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The 16-inch f/4.5 Collapsible-Truss Dobsonian From New Moon Telescopes – Feature Article (Again) In Astronomy Technology Today

And happy new year.

With Operation: How-The-Hell-Do-I-Do-It-In-Gutenberg well underway, a quick post to mention the re-publication of a New Moon Telescopes review in Astronomy Technology Today (Vol 12. Issue 5) that first appeared in ATT’s May-June 2013 issue (a post about that publication resides on this site HERE).

So nice they printed it twice.

While the “classic” NMT scope has gone into discontinuation on the website in favor of the “hybrid” designs (the reprinting of the review of the “classic” model is perhaps not the best of timing), let there be no doubt that the long-short of the article and its reprint stands.

In the last seven year, I’ve bought extra pairs of binoculars. I’ve picked up sky charts. I thought about adding to my Televue collection (then won a Delos at Cherry Springs Star Party 2014 a few years back, scratching that itch). I even went so far as to pick up an iOptron SkyTracker to merely dabble in astrophotography.

In all that time, “Ruby” (NMT #1) has performed so well that I’ve never felt the need to even consider buying another telescope. In a hobby that caters to gear-hounds like no other, that’s about as strong an endorsement as I can make. Simply, Ryan Goodson continues to make the finest Dobsonian scopes on the market today. Period.

And make sure you subscribe/renew your subscription to support Astronomy Technology Today (as I did before the reprint!), which remains one of the best sources for in-depth equipment reviews and excellent commentary from real, honest-to-goodness amateur astronomy contributors.

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Free Astronomy Magazine – November-December 2018 Issue Available For Reading And Download

Above: Hayabusa2 at Ryugu – September 23, 2018: Image captured immediately before hop of Rover-1B. 2018-9-23 09:46 (JST). (Image credit: JAXA)

The November-December issue of Free Astronomy Magazine is available for your reading and downloading pleasure.

To the digest of NASA/ESA articles, excellent updates for a slew of extra-solar research, and general all-around fantastic aggregation of relevant images to make you wish you’d gotten a tablet with higher resolution, this issue wades Andromeda’s-shackled-ankle-deep into recent events at the Sunspot Solar Observatory on/at Sacramento Peak, New Mexico. Depending on your interpretation of events (and, possibly, your choice of late-night radio listening), you may or may not be satisfied with the description and resolution of the circumstances in the article or in the several follow-up news articles concerning the closing-up of the investigation.

Please download, read, and pass along. Also, check out the many back issues at www.astropublishing.com

astropublishing.com/6FAM2018/ | Direct PDF

Click the Table of Contents image below for a full-size view.

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Evaluating The Friction Of Rotary Joints In Molecular Machines

Howard Lovy’s name came across my calendar (happy birthday!) and Josh Hall published a fresh post to “Where is my Flying Car?” – seems like a perfect time to post an everything-new-is-still-new-for-the-first-time-type update.

Published way back in 2017 in Molecular Systems Design & Engineering; reportedly one of the most-read Q3 2017 articles to boot. Also my first foray into arxiv territory for those limited in their journal access (arxiv.org/abs/1701.08202).

Tad Hogg*a Matthew S. Moses*b and Damian G. Allis*c

a. Institute for Molecular Manufacturing, Palo Alto, USA
b. Independent Consultant, Lafayette, USA
c. Department of Chemistry, Syracuse University, Syracuse, USA

Abstract: A computationally-efficient method for evaluating friction in molecular rotary bearings is presented. This method estimates drag from fluctuations in molecular dynamics simulations via the fluctuation–dissipation theorem. This is effective even for simulation times short compared to a bearing’s energy damping time and for rotation speeds comparable to or below typical thermal values. We apply this method to two molecular rotary bearings of similar size at 300 K: previously studied nested (9,9)/(14,14) double-walled carbon nanotubes and a hypothetical rotary joint consisting of single acetylenic bonds in a rigid diamondoid housing. The acetylenic joint has a rotational frictional drag coefficient of 2 × 10^-35 kg m2 s^-1. The friction for the nested nanotubes is 120 times larger, comparable to values reported by previous studies. This fluctuation-based method could evaluate dissipation in a variety of molecular systems with similarly rigid and symmetric bearings.

Mol. Syst. Des. Eng., 2017, 2, 235-252 (10.1039/C7ME00021A, direct link)