By studying how light from eight distant quasars is gravitationally lensed as it propagates towards Earth, astronomers have calculated a new value for the Hubble constant – a parameter that describes the rate at which the universe is expanding. The result agrees more closely with previous “late-universe” probes of this constant than it does with calculations based on observations of the cosmic microwave background (CMB) in the early universe, strengthening the notion that we may be misunderstanding something fundamental about how the universe works.

The universe has been expanding ever since the Big Bang nearly 14 billion years ago. We know this, in part, because of observations made in the 1920s by the American astronomer Edwin Hubble. By measuring the redshift of various galaxies, Hubble discovered that galaxies further away from Earth are moving away faster than galaxies that are closer to us. The relationship between this speed and the galaxies’ distance is known as the Hubble constant, H₀.

Astronomers have developed several techniques for measuring H₀. The problem is that different techniques deliver different values. According to measurements made by the European Space Agency’s Planck satellite of CMB radiation “left over” from the Big Bang, the value of H₀ is about 67 kilometres per second per megaparsec (km/s/Mpc), where one Mpc is 3.3 million light years. In contrast, “distance-ladder” measurements such as those made by the SH0ES collaboration those involving observations of type Ia supernovae yield a value of about 73 km/s/Mpc. This discrepancy is known as the Hubble tension.

Time-delay cosmography

In the latest work, the TDCOSMO collaboration, which includes astronomers Kenneth Wong and Eric Paic of the University of Tokyo, Japan, measured H₀ using a technique called time-delay cosmography. This well-established method dates back to 1964 and uses the fact that massive galaxies can act as lenses, deflecting the light from objects behind them so that from our perspective, these objects appear distorted.

“This is called gravitational lensing, and if the circumstances are right, we’ll actually see multiple distorted images, each of which will have taken a slightly different pathway to get to us, taking different amounts of time,” Wong explains.

By looking for changes in these images that are identical, but slightly out of sync, astronomers can measure the time differences required for the light from the objects to reach Earth. Then, by combining these data with estimates of the distribution of the mass of the distorting galactic lens, they can calculate H₀.

A real tension, not a measurement artefact

Wong and colleagues measured the light from eight strongly lensed quasars using various telescopes, including the James Webb Space Telescope (JWST), the Keck Telescopes and the Very Large Telescope (VLT). They also made use of observations from the Sloan Lens ACS (SLACS) sample with Keck and the Legacy Survey (SL2S) sample.

Based on these measurements, they obtained a H₀ value of roughly 71.6 km s⁻¹ Mpc⁻¹, which is more consistent with current-day observations (such as that from SH0ES) than early-universe ones (such as that from Planck). Wong explains that this discrepancy supports the idea that the Hubble tension arises from real physics, not just some unknown error in the various methods. “Our measurement is completely independent of other methods, both early- and late-universe, so if there are any systematic uncertainties in those, we should not be affected by them,” he says.

The astronomers say that the SLACS and SL2S sample data are in excellent agreement with the new TDCOSMO-2025 sample, while the new measurements improve the precision of H₀ to 4.6%. However, Paic notes that nailing down the value of H₀ to a level that would “definitely confirm” the Hubble tension will require a precision of 1-2%. “This could be possible by increasing the number of objects observed as well as ruling out any systematic errors as yet unaccounted for,” he says.

Wong adds that while the TDCOSMO-2025 dataset contains its own uncertainties, multiple independent measurements should, in principle, strengthen the result. “One of the largest sources of uncertainty is the fact that we don’t know exactly how the mass in the lens galaxies is distributed,” he explains. “It is usually assumed that the mass follows some simple profile that is consistent with observations, but it is hard to be sure and this uncertainty can directly influence the values we calculate.”

The biggest hurdle, Wang adds, will “probably be addressing potential sources of systematic uncertainty, making sure we have thought of all the possible ways that our result could be wrong or biased and figuring out how to handle those uncertainties.”

The study is detailed in Astronomy and Astrophysics.

The post Gravitational lensing sheds new light on Hubble constant controversy appeared first on Physics World.

Congress has approved a fiscal year 2026 spending bill that largely restores funding proposed for deep cuts to NASA while canceling one major mission.

The post Congress passes minibus spending bill that rejects proposed NASA cuts appeared first on SpaceNews.

Astronomers puzzle over newfound feature within the picturesque Ring nebula

Staff at the Panguana biological research station have received death threats

Learn how mapping the Ring Nebula’s light revealed a massive iron bar hidden for decades.

Arianespace will begin launches for its largest commercial customer in February as it works to ramp up its flight rate and attract additional business.

The post Arianespace to begin Amazon Leo launches in February appeared first on SpaceNews.

Learn how CT scans of fossil skulls were used to trace changes in brain regions and sensory priorities in ancient giant rats.

Learn more about the canine temporal lobe and how it helps your dog recognize your face. 

Meet the walking shark, a species of shark that can walk on land, survive low oxygen environments, and reproduce without wasting energy.

Technique could improve models of how ice flows, bolstering predictions of sea level rise

Polluted lakes and lab experiments highlight harms of chronic exposure to chlorpyrifos

A multimillion-dollar plan aims to undo centuries of destruction on islands made famous by Darwin

Enigmatic ‘vaults’ can be engineered to eavesdrop on RNA, aiding cancer studies and more

Merge Labs has emerged from stealth with $252 million in funding from OpenAI and others. It aims to use ultrasound to read from and write to the brain.

Learn how seven naturally preserved cheetahs discovered in northern Saudi Arabia reveal that the Arabian Peninsula once hosted multiple cheetah lineages, raising new possibilities for reintroducing the endangered cats.

In this episode of Space Minds, SpaceNews host David Ariosto talks with Chiara Manfletti, the CEO of Neuraspace and a professor of space mobility and propulsion at the Technical University […]

The post Managing an orbital economy as space grows more congested appeared first on SpaceNews.

The acquisition brings missile-warning and space data analytics capabilities

The post Parsons buys Altamira for $375 million to expand space and intelligence portfolio appeared first on SpaceNews.

The company’s ground station transmitted time and tracking signals to a spacecraft in orbit

The post TrustPoint demonstrates non-GPS navigation for LEO satellites appeared first on SpaceNews.

Atomic-6’s composite material will get its first in-orbit test

The post Portal Space selects ‘Space Armor’ debris shield for 2026 mission appeared first on SpaceNews.

The Space Force is trying to modernize how satellite operators train for conflict in orbit

The post Slingshot wins $27 million Space Force contract for AI training system appeared first on SpaceNews.

SAN FRANCISCO – Hydrosat, a thermal imagery startup focused on water-resource management, has raised $60 million in Series B funding from equity investors and sovereign wealth funds. With the influx […]

The post Hydrosat raises $60 million in Series B funding appeared first on SpaceNews.

A Crew Dragon spacecraft splashed down off the California coast Jan. 15, bringing back four people from the ISS more than a month early because of a medical issue.

The post Crew-11 makes early return from ISS appeared first on SpaceNews.

An Indian startup is entering the satellite servicing market with plans to develop low-cost spacecraft to extend the lives of satellites.

The post Indian startup Aule Space enters satellite servicing market appeared first on SpaceNews.

Taking medication as and when prescribed is crucial for it to have the desired effect. But nearly half of people with chronic conditions don’t adhere to their medication regimes, a serious problem that leads to preventable deaths, drug resistance and increased healthcare costs. So how can medical professionals ensure that patients are taking their medicine as prescribed?

A team at Massachusetts Institute of Technology (MIT) has come up with a solution: a drug capsule containing an RFID tag that uses radiofrequency (RF) signals to communicate that it has been swallowed, and then bioresorbs into the body.

“Medication non-adherence remains a major cause of preventable morbidity and cost, but existing ingestible tracking systems rely on non-degradable electronics,” explains project leader Giovanni Traverso. “Our motivation was to create a passive, battery-free adherence sensor that confirms ingestion while fully biodegrading, avoiding long-term safety and environmental concerns associated with persistent electronic devices.”

The device – named SAFARI (smart adherence via Faraday cage and resorbable ingestible) – incorporates an RFID tag with a zinc foil RF antenna and an RF chip, as well as the drug payload, inside an ingestible gelatin capsule. The capsule is coated with a mixture of cellulose and molybdenum particles, which blocks the transit of any RF signals.

Once swallowed, however, this shielding layer breaks down in the stomach. The RFID tag (which can be preprogrammed with information such as dose metadata, manufacturing details and unique ID) can then be wirelessly queried by an external reader and return a signal from inside the body confirming that the medication has been ingested.

The capsule itself dissolves upon exposure to digestive fluids, releasing the desired medication; the  metal antenna components also dissolve completely in the stomach. The use of biodegradable materials is key as it eliminates the need for device retrieval and minimizes the risk of gastrointestinal (GI) blockage. The tiny (0.16 mm²) RFID chip remains intact and should safely leave the body through the GI tract.

Traverso suggests that the first clinical applications for the SAFARI capsule will likely be high-risk settings in which objective ingestion confirmation is particularly valuable. “[This includes] tuberculosis, HIV, transplant immunosuppression or cardiovascular therapies, where missed doses can have serious clinical consequences,” he tells Physics World.

In vivo demonstration

To assess the degradation of the SAFARI capsule and its components in vitro, Traverso and colleagues placed the capsule into simulated gastric fluid at physiological temperature (37 °C). The RF shielding coating dissolved in 10–20 min, while the capsule and the zinc layer in the RFID tag disintegrated into pieces after one day.

Next, the team endoscopically delivered the SAFARI capsules into the stomachs of sedated pigs, chosen as they have a similar sized GI tract to humans. Once in contact with gastric fluid in the stomach, the capsule coating swelled and then partially dissolved (as seen using endoscopic images), exposing the RFID tag. The researchers found that, in general, the tag and capsule parts disintegrated in the stomach at up to 24 h later.

A panel antenna positioned 10 cm from the animal captured the tag data. Even with the RFID tags immersed in gastric fluid, the external receiver could effectively record signals in the frequency range of 900–925 MHz, with RSSI (received signal strength indicator) values ranging from 65 to 78 dB – demonstrating that the tag could effectively transmit RF signals from inside the stomach.

The researchers conclude that this successful use of SAFARI in swine indicates the potential for translation to clinical research. They note that the device should be safe for human ingestion as its composite materials meet established dietary and biomedical exposure limits, with levels of zinc and molybdenum orders of magnitude below those associated with toxicity.

“We have demonstrated robust performance and safety in large-animal models, which is an important translational milestone,” explains first author Mehmet Girayhan Say. “Before human studies, further work is needed on chronic exposure with characterization of any material accumulation upon repeated dosing, as well as user-centred integration of external readers to support real-world clinical workflows.”

The post RFID-tagged drug capsule lets doctors know when it has been swallowed appeared first on Physics World.