1,264 research outputs found
The inverse-square law and quantum gravity
A program is described which measures the gravitational acceleration of antiprotons. This idea was approached from a particle physics point of view. That point of view is examined starting with some history of physics over the last 200 years
Functional Forms for the Squeeze and the Time-Displacement Operators
Using Baker-Campbell-Hausdorff relations, the squeeze and harmonic-oscillator
time-displacement operators are given in the form , where ,
, , and are explicitly determined. Applications are
discussed.Comment: 10 pages, LaTe
Time-dependent Schr\"odinger equations having isomorphic symmetry algebras. I. Classes of interrelated equations
In this paper, we focus on a general class of Schr\"odinger equations that
are time-dependent and quadratic in X and P. We transform Schr\"odinger
equations in this class, via a class of time-dependent mass equations, to a
class of solvable time-dependent oscillator equations. This transformation
consists of a unitary transformation and a change in the ``time'' variable. We
derive mathematical constraints forthe transformation and introduce two
examples.Comment: LaTeX, 18 pages, new format, edite
A Mission to Test the Pioneer Anomaly
Analysis of the radio tracking data from the Pioneer 10/11 spacecraft has
consistently indicated the presence of an anomalous small Doppler frequency
drift. The drift can be interpreted as being due to 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.
The nature of this anomaly has become of growing interest in the fields of
relativistic cosmology, astro- and gravitational physics as well as in the
areas of spacecraft design and high-precision navigation. We present a concept
for a designated deep-space mission to test the discovered anomaly. A number of
critical requirements and design considerations for such a mission are outlined
and addressed.Comment: Final changes for publication. Honorable Mention, 2002 Gravity
Research Foundation Essay
Propositionalism without propositions, objectualism without objects
Propositionalism is the view that all intentional states are propositional states, which are states with a propositional content, while objectualism is the view that at least some intentional states are objectual states, which are states with objectual contents, such as objects, properties, and kinds. This paper argues that there are two distinct ways of understanding propositionalism and objectualism: (1) as views about the deep nature of the contents of intentional states, and (2) as views about the superficial character of the contents of intentional states. I argue that we should understand the views in the second way. I also argue that the propositionalism debate is fairly independent from debates over the deep nature of intentionality, and that this has implications for arguments for propositionalism and objectualism from claims about the nature of intentional content. I close with a short discussion of how related points apply to the debate over singular content
Search for a Standard Explanation of the Pioneer Anomaly
The data from Pioneer 10 and 11 shows an anomalous, constant, Doppler
frequency drift that can be interpreted as an acceleration directed towards the
Sun of a_P = (8.74 \pm 1.33) x 10^{-8} cm/s^2. Although one can consider a new
physical origin for the anomaly, one first must investigate the contributions
of the prime candidates, which are systematics generated on board. Here we
expand upon previous analyses of thermal systematics. We demonstrate that
thermal models put forth so far are not supported by the analyzed data.
Possible ways to further investigate the nature of the anomaly are proposed.Comment: Changes made for publicatio
Squeezed States for General Systems
We propose a ladder-operator method for obtaining the squeezed states of
general symmetry systems. It is a generalization of the annihilation-operator
technique for obtaining the coherent states of symmetry systems. We connect
this method with the minimum-uncertainty method for obtaining the squeezed and
coherent states of general potential systems, and comment on the distinctions
between these two methods and the displacement-operator method.Comment: 8 pages, LAUR-93-1721, LaTe
Indication, from Pioneer 10/11, Galileo, and Ulysses Data, of an Apparent Anomalous, Weak, Long-Range Acceleration
Radio metric data from the Pioneer 10/11, Galileo, and Ulysses spacecraft
indicate an apparent anomalous, constant, acceleration acting on the spacecraft
with a magnitude cm/s, directed towards the Sun.
Two independent codes and physical strategies have been used to analyze the
data. A number of potential causes have been ruled out. We discuss future
kinematic tests and possible origins of the signal.Comment: Revtex, 4 pages and 1 figure. Minor changes for publicatio
Anderson et al. Reply (to the Comment by Katz on Pioneer 10/11)
We conclude that Katz's proposal (anisotropic heat reflection off of the back
of the spacecraft high-gain antennae, the heat coming from the RTGs) does not
provide enough power and so can not explain the Pioneer anomaly.Comment: LaTex, 3 pages, Phys. Rev. Lett. (to be published
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