Science News Thread (for articles that don't relate to ongoing discussions)

[kerbiloid]

How many produced cells is required to produce this cell?

[AckSed]

8 hours ago, kerbiloid said:

How many produced cells is required to produce this cell?

Kilowatts-to-megawatts-worth. It'll probably need to be bootstrapped with commercial panels brought from earth.

Further, it doesn't give the output. However, if we take them at their word that they're making 99.999% pure silicon, and assume from that the processes are producing monocrystalline silicon, then at a guess this cell's efficiency could range anywhere from 13% to 22-23%.[1] I'm deducting a percentage point for the use of aluminium wiring, even if I think that's one of the cooler things about this.

A lot of commercial modules use conductive silver paste to join the individual cells to the panel, which makes it trickier to recycle.[2] Using aluminium means you can just crush these up and toss them back into the electrolyser.
 

Edit: I was going to make the calcs but it's too early. Just pull the solar irradiance of the moon, the area of a typical commercial 3kW solar panel array (18-20 m2), the number of cells in a panel (60-72) and have fun.

[1] Monocrystalline solar efficiencies taken from NREL.

[2] PV Magazine, "Novel tech to recycle silver, aluminum from end-of-life solar panels"

Edited February 14, 2023 by AckSed

[DDE]

Intergenerational inheritance of DNA methylation, which is a vehicle for epigenetic mutation, in mice; includes at least one case of the artificially induced methylation resurfacing in grand-children

https://www.cell.com/cell/fulltext/S0092-8674(22)01630-0?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867422016300%3Fshowall%3Dtrue

Mechanism and implications uncertain, given how the methylation was induced by gene-solicing and unsplicing, but they've been able to make all offspring overweight without a detectable permanent alterations to the genes themselves.

[Beamer]

Extraordinary claims and all that, but it will definitely be interesting to see where this goes. Solving a couple of problems at once, old supermassive black holes are 7-20 bigger than they should (could) be, and this might explain where all that dark energy is hiding: https://phys.org/news/2023-02-scientists-evidence-black-holes-source.html

Quote

Study first author Duncan Farrah, University of Hawai'i Astronomer and former Imperial Ph.D. student, said, "We're really saying two things at once: that there's evidence the typical black hole solutions don't work for you on a long, long timescale, and we have the first proposed astrophysical source for dark energy."

"What that means, though, is not that other people haven't proposed sources for dark energy, but this is the first observational paper where we're not adding anything new to the universe as a source for dark energy: black holes in Einstein's theory of gravity are the dark energy."

 

[steve9728]

 

 

[Beamer]

Yesterday while watching some YT videos I saw one in my suggestions that was titled something like "Piece of the sun breaks off, scientists baffled!", with a suitably explosive thumbnail and sensationalist typeface. It got a chuckle and a shake of the head and I think I might even have mumbled "Must have been the aliens" to myself before I clicked on to more reputable sources. But apparently, at least something did actually happen in this case (so it can't have been the aliens!). No, it wasn't a piece of the sun breaking off (surprise!). https://www.cbc.ca/news/science/part-of-sun-did-not-break-off-1.6749333

Quote

It all started with a harmless, informative tweet.

And doesn't it always...

 

Edited February 19, 2023 by Beamer

[JoeSchmuckatelli]

Saw that yesterday, too.  Had the same series of reactions! 

[JoeSchmuckatelli]

“It’s rare nowadays to have fundamental discoveries in science,” said lead study author Baptiste Journaux, an acting assistant professor of Earth and space sciences at the University of Washington... 

...now we have these planetary objects that probably have compounds that are very familiar to us, but in very exotic conditions. We have to redo all the fundamental mineralogical science that people did in the 1800s, but at high pressure and low temperature. It is an exciting time.”

 

Water and salts create a hydrate, a rigid icy lattice supported by hydrogen bonds, in cold temperatures...

After the study experiment, the researchers discovered two new hydrates — one utilizing two salt molecules for every 17 water molecules, and another with one salt molecule for every 13 molecule.

... 

Understanding the chemistry present on ocean worlds like Europa will allow scientists to better understand the data collected by missions like JUICE and Europa Clipper in the future.

“These are the only planetary bodies, other than Earth, where liquid water is stable at geological timescales, which is crucial for the emergence and development of life,” Journaux said.

“They are, in my opinion, the best place in our solar system to discover extraterrestrial life, so we need to study their exotic oceans and interiors to better understand how they formed, evolved and can retain liquid water in cold regions of the solar system, so far away from the sun.”

https://www.cnn.com/2023/02/20/world/salty-ice-europa-ocean-moons-scn/index.html

(emphasis added) 

 

[JoeSchmuckatelli]

https://www.science.org/content/article/dark-energy-supermassive-black-holes-physicists-spar-over-radical-idea

 

Some of you may have read about a recent paper suggesting dark energy comes from black holes.

It's a little difficult to grasp, but I guess the gist is that they looked at a bunch of old elliptical galaxies and presumed the sizes of their resident SMBH's and that they're too big to have grown by mergers or accretion... then presumed that because the universe is expanding that the only explanation is that they're coupled to the expansion and thus a, if not the, source of DE.

Not everyone is convinced 

[Beamer]

A clever new way to detect a potential Planet 9: https://phys.org/news/2023-02-planet-unconventional-approach.html

Quote

While looking for moons around a planet that hasn't been found might initially sound like a more difficult task than finding the planet itself, Chan illustrates that if Planet 9 has satellite objects, those objects would have fluctuating heat signatures as they orbit due to the process of tidal heating. These heat signatures would be 2.5 times higher than the expected range for Planet 9 itself, and would also be much higher than any known Kuiper belt objects. Signatures in this range should be detectable by the Atacama Large Millimeter/submillimeter Array Observatory (ALMA), which has recently undergone a capability upgrade.

 

[Beamer]

On 2/22/2023 at 2:01 AM, JoeSchmuckatelli said:

https://www.science.org/content/article/dark-energy-supermassive-black-holes-physicists-spar-over-radical-idea

 

Some of you may have read about a recent paper suggesting dark energy comes from black holes.

It's a little difficult to grasp, but I guess the gist is that they looked at a bunch of old elliptical galaxies and presumed the sizes of their resident SMBH's and that they're too big to have grown by mergers or accretion... then presumed that because the universe is expanding that the only explanation is that they're coupled to the expansion and thus a, if not the, source of DE.

Not everyone is convinced 

Normally Dr. Becky is pretty high level, but Supermassive black holes happen to be her field of specialty. She takes a deeper dive into the claims of the paper here, starting at 20:56. She's not convinced as you might guess from the thumbnail

 

[JoeSchmuckatelli]

1 hour ago, Beamer said:

Normally Dr. Becky is pretty high level, but Supermassive black holes happen to be her field of specialty. She takes a deeper dive into the claims of the paper here, starting at 20:56. She's not convinced as you might guess from the thumbnail

 

Thanks for this! 

I'm far from being able to understand the maths involved but I have been reading research papers on this for years - and my first two read throughs of the paper left me thinking 'this just doesn't make sense' (in relation to the other stuff I've read).  Then I stumbled on the reaction article I posted, and now this.  She was far more capable of articulating what just didn't fit for me (helps that this is her professional area of study!) 

[steve9728]

 

[JoeSchmuckatelli]

On 3/10/2023 at 8:45 AM, steve9728 said:

 

Nice!  Cleaner skies as you guys switch over; I remember LA from the 70s.  Brown air is no fun

[steve9728]

1 hour ago, JoeSchmuckatelli said:

Nice!  Cleaner skies as you guys switch over; I remember LA from the 70s.  Brown air is no fun

I visited this place when I was very young, and the stereotypical image of this place - Qingyuan - is that a little poor, and underdeveloped place. Of course, it's certainly not like that now. It's some kind tourist area with good natural resources. Rafting in the mountain streams here is a pretty famous tourist attraction.

Spoiler

The first "raftwreck" of my life was also here

[JoeSchmuckatelli]

I can't find the original Juno thread, but Io!

 

Just Dropped: New Close-up Images of Io from Juno, With More to Come - Universe Today

[Codraroll]

12 hours ago, JoeSchmuckatelli said:

I can't find the original Juno thread, but Io!

And behold!

[JoeSchmuckatelli]

2 hours ago, Codraroll said:

And behold

Groan! 

[steve9728]

Botanists in Zhejiang have bred a new variety of Sakura blossom with "Luosifen" (Smells like pickled food and "little stronger". It should be available in the average Asian supermarket and is a strange thing that smells strange but tastes quite tasty).

https://tianmunews.com/video.html?id=2418252&duration=88.0&isVertical=1&fsize=25612564&width=720&height=1280&continueFlag=50231596eb15ada56344fb253ccd81b4

Spoiler

I believe this is an act of terrorism. Sorry Japan.

Edited March 12, 2023 by steve9728

[insert_name]

Volcanic activity has been found on Venus in archival Magellan data

 

https://www.jpl.nasa.gov/news/nasas-magellan-data-reveals-volcanic-activity-on-venus

[steve9728]

The video tells an incomplete story of the discovery this time. The excavations revealed a weapon that proves its existence in the ancient texts, the "Pi (铍)", a short sword mounted on a long pole like a modern bayonet, as it is written. Archaeologists found that all long-range projectile weapons, all of which were used, were crossbows. And complete objects that had been carbonised were found. Bag for the crossbow, three bundles of bronze arrows, and the first shield from the Terracotta Pit were also found.

Also evidenced by the bag and the object of this crossbow is the fact that, in ancient documents, crossbow carriages temporarily not in use had 'fixed wood (檠木)' placed between the bowstring and the arm to hold the arm in place and provide some protection for the crossbow. Rather than some kind of support in a bag: because the bag is big enough.

Spoiler

How to use the 'fixed wood'

The bag itself. It is about 1.3m long and about 30cm wide at its widest point.

The arrows

The shield

This one proves that people in the Qin dynasty had swords hanging from their waists rather than carried on their backs: there is this argument because the same Chinese character "负" in ancient texts has a different meaning in ancient and modern times. In the documentary record of Jing Ke's assassination of the King of Qin, "王负剑" is translated as "the king carried the sword on his back", but this artefact proves that it was not "the king carried the sword on his back", but more likely "the king threw the sword behind his back and pulled it out to strike back at the assassin".

I do think that perhaps in addition to the different buns, the hair ornaments wrapped around the buns may have been a different colour for the soldiers and officers who originally carried out different tasks with different weapons.

The original full version of this report, if you want to practice your Chinese skill: https://www.bilibili.com/video/BV19Y4y1Q7mh/?spm_id_from=333.337.search-card.all.click&vd_source=6fef304b8d0c4737896e6b702ddfbfb3

Theoretically, this is already a combined arms, or even some kind "synthetic brigade".

The report also said that the third excavation of the Pit 1 has been ongoing for almost 13 years and the total area excavated is only 3% of the Pit 1.

Edited March 17, 2023 by steve9728

[JoeSchmuckatelli]

10 hours ago, steve9728 said:

crossbow

There is solid evidence of the use of crossbows in Asia and Europe dating to several hundred years BC.  The odd thing, given how effective they can be, is how the popular imagination of ancient times depicts the regular hand-held bow as being so much more common. 

I suspect this is largely due to the fact that you needed a fairly competent craftsman to make one, plus the use of metals for triggers, etc. meant you needed a sophisticated economic base to produce these in any significant numbers.  Comparatively, a simple hand bow is just a good stick that anyone with the knowledge and rudimentary tools can build.  To this I suggest that the use of various forms of militia (where people bring their own weapons) is likely to be the cause for this perception.  Much easier to call up the local farmers and have them bring whatever they had, and then organizing them accordingly.  For many places and times, archery was primarily harassing fire, or used for fixing the enemy rather than as a primary strategic weapon.  (Also, of note, the sling and sling-stones were viewed as often more effective than arrows in many places, and there's evidence that they were a significant part of warfare - especially in dry regions).

More complex and effective bows, however, like the recurve and Japanese war bow generally took skilled craftsmen, similar to making crossbows, but also took nearly a lifetime of training to be able to employ well.  Japanese and English archers were raised from childhood shooting ever stronger bows to be both powerful enough for combat and to have the accuracy and rate of fire to make them effective, rather than merely harassing.  Those cultures and others like the Mongols had economies scaled to produce not only quality bows, but also the arrows in quantities that made them relevant.

I think this evidence of regular use of crossbows at this time in China is interesting.  It was only about a decade ago that I learned that the crossbow's history dates back to ancient times.  I'd previously assumed that they were only prevalent in numbers in the middle ages, preceding the introduction of firearms.

...

Wasn't aware of any controversy about carrying a sword on the back; that's been roundly debunked in most places.  You might sling a swordbelt over your shoulder for a long trek, but if you ever thought you'd have to use it, it was almost always carried on the waist in every culture I've seen.  Having actually carried a sword for ceremonial purposes, (and goofed around with trying to draw it from shoulder-slung position) I can confirm that shoulder slung is virtually impossible.  OTOH a very long sword can be drawn cross-body from the waist.

[steve9728]

Just now, JoeSchmuckatelli said:

I think this evidence of regular use of crossbows at this time in China is interesting.

There is another possibility: the soldier who used the bow was buried in the unexcavated part at the back. After all, although crossbows are quite powerful, until today there is a big difference in the time between reloading a crossbow and bow. As one of the most powerful ancient Chinese empires, I don't really think the types of weapons they use are so limited.

[JoeSchmuckatelli]

11 minutes ago, steve9728 said:

There is another possibility: the soldier who used the bow was buried in the unexcavated part at the back. After all, although crossbows are quite powerful, until today there is a big difference in the time between reloading a crossbow and bow. As one of the most powerful ancient Chinese empires, I don't really think the types of weapons they use are so limited.

 

Agree - they had a very dynamic culture and economy - but it wasn't equal in distribution. 

What I think, however, is that because crossbows required skilled labor, the only person who could acquire and outfit his men in enough numbers to be significant was the regional king/warlord.  They were like prestige weapons; only the best, most trusted and loyal got them.  Petty warlords and weak kings could not command enough resources to outfit their warriors to quite the extent that rich and powerful leaders could.

That alone mitigates in favor of relatively small numbers being fielded.

Edited March 17, 2023 by JoeSchmuckatelli

[DDE]

3 hours ago, JoeSchmuckatelli said:

There is solid evidence of the use of crossbows in Asia and Europe dating to several hundred years BC.  The odd thing, given how effective they can be, is how the popular imagination of ancient times depicts the regular hand-held bow as being so much more common. 

It's understudied to be sure, because in the current narrative they keep popping up (e.g. among Roman hunters) and then disappearing, which is rarely how history works. One of the most interesting understudied tidbits is how all the mentions of crossbows in pre-Mongol Russian manuscripts feature them in the hands of Kumans, who are generally considered your average Eurasian steppe mounted archer culture that would have almost zero use for crossbows. Yet somehow one notable Russian noble got killed explicitly by a mail-piercing crossbow bolt in a cavalry fight involving Kuman mercs.