5 ms·

Behind the dead-water phenomenon

foobarbecue 6y ago
Hunh, interesting. I thought this was going to be similar to vortex ring state, but seems it's different.
RcouF1uZ4gsC 6y ago
> This work is part of a major project investigating why, during the Battle of Actium (31 BC), Cleopatra's large ships lost when they faced Octavian's weaker vessels. Might the Bay of Actium, which has all the characteristics of a fjord, have trapped the Queen of Egypt's fleet in dead water? The Battle of Actium was one of the great inflection points in history. If Caesar has lost, the world would have looked a lot different. One thing I would think that might be against this hypothesis is that Cleopatra’s flag ship was able to make an escape. It likely would have been the biggest ship and given that Cleopatra brought a lot of gold with here, would have been heavily loaded as well.
- mojomark 6y ago
  >>If Caesar has lost, the world would have looked a lot different. If there are any budding film producers out there, I want to see a movie showing this modern alternative universe:)
  - azernik 6y ago
    A book is probably a lower-capital-investment way of testing out the concept
  - a3n 6y ago
    Wasn't there something like that on reddit years back, that got turned into a book or movie?
    - idoh 6y ago
      Maybe you are thinking of this? https://en.wikipedia.org/wiki/Rome,_Sweet_Rome https://en.wikipedia.org/wiki/Rome,_Sweet_Rome
      - a3n 6y ago
        Yep, that.
      - protomyth 6y ago
        In 2013, Warner Brothers hired screenwriter Brian Miller to rewrite the script. Miller was the writer for the film Apollo 18, his most significant writing and production credit at that time. Other than the general concept, Miller did not use Erwin's work as the basis for his script. Why Hollywood adaptations suck in three sentences.
        thombat 6y ago
        Yep, and I feel peculiarly grateful for the next sentences: By 2018, the screenplay had been languishing in development hell for five years since the most recent script rewrite of 2013 and has yet to be picked up for further development.
- ardit33 6y ago
  "If Caesar has lost, the world would have looked a lot different." -- Octavian, Ceaser was already dead by this point... And, no, I don't think the world would have looked a lot different as the system wouldn't have changed... (Mark Antony would have replaced Ocatavian). As the saying goes, "Rome was not build in one day...." one or two particular rulers didn't have that much effect on the long term. Rome was build gradually and expanded through generations of rulers.... If Mark Antony/Cleoptra combo, was terrible, they would have been eventually been dispatched off, by the internal forces... just like Nero. By the time Rome was not facing an outside existential threat (Partha was tough, but never an existential threat to Rome).
  - turndown 6y ago
    >Mark Antony would have replaced Ocatavian Can't emphasize enough how different Mark Antony and Octavian were; the history of the Roman Empire probably would have been significantly different as Antony had little to no political skill.
  - RcouF1uZ4gsC 6y ago
    > Octavian, Ceaser was already dead by this point... Only his enemies referred to him as Octavian. He referred to himself as Caesar as did all his men, and later Romans. >one or two particular rulers didn't have that much effect on the long term. Augustus as he became known was probably the single most consequential ruler in Rome. He was the transition between the upheaval of the Roman Revolution at the end of the Roman Republic and the Roman Empire. Without Augustus, it is likely that Rome would have continually been racked by civil wars. The disaster of the 2nd century where Rome bled itself dry in a series of civil wars would likely have been moved up. If Antony and Cleopatra had won, I think what we saw later as the East/West split with the Eastern capital at Constantinople may have happened much earlier with the Eastern capital at Alexandria.
    - thaumasiotes 6y ago
      > He referred to himself as Caesar as did all his men, and later Romans. Not just him. Every Roman emperor was called Caesar, which is why Caesar is the word for emperor in other nearby languages. (Compare Russian czar; German kaiser.)
mleonhard 6y ago
How can variations in water density put drag on a ship?
- dredmorbius 6y ago
  By creating two or more layers of water which don't mix, and create internal waves. A video demo is likely useful. Here, a (model) boat under a constant force (falling mass to right of screen) creates an internal wave, eventually slowing the boat until the wave catches up with the boat, which then accelerates: https://invidio.us/watch?v=5bqa3KSZrHQ https://invidio.us/watch?v=5bqa3KSZrHQ Internal waves can create dramatic effects within the water column depending on bathymetry, whilst leaving. minimal surface evidence: https://invidio.us/watch?v=U2lq8TpLqR4 https://invidio.us/watch?v=U2lq8TpLqR4 Gibraltar is a natural location in wwhich internal waves develop: https://invidio.us/watch?v=x7GXLJQ2Zn0 https://invidio.us/watch?v=x7GXLJQ2Zn0
  - thombat 6y ago
    That truly was a case of a picture being worth a thousand words - a much more dramatic effect than my puny intuition had guessed, and a nice piece of video editing: a clear view of the salient parts and no blather. Thanks indeed for posting the links.

Hunh, interesting. I thought this was going to be similar to vortex ring state, but seems it's different.

> This work is part of a major project investigating why, during the Battle of Actium (31 BC), Cleopatra's large ships lost when they faced Octavian's weaker vessels. Might the Bay of Actium, which has all the characteristics of a fjord, have trapped the Queen of Egypt's fleet in dead water? The Battle of Actium was one of the great inflection points in history. If Caesar has lost, the world would have looked a lot different. One thing I would think that might be against this hypothesis is that Cleopatra’s flag ship was able to make an escape. It likely would have been the biggest ship and given that Cleopatra brought a lot of gold with here, would have been heavily loaded as well.

mojomark 6y ago
>>If Caesar has lost, the world would have looked a lot different. If there are any budding film producers out there, I want to see a movie showing this modern alternative universe:)
- azernik 6y ago
  A book is probably a lower-capital-investment way of testing out the concept
- a3n 6y ago
  Wasn't there something like that on reddit years back, that got turned into a book or movie?
  - idoh 6y ago
    Maybe you are thinking of this? https://en.wikipedia.org/wiki/Rome,_Sweet_Rome https://en.wikipedia.org/wiki/Rome,_Sweet_Rome
    - a3n 6y ago
      Yep, that.
    - protomyth 6y ago
      In 2013, Warner Brothers hired screenwriter Brian Miller to rewrite the script. Miller was the writer for the film Apollo 18, his most significant writing and production credit at that time. Other than the general concept, Miller did not use Erwin's work as the basis for his script. Why Hollywood adaptations suck in three sentences.
      - thombat 6y ago
        Yep, and I feel peculiarly grateful for the next sentences: By 2018, the screenplay had been languishing in development hell for five years since the most recent script rewrite of 2013 and has yet to be picked up for further development.
ardit33 6y ago
"If Caesar has lost, the world would have looked a lot different." -- Octavian, Ceaser was already dead by this point... And, no, I don't think the world would have looked a lot different as the system wouldn't have changed... (Mark Antony would have replaced Ocatavian). As the saying goes, "Rome was not build in one day...." one or two particular rulers didn't have that much effect on the long term. Rome was build gradually and expanded through generations of rulers.... If Mark Antony/Cleoptra combo, was terrible, they would have been eventually been dispatched off, by the internal forces... just like Nero. By the time Rome was not facing an outside existential threat (Partha was tough, but never an existential threat to Rome).
- turndown 6y ago
  >Mark Antony would have replaced Ocatavian Can't emphasize enough how different Mark Antony and Octavian were; the history of the Roman Empire probably would have been significantly different as Antony had little to no political skill.
- RcouF1uZ4gsC 6y ago
  > Octavian, Ceaser was already dead by this point... Only his enemies referred to him as Octavian. He referred to himself as Caesar as did all his men, and later Romans. >one or two particular rulers didn't have that much effect on the long term. Augustus as he became known was probably the single most consequential ruler in Rome. He was the transition between the upheaval of the Roman Revolution at the end of the Roman Republic and the Roman Empire. Without Augustus, it is likely that Rome would have continually been racked by civil wars. The disaster of the 2nd century where Rome bled itself dry in a series of civil wars would likely have been moved up. If Antony and Cleopatra had won, I think what we saw later as the East/West split with the Eastern capital at Constantinople may have happened much earlier with the Eastern capital at Alexandria.
  - thaumasiotes 6y ago
    > He referred to himself as Caesar as did all his men, and later Romans. Not just him. Every Roman emperor was called Caesar, which is why Caesar is the word for emperor in other nearby languages. (Compare Russian czar; German kaiser.)

mleonhard 6y ago

How can variations in water density put drag on a ship?

dredmorbius 6y ago
By creating two or more layers of water which don't mix, and create internal waves. A video demo is likely useful. Here, a (model) boat under a constant force (falling mass to right of screen) creates an internal wave, eventually slowing the boat until the wave catches up with the boat, which then accelerates: https://invidio.us/watch?v=5bqa3KSZrHQ https://invidio.us/watch?v=5bqa3KSZrHQ Internal waves can create dramatic effects within the water column depending on bathymetry, whilst leaving. minimal surface evidence: https://invidio.us/watch?v=U2lq8TpLqR4 https://invidio.us/watch?v=U2lq8TpLqR4 Gibraltar is a natural location in wwhich internal waves develop: https://invidio.us/watch?v=x7GXLJQ2Zn0 https://invidio.us/watch?v=x7GXLJQ2Zn0
- thombat 6y ago
  That truly was a case of a picture being worth a thousand words - a much more dramatic effect than my puny intuition had guessed, and a nice piece of video editing: a clear view of the salient parts and no blather. Thanks indeed for posting the links.