Survivorship Bias

Samurai armour.

A chart I made showing the names of the various main components of a suit of “modern samurai armour” or tosei gusoku. Tosei gusoku refers to armour worn by samurai that began to appear during the middle of the Muromachi Period (1337-1573) with the introduction of firearms.

A full suit of tosei gusoku as shown in my chart would have weighed in at around 30 kilograms or so including weapons - there is after all a considerable amount of iron plates and lacing!

Lower class samurai such as foot soldiers (ashigaru) would have carried their own rations, bedding, and other equipment, but their armour was somewhat lighter being generally less ornamented.

At this point in time, known in Japanese history as the Sengoku Period or the Warring States Period, the most common samurai weapon was the spear followed by the bow and arrow. The sword at this point in time was a secondary weapon relied upon during close combat.

The sword carried during this period was the longer, gracefully curved tachi and was worn edge down on the left side supported either by it’s own tachi mounting (tachi koshirae) or by using a special leather “sling” (koshiate) if it was mounted without hangers (ashi).

Another shorter sword called a chisagatana - literally “little sword” - was carried together with the tachi at the left hip up until the Momoyama period (1573-1603) when it was abandoned. The chisagatana was originally a throw away weapon reserved for use by conscript foot soldiers (ashigaru), but higher ranking samurai soon took up the carrying of one as a back up weapon. 

Higher ranked samurai, those in charge of troops and generals in particular, also carried a short stout blade called a metezashi at the right hip, with the handle facing forwards. This weapon was designed for extreme close combat and used to penetrate the weak spots in an opponents armour. When swords were crossed, the metezashi could be drawn with the left hand and thrust into the opponent’s armpits. It could also be drawn with the right hand and thrown underarm in an instant to distract and stun an opponent before following up with the sword.

© James Kemlo

Farming amoebae carry around detoxifying food

Five years ago, the Queller-Strassmann lab at Rice University, now at Washington University in St. Louis, demonstrated that the social amoeba Dictyostelium discoideum – affectionately nicknamed “Dicty” – can maintain a crop of food bacteria from generation to generation, giving these farmers an advantage when food is scarce.

Now, new research from the same team shows that these microscopic farmers also rely on their symbiotic bacteria to protect themselves from environmental toxins, a little-studied but increasingly clear role microbes can play for their hosts.

Research scientist Debra Brock led the new work, published April 20 in the Proceedings of the Royal Society B.

These amoebae are content to be loners when food is abundant, but when it’s depleted they come together in the tens of thousands to cooperate. They transform into a mobile slug that migrates in search of fairer conditions and then produces hardy spores to release into the environment and wait out the lean times.

The slug has a tiny pool of specialized cells, called sentinels, that protect it from pests and poisons by ferrying them away.

“The sentinel cells pass through the body, mopping up toxins, bacteria, and essentially serving as a liver, a kidney, and innate immune system and being left behind in the slime trail,” said Joan Strassmann, PhD, the Charles Rebstock Professor of Biology in Arts & Sciences.

Debra A. Brock, W. Éamon Callison, Joan E. Strassmann, David C. Queller. Sentinel cells, symbiotic bacteria and toxin resistance in the social amoebaDictyostelium discoideum. Proceedings of the Royal Society B: Biological Sciences, 2016; 283 (1829): 20152727 DOI: 10.1098/rspb.2015.2727

The social amoeba Dictyostelium discoideum has both solitary and communal life stages. As long as food is abundant, it lives on its own, but when food is scarce the amoebae seek one another out. Together they form a slug that migrates toward the light and then a fruiting body that disperses spores from atop a stalk. The fruiting bodies are pictured here. Credit: Strassmann/Queller lab

Solar System: Things to Know This Week

Add to your electronic bookshelf with these free e-books from NASA!

1. The Saturn System Through the Eyes of Cassini

This work features 100 images highlighting Cassini’s 13-year tour at the ringed giant.

2. Earth as Art 

Explore our beautiful home world as seen from space.

3. Meatballs and more 

Emblems of Exploration showcases the rich history of space and aeronautic logos.

4. Ready for Our Close Up

Hubble Focus: Our Amazing Solar System showcases the wonders of our galactic neighborhood.

5. NASA’s First A 

This book dives into the role aeronautics plays in our mission of engineering and exploration.

6. See More 

Making the Invisible Visible outlines the rich history of infrared astronomy.

7. Ready for a Deeper Dive? 

The NASA Systems Engineering Handbook describes how we get the job done.

8. Spoiler Alert

The space race really heats up in the third volume of famed Russian spacecraft designer Boris Chertok memoirs. Chertok, who worked under the legendary Sergey Korolev, continues his fascinating narrative on the early history of the Soviet space program, from 1961 to 1967 in Rockets and People III.

9. Take a Walk on the Wild Side

The second volume of Walking to Olympus explores the 21st century evolution of spacewalks.

10. No Library Card Needed 

Find your own great read in NASA’s free e-book library.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

On this day, 13th February 1743, Sir Joseph Banks was born.

Sir Joseph Banks was a British botanist and naturalist who sailed with Captain James Cook on the Endeavour voyage of 1770.

Joseph Banks was born on 13 February 1743 in London. His passion for botany began at school. From 1760 to 1763 he studied at Oxford University, during which time he inherited a considerable fortune. In 1766, Banks travelled to Newfoundland and Labrador, collecting plant and other specimens. The same year he was elected a fellow of the Royal Society.

In 1768, he joined the Society’s expedition, led by Captain James Cook, to explore the uncharted lands of the South Pacific. The expedition circumnavigated the globe and visited South America, Tahiti, New Zealand, Australia and Java. Banks collected an enormous number of specimens on the way and, on his return, his scientific account of the voyage and its discoveries sparked considerable interest across Europe.

The journal kept by the then 25-year-old Joseph Banks on board HMS Endeavour is one of the State Library’s most significant manuscripts. It records the first Pacific voyage of Captain James Cook from 1768 to 1771. Following the Endeavour’s return to England in 1771, Banks was hailed as a hero. 

The State Library’s Sir Joseph Banks collection includes correspondence, reports, invoices, accounts, maps and watercolour drawings which document the far reaching influence of Banks on the colony. This significant archive containing over 7,000 pages has recently been digitised and now needs to be transcribed. Once fully transcribed the archive will be keyword searchable which will enhance discovery and access to the collection and increase the research potential in this significant archive.  

Find out more about how to transcribe the Banks Papers

Harmonograph, H. Irwine Whitty, 1893

“The facts that musical notes are due to regular air-pulses, and that the pitch of the note depends on the frequency with which these pulses succeed each other, are too well known to require any extended notice. But although these phenomena and their laws have been known for a very long time, Chladni, late in the last century, was the first who discovered that there was a connection between sound and form.”

source here

Since 2009, Ada Lovelace Day has aimed “to raise the profile of women in science, technology, engineering and maths by encouraging people around the world to talk about the women whose work they admire.”  The day’s namesake, Ada Lovelace (1815-1852), was the daughter of Lord Byron and Anne Isabella Milbanke.  Ada, in possession of a keen intellect and deep passion for machinery, was educated in mathematics at the insistence of her mother. Later in life, Ada studied the workings of the Analytical Engine developed by mathematician and inventor Charles Babbage. In her notes on the engine, Ada described an algorithm for computing numbers – an algorithm which would distinguish Ada as one of the world’s “first computer programmers.”  

In honor of Ada Lovelace Day, we present some images from the CHF Archives of women working in various chemistry labs. Click on each photo for additional information.

And for more women in science content, consider taking a look at the films in The Catalyst Series: Women in Chemistry by the Chemical Heritage Foundation.

On March 2, 1903 the Hotel Martha Washington became New York City’s first women-only hotel. Located on 30 East 30th Street, it served the growing population of professional women who otherwise struggled to find safe and socially acceptable lodging in the city. A far cry from the crowded boarding houses, this was a thoroughly modern operation housed in a twelve-story Renaissance Revival building that featured all the amenities, from a ladies’ tailor to electric lights. Upon opening, it was immediately popular, both with the women it served and with the curious onlookers who had a hard time coming to terms with the whole idea of the place.

George P. Hall & Son. Manhattan: Hotel Martha Washington. undated. photographic print. New-York Historical Society.  

Robert L. Bracklow. The Hotel Martha Washington. February 23, 1903. Glass negative. New-York Historical Society.

E H Shepard illustration from Now we are six by A A Milne 

NASA’s new searchable media library is a treasure trove of space pics and video

Do you like space? Do you like looking at it, wishing you were there instead of here, perhaps? Well NASA just did something that will make your day. The U.S...

The U.S. space agency launched a new web-based search engine for much of its catalog of images, video and audio files, which you can browse by keyword and metadata, so that you never have to remember the dismal reality that you’re earthbound ever again.