8,479 research outputs found

    Lorenz integrable system moves \`a la Poinsot

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    A transformation is derived which takes Lorenz integrable system into the well-known Euler equations of a free-torque rigid body with a fixed point, i.e. the famous motion \`a la Poinsot. The proof is based on Lie group analysis applied to two third order ordinary differential equations admitting the same two-dimensional Lie symmetry algebra. Lie's classification of two-dimensional symmetry algebra in the plane is used. If the same transformation is applied to Lorenz system with any value of parameters, then one obtains Euler equations of a rigid body with a fixed point subjected to a torsion depending on time and angular velocity. The numerical solution of this system yields a three-dimensional picture which looks like a "tornado" whose cross-section has a butterfly-shape. Thus, Lorenz's {\em butterfly} has been transformed into a {\em tornado}.Comment: 14 pages, 6 figure

    I love my children: am I racist? On the wish to be biologically related to one’s children

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    Is the wish to be biologically related to your children legitimate? Here, I respond to an argument in support of a negative answer to this question according to which a preference towards having children one is biologically related to is analogous to a preference towards associating with members of one’s own race. I reject this analogy, mainly on the grounds that only the latter constitutes discrimination; still, I conclude that indeed a preference towards children one is biologically related to is morally illegitimate because, in the context of parental love, biological considerations are normatively irrelevant

    Nonclassical symmetries as special solutions of heir-equations

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    In (Nucci M.C. 1994, Physica D 78 p.124), we have found that iterations of the nonclassical symmetries method give rise to new nonlinear equations, which inherit the Lie point symmetry algebra of the given equation. In the present paper, we show that special solutions of the right-order heir-equation correspond to classical and nonclassical symmetries of the original equations. An infinite number of nonlinear equations which possess nonclassical symmetries are derived

    IVF, same-sex couples and the value of biological ties

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    Ought parents, in general, to value being biologically tied to their children? Is it important, in particular, that both parents be biologically tied to their children? I will address these fundamental questions by looking at a fairly new practice within IVF treatments, so-called IVF-with-ROPA ( Reception of Oocytes from Partner ), which allows lesbian couples to „share motherhood‟ with one partner providing the eggs while the other becomes pregnant. I believe that IVF-with-ROPA is, just like other IVF treatments, morally permissible; but here I argue that the increased biological ties which IVF-with-ROPA allows for do not have any particular value beside the satisfaction of a legitimate wish, because there is no intrinsic value in a biological tie between parents and children; further, I argue that equality within parental projects cannot be achieved by redistributing biological ties

    Drones and the Threshold for Waging War

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    I argue that, if drones make waging war easier, the reason why they do so may not be the one commonly assumed within the philosophical debate – namely the promised reduction in casualties on either side – but a more complicated one which has little to do with concern for one’s own soldiers or, for that matter, the enemy; and a lot more to do with the political intricacies of international relations and domestic politics; I use the example of the Obama Administration’s drone policies to illustrate this argument. My point is meant to have wider methodological significance: philosophy can make an important contribution to this and related applied debates; but it is not by artificially – and optimistically – simplifying realities on the ground that philosophers can be of help

    Sexual Rights, Disability and Sex Robots

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    I argue that the right to sexual satisfaction of severely physically and mentally disabled people and elderly people who suffer from neurodegenerative diseases can be fulfilled by deploying sex robots; this would enable us to satisfy the sexual needs of many who cannot provide for their own sexual satisfaction; without at the same time violating anybody’s right to sexual self-determination. I don’t offer a full-blown moral justification of deploying sex robots in such cases, as not all morally relevant concerns can be addressed here; rather, I put forward a plausible way of fulfilling acute sexual needs without thereby violating anybody’s sexual rights

    Noether symmetries and the quantization of a Lienard-type nonlinear oscillator

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    The classical quantization of a Lienard-type nonlinear oscillator is achieved by a quantization scheme (M.C. Nucci. Theor. Math. Phys., 168:997--1004, 2011) that preserves the Noether point symmetries of the underlying Lagrangian in order to construct the Schr\"odinger equation. This method straightforwardly yields the correct Schr\"odinger equation in the momentum space (V. Chithiika Ruby, M. Senthilvelan, and M. Lakshmanan. J. Phys. A: Math. Gen., 45:382002, 2012), and sheds light into the apparently remarkable connection with the linear harmonic oscillator.Comment: 18 page
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