Last of the West Ford Dipoles

Shapiro, I. I.

doi:10.1126/science.154.3755.1445

Cited by 12 publications

(6 citation statements)

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“…From the electron diffraction pattern and the key diagram of Fig. 6c and d in this work, the following crystallographic orientation relationship between the nickel and nickel triboride Ni 3 B is proposed: This is in good agreement with previous studies [25,27]. In fact, it is known that good lattice matching between two crystals can favour the formation of stable phases due to the lowering of the activation barrier for nucleation during crystallization from undercooled liquid.…”

Section: Crystallographic Orientation Relationships Between the Nickesupporting

confidence: 80%

“…The lattice matchings in the vicinity of about 10% along these two directions could only lead to reasonable epitaxial strains and hence make these directions special. Similar epitaxial matchings have been reported by Fecht [28] in his work on Pb-Sn alloys and Shapiro and Ford [27]. The additional near perfect lattice matching of about 0.1% found along the [1 1 0] //[1 1 0] Ni direction in one of the alloys was believed to have come from some precipitates which were in perfect coherence with the Ni(␣) matrix.…”

Section: Crystallographic Orientation Relationships Between the Nickesupporting

confidence: 70%

“…The crystallographic orientation relationship between the nickel and nickel triboride phases has been extensively studied [25,27]. From the electron diffraction pattern and the key diagram of Fig.…”

Section: Crystallographic Orientation Relationships Between the Nickementioning

confidence: 99%

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Phase transitions in some nickel-rich nickel–boron–titanium hard alloys

Ajao

2010

Journal of Alloys and Compounds

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Section: Crystallographic Orientation Relationships Between the Nickesupporting

confidence: 80%

Section: Crystallographic Orientation Relationships Between the Nickesupporting

confidence: 70%

See 1 more Smart Citation

Phase transitions in some nickel-rich nickel–boron–titanium hard alloys

Ajao

2010

Journal of Alloys and Compounds

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“…As a result, radio astronomers mobilized to protect the radio sky from interference (Robinson 1999). In the end, the impact of the West Ford dipole belt was relatively small (Sandage & Kowal 1963;Tifft et al 1963), and most of the dipoles crashed to Earth as designed a few years later (Shapiro 1966). Still, if the political situation changes, far worse is easily achieved.…”

Section: We Are (Probably) Doomedmentioning

confidence: 99%

Type III Societies (Apparently) Do Not Exist

Lacki¹

2016

Preprint

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Whether technological societies remain small and planet-bound like our own, or ultimately span across galaxies is an open question in the Search for Extraterrestrial Intelligence. Societies that engineer on a galactic scale are classified as Type III on Kardashev's scale. I argue that Type III societies can take the form of blackboxes, entire galaxies veiled in an opaque screen. A blackbox has a temperature that is just above that of the cosmic microwave background, for the maximum possible thermodynamic efficiency. The screen can be made from artificial dust pervading the galaxy, establishing feedback on the diffuse interstellar medium itself. I show that there is enough material in galaxies to build blackboxes if the dust is fashioned into dipole antennas, especially if they are made of carbon nanotubes.The thermal emission of a blackbox makes it a bright microwave source. I examine the Planck Catalog of Compact Sources (PCCS2) to constrain the abundance of blackboxes. None of the 100 GHz sources has the spectrum expected of a blackbox. The null result rules out shrouded galaxy clusters out to z ≈ 1 and shrouded Milky Ways out to (comoving) 700 Mpc. The reach of the results includes 3 million galaxies containing an estimated 300 quadrillion terrestrial planets, as well as tens of thousands of galaxy clusters. A more detailed search of the PCCS2 can find or rule out blackboxes in 30 million galaxies, and the South Pole Telescope Sunyaev-Zeldovich survey can search another 20 million galaxies.Combined with the null results from other searches for Type III societies, I conclude that they are so rare that they basically do not exist within the observable Universe. A hypothesis of "Cosmic Pessimism" is discussed, in which we are alone, our long-term chances for survival are slim, and if we do survive, our future history will be checkered. Our loneliness is suggested by the lack of Type III societies. I discuss the remaining forms of Type III societies not yet well constrained by observation. I argue that the ease of building blackboxes on planetary and Solar System scales may lead, within a few centuries, to environmental catastrophes vastly more devastating than anything we are doing now, boding ill for us.

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“…1 5. About 50 years ago, Shapiro and Ford studied orientation and interfacial relations for Ni–Ni 3 B eutectic in the near equilibrium solidification of hypoeutectic and hypereutectic Ni–Ni 3 B alloys (B<5wt-%) 6. In order to study the effect of additions on solidification behaviours, Ajao et al rapidly quenched several Ni–Ni 3 B (0<B<5 wt-%) alloys by melt spinning 7,8.…”

Section: Introductionmentioning

confidence: 99%

Undercooled solidification of Ni–3·3 wt-%B alloy and cooling curve description

Liu

Dang

2013

Materials Science and Technology

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Undercooled solidification of hypoeutectic Ni-3?3 wt-%B alloy has been studied. The microstructure evolution of Ni-3?3 wt-%B alloy indicates that a transition from regular lamellar eutectic to anomalous eutectic exists with increasing undercooling for eutectic transformation. Here, a new model was proposed to describe the cooling curves of undercooled solidification with two-step transformation. Fits of the present model to the cooling curves after different undercoolings show that the predictions of transformed fractions are compatible with the microstructure observation. Furthermore, for hypoeutectic alloy, the size of the primary phase mainly depends on the undercooling for primary solidification, while the fraction of the primary phase mainly depends on the undercooling for eutectic solidification.

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Last of the West Ford Dipoles

Cited by 12 publications

References 13 publications

Phase transitions in some nickel-rich nickel–boron–titanium hard alloys

Phase transitions in some nickel-rich nickel–boron–titanium hard alloys

Type III Societies (Apparently) Do Not Exist

Undercooled solidification of Ni–3·3 wt-%B alloy and cooling curve description

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