Using Grok as proof that most our prehistory/archeology is garbage.

[reilpmeit]

It always intrigued me why scientific establishment modern of science discarded possibilities of high tech ancient civilizations(that would rapidly advance in few thousand years,but collapse almost completely in very short period) so easily.

Here could be the answer why iron age will be always be few thousand years ago,and bronze age before that. No matter if you are doing the measuring of age of now,2000 years before,or 5000 in future. You will always see same,or similar result.
Oxidazion ie. turning to dust will happen for all metals inevitably.

For metals,there isn't even need for (controversal) carbon dating. Some ,like iron "age" fairly quickly

Here is my discussion with grok:


Question:I have iron cube which is 1 m^3 . How much time is needed for it to oxidize,ie to turn to dust. Lets say cube is out in open,with occasional rain and snow at sea level. Answer me ,think deeply.

Answer:

The oxidation (rusting) of your 1 m³ iron cube—pure iron, I assume, like wrought iron or mild steel—into "dust" (i.e., complete conversion of the metallic iron to loose, powdery iron oxides like rust) is a slow, surface-driven electrochemical process. It requires oxygen, moisture, and electrolytes (from rain, snowmelt, or atmospheric humidity) to proceed. I'll break this down step by step, drawing on established corrosion science (e.g., ISO 9223/9224 standards for atmospheric corrosivity and long-term exposure data from temperate European studies), to arrive at a reasoned estimate. This isn't a lab experiment; it's an approximation based on real-world rates, with uncertainties I'll flag.Step 1: Define the Environment and Corrosion Rate

• Conditions: Open exposure at sea level (assuming ~0-100 m elevation, temperate climate like much of coastal or near-coastal Europe/North America, with average temps 5-15°C, relative humidity 70-85%, and "occasional" rain/snow meaning ~500-800 mm annual precipitation, including ~20-50 snowy days). No heavy industrial pollution (modern low SO₂ levels <10 μg/m³). Sea level hints at possible mild marine influence (e.g., salt aerosols if within 5-10 km of coast), but I'll assume non-extreme coastal for conservatism—not surf-battered, just breezy open air.
• Corrosion mechanism: Rusting (Fe → Fe²⁺ + 2e⁻, then to Fe₂O₃·nH₂O) is uniform-ish on exposed surfaces but accelerates with wetness. Rain provides electrolytes and washes away protective rust layers (exposing fresh metal), while snow/frost cycles can crack rust but slow diffusion in cold. Initial rates are higher (first-year "burst"), then stabilize as rust builds (porous, non-protective on plain iron).
• Rate selection: Based on ISO 9223 (atmospheric corrosivity categories for carbon steel) and long-term data (e.g., 45-year Czech study in similar temperate/rainy conditions):
  
  • This fits C2 (low) to C3 (medium) corrosivity: rural/suburban with moderate wetness and low pollution.
  • First-year penetration: 10-40 μm/year (average ~25 μm/year, or ~0.025 mm/year).
  • Long-term average (over decades): ~60-70% of first-year due to rust buildup and declining pollution—say 15-25 μm/year (I'll use 20 μm/year or 0.02 mm/year as a balanced estimate). Higher if coastal salt boosts it to C3+ (up to 40 μm/year); lower if arid inland (10 μm/year).
  • Sources: ISO 9223 tables (C2: 1.3-25 μm/y; C3: 25-50 μm/y); European field data (10-21 μm/y historical, now lower post-SO₂ reductions); equivalent mass loss ~80-160 g/m²/year initially, stabilizing lower.

Uncertainties: Microbes, UV, wind-driven particulates, or climate variability (e.g., more rain = +20% rate) could tweak this ±30%. No protective coatings assumed.Step 2: Cube Specs and What "Turn to Dust" Means

• Dimensions/mass: 1 m side length (L = 1000 mm), volume 1 m³, density ~7.87 g/cm³ → mass ~7874 kg iron.
• Exposure: All 6 faces (initial surface area 6 m²), fully open—no shelter.
• "To dust": All iron atoms oxidized to rust (volume expands ~2-3x due to lower oxide density ~5 g/cm³), forming a flaky, powdery heap. Rust doesn't instantly disintegrate; it builds as a ~1-10 mm crust before flaking under rain/wind/freeze-thaw. Complete conversion requires consuming every bit of metal, leaving no solid core.

Step 3: Modeling the Time RequiredCorrosion is surface-limited: it eats inward from exposed faces at the penetration rate (r). For complex shapes, exact modeling needs simulation (e.g., finite element), but for a cube:

• Simple penetration model (standard for structural life estimates): Corrosion advances uniformly from all sides. The last metal to go is the center, reached after penetrating half the side length (L/2 = 500 mm) from opposing faces.
  
  • Time t = (L/2) / r = 500 mm / 0.02 mm/year = 25,000 years.
• Why this model? Edges/corners corrode ~1.5-2x faster initially (higher oxygen access), increasing effective surface area over time and shortening real time by 10-20%. But rust accumulation slows inner penetration, balancing it. For thin sheets (e.g., 1 mm fence wire), this predicts ~25 years to perforate—matches real-world rust-through on unprotected garden tools/fences in rainy climates.
• Mass-based check: Initial mass loss 6 m² × 160 g/m²/year = ~0.96 kg/year (first year). Total mass 7874 kg → naive t ~8,200 years if constant, but surface area increases (pitting/irregularity) while rate decreases (rust barrier), netting similar to penetration model (20,000-30,000 years).
• Long-term adjustment (ISO 9224): Uses power-law: cumulative loss after n years ≈ r₁ × n^(1 - b), where b ~0.4-0.6 for steel in wet atmospheres (slower than linear). Solving for n where loss = 500 μm equivalent yields ~1.5-2x the linear time—pushing toward 30,000+ years if conservative.

[th]Scenario[/th]
[th]Penetration Rate (μm/year)[/th]
[th]Time to Full Oxidation (years)[/th]
[th]Rationale[/th] [td]Low (dry rural, minimal rain)[/td]
[td]10[/td]
[td]~50,000[/td]
[td]C1-C2 inland, low wetness.[/td] [td]Base (temperate open, occasional rain/snow)[/td]
[td]20[/td]
[td]~25,000[/td]
[td]C2-C3, low pollution, balanced moisture.[/td] [td]High (mild coastal salt, wetter)[/td]
[td]40[/td]
[td]~12,500[/td]
[td]C3-C4, sea spray boosts electrolytes.[/td] [td]Extreme (industrial/polluted)[/td]
[td]80+[/td]
[td]<7,000[/td]
[td]Not your scenario, but for comparison.[/td]

Step 4: Deeper Considerations and Caveats

• Non-uniformity: Starts fast (100+ μm first months on fresh surfaces), slows to steady-state. Rain events spike it (electrolyte flush); snow insulates but melt cycles crack rust. Over millennia, the "cube" becomes a spongy, hollow relic before crumbling.
• Historical analogs: Iron Age tools (exposed 2,000+ years) show ~10-20 mm penetration in similar climes—scales to your estimate. Modern tests (e.g., NASA coastal sites) hit 100-300 μm/y but are subtropical/hot.
• What accelerates it? More rain/salt (+50%), acid rain (pH<5), or bio-corrosion. Slows with dry spells or alloying (but yours is pure iron).
• Not forever: In 25,000 years, climate shifts (e.g., wetter from global change) could halve time; geology might bury it.
• Bottom line: ~25,000 years for your cube to fully rust to dust under these conditions. It's geologically brief (a human lifetime is 0.004% of that), but your great-great-...-grandkids' statues would still stand. If it's coated or alloyed, multiply by 10-100.

 

[reilpmeit]

So the answer is about ~25 000 years for one meter^3 cube of iron (which is one of the most extreme cases)


For smaller dimensions objects ,it would be much lesser time.

Simply put we can't see use of iron tools in past more than few thousand of years,even if we used it.

All possible such tools used before that, are already dust.

Time ie oxidation will turn everything made of iron to dust in few thousands on average.

I asked similar question for bronze and gold

Here is shared link https://x.com/i/grok/share/gEscXP0JjQiK2dns8lRXYRPl0