Science & TechnologyS


Chalkboard

When light flashes for a quintillionth of a second, things get strange

Rahul Rao
Popular Science
Tue, 09 Nov 2021 16:34 UTC
ultra short light pulses ultrashort
© Moritz B. Heindl via University of BayreuthReal-time spectroscopy reveals the spectra of ultrashort light pulses.
The bulb on an old-style film projector flashes some 24 times a second; a typical CRT television screen changes frame 50 or 60 times every second. The fastest cameras in the world can snap frames lasting just a trillionth of a second — short enough to watch light itself slowly creep across a surface.

That may be fast, but it's still nothing next to the lasers some physicists get to play with. Welcome to the world of ultrashort light pulses: little blips of a light wave, lasting as little as a quadrillionth of a second after they leave the laser that makes them.

At those timescales, strange things start to happen. For instance, pulses often pop out in pairs, one after the other. Now, physicists at the Universities of Bayreuth and Konstanz in Germany have found they can control the pacing of those duos. They published their work on October 19 in the journal Optica.
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Blue Planet

Oldest case of rare genetic condition discovered in 1,000 year-old skeleton from Portugal

Australian National University
Phys.org
Fri, 26 Aug 2022 10:54 UTC
skull
© The Lancet
A group of international researchers has uncovered evidence of a super rare genetic condition that gives men an extra X chromosome, reporting the oldest clinical case of Klinefelter syndrome to date.

The evidence comes from a 1,000-year-old skeleton from Portugal.

Klinefelter syndrome is a rare genetic condition where individuals are born with an extra copy of the X chromosome, occurring in approximately one in 1,000 genetic-male births.

The study coordinated by Dr. João Teixeira, an ARC DECRA Fellow at The Australian National University (ANU), brought together a multidisciplinary team that combined genetic, statistical, archaeological and anthropological information to establish a definitive diagnosis.

Comment: More on Klinefelter syndrome from wiki:
The primary features are infertility and small, poorly functioning testicles.[3][9] Usually, symptoms are subtle and subjects do not realize they are affected.[1] Sometimes, symptoms are more evident and may include weaker muscles, greater height, poor motor coordination, less body hair, breast growth, and less interest in sex.[1] Often, these symptoms are noticed only at puberty.[5] Intelligence is usually normal, but reading difficulties and problems with speech are more common.[1]
See also:

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Microscope 2

Study: Look-Alike Humans Have Similar DNA


Sci News
Tue, 23 Aug 2022 06:54 UTC
Look-alike humans share similar genotypes and differ in their DNA methylation and microbiome landscape
© Joshi et al., doi: 10.1016/j.celrep.2022.111257.Look-alike humans share similar genotypes and differ in their DNA methylation and microbiome landscape.
New research led by Josep Carreras Leukaemia Research Institute scientists shows that people with extreme look-alike faces share common genotypes, but differ in their DNA methylation and microbiome landscapes.
"For decades, the existence of individuals who resemble each other without having any family ties has been described as a proven fact, but only in anecdotal terms and without any scientific justification," said senior author Dr. Manel Esteller, a researcher at the Josep Carreras Leukaemia Research Institute.

"The widespread use of the Internet and social networks for image-sharing has meant that we are now able to identify and study such people."
In their study, Dr. Esteller and his colleagues set out to characterize a set of look-alike humans on a molecular level.

To do so, they recruited human doubles from the photographic work of François Brunelle, a Canadian artist who has been obtaining worldwide pictures of look-alikes since 1999. They obtained headshot pictures of 32 look-alike pairs.

Comment: See also:

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Arrow Down

Lab-made mouse embryos grew brains and beating hearts, just like the real thing

Nicoletta Lanese
Live Science
Thu, 25 Aug 2022 22:11 UTC
The embryos survived for 8.5 days.
Mouse Embryos
© Amadei and HandfordScientists made synthetic mouse embryos (left) that closely resemble natural embryos (right) during the early days of development.
Scientists coaxed mouse stem cells to grow into synthetic embryos that began developing hearts and brains, just like the real thing.

The lab-made embryos, crafted without any eggs or sperm and incubated in a device that resembles a fast-spinning Ferris wheel full of tiny glass vials, survived for 8.5 days. That's nearly half the length of a typical mouse pregnancy. In that time, a yolk sac developed around the embryos to supply nutrition, and the embryos themselves developed digestive tracts; neural tubes, or the beginnings of the central nervous system; beating hearts; and brains with well-defined subsections, including the forebrain and midbrain, the scientists reported in a study published Thursday (Aug. 25) in the journal Nature.

"This has been the dream of our community for years and [a] major focus of our work for a decade, and finally, we've done it," senior study author Magdalena Zernicka-Goetz, a developmental and stem-cell biologist with labs at the University of Cambridge, UK, and the California Institute of Technology in Pasadena, said in a statement.

Although the two recent studies produced similar embryos, the experiments started out slightly differently. In the Cell study, the researchers started by coaxing mouse stem cells into a naive state from which they could morph into any cell type, such as heart, brain or gut cells. From there, the team divided these naive cells into three groups. In one group, they switched on genes to form the placenta, and in another group, they switched on genes to make the yolk sac. The last group they left alone to develop into embryos.
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Blue Planet

The greatest migration on Earth happens under darkness every day

Katherine Harmon Courage
Scientific American
Thu, 25 Aug 2022 17:09 UTC
plankton
© tonaquatic/Getty ImagesTRILLIONS OF ZOOPLANKTON migrate every night from the ocean's depths up to the surface and back. Each species has its own rhythm, which can vary based on age, season and sex.
Every evening around the world trillions of zooplankton, many smaller than a grain of rice, hover hundreds of feet below the surface of the sea, waiting for their signal. Scientists long considered these tiny animals to be drifters, passive specks suspended in the ocean, moved by the whims of tides and currents. And yet, just before the sun disappears, the swarms begin to rise on a clandestine journey to the surface.

As they climb, clusters of other zooplankton join in: copepods, salps, krill and fish larvae. The multitudes remain near the surface at night, but just as the first beams of morning light begin to cascade across the sea, they are already turning back down to the deep. As sunset and sunrise slide from east to west every 24 hours — across the Pacific Ocean, then the Indian, the Southern and the Atlantic — swarm after swarm make the same upward journey, retreating as daylight returns.
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Cassiopaea

NASA's stunning new images of Jupiter show planet in unprecedented detail, including auroras and haze

Elizabeth Landau
NASA
Wed, 24 Aug 2022 11:33 UTC
jupiter webb
© NASA, ESA, CSA, Jupiter ERS Team; image processing by Judy Schmidt.Webb's Jupiter Images Showcase Auroras, Hazes Webb NIRCam composite image of Jupiter from three filters - F360M (red), F212N (yellow-green), and F150W2 (cyan) - and alignment due to the planet's rotation.
With giant storms, powerful winds, auroras, and extreme temperature and pressure conditions, Jupiter has a lot going on. Now, NASA's James Webb Space Telescope has captured new images of the planet. Webb's Jupiter observations will give scientists even more clues to Jupiter's inner life.

"We hadn't really expected it to be this good, to be honest," said planetary astronomer Imke de Pater, professor emerita of the University of California, Berkeley. De Pater led the observations of Jupiter with Thierry Fouchet, a professor at the Paris Observatory, as part of an international collaboration for Webb's Early Release Science program. Webb itself is an international mission led by NASA with its partners ESA (European Space Agency) and CSA (Canadian Space Agency). "It's really remarkable that we can see details on Jupiter together with its rings, tiny satellites, and even galaxies in one image," she said.

Comment: To see these images in greater detail, go to this link.

See also: New report shows micro-meteor impacts have left 'uncorrectable' damage to the Webb telescope's mirror

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Galaxy

Eavesdropping on a black hole: New NASA sonifications with a remix

Lee Mohon
NASA
Wed, 04 May 2022 17:25 UTC
perseus galaxy cluster
The Perseus Cluster is 250 million light years away
Since 2003, the black hole at the center of the Perseus galaxy cluster has been associated with sound. This is because astronomers discovered that pressure waves sent out by the black hole caused ripples in the cluster's hot gas that could be translated into a note - one that humans cannot hear some 57 octaves below middle C. Now a new sonification brings more notes to this black hole sound machine. This new sonification - that is, the translation of astronomical data into sound - is being released for NASA's Black Hole Week this year.

In some ways, this sonification is unlike any other done before(1, 2, 3, 4) because it revisits the actual sound waves discovered in data from NASA's Chandra X-ray Observatory. The popular misconception that there is no sound in space originates with the fact that most of space is essentially a vacuum, providing no medium for sound waves to propagate through. A galaxy cluster, on the other hand, has copious amounts of gas that envelop the hundreds or even thousands of galaxies within it, providing a medium for the sound waves to travel.
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Magic Wand

Navy dolphin's GoPro cameras reveal their weird and wonderful world in a way never seen before

Maddie Bender
Daily Beast
Wed, 17 Aug 2022 15:31 UTC
Dolphin navy
© Ridgway et al.They wanted to learn about how dolphins hunt and feed. They got way more than they bargained for.
At the risk of awarding the title prematurely, we think we've found the weirdest study published in 2022. Scientists strapped GoPro cameras to the bodies of six dolphins trained by the U.S. Navy, and recorded them hunting for food and consuming their prey in grisly detail. According to the study, there was a purpose behind this potential invasion of dolphin privacy; namely, to learn more about how the mammals hunted and ate.

Scientists have previously made two competing assumptions about how dolphins ate. They engaged in either ram feeding, in which the predators swim faster than their prey and clasp the fish in their jaws as they overtake them; or suction feeding, in which predators move their tongues and expand their throats to create negative pressure and slurp up prey. The authors of the study, which was published on Wednesday in the journal PLoS ONE, set out to determine which method dolphins actually used.
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Beaker

Carbon dioxide is not a 'well-mixed gas', can't cause global warming

John O'Sullivan
CO2 Insanity
Sun, 21 Aug 2022 21:22 UTC
carbon dioxide molecule
One of the least challenged claims of global warming science is that carbon dioxide in the atmosphere is a "well-mixed gas." A new scientific analysis not only debunks this assertion but also shows that standard climatology calculations, applicable only to temperature changes of the minor gas, carbon dioxide were fraudulently applied to the entire atmosphere to inflate alleged global temperature rises.

Acceptance of the "well-mixed gas" concept is a key requirement for those who choose to believe in the so-called greenhouse gas effect. A rising group of skeptic scientists have put the "well-mixed gas" hypothesis under the microscope and shown it contradicts not only satellite data by also measurements obtained in standard laboratory experiments.

Canadian climate scientist, Dr Tim Ball is a veteran critic of the "junk science " of the International Panel on Climate Change (IPCC) and no stranger to controversy.

Ball is prominent among the "Slayers" group of skeptics and has been forthright in denouncing the IPCC claims; "I think a major false assumption is that CO2 is evenly distributed regardless of its function."
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Fire

Sorry, climate change hysterics. There are fewer wildfires today than in the 1930s

Chris Morrison
The Daily Sceptic
Sat, 20 Aug 2022 06:58 UTC
Rim Fire
© US Forest ServiceThe Rim Fire Stanislaus National Forest, California 2013
Last Wednesday, Matt McGrath reported on the BBC that the amount of tree cover being burned has nearly doubled over the past 20 years. Of the 9.3 million hectares burnt globally, Russia was alleged to account for more than a half. Of course, climate change was said to be a "key factor" in the increase. There is no factual basis for this claim, needless to say. Take the word of Greenpeace, which recently reported Russian government statistics that showed "nine out of ten wildfires in the country were caused by humans".

McGrath, of course, was complying with the Corporation's strictly-enforced agenda that says that almost every natural disaster and episode of extreme weather should be blamed on humans burning fossil fuel. The ultimate political agenda is the command-and-control Net Zero fantasy. Climate change was said to be the key factor by McGrath because it leads to higher temperatures and drier conditions. Except, it might be added, when global temperatures pause, as they have throughout most of the 21st century, droughts turn into floods, etc., etc.

The data on tree loss comes from Global Forest Watch (GFW), which uses information taken from orbiting satellites. Last year was said to be the second worst year on record. "It's roughly twice what it was just 20 years ago. It is kind of astonishing just how much fire activity has increased over such a short amount of time," said James MacCarthy, an analyst with GFW.

The data used by GFW is taken from a number of Landstat satellites and processed by the Global Land Analysis and Discovery (GLAD) laboratory at the University of Maryland. But the GLAD data comes with a number of important warnings and caveats. The first satellites used in the 20-year record provided less data and there are gaps in the record. There was improved performance from 2012, but GLAD warned that "such changes in the mapping method can result in year-to-year inconsistencies". Additionally, "models have been iterated to improve performance in the 2012-forward period". Care must be taken when comparing change across any interval, it cautioned.
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