Lessons Learned from the Pioneers 10/11 for a Mission to Test the Pioneer Anomaly

Analysis of the radio-metric tracking data from the Pioneer 10/11 spacecraft at distances between 20--70 astronomical units (AU) from the Sun has consistently indicated the presence of an anomalous, small, constant Doppler frequency drift. The drift is a blue-shift, uniformly changing with rate a_t = (2.92 +/- 0.44) x 10^(-18) s/s^2. It can also be interpreted as a constant acceleration of a_P = (8.74 +/- 1.33) x 10^(-8) cm/s^2 directed towards the Sun. Although it is suspected that there is a systematic origin to the effect, none has been found. As a result, the nature of this anomaly has become of growing interest. Here we discuss the details of our recent investigation focusing on the effects both external to and internal to the spacecraft, as well as those due to modeling and computational techniques. We review some of the mechanisms proposed to explain the anomaly and show their inability to account for the observed behavior of the anomaly. We also present lessons learned from this investigation for a potential deep-space experiment that will reveal the origin of the discovered anomaly and also will characterize its properties with an accuracy of at least two orders of magnitude below the anomaly's size. A number of critical requirements and design considerations for such a mission are outlined and addressed.Comment: 11 pages, invited talk given at ``35th COSPAR Scientific Assebly,'' July 18-24, 2004, Paris, Franc

Earth Flyby Anomalies

In a reference frame fixed to the solar system's center of mass, a satellite's energy will change as it is deflected by a planet. But a number of satellites flying by Earth have also experienced energy changes in the Earth-centered frame -- and that's a mystery.Comment: 5 pagea 3 figure

Seeking a solution of the Pioneer Anomaly

The 1972 and 1973 launched Pioneer 10 and 11 were the first missions to explore the outer solar system. They achieved stunning breakthroughs in deep-space exploration. But around 1980 an unmodeled force of \sim 8 \times 10^{-8} cm/s^2, directed approximately towards the Sun, appeared in the tracking data. It later was unambiguously verified as not being an artifact. The origin remains unknown (although radiant heat remains a likely cause). Increasing effort has gone into understanding this anomaly. We review the situation and describe programs to resolve the issue.Comment: 7 pages, 1 figure, invited talk at the Fourth Meeting on CPT and Lorentz Symmetry, 8-11 Aug. 2007, held at Indiana Universit

Distortions to Agricultural Incentives in Asia

Distorted incentives, agricultural and trade policy reforms, national agricultural development, Agricultural and Food Policy, International Relations/Trade, F13, F14, Q17, Q18,

Distortions to Agricultural Incentives in China and Southeast Asia

Distorted incentives, agricultural and trade policy reforms, national agricultural development, Agricultural and Food Policy, International Relations/Trade, F13, F14, Q17, Q18,

The ground state and the long-time evolution in the CMC Einstein flow

Let (g,K)(k) be a CMC (vacuum) Einstein flow over a compact three-manifold M with non-positive Yamabe invariant (Y(M)). As noted by Fischer and Moncrief, the reduced volume V(k)=(-k/3)^{3}Vol_{g(k)}(M) is monotonically decreasing in the expanding direction and bounded below by V_{\inf}=(-1/6)Y(M))^{3/2}. Inspired by this fact we define the ground state of the manifold M as "the limit" of any sequence of CMC states {(g_{i},K_{i})} satisfying: i. k_{i}=-3, ii. V_{i} --> V_{inf}, iii. Q_{0}((g_{i},K_{i}))< L where Q_{0} is the Bel-Robinson energy and L is any arbitrary positive constant. We prove that (as a geometric state) the ground state is equivalent to the Thurston geometrization of M. Ground states classify naturally into three types. We provide examples for each class, including a new ground state (the Double Cusp) that we analyze in detail. Finally consider a long time and cosmologically normalized flow (\g,\K)(s)=((-k/3)^{2}g,(-k/3))K) where s=-ln(-k) is in [a,\infty). We prove that if E_{1}=E_{1}((\g,\K))< L (where E_{1}=Q_{0}+Q_{1}, is the sum of the zero and first order Bel-Robinson energies) the flow (\g,\K)(s) persistently geometrizes the three-manifold M and the geometrization is the ground state if V --> V_{inf}.Comment: 40 pages. This article is an improved version of the second part of the First Version of arXiv:0705.307

Evaluating public expenditures when governments must rely on distortionary taxation

Anderson and Martin provide simple, robust rules for evaluating public spending in distorted economies. Their analysis integrates, within a clean unified framework, previous treatments of project evaluation as special cases. In this paper, the authors use a general system of fiscal accounting for marginal changes in the provision of public that allows them to account for various approaches to the funding of government projects. They obtain two key results that seem likely to be useful for project evaluation. Firstly, the shadow prices of traded (as well as non-traded) goods are not generally equal to their world prices, but differ from world prices by an amount that depends upon the impact of the project on government revenues and on the Marginal Cost of Funds (MCF). Secondly, the costs of a government project need to be adjusted by the Marginal Cost of Funds before being compared with the benefits accruing from the project. The analysis leads to operational rules for project evaluation that are only slightly more complex than the border pricing rule. To conduct the analysis, the authors utilize a framework that makes explicit the role of government in providing public goods and services subject to a budget constraint. They consider first in Section 1 a general welfare analysis of the provision of a public good which is purchased from the rest of the world and paid for out of distortionary tax revenue. In Section 2 they consider the nature of the resulting shadow prices in more detail. In Section 3 the authors consider the role of the MCF in evaluating the cost of project inputs. Section 4 deals with user charges for public goods, which are of course only feasible when such goods are excludable. Section 5 places the results in the context of the earlier literature in order to clarify the relationship between their results and those obtained by earlier authors. Section 6 provides some simple numerical examples to highlight the potential importance allowing for the costs of raising funds.Public Sector Economics&Finance,Environmental Economics&Policies,Markets and Market Access,Economic Theory&Research,Banks&Banking Reform,Public Sector Economics&Finance,Access to Markets,Markets and Market Access,Economic Theory&Research,Environmental Economics&Policies