@nikito : Sorry, but pls. let's stay in reality. Tardigrades do not travel through space and panspermia is more of a belief than actual science, don't let Wikipedia or Star Trek fool you..

That whole tardigrade thing originates from an experiment carried out on the ISS in 2007, some organisms were exposed to low earth orbit (leo) conditions for a few days and some (a few !) t.s survived for a few hours. Most of them died either directly or subsequently when re-hydrated. Keep in mind, leo (here: Thermosphere) is not interplanetary space and still shielded from ionizing radiation by earth's magnetic field and actually pretty warm.

Just sayin', i don't want to battle. But we should stay reasonable. And concentrate on other bugs. Like me on my darn PBR tinkering … :-)

@calin : “End of times” is pure religious/world view expression. It has no significance in paleo-anthropology or earth science, I can tell.

@Green_Baron Thanks, for clarifying that. My information tells me tardigrades can travel through space.

Even, so, humans hardly can destroy life on Earth. Even if humans make all nuclear devices explode, nature will pretty easily survive. Look at the blooming chernobil place. So far there are bacteria living in radiation, bacteria eating petrol, and life that doesn't need the sun. It would be impossible for humans to destroy life on Earth even if they tried to.

If sun explodes… this is only a prediction. It makes sense now, but maybe it will not make sense a hundred times later.

It is like the center of the Earth, nobody was there, and in school they sell us theories as if they were definitive ultimate unbeatable truth. You should know how tricky false positives can be. It all can make sense, but for the wrong reason. Maybe someday the "almighty" science will explain why our poles are moving in the way they do.

So far we are using fire in a cave. Cavemen can do great things with fire, but they can not explain fire.

Plus, we can say the end of Earth is the end of the world, only if we completely IGNORE other planets with biomass. Or if we

NikiTo said:
Even, so, humans hardly can destroy life on Earth. Even if humans make all nuclear devices explode, nature will pretty easily survive. Look at the blooming chernobil place. So far there are bacteria living in radiation, bacteria eating petrol, and life that doesn't need the sun. It would be impossible for humans to destroy life on Earth even if they tried to.

Uh, the only reason life can exist in Chernobyl is that the reactor explosion only caused radiation to spread. Firing a nuke at a place has a huuuge primary impact in the form of heat, shockwave etc… So humanity could easily wipe out all life when all nukes were fired. Not because of the radiation, but because every bomb would leave a kilometers-wide explosion crater, where all life was incinerated.

I mean, look at how long it too for Hiroshima to be habitable again. And that only happened because life continued to exist outside, so ie. plants could grow back in. If everything on the entire continent was ashes, nothing would be able to come back.

And sure, some bacteria might be able to still survive all that, but, whats the point? Technically bacteria is life, but at the point where all plants, animals, humans are extinct I personally wouldn't say “duhh life still exists because theres some single cell organisms crawling around”.

@Juliean few thousands of nukes can not cover the whole dry surface of the Earth.

And the immense ocean will be left full of life.

Creating a constantly growing black hole inside the Hadron Collider is only plausible way humans have to destroy life on Earth. But i doubt it much they can create a constantly growing black hole even by accident.

Having not information about black holes, theories only, we could not bet a black hole can destroy life. Tardigrades could survive it and end up alive an kicking on the other side of the black hole. Did i mention i like water bears a lot?

Unicellular organisms are life just like complex multicellular ones. Unicellular life had already been around for almost 3 billion years (first appearance debated, but not later than 3.6 billion years before now) when complex organisms and biocenoses formed. Its role in the biosphere is existential for the multicellular likes of us. Free oxygen for everybody :-) And cleanup-service after the party ! As well as assistance when metabolising, or so :-)

@nikito : The open ocean is actually a desert. Biological activity is abundant around the continental shelves and in so called upwelling zones and cold, oxygen rich water. The ocean is increasingly becoming deoxygenated these days (global warming and all that). The mentioned scenario and its washings from the continents would quickly push it “over the edge” into an anoxic state. It is not that that is new or phantastic, anoxic events have happened in the geological past and our understanding is good enough for reasonable predictions for the future.

@Green_Baron Who was driving petrol cars in our geological past?

Thank you for “informing” me, so i can “know” that in the middle of the ocean a shark can not eat me, because sharks have nothing to breathe in the middle of the ocean, so no sharks there.

@bregma +1. Until and including “These are better days.” :-)

I wish i had taken computer science and not economics in the early 80s. But, otoh, the choice of that prattle discipline enabled me to study one more time in 2000s (prehistory, a geoscience subject). Now, as i am confined to my 4 walls as many others, i dabble with the computer.

Hey, maybe we'll have more opportunities for studying online in the near future ! That'll be cool.

@nikito Mass extinction and ocean anoxia:

https://www.pnas.org/content/108/43/17631

https://www.pnas.org/content/115/23/5896

not paywalled. Real science :-) Cool stuff (Hirnantian glaciation) and hot stuff (Late Permian warm climate) :-)

@Green_Baron I think school radicalized you. Peace, dude!