Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why and when the Sahara Desert was green: new research

phys.org

Post reply on HN
Print view View original

91–100 of 102 posts

Re: Why and when the Sahara Desert was green: new research

#91

Post by antiatheist »

yakubin wrote: post #79
agent327 wrote: post #75

Earlier quoted context omitted.

I've always thought that being cast out of Eden was not so much a punishment, as merely an unavoidable consequence: having eaten from the tree of knowledge, we now also have the ability to appreciate suffering, and thus no longer experience paradise. That would make paradise a state of mind, rather than a place. After eating the fruit God lists a number of consequences, which sounds somewhat like a punishment, but th…

The snake always seemed to me to be a Promethean figure in this story. It brought us knowledge, like Prometheus brought us fire, and got punished for it by a god.

Thats why should use electricity to free all camels from the servitude of the desert plains.

Re: Why and when the Sahara Desert was green: new research

#92

Post by somenameforme »

meheleventyone wrote: post #85
somenameforme wrote: post #82

Earlier quoted context omitted.

"Harm" is essentially circular logic. Assuming we are acting logically, the only harmful theory is a wrong one. And so when speaking of harm, you are assuming the correctness or incorrectness of some theory. This is why having a free and open society where any theory can be comfortably pursued to its natural limits is absolutely critical. Everything should be being constantly challenged to ensure that we aren't just…

"Assuming we are acting logically"... which a lot/most/all of people don't at any given time which is largely the issue at hand.

I can't think of any examples where this is the case currently. A historic example would be genetics. There's little doubt that genetics influence near to every aspect of our competencies. And that's extremely useful information that can help improve life and society in countless ways. It only became harmful when a man decided to take it to an illogical extreme, predictably creating a very real dystopia in his fanciful efforts to create a very distant utopia.

Re: Why and when the Sahara Desert was green: new research

#93

Post by PaulHoule »

xhkkffbf wrote: post #12
OfSanguineFire wrote: post #9

Earlier quoted context omitted.

Considering that there are archaeological sites in the American Southwest that are posited to have been abandoned due to the disappearance of their water supply, it is hard to blame all the aridness on “white folks”. Moreover, when I cycled through the Anza-Borego State Park in California, several of the information boards discussed how hardscrabble the existence of the Native American peoples in this area was, becau…

This is a solid point. I was at Mesa Verde, the national park with the cliff dwellings. Apparently the people who lived there just up and left, well before Columbus showed up on the other side of the continent. One theory is that the current Hopi people are their descendants. It's pretty clear that bad things happen, even when white people aren't around.

To be fair, North America used to have a lot of megafauna like wooly mammoths and they were hunted to extinction by "native Americans" when they showed up via the land bridge at Alaska.

Re: Why and when the Sahara Desert was green: new research

#94

Post by bennyschmidt »

bgroat wrote: post #31

I'm not a historian, archeologist, or any sort of relevant expert. But I've long had the pet theory that the Green Sahara is the origin of the Eden Myth. Homo Sapiens origin, lush vegetation, turns to dessert for some reason beyond our comprehension...

Think it was a different green area - the Fertile Crescent, not the Sahara. Eden would have been where modern day Kuwait is. As for ancient towns in Sahara, for a long time people wondered how the desert people lived in such a harsh area - but it turns out they've just been there since it was lush. They didn't move to the desert and learn how to survive there, they're just what's left of those populations from the Sahara, and adapted to the changing conditions.

Re: Why and when the Sahara Desert was green: new research

#95

Post by onlyrealcuzzo »

ffgjgf1 wrote: post #86
onlyrealcuzzo wrote: post #16

Earlier quoted context omitted.

Or The Samalas eruption - which is believed to have caused the Little Ice Age - and killed 90% of Europeans & North Americans at the time (55M people). I imagine many millions of large mammals and birds and insects also died.

> and killed 90% of Europeans & North Americans at the time (55M people). That’s very far fetched. > which is believed By whom? The little ice age peaked in the 1600s.

https://en.wikipedia.org/wiki/1257_Samalas_eruption

> The eruption may have helped trigger the Little Ice Age, a centuries-long cold period during the last thousand years.

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

> In a 2012 paper, Miller et al. link the Little Ice Age to an "unusual 50-year-long episode with four large sulfur-rich explosive eruptions, each with global sulfate loading >60 Tg" and notes that "large changes in solar irradiance are not required."[8]

https://globalnews.ca/news/4924534/little-ice-age-death-55-m...

> The elimination of nearly 55 million, or 90 per cent, of Indigenous people in the Americas during European colonization led to global climate change and the “Little Ice Age” of the 17th century, a recent study finds.

In fairness, the Samalas Eruption did not directly lead to Ghengis Khan or Black Death. But during the Little Ice Age - the populations reduced by ~90%.

Re: Why and when the Sahara Desert was green: new research

#96

Post by tim333 »

xhkkffbf wrote: post #18

I've heard about some efforts to regreen the desert by careful planting and geoforming. Anyone know anything about this? It would be cool if it could work, even partially.

They did a bit in China and there is talk of doing the Sinai https://www.theguardian.com/environment/2021/mar/20/our-bigg...

Re: Why and when the Sahara Desert was green: new research

#97

Post by tim333 »

kefabean wrote: post #23

It obviously doesn't cover the why of Sahara's greening, but for anyone who has access to BBC iPlayer, the following programme [1] has a nice summary of humanity's journey out of Africa. It's amazing that the majority of the world's population is descended from the couple of hundred individuals that left during one of these greening periods. [1] https://www.bbc.co.uk/iplayer/episode/b00kfqps/the-incredibl...

or without iplayer https://yandex.ru/video/preview/13243013351978795119

Re: Why and when the Sahara Desert was green: new research

#98

Post by [deleted] »

raylad wrote: post #49
bgroat wrote: post #31

I'm not a historian, archeologist, or any sort of relevant expert. But I've long had the pet theory that the Green Sahara is the origin of the Eden Myth. Homo Sapiens origin, lush vegetation, turns to dessert for some reason beyond our comprehension...

I've always interpreted the Eden myth as a memory of the development of agriculture. Before agriculture, people lived as hunters and (mainly) gatherers. The life of a Hunter-gatherer is, surprisingly, mostly leisure, because of the abundance of food and the low population density. Even Kalahari Bushmen, who had been forced to live in the dessert, were found to average only about 1 1/2 to 2 1/2 hours of productive lab…

[deleted]

Re: Why and when the Sahara Desert was green: new research

#99

Post by bjelkeman-again »

labster wrote: post #26
bjelkeman-again wrote: post #11

Earlier quoted context omitted.

Meteor strikes are also natural. That doesn’t mean they are desirable.

The meteor isn’t the problem. It’s the delta-V of the meteor which is the problem.

Speed and size. But as speed generally is high (11-72 km/s) [1] then size matters more. Anything hitting you at km/s that survives the journey through the atmosphere is going to hurt I think. :)

https://www.amsmeteors.org/meteor-showers/meteor-faq/#3

Re: Why and when the Sahara Desert was green: new research

#100

Post by anonporridge »

agent327 wrote: post #75
raylad wrote: post #49

Earlier quoted context omitted.

I've always interpreted the Eden myth as a memory of the development of agriculture. Before agriculture, people lived as hunters and (mainly) gatherers. The life of a Hunter-gatherer is, surprisingly, mostly leisure, because of the abundance of food and the low population density. Even Kalahari Bushmen, who had been forced to live in the dessert, were found to average only about 1 1/2 to 2 1/2 hours of productive lab…

I've always thought that being cast out of Eden was not so much a punishment, as merely an unavoidable consequence: having eaten from the tree of knowledge, we now also have the ability to appreciate suffering, and thus no longer experience paradise. That would make paradise a state of mind, rather than a place. After eating the fruit God lists a number of consequences, which sounds somewhat like a punishment, but th…

Yes.

The tree of knowledge of good and evil is basically just the spark of consciousness. Humans are unique in our ability to consciously foresee and plan for the future.

On the one hand, that's a blessing because we've made tons of progress towards alleviating objective suffering and scarcity.

On the other hand, it's a curse, because we always have to be aware of the impending inevitability of our death. We can't ever completely live in peace and paradise ever again, because we have become conscious of our existence and the context our life experience exists within.

Would it be better to not have gained that spark of consciousness and live the paradise of ignorance as animals in the wildreness? Lives at peace except for occasional bursts of pain and terror.

Post reply on HN