Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print Examination of radiation left from birth of universe could alter theories

Examination of radiation left from birth of universe could alter theories

April 03, 2007

CHAMPAIGN, Ill. — Using relic radiation from the birth of the universe, astrophysicists at the University of Illinois have proposed a new way of measuring the fine-structure constant in the past, and comparing it with today.

By focusing on the absorption of the cosmic microwave background by atoms of neutral hydrogen, the researchers say, they could measure the fine-structure constant during the "dark ages," the time after the Big Bang before the first stars formed, when the universe consisted mostly of neutral hydrogen and helium.




The fine-structure constant characterizes the strength of the electromagnetic force, which is one of the four fundamental forces in physics. But, the fine-structure constant may not be constant. Recent observations of quasars - starlike objects billions of light-years away - have found a slightly different value for the fine-structure constant.

"If the fine-structure constant does vary over time and space, we could use it as a probe of new physics beyond the standard model and beyond general relativity," said Benjamin Wandelt, a cosmologist at the Illinois, who developed the proposed measurement technique with graduate student Rishi Khatri.

A varying fine-structure constant also could help explain the mysterious dark energy that pervades the universe, Wandelt said, and help constrain what kind of theory would unite the four fundamental forces into a "theory of everything." Using light from quasars, astronomers can look for variations in the fine-structure constant from the present up to 5 billion years ago. Using the spectra of neutral hydrogen, astronomers can peer much further back in time.

"There is a void from about 300,000 years after the Big Bang, when radiation that formed the cosmic microwave background was emitted, to about 500 million years later, when the first stars formed," Wandelt said. "Our measurement technique could probe the fine-structure constant during this period, known as the dark ages."

When a neutral hydrogen atom absorbs a photon of light from the cosmic microwave background, the electron flips its spin, causing a slight difference in its spectrum.

The telltale fingerprint of this atomic transition at a wavelength of 21 centimeters can serve as a sensitive search for past values of the fine-structure constant, said Wandelt and Khatri, who describe their measurement technique in a paper accepted for publication in the journal Physical Review Letters, and posted on its Web site.

While most radio telescopes are too small to look for variations in the fine-structure constant, there are new instruments in the design or construction phase - including the Long Wavelength Array and the Low Frequency Array - that will provide the first limits when brought on line.

"The measurements would be tricky, but not impossible," Wandelt said.

University of Illinois at Urbana-Champaign



Related Radiation Current Events and Radiation News Articles Radiation Current Events and Radiation News RSS Radiation Current Events and Radiation News RSS
Breast cancer treatment offers better outcome to women with implants
Women with early-stage breast cancer who have undergone breast augmentation may be treated successfully with a partial-breast radiation treatment called brachytherapy, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).

Hubble captures outstanding views of mammoth stars
Two of our Galaxy's most massive stars have been scrutinised in an impressive view by the NASA/ESA Hubble Space Telescope. They have, until recently, been shrouded in mystery, but the new image shows them in greater detail than ever before.

Studies show novel device may enhance chemotherapy treatment in brain tumors
NovoCure Ltd. presented results yesterday evaluating the Novo-TTF device in vitro and in a pilot clinical trial that showed the device enhanced the efficacy of standard chemotherapy (temozolomide) treatment in newly-diagnosed glioblastoma multiforme (GBM) patients.

Chandrayaan-1 starts observations of the Moon
The Indian Space Research Organisation's lunar orbiter Chandrayaan-1 released a probe that impacted close to the lunar south pole on 14 November.

Molecular memory a game-changer
A team at Rice University has determined that a strip of graphite only 10 atoms thick can serve as the basic element in a new type of memory, making massive amounts of storage available for computers, handheld media players, cell phones and cameras.

Mystery of missing hydrogen
Something vital is missing in the far distant reaches of the Universe: hydrogen - the raw material for stars, planets and possible life.

Misreading of damaged DNA may spur tumor formation
The DNA in our cells is constantly under assault from oxygen, the sun's radiation and environmental stresses. Most of the time, our cells can repair the damage before it gets copied into a permanent mutation that could lead to cancer.

The Flash Before the Flood
Flash floods are the most common natural disaster in the United States, and because of their unpredictability they're the leading weather-related cause of death for Americans.

Survival of head and neck cancer patients is greatly affected by coexisting ailments
Current estimates for head and neck cancer survival are largely inaccurate because they widely disregard many of the most common diseases such patients have in addition to their primary cancer, says Jay Piccirillo, M.D., a head and neck specialist at Washington University School of Medicine in St. Louis, the Siteman Cancer Center and Barnes-Jewish Hospital.

Carbon dioxide already in danger zone, warns study
A group of 10 prominent scientists says that the level of globe-warming carbon dioxide in the air has probably already reached a point where world climate will change disastrously unless the level can be reduced in coming decades.
More Radiation Current Events and Radiation News Articles


Radiation Detection and Measurement
by Glenn F. Knoll

A Classic Text on Radiation Detection and Measurement Now Updated and Expanded Building on the proven success of this widely-used text, the Third Edition will provide you with a clear understanding of the methods and instrumentation used in the detection and measurement of ionizing radiation. It provides in-depth coverage of the basic principles of radiation detection as well as illustrating...



Workbook for Radiation Protection in Medical Radiography
by Mary Alice Statkiewicz Sherer

Matching the chapters in Radiation Protection in Medical Radiography, 5th Edition, this print workbook enhances learning from the text. Author Mary Alice Statkiewicz Sherer makes the subject of radiation protection and safety more accessible, using her talent for taking difficult topics and explaining them in an easy-to-understand manner. Exercises are provided for each chapter, with these...



Handbook of Radiation Oncology: Basic Principles and Clinical Protocols
by Bruce Haffty, Lynn Wilson

Whether you are a practicing radiation oncologist, resident in radiation oncology, fellow in any oncology discipline, or a student of medicine, nursing, physics, dosimetry, or therapy, this handbook is a valuable resource covering the issues most pertinent to patients undergoing radiation therapy. Handbook of Radiation Oncology covers general oncologic principles, workup, staging, and...



Radiation Oncology: An Evidence-Based Approach (Medical Radiology / Radiation Oncology)

Radiation Oncology: An Evidence-Based Approach (ROEBA) is a reference book designed to enable radiation oncologists, including those in training, to make diagnostic and treatment decisions on the basis of the best available scientific evidence. Ease of use is ensured by a structured, reader-friendly format that offers rapid access to evidence-based recommendations. ROEBA’s orientation is...



Handbook of Evidence-based Radiation Oncology

This handbook serves as a portable reference that utilizes evidence-based medicine as the basis for practical treatment recommendations and guidelines. Organized by body site, concise clinical chapters provide easy access to critical information. Important "pearls" of epidemiology, anatomy, pathology, and clinical presentation are highlighted. Key facets of the work-up are listed, followed by...



A Guide for Delineation of Lymph Nodal Clinical Target Volume in Radiation Therapy

Conformal radiotherapy offers the opportunity to enhance precise delivery of high dose radiation to the target volume while maintaining normal tissues doses at acceptable tolerance levels. This technique requires an exact definition of the treatment volumes: gross tumour volume (GTV), clinical target volume (CTV) and planning target volume (PTV). For this reason, it is important to have a very...



Radiation Therapy Planning
by Gunilla C. Bentel

All new expanded edition provides step-by-step guidelines on performing the technical aspects of radiation therapy. Important new coverage includes treatment preparation, 3-D treatment planning, dosimetry, new technologies, documentation, and quality assurance. In addition, you'll find added treatment planning guidelines by body region, and an expanded art program including many new 4-color...



The Physics of Radiation Therapy
by Faiz M Khan, Faiz M. Khan

This leading reference source devoted to radiation therapy physics is now in its Third Edition. Pertinent to the entire radiation oncology team, it is clinically oriented and presents practical aspects as well as underlying theory to clarify basic concepts. The format begins with underlying physics, then progresses to treatment planning, and ends with radiation. Contains an expanded focus with...



Treatment Planning in Radiation Oncology

Completely updated for its Second Edition, this text is a comprehensive guide to state-of-the-art treatment planning techniques in radiation oncology. The book provides the treatment planning team--radiation oncologists, medical physicists, and medical dosimetrists--with detailed information on both the physics of radiation treatment planning and the clinical aspects of radiotherapy for specific...



Chemotherapy and Radiation For Dummies
by Alan P. Lyss, Humberto Fagundes, Patricia Corrigan

An informative, compassionate guide for cancer patients and their loved ones Each year, more than 1 million people get treated for cancer, and most of these will undergo chemotherapy, radiation therapy, or both. This reassuring, optimistic guide helps people get a handle on treatment options and explains in plain English how chemotherapy and radiation therapy really work. It offers detailed...

© 2008 BrightSurf.com