Starship Asterisk*

owlice wrote:It's missing the moon, but perhaps the other planets will make up for it: http://www.vancleefarpels.com/us/en/art ... -timepiece

https://www.youtube.com/watch?v=LUtUDSltl-M

BillBixby wrote:

Anthony Barreiro wrote:Recently I've been imagining a 24-hour analog clock that displays: sidereal time by rotation of the clock face around the celestial pole; solar time by rotation of the Sun on a hand centered at the ecliptic pole and moving along the ecliptic; and the phase of the Moon by the movement of another hand that moves along the ecliptic, offset by the motion of a cam to show the Moon's path north and south of the ecliptic -- thus you could easily see when the Moon's nodes coincide with new and full Moon, resulting in eclipses. Might as well throw in Jupiter moving along the ecliptic, too.

I've browsed online to look for something comparable, but I haven't found anything either real or virtual exactly like I'm envisioning. Unfortunately I'm neither a clockmaker nor a computer programmer, so I won't actually create this clock. If anybody wants to collaborate on this, please drop me a line.

The time piece you are describing sounds very much like the time piece used by former Headmaster Albus Dumbledor of Hogwarts School. Perhaps his estate would be willing to part with it, for a reasonable sum. I don't recall in which book he referred to this timepiece.

Anthony Barreiro wrote:

CURRAHEE CHRIS wrote:

APOD Robot wrote: Around 270 BC, the Greek astronomer Aristarchus also measured the duration of lunar eclipses - though probably without the benefit of digital clocks and cameras.

information like that never ceases to amaze me.

Recently I've been imagining a 24-hour analog clock that displays: sidereal time by rotation of the clock face around the celestial pole; solar time by rotation of the Sun on a hand centered at the ecliptic pole and moving along the ecliptic; and the phase of the Moon by the movement of another hand that moves along the ecliptic, offset by the motion of a cam to show the Moon's path north and south of the ecliptic -- thus you could easily see when the Moon's nodes coincide with new and full Moon, resulting in eclipses. Might as well throw in Jupiter moving along the ecliptic, too.

I've browsed online to look for something comparable, but I haven't found anything either real or virtual exactly like I'm envisioning. Unfortunately I'm neither a clockmaker nor a computer programmer, so I won't actually create this clock. If anybody wants to collaborate on this, please drop me a line.

Chris Peterson wrote:

Diana wrote:Probably. Probably? Really? Is there a possibility that Aristarchus had a digital clock?

Sure. Every time he counted down from ten on his fingers.

Diana wrote:Probably. Probably? Really? Is there a possibility that Aristarchus had a digital clock?

Diana wrote:

CURRAHEE CHRIS wrote:

APOD Robot wrote: Around 270 BC, the Greek astronomer Aristarchus also measured the duration of lunar eclipses - though probably without the benefit of digital clocks and cameras.

information like that never ceases to amaze me.

Probably. Probably? Really? Is there a possibility that Aristarchus had a digital clock?
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Beautiful sequence picture. One of the best ever. Thank you,

.Diana.

CURRAHEE CHRIS wrote:

APOD Robot wrote: Around 270 BC, the Greek astronomer Aristarchus also measured the duration of lunar eclipses - though probably without the benefit of digital clocks and cameras.

information like that never ceases to amaze me.

CURRAHEE CHRIS wrote:

APOD Robot wrote: Around 270 BC, the Greek astronomer Aristarchus also measured the duration of lunar eclipses - though probably without the benefit of digital clocks and cameras.

information like that never ceases to amaze me.

APOD Robot wrote: Around 270 BC, the Greek astronomer Aristarchus also measured the duration of lunar eclipses - though probably without the benefit of digital clocks and cameras.

Nitpicker wrote:

StewartR wrote:

norman wrote:As I recall the rule of thumb, the moon moves through its own diameter every hour. If that's true, how can exposures ten minutes apart show discreet images of the moon separated by spaces? You don't state that the camera is fixed, true, but neither do you state that it was moved a bit between exposures to separate the images of the moon. Am I way off on this?

Yes, you are way off. The moon moves through its own diameter every two minutes, as does the sun.

(Both the moon an the sun have angular diameters of about half a degree. The motion is dominated by the earth's rotation, 360 degrees in 24*60=1440 minutes, which is 1 degree per 4 minutes. QED.)

Well, the rule of thumb that the moon moves through its own diameter every hour is true, it is just that this movement is relative to the fixed stars, which appear to rotate with the celestial sphere.

StewartR wrote:

norman wrote:As I recall the rule of thumb, the moon moves through its own diameter every hour. If that's true, how can exposures ten minutes apart show discreet images of the moon separated by spaces? You don't state that the camera is fixed, true, but neither do you state that it was moved a bit between exposures to separate the images of the moon. Am I way off on this?

Yes, you are way off. The moon moves through its own diameter every two minutes, as does the sun.

(Both the moon an the sun have angular diameters of about half a degree. The motion is dominated by the earth's rotation, 360 degrees in 24*60=1440 minutes, which is 1 degree per 4 minutes. QED.)

norman wrote:As I recall the rule of thumb, the moon moves through its own diameter every hour. If that's true, how can exposures ten minutes apart show discreet images of the moon separated by spaces? You don't state that the camera is fixed, true, but neither do you state that it was moved a bit between exposures to separate the images of the moon. Am I way off on this?