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Astronomers now coming to the conclusion that our understanding of the universe's expansion is wrong

Leah Crane
New Scientist
Wed, 02 May 2018 00:00 UTC
Light from 87 million stars
© ESA/Gaia/DPAC
Light from 87 million stars shines through dust in our galaxy’s disc
The universe just got even more confusing. Last week, the biggest ever 3D map of our galaxy was released as part of the second batch of data from the European Space Agency's Gaia satellite. The long-awaited measurements revealed the location and brightness of 1.7 billion stars in the Milky Way.

But the first analysis of the data has also crystallised our confusion about the rate of the universe's expansion. We have two ways to determine this rate, expressed in a quantity called the Hubble constant, and they have always come up with different values. Some researchers had hoped that the Gaia data released on 25 April might lessen the divergence, but it has only got worse.

One determination of the Hubble constant comes from the cosmic microwave background (CMB), a relic of the first light in the cosmos after the big bang. Researchers have used the now defunct Planck space observatory to examine this light and figure out how fast the universe was expanding back then. Those values can then be plugged into models of cosmic evolution to predict how fast the universe should be expanding today.

Comment: For some additional theories on the Universe that only reflect our current understanding: Aand on the metaphysical side: Cosmopsychism: Is the universe a conscious mind?

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Archaeology

How a backyard pendulum saw may solve a Bronze Age mystery

Bruce Bower
Science News
Tue, 01 May 2018 18:41 UTC
lions gate Mycenae
© Lulu and Isabelle/Shutterstock
An ancient sculpture known as the Lion Gate relief contains marks in a column (center of image) that may have been made by a pendulum saw. The lions, now headless, stood above the main entrance to the citadel of Mycenae, in what is now Greece.
Researcher's swinging blade offers glimpse into how ancient Mycenaeans built palaces

Nicholas Blackwell and his father went to a hardware store about three years ago seeking parts for a mystery device from the past. They carefully selected wood and other materials to assemble a stonecutting pendulum that, if Blackwell is right, resembles contraptions once used to build majestic Bronze Age palaces.

With no ancient drawings or blueprints of the tool for guidance, the two men relied on their combined knowledge of archaeology and construction.

Blackwell, an archaeologist at Indiana University Bloomington, had the necessary Bronze Age background. His father, George, brought construction cred to the project. Blackwell grew up watching George, a plumber who owned his own business, fix and build stuff around the house. By high school, the younger Blackwell worked summers helping his dad install heating systems and plumbing at construction sites. The menial tasks Nicholas took on, such as measuring and cutting pipes, were not his idea of fun.
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Beaker

Latest epigenetic and 'junk' DNA research shows genes don't hold all the answers


Evolution News
Fri, 04 May 2018 18:36 UTC
Genetics

“It’s probably genetic” seems to be the preferred go-to explanation whenever a doctor or scientist does not know the cause of a chronic disease or condition.
Today, we look at some discoveries that continue to leave the Central Dogma and "junk DNA" in the rear-view mirror. Through the front windshield, we see discoveries about epigenetics coming fast.

New Form of Regulatory DNA

A "mysterious" form of DNA shaped like a four-stranded knot, once thought to exist only in the lab, has been discovered to be active in cell nuclei. Yasemin Saplakoglu reports in Live Science that "many scientists thought that it couldn't possibly exist in human cells," because it loves acidic environment not found naturally in the body. Called an i-motif, the structure has been now reported by Australian scientists in a paper in Nature Chemistry, and the rush is on to see what it does. Saplakoglu thinks "it may play an important role in regulating our genes." Co-author Marcel Dinger sees much more to discover in the forward view:
"There's so much of the genome that we don't understand, probably like 99 percent of it," Dinger said. Seeing DNA folded like this in living cells "makes it possible to decode those parts of the genome and understand what they do." [Emphasis added.]
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Cassiopaea

Hawking's final paper presents a multiverse theory unlike any other

Kristin Houser
Futurism
Wed, 02 May 2018 00:00 UTC
Stephen Hawking
© Anthony Wallace / AFP
Stephen Hawking may have died on March 14, but he's still pushing physics forward.

Today, the peer-reviewed Journal of High Energy Physics (JHEP) published Hawking's final theory on the universe's origin, titled "A Smooth Exit from Eternal Inflation?" The famed physicist wrote the paper in collaboration with Thomas Hertog, a professor at Belgium's Catholic University of Leuven (KU Leuven), and it presents a multiverse theory unlike any other.

Here's a (really) simplified explanation of (one) multiverse theory. The Big Bang happened. The universe expanded. In some places, it kept expanding. In others, it stopped. In the places where it stopped, universes formed - ours, and a potentially infinite number of others.

According to Hertog, Hawking was never a big fan of the multiverse theory, but he knew it was hard to avoid.

Comment: Hawking's Paradox: A brief history of Stephen Hawking and his legacy

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Gem

Physicists find signs of a time crystal - may lead to improvements in atomic clocks, quantum technologies


PhysOrg
Wed, 02 May 2018 00:25 UTC
crystal of monoammonium phosphate time crystal
© Michael Marsland/Yale University
Yale physicists looked for a signature of a discrete time crystal within a crystal of monoammonium phosphate.
Yale physicists have uncovered hints of a time crystal-a form of matter that "ticks" when exposed to an electromagnetic pulse-in the last place they expected: a crystal you might find in a child's toy.

The discovery means there are now new puzzles to solve, in terms of how time crystals form in the first place.

Ordinary crystals such as salt or quartz are examples of three-dimensional, ordered spatial crystals. Their atoms are arranged in a repeating system, something scientists have known for a century.

Time crystals, first identified in 2016, are different. Their atoms spin periodically, first in one direction and then in another, as a pulsating force is used to flip them. That's the "ticking." In addition, the ticking in a time crystal is locked at a particular frequency, even when the pulse flips are imperfect.
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Info

Life created from stem cells

Chris Mahon
Outer Places
Thu, 03 May 2018 23:40 UTC
Life from Stem Cells
© Pixabay
In Henry Greely's book The End of Sex and the Future of Human Reproduction, the professor claims that humans will soon be able to create their own eggs grown from skin cells. Then, based on their genetic makeup, parents can decide which eggs they want to fertilize and develop into children. Well, it turns out the "end of sex" Greely was talking about may be coming sooner than we expected - scientists have created the first synthetic mice embryos using stem cells rather than a sperm and egg, and successfully implanted them into wombs.

The research was meant to investigate the crucial part of pregnancy that happens when an egg develops into a blastocyst: the thin outer sphere of cells that will become the placenta, and a tiny inner sphere of cells that will become the embryo. The scientists found that the stem cells, when properly assembled, will independently organize themselves into an embryo and blastocyst combination (called a blastoid).

According to Nicolas Rivron, one of the authors of the new study: "In a natural embryo, those same stem cells are in three dimensions talking to each other in a language that we barely understand... The embryonic cells were the chatty ones here - they are instructing the placental stem cells to multiply, organise and implant into the uterus."
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Magnify

DNA sequences indicate 250 people made up original Native American founding population

University of Kansas
Phys,org
Wed, 02 May 2018 00:00 UTC
teepee
© University of Kansas
A University of Kansas anthropological geneticist is part of an international research team working to shed light upon one of the unanswered questions concerning the peopling of the New World: Namely, what was the size of the original founding population of the Americas?

Despite numerous genetic studies that have helped contribute to knowledge about how ancient groups populated the Americas, scientists have not reached a consensus about how many Native Americans made up the original population. This analysis of DNA sequences suggests the Native American founding population that migrated from Siberia consisted of approximately 250 people.

The study "How strong was the bottleneck associated to the peopling of the Americas? New insights from multilocus sequence data," published in the journal Genetics and Molecular Biology, includes Michael Crawford, KU professor of anthropology, and the researchers' results corroborate findings of previous studies that were based on smaller datasets.
"Going from a few hundred founders to around 40 million inhabitants of the Americas, who eventually live under different environmental conditions to which they adapt, is pretty exciting stuff," said Crawford, also head of KU's Laboratory of Biological Anthropology. "It's about understanding how evolution operates in terms of genetic diversity."
The researchers examined nine noncoding regions of the DNA samples collected from populations that trace the path of the migration. This included samples of individuals from China, 10 Siberian groups and from 10 Native American populations scattered across Central and South America representing several different tribal affiliations.
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Brain

Scientists believe vasopressin may be possible biomarker for the social deficits in autism

Andy Fell
UC Davis
Wed, 02 May 2018 00:00 UTC
Rhesus macaques
© K. West/CNPRC
Rhesus macaques live in large family groups, but a few animals consistently show less social interaction than others. New research at the California National Primate Research Center at UC Davis and Stanford University shows that these “low social” animals have low levels of the hormone vasopressin in cerebrospinal fluid. A similar result was seen in a small group of children with autism.
One of the characteristics of children with autism spectrum disorder is reduced social ability. It's difficult to study the possible causes of social impairment in children, but a new study shows that rhesus macaques with low sociability also had low levels of the peptide vasopressin in cerebrospinal fluid, as did children with autism spectrum disorder.

The study, by researchers at the California National Primate Research Center at the University of California, Davis, and Stanford University, is published May 2 in the journal Science Translational Medicine.

"At this point, we consider vasopressin concentrations to be a biomarker for low sociability," said John Capitanio, professor of psychology at UC Davis and a research scientist at the CNPRC.

Comment: Vasopressin is the name for a natural endogenous peptide, separate from the exogenous peptide or medication.

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Moon

Last year's solar eclipse set off a wave in the upper atmosphere that was detected as far away as Brazil

Lisa Grossman
Science News
Mon, 30 Apr 2018 16:47 UTC
eclipse
It was the eclipse felt 'round the world. The August 21, 2017, total solar eclipse that crossed the United States launched a wave in the upper atmosphere that was detected nearly an hour later from Brazil (SN Online: 8/11/17).

"The eclipse itself is a local phenomenon, but our study shows that it had effects around the world," says space scientist Brian Harding of the University of Illinois at Urbana-Champaign.

Harding watched the eclipse from St. Louis. But he and his colleagues activated a probe near São João do Cariri, Brazil, to observe uncharged particles 250 kilometers high in a part of the atmosphere called the thermosphere.

The probe recorded a fast-moving wave in the thermosphere go by half an hour after sunset in São João do Cariri and 55 minutes after the end of the total eclipse, the team reported April 24 in Geophysical Research Letters. The wave is produced by the motion of the moon's shadow, which cooled the atmosphere below it. That cold spot then acted like a sink, sucking in the warmer air ahead of it and causing a ripple in the atmosphere as the cold spot moved across the globe.

Comment: Et voila! Non-local effects of cosmic bodies on planetary and human behavior. Turns out the ancients were onto something.

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X

Scientists want to build human cells that are impervious to viruses

George Dvorsky
Gizmodo
Tue, 01 May 2018 16:35 UTC
E. coli
© Agricultural Research Service
E. coli seen through an electron microscope. In 2013, scientists recoded the genome of this bacteria-and now they want to do the same to human cells to prevent infections. Image:
Two years ago, a consortium of scientists, lawyers, and entrepreneurs announced a plan to synthesize an artificial human genome from scratch-an extremely ambitious endeavor that's struggled to secure funding. Project organizers have now disclosed details of a scaled-down version of the venture, but with a goal that's still quite audacious: creating human cells that are invulnerable to infections.

It's called Project Recode, and it's a downsized version of Human Genome Project-Write, or GP-Write. Originally, the leaders of the project, including Harvard geneticist George Church, biotechnology lawyer Nancy Kelley, and NYU Langone Medical Center geneticist Jef Boeke, wanted to synthesize an entire human genome from scratch-a formidable project that would have required an exhaustive and exhausting re-think of the 3 billion DNA base pairs that currently describe the human genome.

But as Nature News reports, GP-Write hasn't been able to secure the $100 million required for the project, prompting the downgrade to Project Recode. Now, instead of re-writing the entire human genome, the geneticists want to make human cells immune to viral infections.

Comment: This consortium think parts of our genome are 'superfluous', similar to those who thought much of our DNA was 'junk', and who have now been proven wrong. Attempting to edit or re-write the genome, to essentially play god, before we even understand it, seems to be quite a perilous endeavor indeed.

Especially when we consider that recent discoveries have shown the symbiotic relationship between human biology and viruses could actually be a significant contributor to life itself, see: Part human, part virus: The body's intimate relationship with viral DNA
scientists have identified numerous cases of viral hitchhikers bestowing crucial benefits to their human hosts -- from protection against disease to shaping important aspects of human evolution, such as the ability to digest starch.


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