APOD: Gaia: Here Comes the Sun (2016 Sep 26)

Comments and questions about the APOD on the main view screen.
Wolf
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Re: APOD: Gaia: Here Comes the Sun (2016 Sep 26)

Post by Wolf » Thu Sep 29, 2016 6:44 pm

Wolf wrote:
ta152h0 wrote:Tdere is another Wolf ere ?
Ja, virtually... but traveling at about 6 kpc/s :?: :rocketship:
If my math is not mistaken, this means this APOD featured traveler is moving at about 617 billion times the speed of light.

It certainly puts into question interstellar travel let alone intergalactic travel... on the other-hand, "where are they?"

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neufer
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Re: APOD: Gaia: Here Comes the Sun (2016 Sep 26)

Post by neufer » Thu Sep 29, 2016 8:11 pm

Wolf wrote:
Wolf wrote:
ta152h0 wrote:
Tdere is another Wolf ere ?
Ja, virtually... but traveling at about 6 kpc/s :?: :rocketship:
If my math is not mistaken,
this means this APOD featured traveler is moving at about 617 billion times the speed of light.
Or the APOD featured traveler is moving at about (1.0 - 1.3x10-24) times the speed of light
while measuring seconds using his own veerrryyyy slow clock.
Art Neuendorffer

Wolf
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Re: APOD: Gaia: Here Comes the Sun (2016 Sep 26)

Post by Wolf » Thu Sep 29, 2016 8:46 pm

neufer wrote: Or the APOD featured traveler is moving at about (1.0 - 1.3x10-24) times the speed of light
while measuring seconds using his own veerrryyyy slow clock.
... or her slow clock... or... not sure...

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johnnydeep
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Re: APOD: Gaia: Here Comes the Sun (2016 Sep 26)

Post by johnnydeep » Tue Nov 14, 2023 8:08 pm

Oh, if only we could really travel as fast as is shown in this video, relativity be damned!
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

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Ann
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Re: APOD: Gaia: Here Comes the Sun (2016 Sep 26)

Post by Ann » Wed Nov 15, 2023 6:02 am

What would it look like to return home from outside our galaxy? Okay, so... If you were outside our galaxy, how could you find your way home (even if it was possible for you to travel impossibly fast)?

It's not as if our Sun looks that remarkable from outside or galaxy, and it's not as if it's holding up a sign to stand out in a crowd, and it is not as if our galaxy is providing a GPS with that teardrop-shaped thing pointing at the Sun to guide wayward travellers on their way home.

The Sun is here ESA Gaia DPAC.png

Don't hold your breath looking for that sort of sign on your way back home from intergalactic space!

Or you mean Gaia would provide that sort of detailed Milky Way map to actually make it possible for intergalactic travellers to find their way home? Really?

Ann
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johnnydeep
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Re: APOD: Gaia: Here Comes the Sun (2016 Sep 26)

Post by johnnydeep » Wed Nov 15, 2023 4:33 pm

Ann wrote: Wed Nov 15, 2023 6:02 am What would it look like to return home from outside our galaxy? Okay, so... If you were outside our galaxy, how could you find your way home (even if it was possible for you to travel impossibly fast)?

It's not as if our Sun looks that remarkable from outside or galaxy, and it's not as if it's holding up a sign to stand out in a crowd, and it is not as if our galaxy is providing a GPS with that teardrop-shaped thing pointing at the Sun to guide wayward travellers on their way home.


The Sun is here ESA Gaia DPAC.png


Don't hold your breath looking for that sort of sign on your way back home from intergalactic space!

Or you mean Gaia would provide that sort of detailed Milky Way map to actually make it possible for intergalactic travellers to find their way home? Really?

Ann
How about using GPPS to navigate home? That would be the Galactic Pulsar Positioning System™. See https://skyandtelescope.org/astronomy-n ... -missions/.

This was also how the Sun's position in the galaxy was etched on the Pioneer and Voyager records/plaques:
https://en.wikipedia.org/wiki/Pioneer_plaque#Sun_and_galactic_landmarks wrote:The radial pattern on the left of the plaque shows 15 lines emanating from the same origin. Fourteen of the lines have corresponding long binary numbers, which stand for the periods of pulsars, using the hydrogen spin-flip transition frequency as the unit. Since these periods will change over time, the epoch of the launch can be calculated from these values.

The lengths of the lines show the relative distances of the pulsars to the Sun. A tick mark at the end of each line gives the Z coordinate perpendicular to the galactic plane.

If the plaque is found, only some of the pulsars may be visible from the location of its discovery. Showing the location with as many as 14 pulsars provides redundancy so that the location of the origin can be triangulated even if only some of the pulsars are recognized.
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}