Lifeboat Foundation

Dark Stars Could Explain Dark Matter and Fast Radio Bursts, Challenging Our Understanding of Black Holes

A theory suggests that black holes, rather than being empty voids in space, might actually be “dark stars” filled with incredibly dense and exotic matter. This concept could provide new insights into two of the universe’s greatest mysteries: the nature of black holes and the elusive dark matter.

Black holes, as understood through Albert Einstein’s general theory of relativity, are regions in space where matter is so compact that it warps space-time, creating a gravitational pull so intense that even light cannot escape. The center of a black hole is believed to contain a singularity, an infinitely small and dense point where gravity becomes infinitely strong. This singularity is surrounded by an event horizon, a boundary beyond which light and matter cannot escape.

Although intracranial atherosclerotic disease (ICAD) is a known risk factor for cerebrovascular ischemic events, its potential role in dementia risk remains unclear. The Atherosclerosis Risk in Communities (ARIC) study was a prospective cohort study that recruited participants from four U.S. communities. From 2011 to 2013, a subset comprising 1,590 participants (mean age, 77; 40% men; 28% Black) underwent ICAD evaluation and neurocognitive testing to ascertain the prospective association of ICAD with dementia risk, independent of other known cardiovascular risk factors. ICAD was diagnosed based on focal-wall thickness on brain MRI, with or without luminal stenosis on magnetic resonance angiography (MRA).

During a median follow-up of 5.6 years, 286 cases of incident dementia were observed. After adjustment for established dementia risk factors, including cardiovascular risk factors, patients with ICAD (regardless of luminal stenosis) had an independently higher risk for incident dementia than those without ICAD (HR, 1.57; 95% CI, 1.17–2.11). The presence of stenosis 50% on MRA was associated with even higher risk (HR, 1.89; 95% CI, 1.29–2.78). An important limitation was the investigators’ inability to determine dementia subtypes.

This prospective trial adds further observational evidence that ICAD is independently associated with dementia. Furthermore, this study provides evidence that earlier stages of atherosclerosis (i.e., involvement of the arterial wall without luminal narrowing) are also associated with increased risk. While the pathophysiology of this association has yet to be elucidated, I will counsel my patients with ICAD about this association and will strongly recommend proven management strategies (e.g., smoking cessation, lipid lowering) to mitigate vascular disease progression, given the higher risk of dementia in those with luminal disease.

When something draws us in like a magnet, we take a closer look. When magnets draw in physicists, they take a quantum look. Scientists from Osaka Metropolitan University and the University of Tokyo have successfully used light to visualize tiny magnetic regions, known as magnetic domains, in a specialized quantum material. Their study was published in Physical Review Letters.

A team of engineers, physicists and quantum specialists at Google Research has found that reducing noise to a certain level allows the company’s sycamore quantum chip to beat classical computers running random circuit sampling (RCS).

The word laser usually conjures up an image of a strongly concentrated and continuous light beam. Lasers that produce such light are, in fact, very common and useful. However, science and industry often also require very short and strong pulses of laser light.

In physics, a system composed of two substances can be modeled in accordance with classical mixture theory, which considers the fraction corresponding to each constituent and the interactions among constituents. Examples include the coexistence of high-and low-density phases in supercooled water, and the coexistence of metal puddles in an insulating matrix in the Mott metal-insulator transition.

Researchers are excited about the potential of microcombs, miniature devices that generate precise time and frequency standards. These microcombs could revolutionize fields from high-speed communication, high-resolution measurements to precise atomic clocks.

Imagine a future where indoor wireless communication systems handle skyrocketing data demands and do so with unmatched reliability and speed. Traditional radio frequency (RF) technologies like Wi-Fi and Bluetooth are beginning to struggle, plagued by limited bandwidth and increasing signal congestion.

UC Santa Barbara researchers have achieved the first-ever “movie” of electric charges traveling across the interface of two different semiconductor materials. Using scanning ultrafast electron (SUEM) techniques developed in the Bolin Liao lab, the research team has directly visualized the fleeting phenomenon for the first time.