Lifeboat Foundation

Scientists discover that interplanetary shocks that strike Earth’s magnetic field head-on cause more powerful ground-level electric currents, threatening pipelines and submarine cables.

Auroras are caused by particles from the sun hitting the Earth’s magnetic field — but these impacts also cause geomagnetically induced currents at ground level, which can damage infrastructure that conducts electricity. Scientists studying these currents to protect critical infrastructure have carried out the first research which compares interplanetary shocks to real-time measurements of geomagnetically induced currents, showing that the angle of the shocks’ impact is key for forecasting possible damage to infrastructure: shocks that hit the magnetic field at an angle produce less powerful currents.

The impact of interplanetary shocks on infrastructure.

NASA ’s OSIRIS-REx mission returned a sample from asteroid Bennu, revealing it contains key solar system materials and possible signs of a watery past. This discovery provides valuable insights into the early solar system’s conditions and the potential origins of life.

A deep dive into the sample of rocks and dust returned from near-Earth asteroid Bennu by NASA’s University of Arizona-led OSIRIS-REx mission has revealed some long-awaited surprises.

Bennu contains the original ingredients that formed our solar system, the OSIRIS-REx Sample Analysis Team found. The asteroid’s dust is rich in carbon and nitrogen, as well as organic compounds, all of which are essential components for life as we know it. The sample also contains magnesium sodium phosphate, which was as a surprise to the research team, because it wasn’t seen in the remote sensing data collected by the spacecraft at Bennu. Its presence in the sample hints that the asteroid could have splintered off from a long-gone, tiny, primitive ocean world.

In a study published recently in Physical Review Letters, researchers unveiled a new type of quantum sensor that they report leverages quantum entanglement to perform detections that, note the quote marks, “travel back in time”. The researchers add the findings could — one day — lead to novel quantum sensors that are ideally suited for astronomical detection and magnetic field investigations.

The study, led by Kater Murch, Charles M. Hohenberg Professor of Physics and Director of the Center for Quantum Leaps at Washington University in St. Louis, introduces a sensor that can probe past events in complex systems. The team, which also included scientists from the National Institute of Standards and Technology (NIST) and the University of Cambridge, described the innovation in the press release as a bit like “sending a telescope back in time to capture a shooting star that you saw out of the corner of your eye.”

The sensor operates by entangling two quantum particles in a quantum singlet state, where their spins point in opposite directions. The process begins with one particle, the “probe,” being subjected to a magnetic field that causes it to rotate. The key breakthrough comes when the second particle, the “ancilla,” is measured. This measurement effectively sends its quantum state back in time to the probe, allowing researchers to optimally set the spin direction of the probe qubit in what Murch refers to as hindsight.

Life’s evolutionary timescale is typically calibrated to the oldest fossil occurrences. However, the veracity of fossil discoveries from the early Archaean period has been contested^11,12. Relaxed Bayesian node-calibrated molecular clock approaches provide a means of integrating the sparse fossil and geochemical record of early life with the information provided by molecular data; however, constraining LUCA’s age is challenging due to limited prokaryote fossil calibrations and the uncertainty in their placement on the phylogeny. Molecular clock estimates of LUCA^13,14,15 have relied on conserved universal single-copy marker genes within phylogenies for which LUCA represented the root. Dating the root of a tree is difficult because errors propagate from the tips to the root of the dated phylogeny and information is not available to estimate the rate of evolution for the branch incident on the root node. Therefore, we analysed genes that duplicated before LUCA with two (or more) copies in LUCA’s genome¹⁶. The root in these gene trees represents this duplication preceding LUCA, whereas LUCA is represented by two descendant nodes. Use of these universal paralogues also has the advantage that the same calibrations can be applied at least twice. After duplication, the same species divergences are represented on both sides of the gene tree^17,18 and thus can be assumed to have the same age. This considerably reduces the uncertainty when genetic distance (branch length) is resolved into absolute time and rate. When a shared node is assigned a fossil calibration, such cross-bracing also serves to double the number of calibrations on the phylogeny, improving divergence time estimates. We calibrated our molecular clock analyses using 13 calibrations (see ‘Fossil calibrations’ in Supplementary Information). The calibration on the root of the tree of life is of particular importance. Some previous studies have placed a younger maximum constraint on the age of LUCA based on the assumption that life could not have survived Late Heavy Bombardment (LHB) (~3.7–3.9 billion years ago (Ga))¹⁹. However, the LHB hypothesis is extrapolated and scaled from the Moon’s impact record, the interpretation of which has been questioned in terms of the intensity, duration and even the veracity of an LHB episode^20,21,22,23. Thus, the LHB hypothesis should not be considered a credible maximum constraint on the age of LUCA. We used soft-uniform bounds, with the maximum-age bound based on the time of the Moon-forming impact (4,510 million years ago (Ma) ± 10 Myr), which would have effectively sterilized Earth’s precursors, Tellus and Theia¹³. Our minimum bound on the age of LUCA is based on low δ⁹⁸ Mo isotope values indicative of Mn oxidation compatible with oxygenic photosynthesis and, therefore, total-group Oxyphotobacteria in the Mozaan Group, Pongola Supergroup, South Africa^24,25, dated minimally to 2,954 Ma ± 9 Myr (ref. ²⁶).

Our estimates for the age of LUCA are inferred with a concatenated and a partitioned dataset, both consisting of five pre-LUCA paralogues: catalytic and non-catalytic subunits from ATP synthases, elongation factor Tu and G, signal recognition protein and signal recognition particle receptor, tyrosyl-tRNA and tryptophanyl-tRNA synthetases, and leucyl-and valyl-tRNA synthetases²⁷. Marginal densities (commonly referred to as effective priors) fall within calibration densities (that is, user-specified priors) when topologically adjacent calibrations do not overlap temporally, but may differ when they overlap, to ensure the relative age relationships between ancestor-descendant nodes. We consider the marginal densities a reasonable interpretation of the calibration evidence given the phylogeny; we are not attempting to test the hypothesis that the fossil record is an accurate temporal archive of evolutionary history because it is not²⁸.

Researchers at Cornell University have designed a novel in-suit urine collection and filtration system, or “Dune” system,” to “promote astronaut wellbeing.”

Welcome to Rethinking the Foundations brought to you by Curt Jaimungal at Theories of Everything. Today, Professor Neil Turok answers questions from the audience! This is Part 2 to Neil’s Rethinking the Foundations episode. Part 1 can be seen here: • Rethinking the Foundations of Physics…

Listen on Spotify: https://open.spotify.com/show/4gL14b9…

Continue reading “Q&A About the Universe with Top Physicist Neil Turok” »

An interplay of light and shadows cast the docking ports for Gateway, humanity’s first space station around the moon, into sharp relief.

Neutrinos have a quantum mechanical property called “flavor.” This flavor can transform as neutrinos move through space. A major challenge is to keep track of both the physical movement of the neutrinos and their change of flavor in astrophysical systems such as core-collapse supernovae and neutron star mergers. The complicated arrangement and large number of neutrinos in these systems make it nearly impossible to follow all or even a subset of the neutrinos.

Astronauts on spacewalks famously have to relieve themselves inside their spacesuits. Not only is this uncomfortable for the wearer and unhygienic, it is also wasteful, as—unlike wastewater on board the International Space Station (ISS)—the water in urine from spacewalks is not recycled.