APOD: Andromeda Rising over the Alps (2015 Aug 17)

Comments and questions about the APOD on the main view screen.
paragkulkarni

Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by paragkulkarni » Tue Aug 18, 2015 1:47 pm

Tszabeau wrote:There appears to be another galaxy, that looks to be even further away from us than Andromeda, just above Andromeda. Would not that galaxy's light be "older"?
M32 ?

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Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by bystander » Tue Aug 18, 2015 1:51 pm

paragkulkarni wrote:
Tszabeau wrote:There appears to be another galaxy, that looks to be even further away from us than Andromeda, just above Andromeda. Would not that galaxy's light be "older"?
M32 ?
bystander wrote:
Image
Tszabeau wrote:There appears to be another galaxy, that looks to be even further away from us than Andromeda, just above Andromeda. Would not that galaxy's light be "older"?
Non Professional wrote:Is that other one M32? It's fairly close to M31, isn't it?
That would be M110. M32 is also visible in the high def image. It looks like a fuzzy star below and to the right of M31.
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Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by Boomer12k » Tue Aug 18, 2015 2:00 pm

wbd wrote:Never seen Andromeda, but it is my #1 on my bucket list of deep sky targets.
I live right down the 'bottom' of Australia, so M31 is below our northern horizon, so I always love seeing pictures of our 'cosmic neighbor'.
I have ALWAYS want to see...the MAGELLANIC CLOUDS...but cannot...being in Oregon, USA...and always appreciate a good image of them....so we are even?

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tomatoherd

Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by tomatoherd » Tue Aug 18, 2015 2:09 pm

Boomer12k wrote: ........
Now...an ELECTRON has mass...and yet...travels at the same speed...:-) ALL electro-magnetic radiation travels at the same speed...so...the question is, WHY can an electron with a mass, travel at the same speed of light, which supposedly has no mass?

I guess as an OBJECT in space...it does not age, as it does not appear to deteriorate, but still takes 100,000 EARTH years to cross the galaxy, or 2.2 million from Andromeda, or 11mly from other galaxies. As a WAVE, I wonder at how it stays the same, as it should dissipate some as it goes outward, and should "widen" as with other waves. Radio waves for example dissipate around 1.5-2 ly away from us...NO ONE is watching Lucy 60 ly out...the signal has long dissipated to the point of being unrecognizable, and blends with the background noise. You need a "tight" beam I guess, and regular radio, television, just does not do that. But Light does not seem to widen, nor dissipate as an energy wave. It is an odd thing. And yet, a projection of light WIDENS from the source, and it does get dimmer with distance.
There are so many illusions with light, it is hard to get past the apparencies, and quandaries.

I still say it is quite the illusion.
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Boomer:
electrons do NOT travel at the speed of light, nor does electric current.
Light, radio, or any EMRs do not decay or dissipate with distance. (perhaps for the very reason that, in a photon's reference frame, no time has elapsed even if it crossed the 14 billion ly diameter of the known universe). But from a point source, radiant waves get more widely separated, as they are not parallel. Sunbeams on earth are nearly parallel for our purposes, but are not absolutely.
BTW, distant simultaneity is the illusion. For the 2 million year old photon we were discussing, to it the universe looks exactly the same at its emission and absorption 2 million years later; only its position has changed. Only what's in a observer's light cone matters. The simultaneous hyperplane/the 'hypersurface of the present', is purely an abstraction.

Guest

Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by Guest » Tue Aug 18, 2015 2:09 pm

Boomer12k wrote: ........
Now...an ELECTRON has mass...and yet...travels at the same speed...:-) ALL electro-magnetic radiation travels at the same speed...so...the question is, WHY can an electron with a mass, travel at the same speed of light, which supposedly has no mass?

I guess as an OBJECT in space...it does not age, as it does not appear to deteriorate, but still takes 100,000 EARTH years to cross the galaxy, or 2.2 million from Andromeda, or 11mly from other galaxies. As a WAVE, I wonder at how it stays the same, as it should dissipate some as it goes outward, and should "widen" as with other waves. Radio waves for example dissipate around 1.5-2 ly away from us...NO ONE is watching Lucy 60 ly out...the signal has long dissipated to the point of being unrecognizable, and blends with the background noise. You need a "tight" beam I guess, and regular radio, television, just does not do that. But Light does not seem to widen, nor dissipate as an energy wave. It is an odd thing. And yet, a projection of light WIDENS from the source, and it does get dimmer with distance.
There are so many illusions with light, it is hard to get past the apparencies, and quandaries.

I still say it is quite the illusion.
:---[===] *
Boomer:
electrons do NOT travel at the speed of light, nor does electric current.
Light, radio, or any EMRs do not decay or dissipate with distance. (perhaps for the very reason that, in a photon's reference frame, no time has elapsed even if it crossed the 14 billion ly diameter of the known universe). But from a point source, radiant waves get more widely separated, as they are not parallel. Sunbeams on earth are nearly parallel for our purposes, but are not absolutely.
BTW, distant simultaneity is the illusion. For the 2 million year old photon we were discussing, to it the universe looks exactly the same at its emission and absorption 2 million years later; only its position has changed. Only what's in a observer's light cone matters. The simultaneous hyperplane/the 'hypersurface of the present', is purely an abstraction.

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Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by chuckster » Tue Aug 18, 2015 4:25 pm

Besides not being able to see the full size and magnificence of Andromeda in visible light from Earth with your own eyes, another thing that gets me about galaxies in general, especially the ones tipped enough to our line of sight to see the whole thing, is that the light from that far rim may be (say) 150,000 yrs older than the light from the near rim, and all along the sides of the elliptical view, the age of the light is different depending on its distance. There's an age gradient throughout the disc, relative to Earth, along our line of sight. Pictures of colliding galaxies are incredible, but what parts of each galaxy don't know they're in collision yet, from our distant viewpoint ? Even locally, the events of the collision (star formation, black holes combining, etc) are far enough from each other to make it impossible for a single observer to see the whole thing in real time. The mind boggles. Even a full-on flat face view has an age gradient in its light. For us, and for the stars and gas and dust on-scene, there are delays as gravity waves orchestrate the collision, and new stars form, etc, and it all gets reported to us, after light travel time delays, and out of sequence, because of the distances involved.

andreadomenici

Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by andreadomenici » Tue Aug 18, 2015 5:37 pm

The picture was not taken from the Alps but from the Alpi Apuane. This is a small mountain range which belongs to the Appennine mountains, but it is called "Alpi" because of its peculiar morphology. It is part of the provinces of Lucca and Massa-Carrara, in Tuscany.

Great picture at any rate. Thank you, NASA!

Andrea Domenici

Claudio

Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by Claudio » Tue Aug 18, 2015 7:17 pm

There is a small error in the caption of the picture: the picture was taken on the Apuan Alps, which are actually NOT the real Alps but part of the Appennini Mountain chain. Nevertheless, great picture!

Alessandro Gardini

Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by Alessandro Gardini » Wed Aug 19, 2015 7:14 am

Please notice that, as explained in the link to the author, Andromeda is rising over the Apuan Alps, not the Alps. Apuan Alps are part of the Apennine Mountains and are renowned for the famous Carrara marble.

Claudio

Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by Claudio » Wed Aug 19, 2015 1:30 pm

To explain the small mistake we are discussing for who is not Italian, Apuan Alps are actually here:
https://goo.gl/maps/n3USf

Even if the Apuan mountains are part of the Appennini range, they are called "Alps" because the landscapes resembles the ones of the real Alps. There are some places known to have good skies for stargazing, but are more known for the marble quarries (Michelangelo used to choose the marble for his sculpture in the quarries of Carrara) and the great landscapes.

Ghoulardi

Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by Ghoulardi » Wed Aug 19, 2015 4:07 pm

Claudio wrote:To explain the small mistake we are discussing for who is not Italian, Apuan Alps are actually here:
https://goo.gl/maps/n3USf
....just south of Parma, a suburb of Cleveland

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Re: APOD: Andromeda Rising over the Alps (2015 Aug 17)

Post by geckzilla » Wed Aug 19, 2015 7:47 pm

Ghoulardi wrote:
Claudio wrote:To explain the small mistake we are discussing for who is not Italian, Apuan Alps are actually here:
https://goo.gl/maps/n3USf
....just south of Parma, a suburb of Cleveland
Link takes me to Italy. It was nothing like Olive Garden.
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