deputy Director Pam Melroy at the Space Foundation's annual space symposium, a scrapped Russian satellite nearly collided with a U.S. exploration satellite in February, and the two passed by only 10 meters away.

Experts say that if a similar event occurs, the consequences will be more than the loss of two satellites: if objects collide in orbit, it could trigger a cascading "Kessler effect" that causes more collisions and debris. This high-speed moving debris is completely uncontrollable and can contaminate the entire orbit, destroy more satellites and spacecraft, and even endanger the lives of astronauts on the space station.

Reference Sources:

https://www.space.com/near-collision-nasa-timed-satellite-russian-space-junk

4.

Credit: Greg Stewart/SLAC National Accelerator Laboratory

As the centerpiece of the new Vera C. Rubin Observatory, the Legacy Survey of Space and Time (LSST) camera, an ultra-high-resolution camera that has been developed and manufactured for 20 years, will soon be shipped to Chile for installation and commissioning.

Credit: Jacqueline Ramseyer Orrell/SLAC National Accelerator Laboratory

The camera weighs 3 tons and has a lens diameter of more than 1.5 meters, which is considered the world's largest high-performance optical lens ever built. It has 201 specially customized CCD sensors with a resolution of 3.2 billion pixels. It will spend the next decade gazing at the night sky in the south, with the main mission of studying dark matter, dark energy, and making more detailed maps of the Milky Way and looking for signs of weak gravitational lensing, in order to deepen our understanding of the expansion of the universe.

Reference Sources:

https://scitechdaily.com/after-20-years-the-construction-of-astronomys-largest-digital-camera-has-finally-been-completed/

5.

图源:NASA/JPL-Caltech

The trajectories of many celestial bodies seem to be influenced by invisible massive celestial bodies, so it has been speculated that there is a special substance in the universe, dark matter, which accounts for more than 85% of the universe's mass, but it has not been confirmed. A new study, published in the Monthly Bulletin of the Royal Astronomical Society, has proposed a hypothesis that these "things" that are not visible but affect visible objects are actually primordial black holes (PBHs), which are formed not by stars at the time of death, but in the first seconds of the Big Bang, with masses that can vary from the mass of dust particles to thousands of times the mass of the sun.

And how to confirm this hypothesis? Because these primitive black holes are relatively small in mass and do not emit any light, they cannot be detected by conventional methods. The authors propose an approach: many primordial black holes with very small masses, as small as a grain of sand and a basketball, would be captured by the gravitational pull of stars much larger than them, but this would be "unlucky" for the stars, which would devour the star from within, feed on hydrogen, fuel it and support nuclear fusion in the core. There is a "high probability" that stellar material will form a spiral-shaped cloud of gas, forming a classic accretion disk. Where there may be enough similar phenomena are ultra-faint dwarf galaxies, future data from the Hubble and James Webb Space Telescope may give some evidence.

Reference Sources:

https://academic.aup.com/manras/article/529/1/32/7560567?login=false