IN HIS PERSPECTIVE “SEEING THROUGH DARK Matter” (3 August, p. 607), Stacy McGaugh describes the success of a modified Newtonian dynamics (MOND) in explaining the flat rotation curves of galaxies without invoking dark matter. In addition to noting that MOND is in accord with available data and observations, it is possible to directly test Newtonian dynamics in the laboratory, even at low acceler...

Integration of the orbit of asteroid (29075) 1950 DA, which is based on radar and optical measurements spanning 51 years, reveals a 20-minute interval in March 2880 when there could be a nonnegligible probability of the 1-kilometer object colliding with Earth. Trajectory knowledge remains accurate until then because of extensive astrometric data, an inclined orbit geometry that reduces in-plane...

Modelling on the MOND proposal, we introduce an empirically motivated gravity law for galactic and sub-galactic scales. This, circumvents the need for the cumbersome and ill-defined transition regime which exists in MOND, when passing from the standard gravitational regime at high accelerations to the MOND regime at low accelerations. We show that the proposed force law does not violate dynamic...

The stellar evolution code Modules for Experiments in Stellar Astrophysics (MESA) is public and widely used by the community. It includes possibility of taking several non-standard processes such as atomic diffusion into account. Even if effect gravitational settling considered a standard ingredient modelling today, this not case radiative accelerations. specific treatment along with accelerati...

We present an efficient structure for the computation of robot dynamics in real time. The fundamental characteristic of this structure is the division of the computation into a high-priority synchronous task and low-priority background tasks, possibly sharing the resources of a conventional computing unit based on commercial microprocessors. The background tasks compute the inertial and gravita...

Microscopic diffusion processes (such as radiative levitation and gravitational settling/thermal diffusion) in the outer layers of stars are important because they may give rise to surface abundance anomalies. Here, we compare radiative accelerations (grad) derived from the new Opacity Project (OP) data 1 with those computed from OPAL and some previous data from OP. For the case where we have f...

This paper presents a scale factor calibration method based on virtual accelerations generated by electrostatic force. uses series of voltage signals to simulate the inertial forces caused acceleration input, rather than frequent and laborious calibrations with high-precision instruments. The error transfer model this is systematically analyzed, geometrical parameters novel micromachined resona...

We propose that future experiments aiming at the detection of deviations from the 1/r 2 gravitational law on submillimetric scales can be used to test the modified Newtonian dynamics theory (MOND). Current experiments are able to test the gravitational field of masses m ≈ 1g at distances r ≈ 200 µm, implying that they are probing accelerations well above the MOND limit (a 0 ≈ 1.2 × 10 −8 cms −2...

Some of the Galactic outer halo globular clusters are excellent tools to probe gravitational theories in the regime of weak accelerations (Baumgardt et al. 2005). The measurement of the line-of-sight velocity dispersion among stars in these clusters will differentiate between the validity of Newtonian dynamics (low velocity dispersion) and the possiblity of modified Newtonian dynamics (MOND) or...