c0nc0rdance

The destruction of protected wildlife sanctuaries in Texas for border wall construction continues long after the slogan was forgotten. Here's what will be lost: 'Green Jay (Cyanocorax luxuosus) on a Collared Peccary (Pecari tajacu)' (📷: Steve Hillebrand, USFWS)

The dense subtropical thorn forest is right along the migratory routes for thousands of rare bird species. It was the best hope for a restoration of native ocelot and jaguarundis. The wall would kill the ability of the area to be a wildlife corridor, effectively blocking animal movement.

The destruction of protected wildlife sanctuaries in Texas for border wall construction continues long after the slogan was forgotten. Here's what will be lost: 'Green Jay (Cyanocorax luxuosus) on a Collared Peccary (Pecari tajacu)' (📷: Steve Hillebrand, USFWS)

This is such a fantastic photo: "The Witches' Tea Party" but I want to use it to explain the origin of the tall, pointy witches hat. The real story of this photo: These are residents at the Hospital of the Holy & Undivided Trinity: an almshouse in Castle Rising, Norfolk, England established 1610.

Out of religious modesty, women wore the "pilgrim hats" properly 'capotains' (which never had buckles), some of which were flat-topped, other sugarloaf. I guess we can't rule out pointy versions, but it's probably a historical misunderstanding. "Witches" were just well-dressed older women.

This is such a fantastic photo: "The Witches' Tea Party" but I want to use it to explain the origin of the tall, pointy witches hat. The real story of this photo: These are residents at the Hospital of the Holy & Undivided Trinity: an almshouse in Castle Rising, Norfolk, England established 1610.

If you don't get "sugarloaf": replaced by granular or cubed sugar, sugar was previously sold as a round-top cone. This is still available in a few countries, including Germany, where a rum-soaked flaming 'Zuckerhut' melts & drips into mulled wine to make holiday 'Feuerzangenbowle'.

This is such a fantastic photo: "The Witches' Tea Party" but I want to use it to explain the origin of the tall, pointy witches hat. The real story of this photo: These are residents at the Hospital of the Holy & Undivided Trinity: an almshouse in Castle Rising, Norfolk, England established 1610.

No-one know who found the 4th century Roman "Lycurgus Cup" or where. For 100 years, it was held by the Rothschild family. In 1958, it was sold to the British Museum. What's clear: it contains nanocrystalline gold & silver that makes it change color depending on the light source.

We've been making dichroic optics since the 1930's, for scientific instruments or protective visors, but always via depositing thin layers of metal on top of glass, not IN it in bulk. Attempts are underway to replicate this effect with a modern understanding of metal nanoparticles.

No-one know who found the 4th century Roman "Lycurgus Cup" or where. For 100 years, it was held by the Rothschild family. In 1958, it was sold to the British Museum. What's clear: it contains nanocrystalline gold & silver that makes it change color depending on the light source.

Two theories: Accidental - this is one of the only surviving pieces with this distinctive optical property, so it could have been a pure serendipity. Expertise - empirical observation showed glassworkers that tiny amounts of silver & gold leaf change the optical properties of glass.

No-one know who found the 4th century Roman "Lycurgus Cup" or where. For 100 years, it was held by the Rothschild family. In 1958, it was sold to the British Museum. What's clear: it contains nanocrystalline gold & silver that makes it change color depending on the light source.

This "magic trick" is a type of 'dichroism', meaning "two-color". If light is behind the viewer, you see REFLECTED light scattered by the nanocrystals, looking jade-green. If light is inside the cup or TRANSMITTED through the glass, the blue/green wavelengths are ABSORBED, leaving only red light.

Timothy the Hippo (Hippopotamus amphibius) at the San Antonio Zoo demonstrates why he's not in the petting area using a Fall pumpkin. 🦛🎃 The bite force of a hippo is ~2000 psi, producing a force of 8100 Newtons. So why does a GRASS-EATER have jaws stronger than a polar bear, jaguar or lion's?

... where a single bull hippo establishes dominance over all other males, solo breeding access to females. A behavior called "yawning" ain't about being sleepy, it's about baring those weapons to any males who might be getting ideas above their station. It's a threat.

Timothy the Hippo (Hippopotamus amphibius) at the San Antonio Zoo demonstrates why he's not in the petting area using a Fall pumpkin. 🦛🎃 The bite force of a hippo is ~2000 psi, producing a force of 8100 Newtons. So why does a GRASS-EATER have jaws stronger than a polar bear, jaguar or lion's?

The hippo lives in & amongst some very ferocious predators, including Nile crocodiles, lions & hyena packs. But predation rates are exceptionally low: only calves are generally at risk from existing predators. A hippo tooth/tusk can easily penetrate the thick, bony armor of a Nile crocodile.

Timothy the Hippo (Hippopotamus amphibius) at the San Antonio Zoo demonstrates why he's not in the petting area using a Fall pumpkin. 🦛🎃 The bite force of a hippo is ~2000 psi, producing a force of 8100 Newtons. So why does a GRASS-EATER have jaws stronger than a polar bear, jaguar or lion's?

Daisy Gilardini captured this footage for NatGeo of a Weddell seal (Leptonychotes weddellii) napping & demonstrating the impressive range of vocalizations. But I want to talk about the sounds you CAN'T hear these enormous sea-puppies make! (📷: Daisy Gilardini for Nat Geo)

... and we're relatively certain they're doing the usual things: communicating socially, moms & babies checking in on each other, territorial marking and challenges, etc. The use of higher sound frequencies might limit range even above water, making messages a little more personal.

Daisy Gilardini captured this footage for NatGeo of a Weddell seal (Leptonychotes weddellii) napping & demonstrating the impressive range of vocalizations. But I want to talk about the sounds you CAN'T hear these enormous sea-puppies make! (📷: Daisy Gilardini for Nat Geo)

~17% of vocalizations are in the ultrasonic range, but not for echolocation, so far as we can tell. Instead, the seals may be taking advantage of the rapid dissipation of ultrasonic sound. It doesn't travel far, so can't be intercepted by distant predators & give you away. They're WHISPERING.

Daisy Gilardini captured this footage for NatGeo of a Weddell seal (Leptonychotes weddellii) napping & demonstrating the impressive range of vocalizations. But I want to talk about the sounds you CAN'T hear these enormous sea-puppies make! (📷: Daisy Gilardini for Nat Geo)