David Rapetti (left), Mustafa Amin (center) and Steve Allen discuss their work.

Standard Cosmological Model Upheld

by Ken Kingery

The heavyweight champion of modern cosmology, the standard cosmological model that includes dark matter and dark energy governed by Einstein's laws of gravity, remains undefeated, despite a rigorous new challenge by a team of scientists led by David Rapetti, a postdoc at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC). The team used observations of supernovae and galaxy clusters to probe the expansion history of the universe.

Studies of the expansion of the universe are not new, but by using an approach called "kinematics," the current study is providing novel insight. The standard theory of how the universe expands uses Einstein's laws to describe cosmic motion, but scientists are always looking for ways to bolster the certainty of the calculations underlying the theory. To that end, the KIPAC team removed assumptions about how gravity works from their models and used multiple sets of data to give different perspectives on the expansion of the Universe.

"Different methods have different uncertainties and different assumptions," said coauthor Mustafa Amin, a Ph.D. student at Stanford. "When they result in the same answers, scientists are reassured that their theories and models are correct." Read more...

Wrap-up on 2nd Annual SSRL Summer School

from SSRL Highlights

Workshop participants.
(Image courtesy of Diana Rogers.)

The second annual Stanford Synchrotron Radiation Laboratory (SSRL) School on Synchrotron X-ray Scattering Techniques in Materials and Environmental Sciences was held at SSRL on May 15-17, 2007. The aim of this workshop was for students, postdocs and researchers to gain practical knowledge in x-ray scattering methods with an emphasis on information that cannot be found in text books. More than 45 researchers, mostly graduate students and postdocs, attended the workshop. The first day consisted of introductory lectures on x-ray diffraction, how to get the most data out of beam time, and how to apply various techniques. The second and third days involved "on-the-experiment" training at four of SSRL's beam lines (1-4, 2-1, 11-3, and 7-2), followed by data analysis demonstrations and Q&A sessions.

Based on the comments received, the workshop was a big success. The practical sessions were well attended, and those who attended said they benefited greatly from these demonstrations. The attendees came away with new knowledge about how to efficiently collect data at SSRL's scattering beam lines.

Copies of all the talks have now been posted on the SSRL website.

Reporting Work-
Related Injuries

by Sharon Haynes

Employees who experience any work-related accident, injury, illness, or exposure must immediately report the incident to:
• Their supervisor
• SLAC Medical Department, A&E Building (Building 41), Room 137
If the SLAC Medical Department is closed, notify the Department by phone: ext. 2281 or email: mggherman@slac.stanford.edu as soon as possible. Leave a message noting:
• The injured person's name
• Nature of the injury
• Time and date of the occurrence
• Name of clinic or hospital where the injured person received treatment

Within 24 hours of any occurrence, the injured person must:
• Obtain, complete, sign, and submit Side A of the Employee's Statement of an Occupational Accident Report (SU-17).

Forms are available at the SLAC Medical Department. The SU-17 fulfills legal requirements, permits determination of the level of investigation required to generate subsequent reports, and suggests possible remediation. Anyone who experiences a work-related accident, injury, illness or exposure must complete an SU-17 even if you do not seek medical treatment.

Within 5 business days, supervisors must complete and sign Side B (Supervisor’s Statement) of the SU-17 and return the form to the SLAC Workers’ Compensation Administrator at MS 11.

Supervisors who do not receive an SU-17 within a few days of a reported injury must obtain an SU-17 from the SLAC Medical Department, complete Side B, and return the form to the SLAC Workers' Compensation Administrator at MS 11.

For more information, please contact Sharon Haynes, Workers' Compensation Administrator, Human Resources Department, at x4533 or shaynes@slac.stanford.edu.

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June 29: (12:30 p.m.) Theory Seminar: The Renormalization Scale Problem

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View online at http://today.slac.stanford.edu/.

David Rapetti (left), Mustafa Amin (center) and Steve Allen discuss their work. Standard Cosmological Model Upheld by Ken Kingery The heavyweight champion of modern cosmology, the standard cosmological model that includes dark matter and dark energy governed by Einstein's laws of gravity, remains undefeated, despite a rigorous new challenge by a team of scientists led by David Rapetti, a postdoc at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC). The team used observations of supernovae and galaxy clusters to probe the expansion history of the universe. Studies of the expansion of the universe are not new, but by using an approach called "kinematics," the current study is providing novel insight. The standard theory of how the universe expands uses Einstein's laws to describe cosmic motion, but scientists are always looking for ways to bolster the certainty of the calculations underlying the theory. To that end, the KIPAC team removed assumptions about how gravity works from their models and used multiple sets of data to give different perspectives on the expansion of the Universe. "Different methods have different uncertainties and different assumptions," said coauthor Mustafa Amin, a Ph.D. student at Stanford. "When they result in the same answers, scientists are reassured that their theories and models are correct." Read more...

Wrap-up on 2nd Annual SSRL Summer School from SSRL Highlights Workshop participants. (Image courtesy of Diana Rogers.) The second annual Stanford Synchrotron Radiation Laboratory (SSRL) School on Synchrotron X-ray Scattering Techniques in Materials and Environmental Sciences was held at SSRL on May 15-17, 2007. The aim of this workshop was for students, postdocs and researchers to gain practical knowledge in x-ray scattering methods with an emphasis on information that cannot be found in text books. More than 45 researchers, mostly graduate students and postdocs, attended the workshop. The first day consisted of introductory lectures on x-ray diffraction, how to get the most data out of beam time, and how to apply various techniques. The second and third days involved "on-the-experiment" training at four of SSRL's beam lines (1-4, 2-1, 11-3, and 7-2), followed by data analysis demonstrations and Q&A sessions. Based on the comments received, the workshop was a big success. The practical sessions were well attended, and those who attended said they benefited greatly from these demonstrations. The attendees came away with new knowledge about how to efficiently collect data at SSRL's scattering beam lines. Copies of all the talks have now been posted on the SSRL website.	Reporting Work- Related Injuries by Sharon Haynes Employees who experience any work-related accident, injury, illness, or exposure must immediately report the incident to: • Their supervisor • SLAC Medical Department, A&E Building (Building 41), Room 137 If the SLAC Medical Department is closed, notify the Department by phone: ext. 2281 or email: mggherman@slac.stanford.edu as soon as possible. Leave a message noting: • The injured person's name • Nature of the injury • Time and date of the occurrence • Name of clinic or hospital where the injured person received treatment Within 24 hours of any occurrence, the injured person must: • Obtain, complete, sign, and submit Side A of the Employee's Statement of an Occupational Accident Report (SU-17). Forms are available at the SLAC Medical Department. The SU-17 fulfills legal requirements, permits determination of the level of investigation required to generate subsequent reports, and suggests possible remediation. Anyone who experiences a work-related accident, injury, illness or exposure must complete an SU-17 even if you do not seek medical treatment. Within 5 business days, supervisors must complete and sign Side B (Supervisor’s Statement) of the SU-17 and return the form to the SLAC Workers’ Compensation Administrator at MS 11. Supervisors who do not receive an SU-17 within a few days of a reported injury must obtain an SU-17 from the SLAC Medical Department, complete Side B, and return the form to the SLAC Workers' Compensation Administrator at MS 11. For more information, please contact Sharon Haynes, Workers' Compensation Administrator, Human Resources Department, at x4533 or shaynes@slac.stanford.edu.	Events (see all \| submit) June 29: (12:30 p.m.) Theory Seminar: The Renormalization Scale Problem Access (see all) Increased construction traffic Blackbox/concrete pad construction near Building 50 Alpine Gate & PEP Ring Road closed Gates 17 & 30 open 24-7 Research Yard bisected Announcements (see all \| submit) Lab Announcements Summer Wellness classes and STAP information 2007 Winter Closure Memo Community Bulletin Board Noon Concert Series Features the Saint Lawrence String Quartet Kyler England in Concert, June 30 News (see all \| submit) NASA Establishes New Office to Study Cosmic Phenomena NASA European Astroparticle Physicists Publish a Roadmap to the Stars Interactions
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<% Response.AddHeader "Last-modified", getArticleDate() 'Response.AddHeader "Last-modified","Mon, 01 Sep 1997 01:03:33 GMT" 'Monday, December 06, 2010 %> View online at http://today.slac.stanford.edu/.


	Thursday - June 28, 2007