by Eclectic Man » Tue Aug 10, 2021 10:26 am
Chris Peterson wrote: ↑Tue Aug 10, 2021 2:20 am
Eclectic Man wrote: ↑Mon Aug 09, 2021 7:23 pm
neufer, thanks for the reference. Lovely images.
@ Chris Peterson: The meteor was far too quick for any possibility of my eyes or the binoculars 'wiggling' and causing any illusion of corkscrew motion. Meteors are not aerodynamically stable like an Apollo capsule, and it is highly likely that they are spinning when they hit the atmosphere. It was very faint and so must have been a small one and therefore its trajectory was more affected by resistance on its path through the atmosphere. Large meteors may have enough mass to be untroubled by aerodynamic turbulence, but small ones, irregular in shape will be buffeted about and therefore not follow a straight line flight path. Not only that but the ram pressure and heating on a meteor is unevenly distributed, causing partial or eventually complete melting of a small item travelling at high supersonic velocity. The only things that don't tumble when entering the atmosphere are either very big or carefully designed to be stable. Note that cannon balls and lead shot are notoriously inaccurate over long distances due to aerodynamic pressures on non-gyroscopically stabilised objects travelling at supersonic speeds (which is why the invention of the rifle was significant for hunting and warfare). I hope this explanation helps.
A meteor cannot move more than a few meters back and forth as it "corkscrews". This has occasionally been recorded with some fancy meteor tracking telescopes. It is potentially something that might be seen in a chance crossing of a meteor through a telescopic field. It isn't visible to the naked eye, or to a camera with a lens having a focal length consistent with normal photography. And it isn't going to be visible through binoculars.
What you saw was an illusion.
OK, Mr Peterson. Firstly, your posts do come across as rather aggressive, so maybe you could, in future, consider how you express yourself. Stating things like "That doesn't happen", and "What you saw was an illusion" could certainly be put more politely. Science is full of people denying things happened when they actually did.
Secondly, please read my original posting more carefully. I wrote that the meteor "appeared' to follow a corkscrew path. I note that you originally claimed that the appearance was due to my eyes or wiggling the binoculars. Maybe you could provide an explanation of how you claim such an illusion may be created. Reference to a published, peer-reviewed academic article in a respected journal would be appreciated. (A reference to a learned article on the sideways motion of meteors in flight supporting your assertions about that would also be appreciated.)
Thirdly, why are you so intent on denying what happened? Maybe I was just very lucky, once, in my over 60 years of inhabiting this planet, to see something extraordinary. Extraordinary events do happen, like the parachutist who was nearly hit by a meteorite in dark flight:
https://www.smithsonianmag.com/smart-ne ... 180950397/ (Skip to about 2m in to see the meteorite drop past.)
Fourthly, I expect that you will insist on 'having the last word', so maybe consider making it a nice one?
[quote="Chris Peterson" post_id=315721 time=1628562010 user_id=117706]
[quote="Eclectic Man" post_id=315717 time=1628536994 user_id=129639]
[quote=neufer post_id=315710 time=1628521443 user_id=124483]
[url=https://britastro.org/node/11973]The curious case of the corkscrew meteors....[/url]
[/quote]
neufer, thanks for the reference. Lovely images.
@ Chris Peterson: The meteor was far too quick for any possibility of my eyes or the binoculars 'wiggling' and causing any illusion of corkscrew motion. Meteors are not aerodynamically stable like an Apollo capsule, and it is highly likely that they are spinning when they hit the atmosphere. It was very faint and so must have been a small one and therefore its trajectory was more affected by resistance on its path through the atmosphere. Large meteors may have enough mass to be untroubled by aerodynamic turbulence, but small ones, irregular in shape will be buffeted about and therefore not follow a straight line flight path. Not only that but the ram pressure and heating on a meteor is unevenly distributed, causing partial or eventually complete melting of a small item travelling at high supersonic velocity. The only things that don't tumble when entering the atmosphere are either very big or carefully designed to be stable. Note that cannon balls and lead shot are notoriously inaccurate over long distances due to aerodynamic pressures on non-gyroscopically stabilised objects travelling at supersonic speeds (which is why the invention of the rifle was significant for hunting and warfare). I hope this explanation helps.
[/quote]
A meteor cannot move more than a few meters back and forth as it "corkscrews". This has occasionally been recorded with some fancy meteor tracking telescopes. It is potentially something that might be seen in a chance crossing of a meteor through a telescopic field. It isn't visible to the naked eye, or to a camera with a lens having a focal length consistent with normal photography. And it isn't going to be visible through binoculars.
What you saw was an illusion.
[/quote]
OK, Mr Peterson. Firstly, your posts do come across as rather aggressive, so maybe you could, in future, consider how you express yourself. Stating things like "That doesn't happen", and "What you saw was an illusion" could certainly be put more politely. Science is full of people denying things happened when they actually did.
Secondly, please read my original posting more carefully. I wrote that the meteor "appeared' to follow a corkscrew path. I note that you originally claimed that the appearance was due to my eyes or wiggling the binoculars. Maybe you could provide an explanation of how you claim such an illusion may be created. Reference to a published, peer-reviewed academic article in a respected journal would be appreciated. (A reference to a learned article on the sideways motion of meteors in flight supporting your assertions about that would also be appreciated.)
Thirdly, why are you so intent on denying what happened? Maybe I was just very lucky, once, in my over 60 years of inhabiting this planet, to see something extraordinary. Extraordinary events do happen, like the parachutist who was nearly hit by a meteorite in dark flight: https://www.smithsonianmag.com/smart-news/watch-skydiver-almost-gets-hit-meteorite-mid-air-180950397/ (Skip to about 2m in to see the meteorite drop past.)
Fourthly, I expect that you will insist on 'having the last word', so maybe consider making it a nice one?