Years after the collapse of the Arecibo Observatory, its extensive datasets remain instrumental in advancing astronomical research. In a study led by Sofia Sheikh from the Search for Extraterrestrial Intelligence (SETI) Institute, data from the observatory was utilised to uncover new details about pulsar signals. These dense neutron stars emit beams of radiation likened to “cosmic lighthouses,” and their signals undergo distortions as they traverse the interstellar medium. Findings from this research were published in The Astrophysical Journal on November 26.

Pulsar Signals and Interstellar Scintillation

The study explored how pulsar signals are affected by interstellar gas and dust. Researchers investigated 23 pulsars, including six previously unstudied, revealing insights into distortive phenomena called diffractive interstellar scintillation (DISS). This phenomenon, which resembles the rippling patterns caused by light passing through water, is attributed to interactions between pulsar signals and charged particles in space.

The Role of Arecibo’s Archival Data

The now-defunct Arecibo radio telescope, once spanning 305 metres, collapsed in December 2020 due to cable failures. Despite its destruction, the data collected over decades continues to contribute significantly to astrophysical discoveries. It was revealed by researchers that pulsar signals exhibit broader bandwidths than predicted by current interstellar models. This discrepancy indicates a need to refine existing frameworks, particularly by incorporating the structural complexity of the Milky Way.

Implications for Gravitational Wave Studies

Reportedly, a better understanding of pulsar signal distortions could enhance projects like the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), which employs pulsar timing arrays to detect space-time distortions caused by gravitational waves. The recent identification of the gravitational wave background, potentially originating from supermassive black hole mergers, underscores the relevance of such advancements.

 

A new hypothesis suggests that dark matter, one of the universe’s greatest mysteries, may have originated in a separate event known as a “Dark Big Bang.” The idea was initially proposed in 2023 by Katherine Freese, Director of the Texas Center for Cosmology and Astroparticle Physics, and Martin Wolfgang Winkler, University of Texas. The theory challenges the traditional understanding that all matter and energy were created simultaneously during the Big Bang. According to reports, researchers from Colgate University have expanded on this theory, proposing new scenarios for such an event and how evidence might be uncovered.

Exploring the Dark Big Bang Theory

In a study published in Physical Review D, researchers Cosmin Ilie, Assistant Professor of Physics and Astronomy, and Richard Casey, Colgate University scientist, outlined the potential mechanisms of a Dark Big Bang. It has been suggested that this event may have occurred up to one year after the Big Bang, introducing dark matter into the cosmos. Ilie, speaking to Space.com, explained that their work highlights a broader range of possibilities than previously considered, making the theory more plausible.

The concept diverges from the prevailing notion that dark and ordinary matter share a common origin. While this idea adheres to Occam’s Razor — favouring the simplest explanation — Ilie pointed out that the universe does not necessarily align with human preferences for simplicity.

Hunting for Evidence

Detecting evidence of a Dark Big Bang could involve identifying gravitational waves, faint ripples in spacetime first predicted by Albert Einstein. According to Ilie, such waves might be observable through ongoing initiatives like the International Pulsar Timing Array and the Square Kilometre Array.

Casey stated to Space.com that the Dark Big Bang theory could also reveal a unique “Dark Sector” with its own particles and interactions, distinct from known physics. This approach might redefine how dark matter and ordinary matter relate, potentially bridging gaps in current scientific understanding.
The researchers emphasised that this work establishes a foundation for future exploration, aiming to confirm or constrain the Dark Big Bang’s role in the creation of dark matter.

 

Nasa has revealed the first look of a full-scale prototype for six telescopes that will enable, in the next decade, the space-based detection of gravitational waves—ripples in space-time caused by merging black holes and other cosmic sources.
This advancement is part of the LISA (Laser Interferometer Space Antenna) mission, a collaborative effort between Nasa and the European Space Agency (ESA). The mission will utilize an array of spacecraft to measure minuscule changes in distance—down to picometers, or trillionths of a meter—across a vast configuration larger than the Sun itself. The triangular formation of spacecraft will span approximately 1.6 million miles (2.5 million kilometers) on each side.
Highlighting the crucial role of twin telescopes aboard each spacecraft, Ryan DeRosa, a researcher at Nasa’s Goddard Space Flight Center said, “Twin telescopes aboard each spacecraft will both transmit and receive infrared laser beams to track their companions, and Nasa is supplying all six of them to the LISA mission.”
Central to this initiative is the Engineering Development Unit Telescope, a prototype designed to inform the construction of the mission’s flight hardware. Manufactured and assembled by L3Harris Technologies in Rochester, New York, the prototype arrived at Goddard in May. Its primary mirror is coated in gold, enhancing the reflection of infrared lasers and minimizing heat loss in the cold vacuum of space. This feature is vital, as the telescope is optimized to function near room temperature.
The Engineering Development Unit Telescope is crafted entirely from a specialized amber-colored glass-ceramic known as Zerodur, produced by Schott in Mainz, Germany. This material is renowned for its thermal stability, ensuring minimal shape distortion over a wide range of temperatures—a critical characteristic for high-precision optical applications.
The LISA mission is set to launch in the mid-2030s, promising to expand understanding by exploring gravitational waves, which are ripples in spacetime caused by cataclysmic events like merging black holes and neutron stars.