Mordecai and Esther are still here, and looking fat, healthy and happy. I thought I’d show a few photos today in lieu of Readers’ Wildlife, and add a couple of videos. (I tried to get a photo of Esther quackling loudly, which she’s wont to do, but she didn’t perform yesterday, when I took all these photos and videos.)
First a photo of the ducks. Here’s Mordecai. Isn’t he handsome?
Here he is getting out of the pond after a bracing swim (It was chilly yesterday). Esther swims nearby (the camera was a bit wonky), about to follow him:
The lovely Queen Esther:
Here’s the pair on their favorite spot: the warm cement ledge on the east side of the Pond, where they rest and dry off in the afternoons. Esther has a quick drink, and they sun themselves and preen.
Mordecai looking around. I love his iridescent head.
The difference in appearance between males (drakes) and females (hens) is surely due to sexual selection. The females are well camouflaged in the grass, while males sacrifice some of that camouflage to attract females. We have no idea why females prefer yellow beaks and metallic green heads; the reason why females in different species prefer different traits is largely a mystery. (Of course there are some sex differences in traits, like antlers in elk and body size used for fighting in elephant seals, that are well understood; males win females–and offspring–by winning contests. Darwin called this the “law of battle.”)
Here they are both out of the water. Towards the end of this short video Mordecai engages in some stretching, which we call “duck yoga”. He also scratches his chin, though ducks don’t have chins.
Esther and Mordecai together on the edge. They’re both oiling their feathers. Mallards have an oil gland at the base of their tail, and they repeatedly dip their beaks in it and then spread the oil on their feathers to waterproof them. Hence the expression, “Like water off a duck’s back.” If you’ve ever seen a duck in the rain, you’ll see that the water just beads up and runs off their oily bodies.
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The post A Review of “In Covid’s Wake”: According to Laptop Class Professors, the Heroes of the Pandemic Were Laptop Class Professors first appeared on Science-Based Medicine.When it comes to safe places for life, supermassive black holes are probably the last place you'd consider safe for nearby planets, let alone life-bearing ones. There are good reasons for this: those monsters at the hearts of galaxies suck down everything that comes into contact with them. When they do that, they blast out killer radiation. Neither activity is necessarily good for life. Or is it? As it turns out, radiation from these active galactic nuclei (AGN) can nurture life under the right circumstances.
Scientists have detected a fascinating spiral galaxy located about one billion light-years away. At the heart of this cosmic goliath, powerful radio jets are blasting out of its centre, stretching six million light years into space. A team of researchers have suggested that a smaller dwarf galaxy plunged into its centre, passing close to its supermassive black hole triggering immense flares, intense radiation and driving the colossal radio jets. Surprisingly however, despite the tremendous amounts of energy, the galaxy has kept its spiral structure.
China’s Chang’e-6 mission has been exploring the largest crater on the Moon. It’s known as Aitken Basin and is found at the South Pole of the Moon where craters are permanently shadowed. The crater is a whopping 2,500 km across and measures 10km deep and Chang’e-6 data has revealed that a giant asteroid smashed into the Moon about 4.25 billion years ago.
We've learned that Interstellar Objects (ISOs) are not strangers to our Solar System. Many have visited, and many more will in the future. The Vera Rubin Observatory is expected to find hundreds each year. Scientists are keen to learn more about them, and a swarm of spacecraft on standby might be the way to do it.
Telescope optics can be made of mirrors or lenses, but in both cases, they're bulky and need to follow a strict mathematical curve to focus light. Researchers have shown that it's possible to make a completely flat lens that focuses light. Traditionally, this has been done with Fresnel lenses, but they distort colors. Their new technique carves tiny concentric rings into a substrate that matches the wavelengths of different colors, allowing a full-color, in-focus image.