(Press-News.org)
For the first time, scientists have used Earth-based telescopes to look back over 13 billion years to see how the first stars in the universe affect light emitted from the Big Bang.
Using telescopes high in the Andes mountains of northern Chile, astrophysicists have measured this polarized microwave light to create a clearer picture of one of the least understood epochs in the history of the universe, the Cosmic Dawn.
“People thought this couldn’t be done from the ground. Astronomy is a technology-limited field, and microwave signals from the Cosmic Dawn are famously difficult to measure,” said Tobias Marriage, project leader and a Johns Hopkins professor of physics and astronomy. “Ground-based observations face additional challenges compared to space. Overcoming those obstacles makes this measurement a significant achievement.”
Cosmic microwaves are mere millimeters in wavelength and very faint. The signal from polarized microwave light is about a million times fainter. On Earth, broadcast radio waves, radar, and satellites can drown out their signal, while changes in the atmosphere, weather, and temperature can distort it. Even in perfect conditions, measuring this type of microwave requires extremely sensitive equipment.
Scientists from the U.S. National Science Foundation’s Cosmology Large Angular Scale Surveyor, or CLASS, project used telescopes uniquely designed to detect the fingerprints left by the first stars in the relic Big Bang light—a feat that previously had only been accomplished by technology deployed in space, such as the U.S. National Aeronautics and Space Administration Wilkinson Microwave Anisotropy Probe (WMAP) and European Space Agency Planck space telescopes.
The new research, led by Johns Hopkins University and the University of Chicago, was published today in The Astrophysical Journal.
By comparing the CLASS telescope data with the data from the Planck and WMAP space missions, the researchers identified interference and narrowed in on a common signal from the polarized microwave light.
Polarization happens when light waves run into something and then scatter.
“When light hits the hood of your car and you see a glare, that’s polarization. To see clearly, you can put on polarized glasses to take away glare,” said first author Yunyang Li, who was a PhD student at Johns Hopkins and then a fellow at University of Chicago during the research. “Using the new common signal, we can determine how much of what we’re seeing is cosmic glare from light bouncing off the hood of the Cosmic Dawn, so to speak.”
After the Big Bang, the universe was a fog of electrons so dense that light energy was unable to escape. As the universe expanded and cooled, protons captured the electrons to form neutral hydrogen atoms, and microwave light was then free to travel through the space in between. When the first stars formed during the Cosmic Dawn, their intense energy ripped electrons free from the hydrogen atoms. The research team measured the probability that a photon from the Big Bang encountered one of the freed electrons on its way through the cloud of ionized gas and skittered off course.
The findings will help better define signals coming from the residual glow of the Big Bang, or the cosmic microwave background, and form a clearer picture of the early universe.
“Measuring this reionization signal more precisely is an important frontier of cosmic microwave background research,” said Charles Bennett, a Bloomberg Distinguished Professor at Johns Hopkins who led the WMAP space mission. “For us, the universe is like a physics lab. Better measurements of the universe help to refine our understanding of dark matter and neutrinos, abundant but elusive particles that fill the universe. By analyzing additional CLASS data going forward, we hope to reach the highest possible precision that’s achievable.”
Building on research published last year that used the CLASS telescopes to map 75% of the night sky, the new results also help solidify the CLASS team’s approach.
"No other ground-based experiment can do what CLASS is doing," says Nigel Sharp, program director in the NSF Division of Astronomical Sciences which has supported the CLASS instrument and research team since 2010. "The CLASS team has greatly improved measurement of the cosmic microwave polarization signal and this impressive leap forward is a testament to the scientific value produced by NSF's long-term support."
The CLASS observatory operates in the Parque Astronómico Atacama in northern Chile under the auspices of the Agencia Nacional de Investigación y Desarrollo.
Other collaborators are at Villanova University, the NASA Goddard Space Flight Center, the University of Chicago, the National Institute of Standards and Technology, the Argonne National Laboratory, the Los Alamos National Laboratory, the Harvard-Smithsonian Center for Astrophysics, the University of Oslo, Massachusetts Institute of Technology, and the University of British Columbia. Collaborators in Chile are at the Universidad de Chile, Pontificia Universidad Católica de Chile, Universidad de Concepción, and the Universidad Católica de la Santísima Concepción.
The observatory is funded by the National Science Foundation, Johns Hopkins, and private donors.
END
The number of armed conflicts in the world reached a historic high in 2024. This is shown by new data from the Uppsala Conflict Data Program (UCDP) at Uppsala University. Despite a marginal decrease in total fatalities, targeted violence against civilians increased significantly.
UCDP recorded 61 active conflicts involving at least one state in 2024, up from 59 the previous year and the highest number since statistics began in 1946. Eleven of these reached the level of war, defined as a conflict causing at least 1,000 battle-related deaths in a year. This is the highest number since 2016.
Despite ...
Precision gene editing is crucial for treating genetic diseases, as it enables targeted correction of specific mutations. A Korean research team has become the first in the world to significantly enhance the low efficiency of a key genome editing mechanism—known as homologous recombination (HR)—by inducing autophagy, a natual process whthin cells.
Dr. Hye Jin Nam’s team at the Korea Research Institute of Chemical Technology (KRICT), in collaboration with Professors Dong Hyun Jo and Sangsu Bae at ...
CLEVELAND, Ohio (June 11, 2025)—Nomograms have a strong reputation as reliable predictive models that simplify statistical prediction models and guide personalized treatment to formulate preventive measures for various diseases. Through a new study, a nomogram was developed and validated to predict the risk of patients with epithelial ovarian cancer developing deep vein thrombosis. Results of the study are published online today in Menopause, the journal of The Menopause Society.
Although ovarian cancer is not one of the more common types of cancer (especially compared with breast or lung cancer), it is serious. It is the fifth-leading ...
Cells taken from the lungs of people with chronic obstructive pulmonary disease (COPD) have a larger accumulation of soot-like carbon deposits compared to cells taken from people who smoke but do not have COPD, according to a study published today (Wednesday) in ERJ Open Research [1]. Carbon can enter the lungs via cigarette smoke, diesel exhaust and polluted air.
The cells, called alveolar macrophages, normally protect the body by engulfing any particles or bacteria that reach the lungs. But, in their new study, researchers found that when these cells are exposed to carbon they grow larger and encourage inflammation.
The research was led by Dr James Baker and Dr Simon Lea ...
When it comes to advanced cancer or Alzheimer’s disease, over half of doctors would consider assisted dying for themselves, but preferences seem to vary according to their jurisdiction’s legislation on euthanasia, reveal the results of an international survey, published online in the Journal of Medical Ethics.
And most say they would prefer symptom relief rather than life sustaining treatment for their own end of life care, indicate the responses.
Previously published research suggests that doctors’ views on their own end of life care inform their clinical practice, and that their perceptions of their patients’ treatment wishes ...
There’s an urgent need to quantify the role of fungal toxins (aflatoxins), found on agricultural crops, such as maize and peanuts (groundnuts), in the escalating rates of liver cancer in Ghana, as well as elsewhere in Africa and Asia, concludes a commentary published in the open access journal BMJ Global Health.
Maize and peanuts are dietary staples in many Asian and African countries. And with one of the highest rates of liver cancer in Africa, at 16/100,000 of the population. Ghana represents a critical case study in furthering international ...
CAMBRIDGE, MA -- For many patients with schizophrenia, other psychiatric illnesses, or diseases such as hypertension and asthma, it can be difficult to take their medicine every day. To help overcome that challenge, MIT researchers have developed a pill that can be taken just once a week and gradually releases medication from within the stomach.
In a phase 3 clinical trial conducted by MIT spinout Lyndra Therapeutics, the researchers used the once-a-week pill to deliver a widely used medication for managing the symptoms of schizophrenia. They found that this treatment regimen maintained consistent levels of the drug in patients’ ...
Smartphone apps that track menstrual cycles are a “gold mine” for consumer profiling, collecting information on everything from exercise, diet and medication to sexual preferences, hormone levels and contraception use, according to a University of Cambridge report.
A report from Cambridge’s Minderoo Centre for Technology and Democracy argues that the financial worth of this data is “vastly underestimated” by users who supply profit-driven companies with highly intimate details in a market lacking in regulation.
The report’s authors caution that cycle tracking app (CTA) ...
Memory problems have long been considered the primary hallmark of dementia, but a team of researchers is now challenging this view. They argue that changes in sensory perception – from vision to balance – may be equally important indicators that many healthcare providers are currently missing.
According to experts, current approaches to the care and support of people with dementia need an overhaul, relying too heavily on the assessment of memory functions, when the condition also impairs taste, touch, balance, hearing, or vision.
Professor Andrea Tales, Professor of Dementia ...
An intensive low-energy diet programme, similar to the NHS Type 2 Diabetes Path to Remission, significantly improved eating disorder symptoms in people with type 2 diabetes and excess weight who were at risk of developing eating disorders, according to a University of Oxford study published today in The Lancet Psychiatry.
Participants enrolled in a total diet replacement (TDR) programme experienced significant improvements in eating disorder symptoms which persisted six months after the programme finished when participants had regained some weight. This directly addresses a research gap highlighted by recent National Institute for Health and Care Excellence (NICE) guidance on the use of ...
