Happy Me Thread

[Spherical Cow]

Originally Posted by ewmayer

This winter's handiwork project - begun the week after Christmas - was to build a display mount for a large (45kg) iron meteorite I'd bought some years back on eBay, which had been sadly languishing in a 5-gallon industrial-paint-style bucket at back of my bedroom closet ever since.

Wow- Very impressive. Do you have any idea what fall that meteorite came from, or where it was found?

Norm

[ewmayer]

Originally Posted by Spherical Cow

Wow- Very impressive. Do you have any idea what fall that meteorite came from, or where it was found?

Norm

It's a chunk of the well-known Argentinean Campo del Cielo fall - this particular exemplar is apparently part of a more-recently-discovered strewnfield. You can find plenty of chunks of same for sale on the web. If you don't fancy spending lots of time and effort on a fancy mount, a simple hollowed-out block of wood or clear acrylic ring-shaped mount as one can find e.g. on Amazon.com will serve nicely.

[kriesel]

Originally Posted by ewmayer

This winter's handiwork project - begun the week after Christmas - was to build a display mount for a large (45kg) iron meteorite I'd bought some years back on eBay

We really can get just about anything legal on eBay.

Looks nice. Judging by mass and current pricing (of a sampling of the >13,000 meteorite listings!), that's worth more than my car.

[ewmayer]

Originally Posted by kriesel

We really can get just about anything legal on eBay.

Looks nice. Judging by mass and current pricing (of a sampling of the >13,000 meteorite listings!), that's worth more than my car.

My total material costs were under $3000, so you must drive a real beater. :) Seriously, I suggest you focus on the heavier weights and the specific fall in question - the price per unit weight drops when one buys in bulk, as it were. Of course I bought my chunk ~10 years ago and even for then the prices the particular seller was asking seemed like bargains, so it might well cost perhaps 2x more to obtain similar today. Since we're using automotive-based comparative pricing, call it roughly the cost to fix a small fender dent on of a Tesla roadster.

[chalsall]

So, Barbados went to the polls yesterday...

For the last ten years we've been "led" by an utterly incompetent group of fools (the Democratic Labour Party (DLP)) who have driven our economy to the brink of bankruptcy. We only have something like eight weeks of foreign exchange at the moment, and there's been serious discussion of the IMF having to come in, and/or the Bajan dollar being devalued!

At ~0400 this morning is was announced that the Bajan people had spoken, and the Barbados Labour Party (BLP) had won every single one of the 30 constituency seats!

While not having an opposition is not necessarily the best situation to be in (and it's unprecedented in Barbados), the good news is the leader of the "B's", Mia Mottley, is a *very* smart and driven woman, and I have at least a bit of hope she and her government will be able to turn things around.

[kladner]

May your hopes pan out!

[kriesel]

Originally Posted by ewmayer

My total material costs were under $3000, so you must drive a real beater. :) Seriously, I suggest you focus on the heavier weights and the specific fall in question - the price per unit weight drops when one buys in bulk, as it were. Of course I bought my chunk ~10 years ago and even for then the prices the particular seller was asking seemed like bargains, so it might well cost perhaps 2x more to obtain similar today. Since we're using automotive-based comparative pricing, call it roughly the cost to fix a small fender dent on of a Tesla roadster.

Or, comparable to the bids to replace the hybrid battery in my 2006 Insight 2-seater hybrid recently. As far as I know, even though it's been out of production for about 12 years, it's still the highest fuel economy gasoline fueled production car ever. And buckets of fun to drive, and with less than 20,000 ever built, somewhat exclusive. If I ever run out of fuel, it can be pushed with two fingers. Range up to 600+ miles on 10.5 gallons. I tend to buy good vehicles and keep them until the independent repair shop owner doesn't want to see them any more.

Newer does not always mean better. I own a small farm tractor from the late 1940s.
I can leave it sit idle for months and it starts right up. I don't think there's so much as a diode in the whole thing. When the ignition is off, there is no parasitic electrical draw on the battery. It's pretty EMP-proof. There's still a considerable aftermarket for parts for them.

My ebay quick price gauge for your meteorite was probably biased by sorting highest price first. I didn't want to wade through 10,000 inexpensive little nuggets.

Do you know what its composition is, other than iron? When I saw it, I thought of the story (apparently fictional) about Jim Bowie's knife made from a presumably high cobalt ferrous meteorite and thought you could get a LOT of blades out of yours, even if as robustly styled as Bowie's was. http://www.mountainhollow.net/knife-meteorite.php

[ewmayer]

Originally Posted by kriesel

Do you know what its composition is, other than iron? When I saw it, I thought of the story (apparently fictional) about Jim Bowie's knife made from a presumably high cobalt ferrous meteorite and thought you could get a LOT of blades out of yours, even if as robustly styled as Bowie's was. http://www.mountainhollow.net/knife-meteorite.php

According to the Campo del Cielo Wikipage I linked, 92.9% Fe, 6.7% Ni, 0.4% Co, which is apparently more or less typical of iron-nickels, i.e. typical of these near-iron-atomic-number elements in Supernova ejecta, and thus also of the cores of rocky-metallic planets like earth which commonly form from gaseous nebulae enriched by such ejecta. (It's not clear to me whether the >iron-atomic-number elements are produced in the SN explosion itself or before ... Fe is the highest-atomic-number element for which fusion produces net energy, but I see no reason why the fusion of Fe in late-stage massive star cores could not also be accompanied by a small % of energy-absorbing fusion of higher-atomic-number elements.)

[xilman]

Originally Posted by ewmayer

(It's not clear to me whether the >iron-atomic-number elements are produced in the SN explosion itself or before ... Fe is the highest-atomic-number element for which fusion produces net energy, but I see no reason why the fusion of Fe in late-stage massive star cores could not also be accompanied by a small % of energy-absorbing fusion of higher-atomic-number elements.)

The answer is both. The s-process nuclei are made before explosion by soaking up the low concentration of neutrons one at a time and undergoing beta decay. r-process nuclei are made from the torrent of neutrons released by the consequences of core collapse being absorbed many times before the nuclei have time to decay. A few other mechanisms exist but those are the principal ones.

A search on "nucleosynthesis" should turn up more information than you are likely to want to read.

[VictordeHolland]

One source of r-process neucleosynthesis are neutron star mergers according this recently published paper (October 2017):

Light curves of the neutron star merger GW170817/SSS17a: Implications for r-process nucleosynthesis.DOI: 10.1126/science.aaq0049

"we estimate that at least ~0.05 M(solar) of r-process material is generated in this event from the late-time light curve"

[ewmayer]

Thanks, Paul & Victor - Victor, your Science link somehow got fused into a mersenneforum.org-prefixed mash-up which leads nowhere, but I found the article (abstract w/link to paywalled full piece) here.