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11 hours ago, Green Baron said:

Cosmic ping-pong, most probably single player:

http://www.eso.org/public/news/eso1802/

tl,dr: a star goes so fast here and there that it is most certainly orbiting a close black hole with ~4.4 solar masses. The alternative explanation that two very close neutron stars represent the central mass is considered improbable, but not impossible. That would be the first stellar black hole observed directly by its gravity in a globular cluster.

 

17 hours ago, Bill Phil said:

Not really. There's not enough evidence to suggest that he even said that during the flight, let alone while in space. Some have attributed him of saying something similar after his flight, but not during it. Really, there's not much of a reliable way to tell what the first words in space were...

Still, a brave man. 

Now, to be somewhat on-topic... The drag equation and the lift equation are nearly identical, the main difference being that the area used in the calculation is different (reference area vs. wing area) and the coefficients are different (drag vs. lift). Of course, these are the simple drag and lift equations, in reality, it gets much more complex then that.

Hey, don’t kill the messenger. I just read it in a book.

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Oxygen production on earth 2.97Gy ago:

https://www.nature.com/articles/s41561-017-0036-x

That does not mean that the atmosphere was not reduced any more (still ate up oxygen if provided), but that at least in oases in shallow oceans oxygen production was running. And it means that the hypothetical Great Oxygenation Event was preceded by more gradual steps of oxygen rise.

Edited by Green Baron
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On 1/10/2018 at 7:52 AM, Green Baron said:

Another victim of climate change: the green sea turtle.

The gender is determined by the temperature of the eggs during breeding. Higher temp. means more females. Female ratio is up to 99.8% in one place, 60-90% elsewhere. Effect observable since 20 years.

Published in "Current Biology".

But the male sea turtles are very happy.

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On 1/10/2018 at 8:52 AM, Green Baron said:

Another victim of climate change: the green sea turtle.

The gender is determined by the temperature of the eggs during breeding. Higher temp. means more females. Female ratio is up to 99.8% in one place, 60-90% elsewhere. Effect observable since 20 years.

Published in "Current Biology".

Isn't it a bit rash to rush from "observed change in sex ratio of green sea turtles" to "victim of climate change?"

Granted it probably is temperature mediating the observation, but why is a change in temperature necessarily a sign of "climate change?" Doesn't climate change "routinely," and pretty much always has? The term itself seems to rely on a fanciful notion that there has EVER been a time in Earth's history when climate was "stable," which as far as I can tell has happened never.

 

Edited by Diche Bach
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10 minutes ago, Diche Bach said:

Isn't it a bit rash to rush from "observed change in sex ratio of green sea turtles" to "victim of climate change?"

Without wanting to risk getting into a discussion about conspiracy theory and the state of the current body of knowledge on the matter, would it please you better if it had said:

"....victim of anthropogenic climate change"?

 

However, I would point out that you are making the very common mistake of conflating "weather" and "climate".

Weather fluctuates rapidly, day-to-day, year-to-year and can be unpredictable and chaotic.

Climate stays stable over very long periods because it is not defined by the conditions on any given day or in any given place.

And yes, climate does naturally change over time, but evidence points to the liklihood that human emissions are having a significant effect on it.

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@Diche Bach, i haven't watched the video because it smells like pseudo science and i have limited bandwidth. There is no new ice age coming because we actually live in an ice age. Yet.

No, it is not "rash", in contrary, it is conclusive and a direct observation, perfectly collimated with anthropogenic climate change. I was on the same side until just a few years ago (have studied geoscience as a side subject but do not practice). We are getting better at distinguishing between natural and the anthropogenic signals. It is too simple to say "wasn't climate always changing ?". Yes, it was and will be, we want to know how much of the change is natural and how much is human induced and we are getting better with the analyses.

Ignoring or denying the published results isn't helpful any more.

I linked one report for 2016 farther up in the thread, so you can read things up, the 2016 report can be read without fear of political influence and is not behind a paywall. Let me add since that in the past 2 years a lot of advancements have been made and newer publications draw a picture of accelerated ocean warming and ice retreat in the Northern sea, Greenland and Antarctica (shelf ice and glaciers).

If you want to know more i suggest you let go of the so called social networks and get to the sources, in condensed form but behind paywalls Nature Geoscience, Science Magazine (AAAS), or the AGU, publications by your countries Geological Survey, ...

 

And, yes, @p1t1o, got a point: weather is not climate ! But more energy in the atmosphere and higher contrasts in temperature and atmospheric water may express themselves in local phenomena, like the snowstorms and cold in northern America. But this in no way contradicts oceanic and atmospheric temperature rise, and again, it a local phenomenon.

Edited by Green Baron
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6 hours ago, Green Baron said:

@Diche Bach, i haven't watched the video because it smells like pseudo science and i have limited bandwidth. There is no new ice age coming because we actually live in an ice age. Yet.

No, it is not "rash", in contrary, it is conclusive and a direct observation, perfectly collimated with anthropogenic climate change. I was on the same side until just a few years ago (have studied geoscience as a side subject but do not practice). We are getting better at distinguishing between natural and the anthropogenic signals. It is too simple to say "wasn't climate always changing ?". Yes, it was and will be, we want to know how much of the change is natural and how much is human induced and we are getting better with the analyses.

Ignoring or denying the published results isn't helpful any more.

I linked one report for 2016 farther up in the thread, so you can read things up, the 2016 report can be read without fear of political influence and is not behind a paywall. Let me add since that in the past 2 years a lot of advancements have been made and newer publications draw a picture of accelerated ocean warming and ice retreat in the Northern sea, Greenland and Antarctica (shelf ice and glaciers).

If you want to know more i suggest you let go of the so called social networks and get to the sources, in condensed form but behind paywalls Nature Geoscience, Science Magazine (AAAS), or the AGU, publications by your countries Geological Survey, ...

 

And, yes, @p1t1o, got a point: weather is not climate ! But more energy in the atmosphere and higher contrasts in temperature and atmospheric water may express themselves in local phenomena, like the snowstorms and cold in northern America. But this in no way contradicts oceanic and atmospheric temperature rise, and again, it a local phenomenon.

You'll be happy to know that 2017 is not the hottest year on record, only the second hottest . . . . global cooling!!!!! [snicker, snicker]

At the lowstand the temperature in the North Atlantic shoreline was something like 5'C cooler than 1900 average, so as long as temperature rise stays below that there is a risk of getting colder. I suspect that some of that has been gobbled up by anthropogenic effects during the industrial age before 1900 and also we have to look at positive feed back as a contributor to climate change during the ice age, if anthropogenic effects negate that then I suspect the potential for entering an ice-age, even now is close to zero. 

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To sum up: entering a new ice age stadial would not be visible during a human lifetime. Ice shield dynamics in the Pleistocene in principle follow a timeline of long buildup (10.000s of years) and quick retreat (thousands of years). There are short term fluctuations of course, especially during OIS-3 (oxygen isotope stage) but these did not disrupt a trend.

Otoh these days greenhouse gases are accumulating so fast since the onset of industrialization and especially in the last decades that the retreat is about to break all past records. It hasn't yet done so, there is one example of ice retreat after the last stadial that was around 1.5 times faster than the observed actual retreat. But that started from a point of maximum spread.

 

Current weather: The ocean and especially the northern Atlantic is not a homogeneous soup. Currents at different levels transport salinity and temperature. A main motor of the global conveyor belt lies there as part of the thermohaline circulation (deep water formation), where warm saline water flows down in a giant elevator off the coast of northern America and Greenland. That can switch states in front of ocean floor thresholds (ridges), thus transporting the warmth and moisture farther north or not, depending on where that elevator resides.

Atmospheric polar fronts and subtropical air can meet, and if the differences in energy are huge then a lot of energy can be released. The polar front and the circumpolar jet stream can form "bights", causing pressure differences and fast formation of cyclones. Depending on the pressure differences these can develop into proper storms.

Oceanic and atmospheric circulation function together with mutual influence.

 

I didn't want to write a sermon so i stop, but i hope i could transport the insight that a lot of energy in the system means higher contrasts and so more impressive events :-). All not that easy, but not impossible to grasp ....

Edited by Green Baron
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7 hours ago, Green Baron said:

To sum up: entering a new ice age would not be visible during a human lifetime. Ice shield dynamics in the Pleistocene in principle follow a timeline of long, short buildup (10.000s of years) and quick retreat (thousands of years). There are short term fluctuations of course, especially during OIS-3 (oxygen isotope stage) but these did not disrupt a trend.

Tell that to people living in the Greenland 742 years ago. Without anthropogenic climate change we really do not know how advanced the Ice Pack might be now.

Quote

Current weather: The ocean and especially the northern Atlantic is not a homogeneous soup. Currents at different levels transport salinity and temperature. A main motor of the global conveyor belt lies there as part of the thermohaline circulation (deep water formation), where warm saline water flows down in a giant elevator off the coast of northern America and Greenland. That can switch states in front of ocean floor thresholds (ridges), thus transporting the warmth and moisture farther north or not, depending on where that elevator resides.

Don't forget that CO2 can also drive circulation and mixing, while the oceans are really basic, if the CO2 levels go to high on the benthic layers the expansion of H3CO2 into CO2 + H20 ---> CO2 gas (In upwellings approaching the surface) can drive the increase of the surface currents. Since CO2 is heavier than O2 and N2 when it displaces these from Ice, the hyper-saline density is higher and thus it falls more quickly from the arctic and antarctic. We are already seeing the consequences in the Pacific Northwest were the water is undergoing acidification. The greatest carbon sink was the perennial ice stores in the arctic (CO2 likes cold icy water) and this drove carbon to the benthic shelf which then dropped into the midatlantic (as the oceans warm in the tropics this will be faster). Since then it gets distrubuted around the world and reappears in the Major upwellings at periods of up to 10,000 years. The carbon 'pump' is likely to increase the rate markedly particularly as the CO2 potential of the deep oceans saturate. All signs are now that the Oceans carbon sink has begun to saturate.

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The largest planet in the Sol system is Saturn, because Jupiter is so large, it's technically a very small brown dwarf. 

This makes Titan the largest moon in the Sol system, while the Galilean moons are small planets.

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19 minutes ago, KAL 9000 said:

The largest planet in the Sol system is Saturn, because Jupiter is so large, it's technically a very small brown dwarf. 

This makes Titan the largest moon in the Sol system, while the Galilean moons are small planets.

The lower cutoff for brown dwarves isn't well defined but it is commonly thought to be where deuterium fusion is possible at around 13MJ.

You can rest assured that what you were taught at primary school (as long as you went to primary school after 2006) is correct, there are 8 known planets in our solar system.

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

Edited by tomf
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8 minutes ago, tomf said:

The lower cutoff for brown dwarves isn't well defined but it is commonly thought to be where deuterium fusion is possible at around 13MJ.

You can rest assured that what you were taught at primary school (as long as you went to primary school after 2006) is correct, there are 8 planets in our solar system.

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

True, the only thing Jupiter has in common with small brown dwarfs is that it size will not increase much even if it was more massive, 

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Jupiter is full featured planet. It could be a proposed, but not yet accepted object called a Fusor, but it is around 13 times too light to start an own fusion (overcome the Coulomb barrier). But the boundary, though being several times above Jupiter's mass, isn't exactly a sharp one.

A quick search:

http://ukads.nottingham.ac.uk/abs/2011ApJ...727...57S

Jupiter's internal excess heat is mainly attributed to gravitational energy release ("sedimentation" in the following link), maybe some D-D fusion may contribute http://iopscience.iop.org/article/10.1086/305797/fulltext/

but that is less than clear.

Edited by Green Baron
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22 hours ago, tomf said:

-snippety snip-

 

22 hours ago, magnemoe said:

-snippety snip-

 

21 hours ago, Green Baron said:

-snippety snip-

Huh. I could've sworn I read that it was a brown dwarf in a science book somewhere... Ah, well. Learn something new (or old, in this case) every day!

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If you ask me, they should seperate the classification of "gas giant" and "planet".

If Pluto is too small to be a planet, but is still a rocky ball of the same order of magnitude as Earth...how can Jupiter be a planet and Pluto not?

Im not saying Pluto should be a planet, but Jupiter is WAY more different, if you take Earth to be a "textbook" planet.

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47 minutes ago, cfds said:

Earth is not a textbook planet, the first observed planets where probably Venus, Jupiter and Mars. You cannot get much more textbook than Jupiter...

Im pretty sure the first observed planet was Earth... XD

 

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2 hours ago, p1t1o said:

If you ask me, they should seperate the classification of "gas giant" and "planet".

If Pluto is too small to be a planet, but is still a rocky ball of the same order of magnitude as Earth...how can Jupiter be a planet and Pluto not?

Im not saying Pluto should be a planet, but Jupiter is WAY more different, if you take Earth to be a "textbook" planet.

The Earth is 455 times the mass of Pluto. Jupiter is only 318 times the mass of Earth.

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2 hours ago, Brotoro said:

The Earth is 455 times the mass of Pluto. Jupiter is only 318 times the mass of Earth.

Showing that, mass-wise, in the order of Jupiter-Earth-Pluto, they are all 2 orders of magnitude different from the next, none of the 3 can easily be grouped together by mass.

Size-wise, Jupiter is 11 times larger than Earth, but Pluto only 5 times smaller - Pluto is within the same order of magnitude, Jupiter is not.

Both metrics however, pale into insignificance given that one is solid and the other is fluid!

 

Edited by p1t1o
2 orders of magnitude
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