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

[darthgently]

5 hours ago, JoeSchmuckatelli said:

Funny thing is that I want to do it because I got asked about Aliens the Pyramids and Stonehenge. 

There is some evidence that the smooth facing stones on the pyramids at Giza (of which few remain) may have been cast in place from a sort of concrete, not carved, I gather, but I haven't done a dive on it yet to see how well the evidence holds up

Edited April 16 by darthgently

[JoeSchmuckatelli]

1 hour ago, darthgently said:

ay have been cast in place

That is a new one.  At least to me. 

I'll look into it. 

I remember shows from the 80s where they demonstrated possible technology including the use of logs, ropes, people and animals.  All very advanced! 

Here's a newer one 

 

[darthgently]

1 hour ago, JoeSchmuckatelli said:

That is a new one.  At least to me. 

I'll look into it. 

I remember shows from the 80s where they demonstrated possible technology including the use of logs, ropes, people and animals.  All very advanced! 

Here's a newer one 

 

First stab at a dive:

https://search.brave.com/search?q=giza+facing+stones+concrete

 

[kerbiloid]

7 hours ago, darthgently said:

There is some evidence that the smooth facing stones on the pyramids at Giza (of which few remain) may have been cast in place from a sort of concrete, not carved, I gather, but I haven't done a dive on it yet to see how well the evidence holds up

The famous cyclopic stone wall of Machu Picchu after "thousand years" and  one heavy rain.
https://whc.unesco.org/en/news/580

Spoiler

 

And thousands of other photos and videos of the "ancient" temples and statues, cracked or being destroyed by IS in Mesopotamia.

Casted concrete as "stones", steel or cast iron rebar (from the Bronze Age, yeah) inside the "stones", huge monoliths hanging in air definitely without any support (except an invisible rebar), iron rebar and disks inside the "Ancient Egyptian" and "Ancient Greek" columns, booted junk inside the "stones", pictures and paintings of XVI...XIX great artists who definitely hadn't seen real "Ancient Egyptian" pyramids, temples, and paintings.

Old pictures of giant Stonehenge in wild mountains, while the real one is small, situates on a bare meadowland, and was an artillery range in mid-XX.
Myriads of "ancient" photo-realistic statues, being found one-by-one in a kitchen-garden.

All significant temples, castles, cathedrals, intensively rebuilt since XVI, and especially in XIX.
Cologne Cathedral of XII... Wait... Being a semi-built something without towers on the early XIX photos, built in late XIX.

The Sphinx, depictied as a head on a standalone block by the XIX artists, a set of four standalone blocks of stones and construction junk on the late XIX photo, and becoming a lion "made of monolith rock", with added limbs and tail, with the rear part reinforced with bricks.

Many, many other "ancient ruins" of the "antique civilisations".

Pompeii and Herculanum, officially (even on the silver memorial table) buried by Vesuvius eruption in 1631, and unburied several decades later as an ancient Roman town, described by Tacitus.

Wait, but how we do know about the Tacitus itself? A miracle! Nobody else, by famous Petrarca had occasionally found his manuscripts in the derelict monastery. What a coincidence. What a pity, the manuscript itself and Petrarca's translation are lost, only printed version exists.

Where do we know about Sparta and its weird sadistic (but actually true stupid and unreaslistic for long time) macho rituals? From Pausanias. And where do we know from about Pausanias? From the XV printed version of (guess, what? yes, lost) his manuscript. A strange fact, it was the epoch of "utopic socialism" fantasies of all kinds, and Sparta looks exactly like another one of them, just with strong homosadistic background. Usually they just blow somebody with powder, or something like that, and divide the ideal city populations in stratas of "damoiselles", "mesdamoiselles", "damoisels", and so on. Probably written for the local Blue Oyster club, or so, but popularized for the sake of military inspiration.

Easter Island with its statues, never painted correctly until early XX, and mentioned as "I wished so much to see them, but had seen nothing" by Miklouho-Maclay, the famous daredevil scientist and traveller.

Famous Otto von Guericke (XVII), and his experiments with primitive electrostatic generators and primitive vacuum pumps.
Coincidentally same as Thales of Miletus and Hero of Alexandria. What a pity, we don't know the century of their lives (from V BC to III AD, iirc).
Did they even exist?

Triremes made of thin planks (when they even didn't have steel saws, thin and flexible, with teeth looking aside), no one of which was ever found.
Wait... One was. In Italy. But lost in fire under bombs, what a pity.

***

Everything before XV looks like a belles-lettres, and theatric scenery. Probably is.

The super-duper cyclopic stones recipe: gather expendable humans (peasants and prisoners), make them carry baskets.
You need:
lime (made of limestone, easily crashable even without tools, with another piece of limestone, if the labour force is not what you care about; if no limestone, just burn the bones of eaten cattle)
milled beautiful stone (granite, sandstone, marble, whatever else, you want to make the result look like);
sand;
water;
organic component (any glue from boiled butchery junk, fish, etc; dead labourers are also good enough; for artifical marble they use cheese);

Mix, then put an empty bag made of straw to the wall (it will decay after several years without traces), and start filling it with layers of the wet concrete, letting it harden.
To make its front and side faces flat use bended metal (copper, lead, aluminium) sheets. Don't forget to pull them out, otherwise you get those aluminium sheets between the ancient egyptian stones.

If you want a curvy hole through the stone monolith, put a rope soekd with gypsum, let them get solid, they pull the rope away.
Bingo, you have a stone with a hole made by magic worm, exactly like King Solomon did it.

The same with sword-in-stone or ironhook-in-stone.-

Or pour it into a clay form, made from wax model of the human model.
(Why, do you think, the antique statues are always shaved and have small man parts? The wax melting point is 60 C hot, then you have to cool down to let the wax get solid, and finally, if you haven't shaved, a sudden depilation happens. The models were hardly able to see the sculptor without panic.)

***

Now imagine that you are, say, Rodrigo Borgia aka Pope Alexander VI.
(Taken just as an example, being known for his soft humour and kind jokes, often lethal for the opponents.)

The museum overseer has brought a wooden-microlith German sword (can't find the photo, looks exactly like the "Ancient Greek xyphos").
You have two cubic metres of bronze, i.e. ~16 t.

"What else ancient to make? Another big bronze statue? Too trivial. A fountain? Too much water is needed. Stop, an idea."

You call the head artist and give him the wooden-stone sword and the bronze.
"It's autumn now. I want 10 000 of them in bronze by the spring. And use your imagination, let them be different and old".

Now you are the artist.
You go to the museum, take several strange-looking tools, like khopesh and so on.
A sword weights 1.5 kg. You need 10 000 of them

You make a clay form for several swords, and all winter long the workshop is melting bronze and casting swords. Boys are breaking and scratching the, put into vinegar, to make them old.

By the winter the 10 000 swords sre ready.

Now you're again Borgia.

You call 10 archbishops and tell them: "Dear comrades, the Party wants you to distribute 1 000 swords everyone".

Every archbishop returns to his residence and calls 10 bishops. "Comrades, the Party wants you to take a hundred of swords and distribute in your region."

Every bishop calls 10 abbots and orders them to take and bury ten swords.

Every abbot call several priests, gives to each a bronze sword and says "Hide it somewhere".
Then he calls the obedientiary, gives him other swords and tells the same.

The obedientiary hides one between wine barrels, buries another one under a tree, goes to the inn and sells the rest to the locally known thief, who sells them to the people who pay for them.

Next year the whole Europe is full of ancient xyphoses and khopeshes, in amounts, about which the Agamemnon and Tutankhamen could only dream, because where should they take 15 t of good bronze...

Edited April 16 by kerbiloid

[magnemoe]

Its lots of reconstruction of ancient sites, sometime just to protect them from weather but more important prestige and make them better tourist destination, this has happened for hundreds of years now. 

 

[JoeSchmuckatelli]

8 hours ago, darthgently said:

First stab at a dive:

The MIT article is interesting - they talk about how... difficult... it is to get funding/be taken seriously when trying to explore that theory, then point out that it's not so loopy after all.  The concrete, if true, would be poured with a jello like consistency that for *reasons* cures in a way that avoids shrinkage common to other concretes.

It's an interesting theory.

 

Back to moving logs with mechanical advantage - this one is interesting.  The use of the bipod is totally different.  With the rope at the top of the bipod and the fulcrum forward of the log, they just pull it up and over.

 

Side note - I got the funding to try this with my students.  So later next week I'll report back on how it went.  Using 2x4x10s, making some beams from 2x6x12s and a few other things.

Should be fun!

[StrandedonEarth]

Geez, it might have been back in the 80s or 90s (maybe later, but don’t think so) that I came across an article suggesting that the blocks that built the Pyramids were poured, based on inclusions like hair. But apparently the theory never gained traction at the time…

[AckSed]

That dark energy's a bit elusive and hard to track. I'd better use the BIG lens: https://www6.slac.stanford.edu/news/2024-04-03-slac-completes-construction-largest-digital-camera-ever-built-astronomy

Spoiler

 

[kerbiloid]

The Dark Matter ^(tm) is also invisible for optics.

[AckSed]

Well of course. Which is why this is designed to track subtle gravitational shifts from the norm in astronomical observations.

[magnemoe]

On 4/17/2024 at 12:30 AM, StrandedonEarth said:

Geez, it might have been back in the 80s or 90s (maybe later, but don’t think so) that I came across an article suggesting that the blocks that built the Pyramids were poured, based on inclusions like hair. But apparently the theory never gained traction at the time…

If they had concrete they would used it lots of places like the Romans did. If you find use of concrete in ancient Egypt its probably Roman one, remember Cleopatra lived closer to our time than the construction of the pyramids. 

The interior blocks are pretty rough cuts, only the top and bottom needed to be flat for stability.  The outer layer would likely to be stone anyway, this was common in Rome and today for prestige buildings. 

Edited April 18 by magnemoe

[Codraroll]

4 hours ago, AckSed said:

That dark energy's a bit elusive and hard to track. I'd better use the BIG lens: https://www6.slac.stanford.edu/news/2024-04-03-slac-completes-construction-largest-digital-camera-ever-built-astronomy

  Hide contents

 

Looks slightly smaller than the type of lens paparazzi use to take pictures of various royal families on vacation from mountaintops ten kilometers away.

[kerbiloid]

13 hours ago, magnemoe said:

The interior blocks are pretty rough cuts, only the top and bottom needed to be flat for stability.

There are probably no interior blocks, they're a fantasy.

The whole thing is probably a ground hill above the rocky hill, covered with thin layer of quick-and-dirty "concrete" blocks, somewhere with photographed steel (sic! in so-called "Bronze Age") rebars and wires, somewhere with metal sheets stuck between the "stone" blocks.
That's why the "stone block" rows are not straight, but waving. The ground inside is settling, the blocks are tilting inside.

Up to 25% of internal volume is a flat rocky hill, on which the so-called "Grotto" chamber is placed.

Next, a "mastab" is built above, with the so-called "Queen's chamber", and the open corridor to it.

Later, the corridor was covered with stone roof.

Then they added some height and built the so-called "King's chamber".

Old pencil paintings are betraying the construction process.
Like the old egyptologist pyramid scheme, where the "Great Gallery" yet has no roof on top, lol.
Or the note that the rain has washed the ground from the gallery, and it became available. Inside the pyramid, lol.

All pre-XVIII paintings depict the pyramids having sharper shape of the so-called "pyramid of Cestius in Rome", and of the so-called "Nubian pyramids", which are much smaller. It proves, that nobody had seen real pyramids until they were finished in XVIII.
But the attempt to scale that shape up had fruited into the so-called "Snofru pyramid", having three different angles, because the ground inside the "stone pyramid" was sliding, so they had to make it more flat, then even more flat.
Finaly, the so-called "Hufu pyramid" (I believe, it's a joke from "Jefe") and others have the angle of the top segment of "Snofru", at which the ground hill was not sliding.

The "secret chamber", detected with muonometry right above the so-called "Great Gallery", is just less dense volume of the ground, settling above the gable roof of the gallery.

The so-called "Ancient Egyptian" "temples" and statues have countless autographs of the builders, stamped on the soft material, rather than the tourist scratches.

13 hours ago, magnemoe said:

Cleopatra lived closer to our time than the construction of the pyramids. 

While Cleo #7 and her brohusband Ptolemy #13 were thought out in early years of printing epoch (like other Ramesseses XVIII, the authors were tired of thinking out names and foreign marriages, so gave them numbers and forced to marry their sis and bros), i.e. in XV, it took two centuries to build the stone heaps, finished by the end of XVIII, in the Age of Steel.

So, I would guess the pyramids are much closer to us.

***

Famous Athanasius Kircher said that he had the whole Catholic world built in his workshop yard.

And the famous Bessarion of Nicaea had brought ~800 "Ancient Greek" books, translated into Latin, and was managing a whole literature fabric, "translating" the Platonists, Plotinists, Neo-Platonists, and so on.

***

To know the truth,
 

Spoiler

Spoiler

https://en.wikipedia.org/wiki/GBU-57A/B_MOP

 

 

Edited April 19 by kerbiloid

[AckSed]

https://arstechnica.com/science/2024/04/metafluid-gives-robotic-gripper-a-soft-touch/

tl;dr adding hollow rubber spheres to a liquid allows you to make a colloid that decreases in volume but doesn't increase in pressure when exerting an external force. Thus, if you overpressurise a 'soft' gripper, the force it exerts does not exceed a certain threshold. This lets you engineer behaviours without using any control algorithms or electronics. It can be tuned by varying the size of the spheres, and stepped by adding different sizes of sphere.

By reducing the size of the spheres to micrometre sizes and using the right materials, they found that they could also tune the rheology (thickness) and opacity with pressure, as the clear spheres collapsing turned themselves into something like lenses.

I love simple things like this that have emergent behaviours.

I don't love the resistance the researchers faced because "this was not an interesting idea".

[AckSed]

Someone's looking to build a high-delta-V solar-thermal space-tug:

https://arstechnica.com/space/2024/04/new-space-company-seeks-to-solve-orbital-mobility-with-high-delta-v-spacecraft/

Honestly, best wishes and good luck to them. The solar moth was always one of my favourite concepts.

[AckSed]

German company HyImpulse launched a hybrid paraffin wax/LOX sounding rocket from Australia:

 

[AckSed]

Obsidian-covered lava lake found on Io: https://www.nasa.gov/missions/juno/nasas-juno-gives-aerial-views-of-mountain-lava-lake-on-io/

[DDE]

3 hours ago, AckSed said:

Obsidian-covered lava lake found on Io: https://www.nasa.gov/missions/juno/nasas-juno-gives-aerial-views-of-mountain-lava-lake-on-io/

Must they so obsessively refer to the probe as "solar-powered"?

[RKunze]

1 hour ago, DDE said:

Must they so obsessively refer to the probe as "solar-powered"?

Well, it is the first ever solar powered probe that operates in the Jupiter system, and getting enough energy from solar panels that far out is quite an achievement.

All other craft visiting Jupiter so far were powered by RTGs.

Edited May 8 by RKunze
Fixed typo

[Vanamonde]

8 hours ago, AckSed said:

Obsidian-covered lava lake found on Io: https://www.nasa.gov/missions/juno/nasas-juno-gives-aerial-views-of-mountain-lava-lake-on-io/

You'll need a diamond pick for that. 

[magnemoe]

23 minutes ago, Vanamonde said:

You'll need a diamond pick for that. 

LOL for reference but obsidian is sharp not hard, sill its an material I did not existed outside Earth or earth like planets for reasons  

[AckSed]

Is it possible for a space program to be endearing?

I say to you that JP Aerospace is that space program. This is Grandad's garden shed hobby run on a shoestring, with a notable focus on practical testing and taking small steps towards a big goal. So far they've sustained themselves by launching 'Pongsats' and other payloads on high-altitude balloons, slowly working out their weird magnetic/electric/chemical engines that they are going to fit to a *deep breath* mile-wide, solar-powered, inflatable VLEO -> LEO launch vehicle that they propose to launch from a honest to goodness high-atmosphere aerostat station:

Instead of saying, "Ohh, this won't work," I take a different tack. Someone has been trying to build this for 40 years, using prototyping and design changes where needed. I don't care how realistic it might be, I just absorb the sense of wonder at seeing someone dream big and actually trying in a reasoned manner.

[magnemoe]

7 hours ago, AckSed said:

Is it possible for a space program to be endearing?

I say to you that JP Aerospace is that space program. This is Grandad's garden shed hobby run on a shoestring, with a notable focus on practical testing and taking small steps towards a big goal. So far they've sustained themselves by launching 'Pongsats' and other payloads on high-altitude balloons, slowly working out their weird magnetic/electric/chemical engines that they are going to fit to a *deep breath* mile-wide, solar-powered, inflatable VLEO -> LEO launch vehicle that they propose to launch from a honest to goodness high-atmosphere aerostat station:

Instead of saying, "Ohh, this won't work," I take a different tack. Someone has been trying to build this for 40 years, using prototyping and design changes where needed. I don't care how realistic it might be, I just absorb the sense of wonder at seeing someone dream big and actually trying in a reasoned manner.

Well we will live an world of fully reusable heavy lift soon. Not that this technology is pointless but more on staying over an area for long times
The drag would be the killer here I say, low trust work in space not in atmosphere. 

[AckSed]

1 hour ago, magnemoe said:

Well we will live an world of fully reusable heavy lift soon. Not that this technology is pointless but more on staying over an area for long times.
The drag would be the killer here I say, low thrust works in space not in atmosphere. 

They plan on using a plasma leading-edge to reduce drag (that's the purple edge on the render) and cite several papers where the general concept was proved in the lab, but admit it's another thing entirely to scale it up.

One of the papers they cite is really quite interesting: "Lines of Energy Deposition for Supersonic/Hypersonic Temperature/Drag- Reduction and Vehicle Control"

Not only do you gain something like a 40-90% reduction in drag and skin temperature by firing frickin' lasers ahead, it is also possible to use the reduction in drag to control a fixed wing by moving the plasma-induced low-pressure area off-centre. Note this is at normal altitudes. At their proposed altitude for the first stage high-altitude balloon (42 km or so), air-pressure is less than 1/20th of normal or ~5 kPa, almost as low as some neon tubes (3 kPa), and the power requirements to strike a plasma are lower.

Bonus: check the infographic for the Airship To Orbit:

Spoiler

Mad. But I'm glad they're doing it.

Edited May 15 by AckSed

[AckSed]

So when I was searching for how high a high-altitude balloon can go, I found that the Pongsats had their own Wikipedia page: https://en.wikipedia.org/wiki/PongSat

Buried in the references is a 2020 roundtable by Weekly Space Hangout where they interview John Powell (segment starts 10:34, ends 20:31) and he lays out the whole rationale behind the Airship To Orbit program:

Condensed transcript (to read the transcript for yourself instead of watching the video - and this works on all subtitled YT vids - go to the page, expand the description and click on "Show Transcript"):

JP Aerospace is a volunteer aerospace company with a small paid staff and about 70 volunteers.

The airship-to-orbit thing is their patented(!) idea, and the Pongsat was a side thing about 15 years ago of taking student payloads to orbit for free, that's kinda grown to this "giant, unwieldy monster" that's now about half of what they do.

Airship-to-orbit is a new way to get to space that doesn't use rockets. Not until the end, at least.

Unlike Orbital Sciences and Pegasus' 50,000 feet, they want to start at mach ten and about 300,000 feet (91,440m) and go from there.

Starting with the predecessors to Echo 1 in 1959 and onwards to something called the ROBIN program, almost to the present day people have been firing off sounding rockets and deploying balloons at very high altitudes and at Mach 10. (The latest reference I found on a cursory search is of a 1991 paper, "The inflatable sphere: A technique for the accurate measurement of middle atmosphere temperatures." Fire rocket up to 85km, deploy balloon, track with radar as it sinks, gain accurate density and thus temperature data on the middle atmosphere.)

There's actually been a dozen of these balloons, and they're all about the same: getting balloons to cruise at Mach 10 for atmospheric research, measuring drag, consistency, and after a while they started putting solar panels, radio, instruments on them. They also dovetailed into using them as nuclear weapon decoys which ended up as big sources of funding of such work; the science ended up being a rider of the decoy program.

When an ICBM comes in it deploys quite a few decoys, and these are reentry vehicles at hypersonic speeds, but they're also balloons. (Found under "Penetration aid" *snrk* on Wikipedia, where mylar balloons are indeed mentioned. For pictures, see also: https://www.globalsecurity.org/space/systems/decoys.htm. I love the dummy nuclear warhead.)

Their thinking was: what if you made it more aerodynamic? What if you went faster? What could you do with 60 years of advances in technology: Mach 14? 500,000 feet (152,400m)? Mach 18? 800,000 feet (243,840m, which is above the final 224km VLEO of ESA's GOCE, which had xenon ion thrusters)?

That's the question they're trying to answer: can you take it all the way to orbit? He has no idea!

V-shape of high-altitude-to-orbit vehicle is because it ended up being statically stable in all three regimes: subsonic, supersonic and hypersonic.

Craziest part is this has to be so big: you end up as a gossamer structure that goes at hypersonic speeds. An airship like that doesn't survive in the lower atmosphere. With a 5MPH crosswind you suddenly have 800,000 tons (assuming US imp. tons, that's 725,600 metric tons) acting on the side, and then you have confetti. It basically cannot fly any lower than the edge of space.

So they have three stages: the blunt, minimally-aerodynamic v-shaped bulk load-lifter that goes to 140,000 feet (42.6 km) and no higher, the Dark Sky Platform high-altitude station and the high-altitude-to-orbit launch vehicle that docks and lives there. They tested their 100-foot (30m) long Ascender 9 prototype [in 2019] and their DS is made of 5 of them connected together, which makes a stable platform.

The giant things they launch are completely silent as they streak away. They had some nasty official outs from that as it kinda freaks out the authorities - which they enjoy.

Orbital vehicle, as mentioned, has to live on the platform, and has to be assembled - well, inflated - there. It's buoyant to 180,000 feet (54.8km) then slowly starts to move forward. Not even breaking Mach (presumably Mach 1) till they get to 200,000 feet (61km).

Engines are plasma engines. Had 200 test firings and literally 800-900 more test firings to go, probably 5-6 more years (from 2020. Most recent Dec. 2023 update they had just started on the magnetohydrodynamic tests, where they added energy by making a spark gap in a magnetic field, and turned on the propellant).

Ion engines are too low thrust, chemical rockets would rip the ship apart. Their solution is essentially 'dirty' ion engines: the mixed gas coming out of the combustion chamber is the plasma to be ionised (Editor's note: sounds like a magnetically-contained arcjet-boosted rocket). The engines they're running right now (in 2020) could be thought of as the world's worst ion engines: instead of about 60,000 ISP, theirs are about 1200 ISP. Which is actually good for chemical. It's a stupid engine that only has one use: it's "a steamship engine that goes putt-putt-putt for days". (Propellant is paraffin seeded with potassium. No note on oxidiser.)

Once they get to the altitude of the rocket-launched weather balloons, they have a little more structure and aero and hopefully they can go faster.

Once clear of the atmosphere, they turn off the electrical stage to have a final chemical-only orbital insertion burn.

On the way down they fly at mach 1. Sounds impressive for a structure made out of foam and carbon fibre, but at 100,000 feet (30km) they've kinda pulled the teeth out of that; it's really not impressive.

Efficiency-wise it's not very efficient; a more instantaneous release of propellant is the most efficient. What you gain is thinking time for emergencies: he cites the narrow windows of escape in the space shuttle; a loss of an engine is a loss of crew.

With this, say you're Mach 15, you're only three quarters of the way through the entire process and you have a big engine failure. Well you go back and you take a look at it. You sit down and have a meeting while you're drifting back down to try to get it to work. If you do, you continue on. If you don't you can float back down and rejoin the station. You really don't have that in rocketry. (I will note that their focus in 2024 has shifted to bulk cargo transport, with a humongous 30-metre payload bay that'd let them capture Hubble intact.)

Pongsat has become so overwhelming with 80,000 ping-pong balls flown and 3-4 missions a year, it's being spun off into its own non-profit.

They get so much flat-earth hate mail.

Edited May 15 by AckSed