Starship Asterisk*

[quote=ecdowney post_id=302898 time=1591550229 user_id=119229]
If radius is proportional to time back, it looks like at first there was no rotation (outer third), then equal emission in all directions (middle third), and now leisurely rotation (inner third). Is this a correct interpretation? If so, what caused the change in rotation, perhaps asymmetric emission?
[/quote]

Interesting conjecture. I'm not sure the different appearances of the various layers reflects rotational speed. But, I think it would be true that as material was ejected, it would steal angular momentum from what remained causing it to rotate more slowly?

[quote=Ann post_id=302904 time=1591589397 user_id=129702]
[quote=ta152h0 post_id=302903 time=1591582857 user_id=100922]
Earth is a product of accretion of particles over a long time. What makes the center of the Earth a fireball? pass the ice cold one
[/quote]

Doesn't it have to do with radioactive decay in the large iron/nickel core of the Earth?

Ann
[/quote]

Yes, plus two other factors. From https://www.scientificamerican.com/article/why-is-the-earths-core-so/ :

[quote=SCIENTIFIC AMERICAN]There are three main sources of heat in the deep earth: (1) heat from when the planet formed and accreted, which has not yet been lost; (2) frictional heating, caused by denser core material sinking to the center of the planet; and (3) heat from the decay of radioactive elements.[/quote]

All three phenomena are pretty amazing to me: that there is heat STILL left over from when the Earth formed 4.5 gys ago; that there is any significant amount of FRICTION caused just by slowly sinking rock; and that the core is full of radioactive elements!

The upshot is that were the sun to go dark, we could still survive for quite a long while by digging deep enough. Or at least we would be nice and warm. There's still the not so minor matters of oxygen and food to worry about :-)

[quote="Sa Ji Tario" post_id=302896 time=1591548490]
¿Can anyone explain what the spokes are like Japanese parasol rods seen in some images?
[/quote]

I don't seek "spokes" in this image of the cat's eye nebula, rather, there seem to be net-like filaments of denser gas. Not sure what causes that - perhaps magnetic fields? Or maybe it's just random density variations.

[quote=ta152h0 post_id=302903 time=1591582857 user_id=100922]
Earth is a product of accretion of particles over a long time. What makes the center of the Earth a fireball? pass the ice cold one
[/quote]

Doesn't it have to do with radioactive decay in the large iron/nickel core of the Earth?

Ann

Earth is a product of accretion of particles over a long time. What makes the center of the Earth a fireball? pass the ice cold one

[quote=neufer post_id=302894 time=1591546223 user_id=124483]
[float=left][img3=Tweety's debut in 1942's A Tale of Two Kitties (Babbit & Catstello)]https://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Ataleoftwokitties_restored.jpg/800px-Ataleoftwokitties_restored.jpg[/img3][/float][quote="APOD Robot" post_id=302887 time=1591502737 user_id=128559]

The [url=https://apod.nasa.gov/apod/ap091227.html]Cat's Eye Nebula[/url] ([b]NGC [size=200]6[/size][size=170]5[/size][size=140]4[/size][size=100]3[/size])'s haunting [url=https://apod.nasa.gov/apod/ap080804.html]symmetries[/url] are seen in the very central region of this stunning false-color [url=https://www.spacetelescope.org/images/heic0414b/] picture[/url], processed to reveal the enormous but extremely faint halo of gaseous material, over three [url=https://candra.harvard.edu/photo/cosmic_distance.html]light-years[/url] across, which surrounds the brighter, familiar [url=https://en.wikipedia.org/wiki/Planetary_nebula]planetary nebula[/url].

This [[url=http://www.not.iac.es/]NOT[/url] in the [url=http://en.wikipedia.org/wiki/Canary_Islands]Canary Islands[/url]] composite picture shows extended emission from the nebula.[/quote]
[/quote]

I thaut I saw a putty-cat! I don't think that's Sylvester though! :shock:
Sylvester & Tweety today
> [attachment=0]th.jpg[/attachment]

Picture from image results

If radius is proportional to time back, it looks like at first there was no rotation (outer third), then equal emission in all directions (middle third), and now leisurely rotation (inner third). Is this a correct interpretation? If so, what caused the change in rotation, perhaps asymmetric emission?

[quote=neufer post_id=302894 time=1591546223 user_id=124483]
[float=left][img3=Tweety's debut in 1942's A Tale of Two Kitties (Babbit & Catstello)]https://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Ataleoftwokitties_restored.jpg/800px-Ataleoftwokitties_restored.jpg[/img3][/float][quote="APOD Robot" post_id=302887 time=1591502737 user_id=128559]

The [url=https://apod.nasa.gov/apod/ap091227.html]Cat's Eye Nebula[/url] ([b]NGC [size=200]6[/size][size=170]5[/size][size=140]4[/size][size=100]3[/size])'s [b][size=150][color=#00BFFF]haunting[/color][/size][/b] [url=https://apod.nasa.gov/apod/ap080804.html][b][size=150][color=#00BFFF]symmetries[/color][/size][/b][/url] are seen in the very central region of this stunning false-color [url=https://www.spacetelescope.org/images/heic0414b/] picture[/url], processed to reveal the enormous but extremely faint halo of gaseous material, over three [url=https://candra.harvard.edu/photo/cosmic_distance.html]light-years[/url] across, which surrounds the brighter, familiar [url=https://en.wikipedia.org/wiki/Planetary_nebula]planetary nebula[/url].

This [[url=http://www.not.iac.es/]NOT[/url] in the [url=http://en.wikipedia.org/wiki/Canary_Islands]Canary Islands[/url]] composite picture shows extended emission from the nebula.[/quote]
[/quote]


[float=right][img3="Copy A of William Blake's original printing of The Tyger, c. 1795. Copy A is held by the British Museum."]https://upload.wikimedia.org/wikipedia/commons/9/91/The_Tyger_BM_a_1794.jpg[/img3][/float]Tyger Tyger, burning bright,
In the forests of the night;
What immortal hand or eye,
Could frame thy fearful [b][size=150][color=#FFBF40]symmetry[/color][/size][/b]?

Ann

¿Can anyone explain what the spokes are like Japanese parasol rods seen in some images?

[float=left][img3=Tweety's debut in 1942's A Tale of Two Kitties (Babbit & Catstello)]https://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Ataleoftwokitties_restored.jpg/800px-Ataleoftwokitties_restored.jpg[/img3][/float][quote="APOD Robot" post_id=302887 time=1591502737 user_id=128559]

The [url=https://apod.nasa.gov/apod/ap091227.html]Cat's Eye Nebula[/url] ([b]NGC [size=200]6[/size][size=170]5[/size][size=140]4[/size][size=100]3[/size])'s haunting [url=https://apod.nasa.gov/apod/ap080804.html]symmetries[/url] are seen in the very central region of this stunning false-color [url=https://www.spacetelescope.org/images/heic0414b/] picture[/url], processed to reveal the enormous but extremely faint halo of gaseous material, over three [url=https://candra.harvard.edu/photo/cosmic_distance.html]light-years[/url] across, which surrounds the brighter, familiar [url=https://en.wikipedia.org/wiki/Planetary_nebula]planetary nebula[/url].

This [[url=http://www.not.iac.es/]NOT[/url] in the [url=http://en.wikipedia.org/wiki/Canary_Islands]Canary Islands[/url]] composite picture shows extended emission from the nebula.[/quote]

[float=left][img3="Hats off..."]https://www.nonprofitsfirst.org/resource/resmgr/HatsOff_logo.png[/img3][/float][float=right][img3="...to cat's eyes..."]https://i.pinimg.com/originals/38/2f/35/382f3540c06724455cf8fa9ce7bd6b51.jpg[/img3][/float]










😺😻 :kitty:






[float=left][img3="...nebula..."]https://apod.nasa.gov/apod/image/2006/catseye2_not_960.jpg[/img3][/float] [float=right][img3="...hail! I mean, halo!"]https://lh3.googleusercontent.com/proxy/tl6Qze4bpK1tOjjiWnVR3E4QdUu9iqRkm_nMs2sheSKMALARZd-VlFAx_D13-JFe7txM-ra4LPIAxa2ZIZInppn30lxNF5vbfiyA4rsUhCMNKUHKk1cdFnfkAVI1259vkHHOE9SeRlfkrVuU7IWBS1ErKndlH7xnKIA[/img3][/float]

[attachment=0]catseye2_not_960.jpg[/attachment]

Reminds me of a beautiful flower, burst into bloom! :D

[url=https://apod.nasa.gov/apod/ap200607.html] [img]https://apod.nasa.gov/apod/calendar/S_200607.jpg[/img] [size=150]Halo of the Cat's Eye[/size][/url]

[b] Explanation: [/b] The [url=https://apod.nasa.gov/apod/ap091227.html]Cat's Eye Nebula[/url] (NGC 6543) is one of the best known planetary nebulae [url=https://apod.nasa.gov/apod/ap190501.html]in the sky[/url]. Its haunting [url=https://apod.nasa.gov/apod/ap080804.html]symmetries[/url] are seen in the very central region of [url=https://www.spacetelescope.org/images/heic0414b/]this stunning false-color picture[/url], processed to reveal the enormous but extremely faint halo of gaseous material, over three [url=https://chandra.harvard.edu/photo/cosmic_distance.html]light-years[/url] across, which surrounds the brighter, familiar [url=https://en.wikipedia.org/wiki/Planetary_nebula]planetary nebula[/url]. Made with data from the [url=http://www.not.iac.es/]Nordic Optical Telescope[/url] in the [url=http://en.wikipedia.org/wiki/Canary_Islands]Canary Islands[/url], the composite picture shows extended emission from the nebula. [url=https://www.noao.edu/jacoby/pn_gallery.html]Planetary nebulae[/url] have long been appreciated as a final phase [url=http://imagine.gsfc.nasa.gov/docs/teachers/lifecycles/stars.html]in the life[/url] of a Sun-like star. Only much more recently however, have some planetaries been [url=https://apod.nasa.gov/apod/ap140522.html]found to have halos[/url] like this one, likely formed of material shrugged off during earlier active episodes in the [url=https://science.nasa.gov/astrophysics/focus-areas/how-do-stars-form-and-evolve]star's evolution[/url]. While the [url=https://www.youtube.com/watch?v=pQ4-m1vtTmE]planetary nebula phase[/url] is [url=https://cdn.pixabay.com/photo/2019/09/04/08/24/cat-4451003_1280.jpg]thought to[/url] last for around 10,000 years, astronomers estimate the age of the [url=http://www.youtube.com/watch?v=tw0VJ1K93PM]outer filamentary portions[/url] of this halo to be 50,000 to 90,000 years.


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