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July 29th, 2012, 12:40 AM
We all know it is impossible for human kind to go out of our galaxy. So how in the world (no pun intended) do we know the shape of our galaxy, and if there are other galaxies? How do we have photos? Are those photos we have just paintings or something? Is it possible to send satellites out of our galaxy?
We know what our galaxy looks like from photos of other galaxies. It is not "impossible" to get out of our galaxy. At current technology it will simply take too long. By the way, we are situated on the edge of our galaxy.
We live in a galaxy known as a barred spiral galaxy. We can see others of this type through various telescopes. They are real images, not an artists' impression. The light had time to travel at light speed towards Earth.
Also,
picture of a galaxy is really really small. They are as big as a dot in sky. But with awesome telescope you can zoooooom in... and it appears as galaxy.
P/S: they are insanely far away...
As I understand it, these so called pictures/images are highly doctored and the actual images are nothing more than tiny little specs.Originally Posted by msafwan
Here is what hubble can do.. Here is an actual picture of pluto.
Contrary to popular belief, it is more difficult to capture images/ evidence of bodies close to Earth. When we zoom out, the sheer immensity of the far away target appears extremely "crisp".As I understand it, these so called pictures/images are highly doctored and the actual images are nothing more than tiny little specs.
Here is what hubble can do.. Here is an actual picture of pluto.
Your picture of the satellites of Pluto are images of extremely small objects. Think of finding a needle in a haystack.
No, you are not being "fooled". But your asking questions is a good thing. Keep asking
Okay... after some re-searching I found out that Hubble really do capture pictures of galaxy. It wasn't simple: they need 3 week of camera exposure to get the picture. I think the technique is called "Hubble Deep Field" or something.
Here's a vid from HubbleSite:
HubbleSite - Gallery - Behind the Pictures
REMEMBER: 3 week of space-camera exposure! (if you try that with pluto... it will glow like a sun!)
The "deep field" that Hubble did was to demonstrate that in a really small piece of sky there are worlds of unimaginable size and magnitude.
You can see galaxies with simple, cheap light telescopes. In fact, you can see them with a good set of binoculars.
These are all things we "can see" or "observe" as being real.
Pluto is relatively nearby. Imagine trying to focus on a little bird that is flying past you. That is what it is like trying to focus on a satellite of a nearby solar system planet. If there is something much larger and a long way away, it is easier to take a photo.
Keep the questions going
Sure, cameras are farsighted and those images have not been doctored..Contrary to popular belief, it is more difficult to capture images/ evidence of bodies close to Earth. When we zoom out, the sheer immensity of the far away target appears extremely "crisp".As I understand it, these so called pictures/images are highly doctored and the actual images are nothing more than tiny little specs.
Here is what hubble can do.. Here is an actual picture of pluto.
Your picture of the satellites of Pluto are images of extremely small objects. Think of finding a needle in a haystack.
No, you are not being "fooled". But your asking questions is a good thing. Keep asking
Those picture are real, and I think it is Andromeda galaxy(???).
I found it here after searching about how to find galaxy: How to Find the Andromeda Galaxy: 7 steps (with pictures)
You don't need the Hubble to photograph galaxies. This was taken by a poster on another forum, using a motorized mount and a six hour exposure.
It is galaxy NGC2903. damn it, I can't post it full size.
ngc2903.jpg
Pluto is not flying by like a bird. It takes 248 years to go around the sun. This means that pluto is relatively, concerning taking pictures, pretty stable and not a flying bird.The "deep field" that Hubble did was to demonstrate that in a really small piece of sky there are worlds of unimaginable size and magnitude.
You can see galaxies with simple, cheap light telescopes. In fact, you can see them with a good set of binoculars.
These are all things we "can see" or "observe" as being real.
Pluto is relatively nearby. Imagine trying to focus on a little bird that is flying past you. That is what it is like trying to focus on a satellite of a nearby solar system planet. If there is something much larger and a long way away, it is easier to take a photo.
Keep the questions going
Compared to the galaxies, Pluto is flitting around like a hummingbird.
Something that is a few light minutes away and flying around is much harder to image than something that is 100 million light years away. Can I have a high-5 on "obvious"?
In science we like to magically invoke something called angular velocity.
No statement at all other that it is best to look at the actual/real images.
Take a look at the actual image here.
on edit, never mind, the link only works if you're already signed in to PF.
So... "scientists" and "pretty smart people" have "looked at" them. Are you calling then naive? Make a statement. Don't be afraid.No statement at all other that it is best to look at the actual/real images.
If you can take pictures of amazing detail of objects 100 million light years away but cant take a decent picture of something in your own back yard, well then, most would scoff at your claims. And I can take a picture of a speeding bullet or rocket flying past a camera with ease... Beautiful thing about technology.
Not naive, perhaps easily led, over eager or even full of their own ideas/ego.So... "scientists" and "pretty smart people" have "looked at" them. Are you calling then naive? Make a statement. Don't be afraid.No statement at all other that it is best to look at the actual/real images.
I think that this shows you know nothing about optical astronomy or photography. One of the big differences between galaxies and Pluto is that galaxies actually radiate light, and Pluto doesn't. Another big difference is that pluto is very, very, very small.If you can take pictures of amazing detail of objects 100 million light years away but cant take a decent picture of something in your own back yard, well then, most would scoff at your claims.
Nice picture.
More of a psychological, and perhaps off-topic subject: why do you want to be seen as a fool?Not naive, perhaps easily led, over eager or even full of their own ideas/ego.So... "scientists" and "pretty smart people" have "looked at" them. Are you calling then naive? Make a statement. Don't be afraid.No statement at all other that it is best to look at the actual/real images.
RED FLAG!
warning warning
You should not reply. Reader are not idiot. They know you are being emotional.
Quite simply, Hubble can't focus properly on nearby objects. It was not built for that. I don't know what Gonzales is trying to imply. Yes, NASA "doctors" images, but mostly simply to highlight certain features and different wavelengths of light etc. There is nothing dishonest about that. Gonzales seems to have a general mistrust of science for some reason.
I have nothing but trust for science, i just do not like images that are an artist's "interpretation", non visible wavelengths being added in on top of or around visible light/matter, colors being fabricated/made up, etc.....
Artistic imagination is not science.
Minus the colors and imaginations, here are actual images produced by hubble... Link
Last edited by gonzales56; July 29th, 2012 at 07:59 AM.
You can see Andromeda with the naked eye, or with a set of binoculars. It is obviously a galaxy.
What's the problem here?
Great question. I don't know. Its one of those things which I've always wanted to learn. There are many kinds of galaxies and therefore many different shapes for galaxies. How we know which one is ours is beyond me.
An acquantance of mine is an astronomer. I asked him this question. Here is his response
I hope that helps you.Concerning the shape of our galaxy, the spiral arms are pretty well mapped out by radio emissions from hydrogen atoms. In addition it has been possible to get direct evidence for the black hole in the center of the Milky Way. We have known since the 1930s about the speed of rotation around the center.
I'm not sure what the problem is with colour enhancement to make visible what would otherwise be difficult to see. Astronomical images can and often do include wavelengths of light our eyes can't see - but that doesn't mean they aren't images of real things - Seeing images of the sun in X-rays for example is as real as seeing the interior of the human body with a CAT scan.
I'm not up on the latest astro-photography technologies but my understanding is that "true" colour final images are still made up of several separate monochrome ones taken through colour filters, so even the true colour images are not strictly true. The images by David Malin at the Australian Astronomical Observatory for example are intended to show 'true' colours as the human eye would see them (if they were capable of it) and the how's of that are described here.
False colour images can make detail of real things clearly visible that otherwise would be difficult to notice - I suspect that for the scientific purposes intended the choices for such 'enhancement' would not be for the sake of making the images pretty but for the general consumption of non-astronomers I don't have any problem with colour choices that maximise the visual impact.
Most clear nights I can see the Large and Small Magellanic Clouds (besides the main part of our own Galaxy) - not spiral galaxies but galaxies all the same. They are large and bright. Any decent introductory astronomy text should include the history of the when and how galaxies were identified as such.
A spiral galaxy in Antlia, NGC 2997 by David Malin, AAO - as the human eye would see it -
Last edited by Ken Fabos; July 29th, 2012 at 07:41 PM. Reason: Tried to delete unwanted thumbnails - but failed.
Not if they understood something about the apparent visual sizes of the two. If you divide the distance from Earth to Pluto by its diameter, you get a factor of 2506052. If you do the same for the Andromeda galaxy at 2.5 million ly, you get 11.4. For a galaxy of similar size and 100 million ly, you get 454. This means that if you compare images taken of pluto and the galaxy taken with the same equipment, the image of the galaxy will be 5520 times larger with that much more resolutionFor which you need very strong light to make up for the short exposure time. You do not have that luxury with astronomical objects, you have to work with the light available. And for Pluto, that it very little. In fact, at its brightest, it would actually be ~ 1/8 as bright as the galaxy 100 million ly distant. The galaxy may be much further away but it is lit by the light of 100's of billions of stars, While Pluto is only lit by one star and that one is billions of kilometers away( and then that reflected light must travel billions of km to reach us).
And I can take a picture of a speeding bullet or rocket flying past a camera with ease... Beautiful thing about technology.
This means that you would need even a longer exposure for Pluto than you would for the Galaxy. So for example, if you needed a 6 hr exposure for the galaxy, Pluto would take a 2day exposure.
However, Pluto rotates in ~6 days, so during your exposure, Pluto will make about 1/3 of a rotation, and you will get a blurred image. (the galaxy, which takes hundred of millions of yrs to complete a rotation will have not changed noticeably during its exposure.
Thus it is actually easier to get an image of a galaxy 100 million light years away than Pluto in both image size/resolution and brightness/exposure time.
In fact, M31, the Andromeda Galaxy, pictured in post #5 can be seen with the unaided eye under dark skies. Of course your eye does not magnify or collect photons over a long period of time as that image does, so it's not as spectacular.
Still there's something quite satisfying about seeing something 2.5 million light years away with just your eyes!
I have a coffee table sized book of photographs, titles simply Galaxies by Timothy Ferris. It was published in 1980, before the Hubble, and all the images were produced by ground based optical observatories.
I wish I could post some of them here, because they are simply spectacular images.
I have split off Mother/Father's off topic posts and replies thereto to a separate thread in pseudo.
Thanx Harold, I just didnt have the energy.
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I have that book, but mine is a reprint in 1982.
Here's a scan of one of the images. it is of the Triffid Nebula
Looking a little closer, I see that mine is a 1987 edition.
It's a stunning book. And my four year old granddaughter is entranced with it.
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