How many times has humanity been wiped down to near extinction?

[westwall]

So you do believe in magic? ... you're defending the claim that this was done with copper and antler tools ... or that this cave was carved by extraterrestrial aliens ...

I find the work remarkable as well ... but still of human manufacture ... if you want to promote voo-doo hexes, don't expect me to respect your scientific opinions ...

Where did I say that? I merely stated simple facts, then said I find them interesting.

You are engaging in a logic fail akin to both non sequitur, and appeal to authority.

Do better. Address my points. Not me.

 

[CrusaderFrank]

So you do believe in magic? ... you're defending the claim that this was done with copper and antler tools ... or that this cave was carved by extraterrestrial aliens ...

I find the work remarkable as well ... but still of human manufacture ... if you want to promote voo-doo hexes, don't expect me to respect your scientific opinions ...

"Any sufficiently advanced technology is indistinguishable from magic"-- Arthur C. Clarke

The people that once populated the planet were far more technologically advanced.

The had a technology to turn granite into putty and move heavy stones with impunity

Not aliens, not magic

 

[CrusaderFrank]

Enough, Reiny with your nonsense. I find nothing fantastic about anything West has said and place him in the 99th percentile within this group. You, not as much.

West indeed hit the problem right on the nail-head: the difficulty in obtaining so perfect a polish on so flat a surface over such a large AREA is easily 4X harder than a surface just half the area! Then they achieved precise cuts and fits.

There is no question this was done, the stones are still out there. No one has implied magic nor UFOs, just a knowledge and mastery of tool-working that escapes our computer-controlled, steel, hydraulically-operated world today.

This is not as much an attack upon our modern manufacturing science as it is to a hats-off to our underestimation of and lack of understanding of what ancient civilizations really knew and could do.

We could probably plunk down a man from 25,000 years ago right into our world, and with a little training and education, a shave and a bath, we could put him out in the middle of a modern city, and you might not tell him apart from anyone else.

The (altered) human genetics and brain has been the same for 250,000 years. Could mean that there were Einstein and Elon Musk long, long ago

 

[CrusaderFrank]

Update on Giza

4 separate satellites confirmed the existence of 2,000 foot deep spiral tubes under the 3 main Giza Pyramids and the Sphinx

The satellite imagery is accurate. It was tested against an underground physics lab in Italy and detailed it accurately.

The technology is used in mining and defense industries

^ Italian underground lab

The sky is blue

Water is wet

We are not the first technologically advanced civilization on Earth

 

[ReinyDays]

Where did I say that? I merely stated simple facts, then said I find them interesting.

You are engaging in a logic fail akin to both non sequitur, and appeal to authority.

Do better. Address my points. Not me.

This is what you're defending ...

So are you saying the Barabar Caves was a piece of cake for a civilization with copper chisels and deer antlers?

... or are you ignorantly arguing with a strawman ...

Please explain why you think 50 nm is impossible in pre-industrial times with garnet or emery ... and IRON tools ...

My claim is quoted from C'Frank's link ... "This isn't aliens. This is the mastery of the Ancient Indus. Read the Vedas" ...
Since you disagree, you must be believing in magic ...

 

[CrusaderFrank]

This is what you're defending ...



... or are you ignorantly arguing with a strawman ...

Please explain why you think 50 nm is impossible in pre-industrial times with garnet or emery ... and IRON tools ...

My claim is quoted from C'Frank's link ... "This isn't aliens. This is the mastery of the Ancient Indus. Read the Vedas" ...
Since you disagree, you must be believing in magic ...

"Any sufficiently advanced technology is indistinguishable from magic"-- Arthur C. Clarke, clearly talking about the builders of the Giza plateau, megaliths the world over, Barabar Caves, Longyou Caves, etc.

Well, first off, you're thinking that they used slave labor with iron tools to carve the vast opening in the first place, right, because isn't that always the default explanation when you set ancient technology to near absolute zero?

Then they sent in subsequent legions of slave laborers to make these precise polished surface during the scant daylight hours, most of whom died of dust inhalation in the confined spaces

 

[westwall]

This is what you're defending ...



... or are you ignorantly arguing with a strawman ...

Please explain why you think 50 nm is impossible in pre-industrial times with garnet or emery ... and IRON tools ...

My claim is quoted from C'Frank's link ... "This isn't aliens. This is the mastery of the Ancient Indus. Read the Vedas" ...
Since you disagree, you must be believing in magic ...

There you go with your very own strawman yet again. Once again, to get your 50 nm precision, you MUST first make your tools that are capable of getting you that precision. How is your garnet, or emery tooling made to work?

Why are there no examples of those tools found anywhere in the world? The earliest I can recall for use of a grinding wheel to grind gemstones is the early 1600's. Before that, nothing.

The techniques you are describing ONLY exist in industrial societies. It takes at least steam power to generate enough force for large scale grinding.....and WE didn't start doing that till the middle 1800's.

So...yet again. How do you grind a slab of granite 20 feet long by 10 feet high, and have it smooth, and at nearly perfect right angles.

Show me your methodology. Not magic. But a tool that will do that without any sort of steam, or electrical power.

Go.

 

[CrusaderFrank]

Below The Giza Pyramid Plateau—New Radar Discoveries Will Shock The World.

I can't paste it correctly

"Finally, beyond the immediate area of the Khafre pyramid, the radar survey suggests a web of horizontal tunnels and additional chambers fanning out across the plateau . The team claims the entire subterranean system stretches roughly 2 kilometers end-to-end, reaching underneath the Great Pyramid (Khufu) on one side and the smaller Pyramid of Menkaure on the other . In essence, all three of the main Giza pyramids are underpinned by this interconnected underground complex. If this interpretation is accurate, it means the ancient builders excavated or constructed a truly massive multi-level infrastructure under Giza – something that has never been documented in mainstream Egyptology. Such an extensive network calls to mind the long-rumored “lost city” or labyrinth beneath the pyramids, a concept that until now was relegated to myth and speculation."

Modern technology confirms "Any sufficiently advanced technology is indistinguishable from magic"-- Arthur C. Clarke,

 

[CrusaderFrank]

There was a very advanced civilization here before us

 

[sparky]

seems we're a race with amnesia.........~S~

 

[westwall]

seems we're a race with amnesia.........~S~

No other race even cares about its history so that at least gives us a leg up.

 

[CrusaderFrank]

"The Barabar Hill Caves are the oldest surviving rock-cut caves in India, dating from the Maurya Empire (322–185 BCE), some with Ashokan inscriptions, located in the Makhdumpur region of Jehanabad district, Bihar, India, 24 km (15 mi) north of Gaya."

Wikipedia cites Sir Alexander Cunningham (1871) page 43 ...

I'm saying they used iron ... or the best steel in the local area ... Iron Age India ... 2 millenia after Giza ...

According to these measures, Barabar Caves are 20 times smoother than we can accomplish with modern technology and machimery.

“The 2,200-year-old Barabar Caves in India feature, famously, highly polished interior granite walls that possess an Rz
(mean roughness depth) of approximately

0.466
This surface finish is roughly 20

times smoother than modern industrial granite polishing, which generally has an

Rz
value of about 9”

I dispute the 2,200 year old date. These were the product of an ancient, far advanced civilization

 

[ReinyDays]

Did you even bother looking up what Rz values mean? ... are you seriously claiming modern polishing leaves 9 inch pits in the surface? ...

... 9 inch pits ...

I can only suppose you misread whatever you're reading and that should be 9 micro-inches ... or 225 nanometers ... cheap Walmart sunglasses are 500 nanometers, same as the rocks I'm tumbling ... telescopes have to be below 200 nanometers or they won't work ...

Here's a place you can buy 50 nanometer polishing powder ... Chem Impex ... so polishing on the kitchen counter gets an Rz of 2 µin ...

I know you hate scientific papers ... because this one claims X-ray telescope mirrors are smooth at the atomic level ...
"Atom-scale smoothing of monocrystalline silicon via non-abrasive catalytic polishing" -- Peng et al -- Dec 12th, 2025 ...

"Monocrystalline silicon is the preferred substrate material for X-ray mirrors, which highly demand atomically precise, ultra-smooth and damage-free surfaces."

So ... 200 picometers is our industrial limit on smoothness ... that would be an Rz of 0.0079 µin ... the diameter of a Silicon atom ...

ETA: ZZ Top (set volume to 11)[/URL]

 

[toobfreak]

Home made telescopes mirrors need to be smooth within 50 nanometers ... 1/4 of a wavelength of blue light ...

Wrong on all accounts Reiny, now you've stepped into an area that I know more than a little about. First of all, the Raleigh Criteria sets forth a quarter-wave threshold based on the Dawes limit of partial resolution of two airy discs at null frequency generally accepted to be around 550nm, the wavelength of yellow-green light where the eye's peak sensitivity is, since home made personal telescopes are used optically and not generally as some far off wavelength, thus, the strehl ratio for the blue and red generally fall well below 1/4wave accuracy (about 0.89 strehl) unless the instrument will be used for digital imaging where having it optimized farther into the red/IR may be a benefit due to CMOS and CCD sensors being IR sensitive.

Home made optical telescopes always perform worst in the blue end where (unless you are using blue-sensitive emulsion) the eye is poorly sensitive to anyway. Scotopic vision sucks in the blue. So why would anyone null out an optic to perform best at that wavelength?

So they generally set 1/4 lambda as a preferred minimal threshold whereas gains are often seen even up to 1/10th wave. I've owned 1/50th wave optics that approached 0.996 strehl in the yellow-green. And 50nm is not quarter wave of blue or green as blue is about 450nm and like I said, yellow-green is like 550nm. So how does 1/4 wave of any of them = 50nm?? Actually, a home made mirror that is only 1/4𝛌 accurate is a rather poor one. A good home made mirror is more around between 1/8th wave to 1/20th wave. Also, when it comes to mirrors, silvered or aluminized, their strehl intensity is not contingent upon wavelength anyway since they are not reactive to frequency as a glass lens is!

Also, keep in mind that an optical mirror must be twice as smooth as its intended final wavefront accuracy is because any reflected image involves TWO interactions--- first the photon is absorbed by the coating, then a new photon is released back in the original direction, as opposed to a glass substrate where the original photon is redirected through refraction in the same direction as the subtract itself then becomes involved in the image forming process as a reactive component.

... telescopes have to be below 200 nanometers or they won't work ...

200nm is well into the UV band.

I know you hate scientific papers ... because this one claims X-ray telescope mirrors are smooth at the atomic level ...
"Monocrystalline silicon is the preferred substrate material for X-ray mirrors, which highly demand atomically precise, ultra-smooth and damage-free surfaces."

Actually, x-ray optics is a bit off from my experience, but generally, you don't grind a flat first surface mirror to form x-ray images--- for one thing, no matter how smooth the substrate is, what really matters is the smoothness of the final reflective overcoat, which is generally aluminum, silver oxide or gold, none of which will do you a damn bit of good in x-rays. X-rays are are too high energy to reflect as normal light, they are around 10 angstroms or around 1 nm in wavelength--- in my experience, telescopes designed for work in x-ray alone are not mirrors at all in the conventional sense but complex things which the x-ray photon strikes in a series of precision concentric rings such that the x-rays hit it at an extremely low grazing incidence so that it is only marginally deflected from its original path so that across an area, all x-rays can be deflected to a common prime focus to form an "image."

This all said, none of this has a thing to do with humanity being wiped out much less addresses what I think West's original point was about how primitives could grind huge, flat stones to a precision far beyond the technology of today where essentially they fit so well together that no mortar was needed.

 

[ReinyDays]

Actually, x-ray optics is a bit off from my experience, but generally, you don't grind a flat first surface mirror to form x-ray images--- for one thing, no matter how smooth the substrate is, what really matters is the smoothness of the final reflective overcoat, which is generally aluminum, silver oxide or gold, none of which will do you a damn bit of good in x-rays. X-rays are are too high energy to reflect as normal light, they are around 10 angstroms or around 1 nm in wavelength--- in my experience, telescopes designed for work in x-ray alone are not mirrors at all in the conventional sense but complex things which the x-ray photon strikes in a series of precision concentric rings such that the x-rays hit it at an extremely low grazing incidence so that it is only marginally deflected from its original path so that across an area, all x-rays can be deflected to a common prime focus to form an "image."



This all said, none of this has a thing to do with humanity being wiped out much less addresses what I think West's original point was about how primitives could grind huge, flat stones to a precision far beyond the technology of today where essentially they fit so well together that no mortar was needed.

Thank you for the corrections ... my point still stands ... these caves in India are NOT smooth to 10 nm ... why are you defending such nonsense? ... is granite the hardest rock known? ... so hard is can't be worked by iron tools? ...

Citation please ... especially how we measure 10 nm pitting ... that's an Rx value, so these 10 nm pits will be few and far between ...

 

[CrusaderFrank]

Did you even bother looking up what Rz values mean? ... are you seriously claiming modern polishing leaves 9 inch pits in the surface? ...

... 9 inch pits ...

I can only suppose you misread whatever you're reading and that should be 9 micro-inches ... or 225 nanometers ... cheap Walmart sunglasses are 500 nanometers, same as the rocks I'm tumbling ... telescopes have to be below 200 nanometers or they won't work ...

Here's a place you can buy 50 nanometer polishing powder ... Chem Impex ... so polishing on the kitchen counter gets an Rz of 2 µin ...

I know you hate scientific papers ... because this one claims X-ray telescope mirrors are smooth at the atomic level ...
"Atom-scale smoothing of monocrystalline silicon via non-abrasive catalytic polishing" -- Peng et al -- Dec 12th, 2025 ...

"Monocrystalline silicon is the preferred substrate material for X-ray mirrors, which highly demand atomically precise, ultra-smooth and damage-free surfaces."

So ... 200 picometers is our industrial limit on smoothness ... that would be an Rz of 0.0079 µin ... the diameter of a Silicon atom ...

ETA: ZZ Top (set volume to 11)[/URL]

Yeah 9"

That was copied from a website and it got facocked

You really thought it was 9 inches of smoothness?

 

[toobfreak]

Thank you for the corrections ... my point still stands ... these caves in India are NOT smooth to 10 nm ... why are you defending such nonsense? ... is granite the hardest rock known? ... so hard is can't be worked by iron tools? ...

West is the expert here on geology but I would wager that basalt is harder than granite if I had to guess. Granite is the light "foamy froth" that rises out from basalts, if I may put it in a rather non-technical way. As to a smoothness of 10nm? That is about 10,000 picometers is it not? Or about a 100Å, pretty damn smooth. I suppose if one has the right grinding material and the right rock it might be possible, but I will defer to someone with expert mineralogical experience.

 

[Fort Fun Indiana]

The people that once populated the planet were far more technologically advanced.

This didn't happen.

 

[westwall]

West is the expert here on geology but I would wager that basalt is harder than granite if I had to guess. Granite is the light "foamy froth" that rises out from basalts, if I may put it in a rather non-technical way. As to a smoothness of 10nm? That is about 10,000 picometers is it not? Or about a 100Å, pretty damn smooth. I suppose if one has the right grinding material and the right rock it might be possible, but I will defer to someone with expert mineralogical experience.

Basalt measures between 5 and 6 on Moh's scale. Granite measures between 6 and 7.

Granite has a high percentage of quartz typically 20 to 70%, while basalt is 20% or less. The intrusive igneous rock closest to basalt is gabbro.

Grinding granite, because of the high quartz content is very difficult and requires a very high amount pressure to accomplish. Small samples can be ground with diamond impregnated grinding wheels with not a great amount of pressure, but require very high speed and copious water to keep the grinder cool in the place of the pressure.

 

[CrusaderFrank]

This didn't happen.

Oh?

How did the copper chisel and slave labor guys build the complex subterranean infrastructure under Giza?