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> seals are available in many places that don't support ruminants. My point about shellfish subsistence is that, compared to the island hopping along the Malay

> seals are available in many places that don't support ruminants. My point about shellfish subsistence is that, compared to the island hopping along the Malay Archipelago, any hypothesis about a migration along Beringia has to consider clothing/shelter due to the challenging temperatures. A focus on food energy alone is not sufficient. It was a reminder, not a falsification. The "ancient civilization pseudo-science" I'm referring to is implied from the parent comment [1] that I replied to [2]: > This episode of the Joe Rogan podcast is with "master builder and architectural designer, teacher, geometrician, geomythologist, geological explorer and renegade scholar" Randall Carlson. [1] Randal Carlson and Graham Hancock are my target pseudo-scientists. Carlson cites the Younger Dryas era delta-O-18 Greenland ice core data as evidence that a cataclysmic event may have occurred to account for the drastic temperature fluctuations. My point was that delta-O-18 data is often graphed as delta-temperature-equivalents and it is a mistake to interpret this value as true temperature independent of the influx of meltwater into the Atlantic. If you mention an ancient civilization like Atlantis in the context of the Younger Dryas, I'm going to assume that you flirting with Randal-Carlson-like topics that pop-up in HN comments. I'm aware that you are intrigued by the possibility of discovering archeological artifacts covered by the rising sea levels since the last glacial maximum; a valid assumption. [1] https://news.ycombinator.com/item?id=23820540 https://news.ycombinator.com/item?id=23820540 [2] https://news.ycombinator.com/item?id=23821726 https://news.ycombinator.com/item?id=23821726

ncmncm 6y ago
It seems to me that pseudo-science requires a pseudo-scientist. I don't know anything more about Carlson than your link suggests, but scientist doesn't seem to be in the list. Graham Hancock certainly makes no pretense of being a scientist. He is a mythographer, forthright about seeking evidence for a factual basis of received myth. Unusually among writers in his genre, in print he is very careful to distinguish established fact from speculation. But I am still trying to understand your implication about the O-18 data. The graph encompassing the YD period showing a period of sharply lower temperature is commonplace. Are you saying that should be interpreted, instead, as a sharp increase in terrestrial water retention at YD onset, followed by a sharp reduction at the end, rather than a change in temperature? What do you interpret as might cause such retention? Or does it, instead, refer to a change in the rate of release of terrestrial water to the ocean, pausing for millennia, then resuming at the end? Thank you for your patience. This is not my field.
- sradman 6y ago
  The Younger Dryas (YD) delta-O-18 changes are most extreme in the Greenland ice core values; the result of precipitation from Atlantic surface evaporation. There are multiple variables that influence this value like 1. Sea Surface Temperature, 2. delta-O-18 of the surface water, and 3. distance from source to destination (how monsoon data is extracted from Asian cave stalactites). The YD was initiated by massive meltwater pulses. Depending on the fluid dynamics of freshwater mixing in the Atlantic, the early YD should logically result in delta-O-18 spikes due to the influx of freshwater. The meltwater pulses are not caused by sudden temperature spikes though it is plausible that the freshwater influx disrupts the major Atlantic currents and has localized temperature impacts. YD-style spikes occur after each glacial termination in the era of 100-ky glacial cycles as seen in the LR04 data set; parallel meltwater pulse events every 100 ky. You are correct, the graphs showing sharply lower temperatures are common and these graphs are technically correct because they are plotting delta-temperature-“equivalents”, but drastic changes can be the result of freshwater changes alone at a constant temperature.

ncmncm 6y ago

It seems to me that pseudo-science requires a pseudo-scientist. I don't know anything more about Carlson than your link suggests, but scientist doesn't seem to be in the list. Graham Hancock certainly makes no pretense of being a scientist. He is a mythographer, forthright about seeking evidence for a factual basis of received myth. Unusually among writers in his genre, in print he is very careful to distinguish established fact from speculation. But I am still trying to understand your implication about the O-18 data. The graph encompassing the YD period showing a period of sharply lower temperature is commonplace. Are you saying that should be interpreted, instead, as a sharp increase in terrestrial water retention at YD onset, followed by a sharp reduction at the end, rather than a change in temperature? What do you interpret as might cause such retention? Or does it, instead, refer to a change in the rate of release of terrestrial water to the ocean, pausing for millennia, then resuming at the end? Thank you for your patience. This is not my field.

sradman 6y ago
The Younger Dryas (YD) delta-O-18 changes are most extreme in the Greenland ice core values; the result of precipitation from Atlantic surface evaporation. There are multiple variables that influence this value like 1. Sea Surface Temperature, 2. delta-O-18 of the surface water, and 3. distance from source to destination (how monsoon data is extracted from Asian cave stalactites). The YD was initiated by massive meltwater pulses. Depending on the fluid dynamics of freshwater mixing in the Atlantic, the early YD should logically result in delta-O-18 spikes due to the influx of freshwater. The meltwater pulses are not caused by sudden temperature spikes though it is plausible that the freshwater influx disrupts the major Atlantic currents and has localized temperature impacts. YD-style spikes occur after each glacial termination in the era of 100-ky glacial cycles as seen in the LR04 data set; parallel meltwater pulse events every 100 ky. You are correct, the graphs showing sharply lower temperatures are common and these graphs are technically correct because they are plotting delta-temperature-“equivalents”, but drastic changes can be the result of freshwater changes alone at a constant temperature.