Particles near absolute zero do not break the laws of physics after all

A change of models demystifies anomalous particle behavior at very low temperatures, confirming that the third law of thermodynamics cannot be violated

2014-05-20

(Press-News.org) In theory, the laws of physics are absolute. However, when it comes to the laws of thermodynamics—the science that studies how heat and temperature relate to energy—there are times where they no longer seem to apply. In a paper recently published in EPJ B, Robert Adamietz from the University of Augsburg, Germany, and colleagues have demonstrated that a theoretical model of the environment's influence on a particle does not violate the third law of thermodynamics, despite appearances to the contrary. These findings are relevant for systems at the micro or nanometer scale that are difficult to decouple from the heat or the quantum effects exerted by their environment.

The authors focused on a model system favored by thermodynamics experts that consists of a free particle strongly coupled to a heat bath, representing the effect of its environment. Studies of such systems typically focus on how much energy is needed to raise their temperature by a certain amount, or so-called specific heat. Previous theoretical predictions suggested that, under certain circumstances, the specific heat can decrease below zero at a temperature of strictly zero (−273.15°C). This prediction appears to breach the third law of thermodynamics, which states that the specific heat must drop to zero value at strictly zero temperature.

The authors demonstrated that the third law of thermodynamics is not actually violated. In fact, a real particle will always be confined to a finite volume—even if that volume may be extremely large. Therefore, they discovered that previous studies need to be modified in order to account for a spatial confinement of the particle. The new model demonstrates how the negative specific heat for a truly free particle is related to a dip in the specific heat, which should be observable in the presence of a confinement.

INFORMATION: Reference: R. Adamietz, G.-L. Ingold, and U. Weiss (2014), Thermodynamic anomalies in the presence of general linear dissipation: from the free particle to the harmonic oscillator, European Physical Journal B, DOI 10.1140/epjb/e2014-50125-2

For more information visit: http://www.epj.org

The full-text article is available to journalists on request.

ELSE PRESS RELEASES FROM THIS DATE:

Busting rust with light: New technique safely penetrates top coat for perfect paint job

2014-05-20

WASHINGTON, May 20, 2014 – To keep your new car looking sleek and shiny for years, factories need to make certain that the coats of paint on it are applied properly. But ensuring that every coat of paint—whether it is on a car or anything else—is of uniform thickness and quality is not easy. Now researchers have developed a new way to measure the thickness of paint layers and the size of particles embedded inside. Unlike conventional methods, the paint remains undamaged, making the technique useful for a variety of applications from cars to artifacts, cancer detection ...

Pine bark substance could be potent melanoma drug

2014-05-20

A substance that comes from pine bark is a potential source for a new treatment of melanoma, according to Penn State College of Medicine researchers. Current melanoma drugs targeting single proteins can initially be effective, but resistance develops relatively quickly and the disease recurs. In those instances, resistance usually develops when the cancer cell's circuitry bypasses the protein that the drug acts on, or when the cell uses other pathways to avoid the point on which the drug acts. "To a cancer cell, resistance is like a traffic problem in its circuitry," ...

Flu vaccines in schools limited by insurer reimbursement

2014-05-20

AURORA, Colo. (May 20, 2014) – School-based influenza vaccine programs have the potential to reach many children at affordable costs and with parental support, but these programs are limited by low rates of reimbursement from third-party payers, according to recently published study results by researchers from the University of Colorado School of Medicine. A school-based flu vaccine program in the Denver Public Schools was effective at reaching nearly one-third of the students, but billing and reimbursement issues posed significant problems for administrators of the program. "The ...

Study shows how streptococcal bacteria can be used to fight colon cancer

2014-05-20

Researchers at Western University (London, Canada) have shown how the bacteria primarily responsible for causing strep throat can be used to fight colon cancer. By engineering a streptococcal bacterial toxin to attach itself to tumour cells, they are forcing the immune system to recognize and attack the cancer. Kelcey Patterson, a PhD Candidate at Western and the lead author on the study, showed that the engineered bacterial toxin could significantly reduce the size of human colon cancer tumours in mice, with a drastic reduction in the instances of metastasis. By using ...

Parents of overweight kids more likely to give schools failing grades for fighting obesity

2014-05-20

ANN ARBOR, Mich. – Parents – especially those of overweight children – give schools a failing grade for efforts to encourage healthy habits that combat childhood obesity, according to a new poll from the University of Michigan. According to the latest University of Michigan C.S. Mott Children's Hospital National Poll on Children's Health, parents with at least one overweight child (25 percent of all parents in the poll) were more likely to give schools a failing grade of D or F for obesity-related efforts than parents of normal-weight children. Parents of overweight ...

Simulated learning in medical education improves patient care and outcomes

2014-05-20

MAYWOOD, Ill. -- The use of simulation techniques in medical education, such as lifelike mannequins and computer systems, results in improved patient care, better outcomes and other benefits, according to a study led by a Loyola University Chicago Stritch School of Medicine researcher. William C. McGaghie, PhD, and colleagues analyzed 23 medical education studies that measured the effects of simulation-based mastery learning (SBML). A qualitative synthesis of these studies found that SBML improved outcomes in four areas: the educational laboratory, patient care practices, ...

Cost-saving, coordinated brain care model for older adults attracting nationwide interest

2014-05-20

INDIANAPOLIS -- The patient and caregiver-centered Aging Brain Care program, developed by researchers at the Regenstrief Institute and the Indiana University Center for Aging Research, is attracting nationwide interest for its ability to improve health outcomes and quality of care for those with cognitive impairment while dramatically lowering costs to patients and health care systems. On May 22 and 23, a team of physicians and nurse managers from the Geisel School of Medicine at Dartmouth and the Dartmouth-Hitchcock Medical Center will visit Indianapolis and Lafayette, ...

Students swayed by 'relaxing, fun' image of hookah smoking ignore health harms

2014-05-20

PITTSBURGH, May 20, 2014 – Educational campaigns meant to dissuade college students from initiating hookah tobacco smoking may be more successful if they combat positive perceptions of hookah use as attractive and romantic, rather than focusing solely on the harmful components of hookah tobacco smoke, a new University of Pittsburgh School of Medicine study found. The research, supported by the National Cancer Institute, examined the sequence of events around which university students first smoke tobacco from a hookah, also known as a water pipe, in an effort to determine ...

Women repeatedly short-changed in case of premature ejaculation

2014-05-20

Premature ejaculation is one of the most common sexual disorders in men. But it is not just the men who suffer; it also causes increased psychological strain and stress in women, as a new survey conducted by Andrea Burri, a clinical psychologist at the University of Zurich, reveals. Around 40 percent of over 1,500 women polled from Mexico, Italy and South Korea indicated that ejaculation control is very important for satisfactory intercourse. It is not the short duration of the act of lovemaking that is primarily regarded as the main source of sexual frustration by the ...

National survey on long-term care: Expectations and reality

2014-05-20

Chicago, May 19, 2014—The Associated Press-NORC Center for Public Affairs Research has released the results of a major survey on long-term care in the United States. The study, the second on this topic done by AP-NORC, provides much-needed data on how Americans are, or are not, planning for long-term care as policy makers grapple with how to plan for and finance high-quality long-term care in the United States. "Families are essential to providing long-term care so we wanted to explore their role further," said Trevor Tompson, director of the AP-NORC Center. "We conducted ...

Particles near absolute zero do not break the laws of physics after all

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: