Funny, yeah they look like normal concretions to my eye.

https://en.wikipedia.org/wiki/Concretion#Cannonball_concreti...

I grew up near cannonball river, things like this are all over. High iron content too because of water. I even have a version that looks like a cube but its just shale inside, paramagnetic too but thats due to water processes according to a geologist I talked to.

I'm not convinced it was made by people until you crack it open.

Exactly - scroll down to the bottom on this page and you'll see concretions that look almost like the one in this article: https://www.dmr.nd.gov/ndgs/ndnotes/concretions/concretions....

Image here: https://www.dmr.nd.gov/ndgs/ndnotes/concretions/images/canno...

There's a beach near where I live that's littered with thousands of perfectly round, hand-sized stone discs, presumably created by some special wave and/or ancient glacial movement there. I'm pretty sure someone thinks it was aliens, though.

That Wikipedia page lists Zavidovići as a place where these things are found - which is the location in Bosnia described in the article.

Not a new addition either, the overall Bosnia reference has been there since the article was expanded from stub in 2006 and Zavidovici itself has been listed since May 2007.

Mandy Edwards belongs to the School of Earth, Atmospheric and Environmental Sciences of the University of Manchester, and she claims..."The [iron] sphere could have actually been produced by a natural occurrence known as concretion, which is caused by the “precipitation of natural mineral cement within the spaces between sediment grains”."

It's in Bosnia. Alternatively, the article quotes Dr Sam Osmangich, a proponent of the theory that an "ancient civilisation that was once present here, dating back more than 1,500 years."

> Dr Sam Osmangich, a proponent of the theory that an "ancient civilisation that was once present here, dating back more than 1,500 years."

Wait, what? It's not like Bosnia is some unknown place - 1500 years ago would put you at the tail end of the Western Roman Empire, with the Byzantines still in full swing. There's a very well attested historical record of who was living there then. If there was some ancient Balkan civilization obsessed with creating massive iron balls, we'd know about it. Hell, it'd probably have been a tourist attraction.

That would be true if concretion could form metal objects but it can't.

They can form Iron Oxide, and Iron Sulfide spheres but they are usually very small like these: https://en.wikipedia.org/wiki/Klerksdorp_sphere

It's not a metal object, it's a stone sphere with a "high" (unspecified) level of iron content.

You are correct, I've seen this linked before as some silly "Iron Sphere". Could be concretion, would be still very strange indeed, The smaller "iron spheres" were usually found in mines where there was already a high concentration of iron content that could be used to form iron minerals, not sure where did the iron came from to form this one.

The world is a very large place with lots of room for strange things to happen in it.

That's not a rock! That's a Terrie[1]!!

... or possibly a Fermie?

I'd not linger around for too long in any case. They might be feeling sporty.

[1] https://en.wikipedia.org/wiki/Land_Beneath_the_Ground!

If a nearly pure wad of space iron became molten on entering ancient earth's atmosphere and buried itself in relatively soft crust/clay, some sort of planetary "shot tower"[1] effect is out of the question? (and/or why no mention of "meteor"?)

[1] https://en.wikipedia.org/wiki/Shot_tower

Were talking about different velocities a shot tower works because the molten lead solidifies in the air, they travel at 50-100 m/s and land in water.

An Iron rod that falls from space will melt when hitting the ground just from the impact force regardless if it somehow managed to melt and solidify during reentry.

That much mass wouldn't bury itself, it would blow itself apart and leave a huge crater. It would be coming in at horrendous velocity, and the outer layers would flash to plasma on impact I think.

Or it could have been a ball of molten iron (from a meteor) that splashed into water, turned into sphere, and eventually found its way to the surface.

A ball of iron that size won't solidify into a sphere the sphere thing only works when the surface tension force is the big actor when something is that massive it's not longer the case.

This is why if you drip water from a bucket it would form drops but if you pour it all at once it wouldn't form one big drop.

They look similar to the Moeraki Boulders in New Zealand, also concretions which these might be too according to the article.

https://en.wikipedia.org/wiki/Moeraki_Boulders

Has nobody thought to ask the Bosnian guy _why_ this ancient (which it isn't either) civilization would create these balls? Every archaeologist I have ever met, and I've met a few, would tell you what it is based upon what it would be used for. Not the other way around. If he's just going to blindly speculate then it might just as well be a Minotaurus Humungus's testicle.

"The sphere could have actually been produced by a natural occurrence known as concretion"

'Concretion: The Enigmatic Stone Spheres of Franz Josef Land'

http://www.urbanghostsmedia.com/2015/07/stone-spheres-concre...

Some people hear hoofsteps and absolutely know it's a zebra

There is no division. Unless you include flat earthers dividing opinion on the earth is round.

It natural. Probably a concretion.

People have such a low opinion of the feats of engineering that our ancestors were capable of that they invent all sorts of magic explanations.

Giants, cyclops, menehune, elves, and such have been invoked frequently to "explain" the achievements of past humans. Now aliens are popular because apparently past humans didn't have brains, manpower, and time.

I think it was David Brin who wrote a short story and a foreward explaining that aliens have taken the place of faeries in our culture.

People have made stone spheres with primitive means already. See: https://en.wikipedia.org/wiki/Stone_spheres_of_Costa_Rica

I thought the Menehune were just considered to be other people who got there first...

Indeed, it should be noted that our technological civilization has been developped very quickly, in basically two or three hundred years (and we're on the verge of self destruct thru nuclear weapons, of which there are signs or legends of prehistoric use all over the planet).

It is certain that our ancestors have had more than enough time to develop powerful technolonologies several times over, and we have remnants of their technology all over the planet too (the pyramids and other megalithic constructions being only the most visible, since the most sustainable).

The use, and more importantly the development, of nuclear weapons leaves distinctive isotopic signatures that last for literally billions of years. In fact, an ancient naturally occurring "fission reactor" that is 2 billion years old has been discovered in this way. There is no other evidence of such activity in that time frame, a time frame that includes the history of all multicellular life on the planet. We can, with fair certainty, rule out the existence of any previous nuclear capable civilizations on Earth.

playing the advocate of the devil here, maybe the civilizations cleaned it all up and went solarpunk just before they transcended and vanished...

Basically an impossible task, and why would they?

Imagine how hard it would be to completely cover up the evidence of human existence on Earth, for example. You'd have to find and excavate every single arrowhead out of the Earth, every single bit of plastic from the ocean. You'd have to figure out something to do about all the mines. You couldn't just fill them up, that would leave evidence. And even that would just be scratching the surface.

Creatures complex enough and with big enough bodies and brains to potentially evolve into something that might build a technological civilization have only been around on Earth for a couple tens of millions of years, which isn't very long in geological terms. We don't see any evidence in the fossil record of ancient big brained creatures developing, and that's pretty much a pre-requisite for a technological species. There aren't any candidate creatures in the fossil record that could have conceivably evolved into a technological species in only a few million years, which means it would take a very big gap in the fossil record to have zero clues about such a thing, if it did happen. Also remember that fossil fuels are part of the fossil record, so we can be pretty confident that they didn't use fossil fuels.

And, as mentioned, if they'd ever developed nuclear technology we would know about it, because the isotopic signatures from either their mining activities, enrichment activities, the operation of their reactors, or the above ground testing or use of nuclear weapons would be like a beacon.

So, absent Slartibartfast levels of world-making or re-making, it's not a plausable theory, even as a stretch.

Overall it would only make sense if they never used fossil fuels, never mined, never developed nuclear technology, never cut down forests, never had farms, never left behind artifacts made out of bone, metal, stone, ceramic, glass, plastic, etc, never modified the landscape in any way. And never had any evolutionary predecessors that left a fossil record. If you can figure out how to squeeze a plausible technological civilization into those constraints, good luck.

Second time I get to mention David Brin in this submission!

You might enjoy his Uplift series; it deals with scenarios not unlike what you mention.

> nuclear weapons, of which there are signs or legends of prehistoric use all over the planet

Er, are there?

Well no, but I remember a long time ago reading some theory about "red indians" having atomic weapons and it was somehow linked to ORME (http://rationalwiki.org/wiki/ORMUS) - absolutely crazy, yet entertaining.

It seems reasonable to assume that any earlier iterations of a global civilization would also have relied heavily on the burning of coal and oil for energy, at least for a while. And yet there has been no spike in atmospheric CO2 concentration in the last 400,000 years like the one we have now:

http://www.geocraft.com/WVFossils/last_400k_yrs.html

What "powerful technology" are the pyramids evidence of? Slave labor? Ropes and logs?

The pyramids were probably massive public works projects, with off-season farmers making up the workforce, paid in beer. Not slave labor.

Actually, a metal machinist from the Midwest named Christopher Dunn has a fascinating theory that the great pyramids may have actually been 'power plants' of a sort.

Giant harmonic resonators that siphon energy off of the earths expansion and contraction caused by orbit of the moon.

http://www.amazon.com/Giza-Power-Plant-Technologies-Ancient/...

His writing is a bit dense, and maybe not as smooth as it could be...but his exploration of the possibility is quite impressive.

As you're by all appearances unaware of the concept, a bit of light reading...

https://en.wikipedia.org/wiki/Pseudoscience

and https://en.wikipedia.org/wiki/Scientific_theory (with an emphasis on the "well substantiated" bit)