We present an improved laboratory test of Lorentz invariance in electrodynamics by testing the isotropy of the speed of light. Our measurement compares the resonance frequencies of two orthogonal optical resonators that are implemented in a single block of fused silica and are rotated continuously on a precision air bearing turntable. An analysis of data recorded over the course of one year sets a limit on an anisotropy of the speed of light of Ác=c $ 1 Â 10 À17 . This constitutes the most accurate laboratory test of the isotropy of c to date and allows to constrain parameters of a Lorentz violating extension of the standard model of particle physics down to a level of 10 À17 .

Lorentz symmetry is a foundational property of modern physics, underlying the standard model of particles and general relativity. It is anticipated that these two theories are low-energy approximations of a single theory that is unified and consistent at the Planck scale. Many unifying proposals allow Lorentz symmetry to be broken, with observable effects appearing at Planck-suppressed levels; thus, precision tests of Lorentz invariance are needed to assess and guide theoretical efforts. Here we use ultrastable oscillator frequency sources to perform a modern Michelson–Morley experiment and make the most precise direct terrestrial test to date of Lorentz symmetry for the photon, constraining Lorentz violating orientation-dependent relative frequency changes Δν/ν to 9.2±10.7 × 10−19 (95% confidence interval). This order of magnitude improvement over previous Michelson–Morley experiments allows us to set comprehensive simultaneous bounds on nine boost and rotation anisotropies of the speed of light, finding no significant violations of Lorentz symmetry.

Purpose – This paper aims to conduct two studies to investigate the use of social media tools by wineries in Germany and assess the impact of Facebook membership on customers by comparing them with customers who were not members. Today, a vast number of books and studies are being published about social media in general, but less is known about their usage and effectiveness in the wine industry. Design/methodology/approach – The first study was conducted among 321 German wineries. It focused on the attitudes and preferences of the winemakers regarding social media, and it analysed the daily use of this new communication tool. The second study took place in August 2012, and it set out to define the value that accrued to a winery from having Facebook fans. This analysis was based on an online survey with customers of the winery as well as on a comparative analysis of the buying patterns of customers who were Facebook fans and those who were not. The analysis compared the turnover from the purchases of both groups over a period of three years. Findings – It was determined that 60 per cent of German wineries did communicate with their customers using social media. Facebook was the most important social media channel, followed by Twitter and YouTube. Of the winemakers interviewed, 40 per cent planned, in the near future, to implement additional activities involving social media. The consumer study proved that Facebook fans had a higher turnover compared to the non-Facebook fans of the winery studied. This finding emphasises the loyalty of Facebook fans. In addition, the study revealed that Facebook fans are open to receiving sales offers from the company which they support. Practical implications – Winery owners should be aware of the effectiveness of this modern communication tool. This is not only because Facebook fans generate a much higher turnover but also because of the possibility that they are interested in additional special offers on Facebook, which could mean an expansion of the available sales channels. Originality/value – To our knowledge, this kind of overview about the Germany wine sector as well as about the value of a Facebook-fan of a winery has not yet been undertaken.

+,*+ 3(5)250$1&( ,2',1( )5(48(1&< 5()(5(1&( )25 7(676 2) 7+( /,6$ /$6(5 6<67(0 .ODXV '|ULQJVKRII .DWKDULQD 0|KOH 0RULW] 1DJHO (YJHQ\ 9 .RYDOFKXN $FKLP 3HWHUV +XPEROGW8QLYHUVLWlW ]X %HUOLQ ,QVWLWXW IU 3K\VLN $* 420 +DXVYRJWHLSODW] %HUOLQ *HUPDQ\ (PDLO .ODXV'RHULQJVKRII#SK\VLNKXEHUOLQGH $%675$&7Forthcoming space missions like the Laser Interferometer Space Antenna (LISA) or the Space-Time Asymmetry Research (STAR) project call for optical frequency references with high frequency stability better than 10 -14 at averaging times longer than 1000 s. Since Nd:YAG lasers are planned to be used on these missions, new interest has arisen in the frequency stabilization of Nd:YAG lasers to hyperfine transitions in molecular iodine. Iodine stabilized lasers offer an absolute optical frequency reference with high frequency stability and low sensitivity to temperature fluctuations and magnetic fields in relative simple setups. Here we present our iodine frequency standard using modulation transfer spectroscopy with a multi-pass iodine cell showing a frequency stability of 1·10 -14 at 1 s averaging time. ,1752'8&7,21Future space missions like the Laser Interferometer Space Antenna (LISA) [1] or the Space-Time Asymmetry Research (STAR) project [2, 3] will test fundamentals of space-time at unprecedented precision: LISA should for the first time detect and observe gravitational waves from astronomical sources with a sensitivity of 10 -21 , the STAR1 mission goal is to measure the constancy of the speed of light to 10 -17 and the Kennedy-Thorndike coefficient of the Mansouri-Sexl test theory to 7·10 -10 .

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