5 ms·

The change in orbital shape was already known as one of the Milankovitch cycles [1]. This study seems to give us the most precise measurement. In the context o

by mkempe 8y ago

The change in orbital shape was already known as one of the Milankovitch cycles [1]. This study seems to give us the most precise measurement. In the context of climate change, when Earth's orbit becomes more eccentric (our path over the next 200k years) seasonal changes increase in magnitude. [1] https://en.wikipedia.org/wiki/Milankovitch_cycles#Orbital_shape_(eccentricity) https://en.wikipedia.org/wiki/Milankovitch_cycles#Orbital_sh...

milankovic 8y ago
It's Milanković actually, and that guy also has his own entry on Wikipedia: https://en.wikipedia.org/wiki/Milutin_Milankovi%C4%87 https://en.wikipedia.org/wiki/Milutin_Milankovi%C4%87 I'm repeating myself again here, but it's funny to see when your nickname on HN suddenly becomes relevant. * EDIT: Just because it is apparently not clear enough. No, this is not a coincidence, no, my real name is not milankovic or similar, and yes, I've chosen my handle in honor of this scientist. * But you are right, I am completely with you in regard to this certain point: > The change in orbital shape was already known as one of the Milankovitch cycles It was already known, yeah. Or so I (we?) assumed. I'm just some poor slob who visited an ordinary school, not an astronomer, not special in any other way, and I still remember that we learned this stuff back then. Astronomy 101. I bring this up in a comment here, and all I get is downvotes. Which tells a lot about HN, I think. The context of climate change, now that is the really interesting question. I am really fascinated to see that Milankovic is finally becoming more relevant today. (Ask about a famous Serbian scientist, and everyone can mention Tesla. Ask for the next one, and observe. But that's a good test, to see who really gives a damn about science) Interestingly, I did a Ctrl+F on that NYT article for the name, and nothing came up. They even fail to mention the relevance to climate change at all, which is, as everyone knows, totally not an important current issue in, well, 2018; and maybe it is just me, but one would assume that this could be something newsworthy. Again, the fake news NYT utterly fails once more. I should really not be surprised at this point.
- flukus 8y ago
  > I bring this up in a comment here, and all I get is downvotes. Which tells a lot about HN, I think. You've managed to be dismissive of everyone that knows slightly less than you, everyone that didn't cover this in school, and at the same time dismissive of everyone that knows much more, climate scientists. Apparently you think this is universal knowledge but somehow has escaped the attention of climate scientists.
- saagarjha 8y ago
  > I'm just some poor slob who visited an ordinary school, not an astronomer, not special in any other way, and I still remember that we learned this stuff back then. Astronomy 101. Not everyone is required to take Astronomy courses in school. For example, my formal education never included it. > I am really fascinated to see that Milankovic is finally becoming more relevant today. (Ask about a famous Serbian scientist, and everyone can mention Tesla. Ask for the next one, and observe. But that's a good test While Tesla was ethnically Serbian, I'd consider him to be an American scientist since that's where he lived for most of his life, and did most of his work. Plus he was born in what is today Croatia. Honestly, though, does it really matter other than for fictional nationalistic bragging rights? > I bring this up in a comment here, and all I get is downvotes Because you're acting like a snob? > It's Milanković actually, and that guy also has his own entry on Wikipedia Had you taken the care to actually read the article you linked, you'd notice that the name of the cycle is Milankovitch, regardless of the actual name of its eponym: > The second contribution is the explanation of Earth's long-term climate changes caused by changes in the position of the Earth in comparison to the Sun, now known as Milankovitch cycles
  - coldtea 8y ago
    >While Tesla was ethnically Serbian, I'd consider him to be an American scientist since that's where he lived for most of his life, and did most of his work. Plus he was born in what is today Croatia. Honestly, though, does it really matter other than for fictional nationalistic bragging rights? Yes. It matters if one keeps a tally of what one civilization or another did, like we do for ancient times, and the future will do for us for example. It also matters if one wants to get an estimation which country, kind of educational system, laws, etc, produces more or less good outcomes (e.g. innovation) in this or that field. And of course, if the person claimed he is so or that, and cherished that, we should respect them, and not rebrand them. For example there are examples of famous immigrants to US, France, and other places, in literary and other circles, that don't like to adopt their country of citizenship as their nationality. For them their culture is always their other one, and their citizenship is only a matter of residence, convenience etc.
    - 8y ago
- JetSetWilly 8y ago
  > Ask about a famous Serbian scientist, and everyone can mention Tesla. Ask for the next one, and observe. But that's a good test, to see who really gives a damn about science It is a horrible test. There’s a large difference between being interested in the history of science, and who did what and where they hailed from, and actually being interested in science. Just because I don’t care to read tabloids about the personal lifes of actors and where they are from doesn’t mean I don’t like movies.
  - milankovic 8y ago
    Wrong. It's a perfect test, to see whether a so called climate scientist is actually worth his salt. > There’s a large difference between being interested in the history of science, and who did what and where they hailed from, and actually being interested in science. I fundamentally disagree. If you are really interested in science, but not in the history of science, you are doing something very, very wrong, and you are bound to repeat a lot of mistakes if you are not willing to learn lessons from history. But my suspicion is, while many people claim to be interested in science, because it's 2018 and it is definitely fancy to do so, they deep down do not care. Participating in bullshit events like "marches for science" is a really poor disguise, in my opinion.
- oldcynic 8y ago
  Perhaps you were educated in Serbia? They might cover in much more depth contributions from a significant Serb scientist than other countries. From my recollection of what they covered in school it went no further than that the orbit is an ellipse. I got more detail from my years on the net.
  - milankovic 8y ago
    I was not, I have never been to Serbia in my whole life. I learned this in school nonetheless, I don't know what so say anymore. Many more had this covered in school as well, I believe, but hey, maybe you simply forgot? I find that lack in general education in that regard a bit disturbing. But let me compliment you that you actually went ahead and learned a bit more about the details on your own volition. That means there are at least two of us on here..
- my_first_acct 8y ago
  > Ask about a famous Serbian scientist, and everyone can mention Tesla. Ask for the next one, and observe. I was going to mention Mohorovičić [1], but it turns out he was Croatian (which to me means that Milanković and Mohorovičić were both Yugoslavians, but the Serbs and the Croats don't seem to view things that way). Then I remembered the Serbian-American inventor/engineer Michael (or Mihajlo) Pupin [2], who really deserves to be better known. Besides being an inventor, he won a Pulitzer prize in 1924 for his autobiography, "From Immigrant to Inventor". Anyway, that's the main reason I'm posting this comment, to attempt to rescue Pupin from semi-obscurity. But while I'm here, I'll mention that I didn't learn about Milankovitch cycles in astronomy courses, but in geology courses, because of the cycles' influence on the timing of the Ice Ages. [1] https://en.wikipedia.org/wiki/Andrija_Mohorovi%C4%8Di%C4%87 https://en.wikipedia.org/wiki/Andrija_Mohorovi%C4%8Di%C4%87 [2] https://en.wikipedia.org/wiki/Mihajlo_Pupin https://en.wikipedia.org/wiki/Mihajlo_Pupin
  - milankovic 8y ago
    But at least you learned about it.. thank god, I was starting to lose my faith in humanity. And thanks for the shout-out to Mr Pupin and Mr Mohorovičić, and for providing some links as well, I wholeheartedly approve of any attempts to rescue important characters from their undeserved obscurity. Really appreciate it.
patall 8y ago
> In the context of climate change, when Earth's orbit becomes more eccentric (our path over the next 200k years) seasonal changes increase in magnitude. Isn't that only so on one of the hemispheres? Right now, earth is slightly further away from the sun when its summer on the northern hemisphere which means that our summers are some 5-7 days longer than our winters and our seasons are actually less intense here.
- madaxe_again 8y ago
  It’s more complex than either case. The eccentricity of earth’s orbit precesses, as well as earth’s axial tilt. In a circular orbit, the seasonal variation is driven solely by the axial tilt and relative hemispherical insolation bought about by earth’s own shadow, and angle of the sun to terrain. With a variable distance from the sun, the seasons become erratic, as these two variables precess out of sync - you end up with winters in one hemisphere where the earth is close to the sun, making for mild winter and scorching summer in the other hemisphere. Equally you end up with the earth far from the sun, and bitter winters and cool summers. Finally, you have the precessions 180 degrees out of sync, and you end up with almost no seasonal variation. So - it makes the overall swings far more extreme, but in some phases can result in milder seasons.
  - Unkechaug 8y ago
    Where are we now and where are we headed?
    - mkempe 8y ago
      We're headed to the end of the current interglacial, returning to a drastically cooler climate. The last interglacial (the Eemian [1]) lasted 15k years and was warmer than what we experience today; sea level at peak was probably 6 to 9 m (20 to 30 feet) higher than today; Scandinavia was an island. Then the glaciation returned for 100k years with mile-thick ice sheets covering huge parts of Europe and North America, until the current interglacial got going almost 12,000 years ago. [2] "The axial tilt varies between 22.1° and 24.5°, over a cycle of about 41,000 years. The current tilt is 23.44°, roughly halfway between its extreme values. The tilt last reached its maximum in 8,700 BCE. It is now in the decreasing phase of its cycle, and will reach its minimum around the year 11,800 CE. ... decreasing tilt may encourage the onset of an ice age ..." [3] [1] https://en.wikipedia.org/wiki/Eemian https://en.wikipedia.org/wiki/Eemian [2] https://en.wikipedia.org/wiki/Last_glacial_period https://en.wikipedia.org/wiki/Last_glacial_period [3] https://en.wikipedia.org/wiki/Milankovitch_cycles#Axial_tilt_(obliquity) https://en.wikipedia.org/wiki/Milankovitch_cycles#Axial_tilt...

by mkempe 8y ago

milankovic 8y ago

It's Milanković actually, and that guy also has his own entry on Wikipedia: https://en.wikipedia.org/wiki/Milutin_Milankovi%C4%87 https://en.wikipedia.org/wiki/Milutin_Milankovi%C4%87 I'm repeating myself again here, but it's funny to see when your nickname on HN suddenly becomes relevant. * EDIT: Just because it is apparently not clear enough. No, this is not a coincidence, no, my real name is not milankovic or similar, and yes, I've chosen my handle in honor of this scientist. * But you are right, I am completely with you in regard to this certain point: > The change in orbital shape was already known as one of the Milankovitch cycles It was already known, yeah. Or so I (we?) assumed. I'm just some poor slob who visited an ordinary school, not an astronomer, not special in any other way, and I still remember that we learned this stuff back then. Astronomy 101. I bring this up in a comment here, and all I get is downvotes. Which tells a lot about HN, I think. The context of climate change, now that is the really interesting question. I am really fascinated to see that Milankovic is finally becoming more relevant today. (Ask about a famous Serbian scientist, and everyone can mention Tesla. Ask for the next one, and observe. But that's a good test, to see who really gives a damn about science) Interestingly, I did a Ctrl+F on that NYT article for the name, and nothing came up. They even fail to mention the relevance to climate change at all, which is, as everyone knows, totally not an important current issue in, well, 2018; and maybe it is just me, but one would assume that this could be something newsworthy. Again, the fake news NYT utterly fails once more. I should really not be surprised at this point.

flukus 8y ago
> I bring this up in a comment here, and all I get is downvotes. Which tells a lot about HN, I think. You've managed to be dismissive of everyone that knows slightly less than you, everyone that didn't cover this in school, and at the same time dismissive of everyone that knows much more, climate scientists. Apparently you think this is universal knowledge but somehow has escaped the attention of climate scientists.
saagarjha 8y ago
> I'm just some poor slob who visited an ordinary school, not an astronomer, not special in any other way, and I still remember that we learned this stuff back then. Astronomy 101. Not everyone is required to take Astronomy courses in school. For example, my formal education never included it. > I am really fascinated to see that Milankovic is finally becoming more relevant today. (Ask about a famous Serbian scientist, and everyone can mention Tesla. Ask for the next one, and observe. But that's a good test While Tesla was ethnically Serbian, I'd consider him to be an American scientist since that's where he lived for most of his life, and did most of his work. Plus he was born in what is today Croatia. Honestly, though, does it really matter other than for fictional nationalistic bragging rights? > I bring this up in a comment here, and all I get is downvotes Because you're acting like a snob? > It's Milanković actually, and that guy also has his own entry on Wikipedia Had you taken the care to actually read the article you linked, you'd notice that the name of the cycle is Milankovitch, regardless of the actual name of its eponym: > The second contribution is the explanation of Earth's long-term climate changes caused by changes in the position of the Earth in comparison to the Sun, now known as Milankovitch cycles
- coldtea 8y ago
  >While Tesla was ethnically Serbian, I'd consider him to be an American scientist since that's where he lived for most of his life, and did most of his work. Plus he was born in what is today Croatia. Honestly, though, does it really matter other than for fictional nationalistic bragging rights? Yes. It matters if one keeps a tally of what one civilization or another did, like we do for ancient times, and the future will do for us for example. It also matters if one wants to get an estimation which country, kind of educational system, laws, etc, produces more or less good outcomes (e.g. innovation) in this or that field. And of course, if the person claimed he is so or that, and cherished that, we should respect them, and not rebrand them. For example there are examples of famous immigrants to US, France, and other places, in literary and other circles, that don't like to adopt their country of citizenship as their nationality. For them their culture is always their other one, and their citizenship is only a matter of residence, convenience etc.
  - 8y ago
JetSetWilly 8y ago
> Ask about a famous Serbian scientist, and everyone can mention Tesla. Ask for the next one, and observe. But that's a good test, to see who really gives a damn about science It is a horrible test. There’s a large difference between being interested in the history of science, and who did what and where they hailed from, and actually being interested in science. Just because I don’t care to read tabloids about the personal lifes of actors and where they are from doesn’t mean I don’t like movies.
- milankovic 8y ago
  Wrong. It's a perfect test, to see whether a so called climate scientist is actually worth his salt. > There’s a large difference between being interested in the history of science, and who did what and where they hailed from, and actually being interested in science. I fundamentally disagree. If you are really interested in science, but not in the history of science, you are doing something very, very wrong, and you are bound to repeat a lot of mistakes if you are not willing to learn lessons from history. But my suspicion is, while many people claim to be interested in science, because it's 2018 and it is definitely fancy to do so, they deep down do not care. Participating in bullshit events like "marches for science" is a really poor disguise, in my opinion.
oldcynic 8y ago
Perhaps you were educated in Serbia? They might cover in much more depth contributions from a significant Serb scientist than other countries. From my recollection of what they covered in school it went no further than that the orbit is an ellipse. I got more detail from my years on the net.
- milankovic 8y ago
  I was not, I have never been to Serbia in my whole life. I learned this in school nonetheless, I don't know what so say anymore. Many more had this covered in school as well, I believe, but hey, maybe you simply forgot? I find that lack in general education in that regard a bit disturbing. But let me compliment you that you actually went ahead and learned a bit more about the details on your own volition. That means there are at least two of us on here..
my_first_acct 8y ago
> Ask about a famous Serbian scientist, and everyone can mention Tesla. Ask for the next one, and observe. I was going to mention Mohorovičić [1], but it turns out he was Croatian (which to me means that Milanković and Mohorovičić were both Yugoslavians, but the Serbs and the Croats don't seem to view things that way). Then I remembered the Serbian-American inventor/engineer Michael (or Mihajlo) Pupin [2], who really deserves to be better known. Besides being an inventor, he won a Pulitzer prize in 1924 for his autobiography, "From Immigrant to Inventor". Anyway, that's the main reason I'm posting this comment, to attempt to rescue Pupin from semi-obscurity. But while I'm here, I'll mention that I didn't learn about Milankovitch cycles in astronomy courses, but in geology courses, because of the cycles' influence on the timing of the Ice Ages. [1] https://en.wikipedia.org/wiki/Andrija_Mohorovi%C4%8Di%C4%87 https://en.wikipedia.org/wiki/Andrija_Mohorovi%C4%8Di%C4%87 [2] https://en.wikipedia.org/wiki/Mihajlo_Pupin https://en.wikipedia.org/wiki/Mihajlo_Pupin
- milankovic 8y ago
  But at least you learned about it.. thank god, I was starting to lose my faith in humanity. And thanks for the shout-out to Mr Pupin and Mr Mohorovičić, and for providing some links as well, I wholeheartedly approve of any attempts to rescue important characters from their undeserved obscurity. Really appreciate it.

patall 8y ago

> In the context of climate change, when Earth's orbit becomes more eccentric (our path over the next 200k years) seasonal changes increase in magnitude. Isn't that only so on one of the hemispheres? Right now, earth is slightly further away from the sun when its summer on the northern hemisphere which means that our summers are some 5-7 days longer than our winters and our seasons are actually less intense here.

madaxe_again 8y ago
It’s more complex than either case. The eccentricity of earth’s orbit precesses, as well as earth’s axial tilt. In a circular orbit, the seasonal variation is driven solely by the axial tilt and relative hemispherical insolation bought about by earth’s own shadow, and angle of the sun to terrain. With a variable distance from the sun, the seasons become erratic, as these two variables precess out of sync - you end up with winters in one hemisphere where the earth is close to the sun, making for mild winter and scorching summer in the other hemisphere. Equally you end up with the earth far from the sun, and bitter winters and cool summers. Finally, you have the precessions 180 degrees out of sync, and you end up with almost no seasonal variation. So - it makes the overall swings far more extreme, but in some phases can result in milder seasons.
- Unkechaug 8y ago
  Where are we now and where are we headed?
  - mkempe 8y ago
    We're headed to the end of the current interglacial, returning to a drastically cooler climate. The last interglacial (the Eemian [1]) lasted 15k years and was warmer than what we experience today; sea level at peak was probably 6 to 9 m (20 to 30 feet) higher than today; Scandinavia was an island. Then the glaciation returned for 100k years with mile-thick ice sheets covering huge parts of Europe and North America, until the current interglacial got going almost 12,000 years ago. [2] "The axial tilt varies between 22.1° and 24.5°, over a cycle of about 41,000 years. The current tilt is 23.44°, roughly halfway between its extreme values. The tilt last reached its maximum in 8,700 BCE. It is now in the decreasing phase of its cycle, and will reach its minimum around the year 11,800 CE. ... decreasing tilt may encourage the onset of an ice age ..." [3] [1] https://en.wikipedia.org/wiki/Eemian https://en.wikipedia.org/wiki/Eemian [2] https://en.wikipedia.org/wiki/Last_glacial_period https://en.wikipedia.org/wiki/Last_glacial_period [3] https://en.wikipedia.org/wiki/Milankovitch_cycles#Axial_tilt_(obliquity) https://en.wikipedia.org/wiki/Milankovitch_cycles#Axial_tilt...