Astronomy is awesome

[Surlethe]

So, we have this black hole in the center of the Milky Way. How do we know it's there? Well ...



We have video of it. That's right. This is not a computer-generated animation; this is not an artist's representation; this is not an abstraction of other data; this is direct video of stars orbiting the black hole. How fucking awesome is that? (Source: Cosmic Variance.)

This thread is for fucking awesome stuff about astronomy, the sky, and other neat things.

[Thanks, XaLeV, for the catch on the attribution.]

[Witch]

Given the fact that stars don't actually look like that, I'm sceptical about this being a direct video. It's a model.

[Ryan Thunder]

I've seen that before. It was recorded with a telescope.

[Crossroads Inc.]

Given the fact that stars don't actually look like that, I'm sceptical about this being a direct video. It's a model.

It could very easily be a "video" taking under some different spectrum, I very much doubt we'd see anything in visable light near The Hub

[Witch]

Given the fact that stars don't actually look like that, I'm sceptical about this being a direct video. It's a model.

It could very easily be a "video" taking under some different spectrum, I very much doubt we'd see anything in visable light near The Hub

This is what makes it something different from a 'direct video'. Devices such as telescopes are heavily theoryladen, and the results they produce can be highly abstract and indirect. It's important to keep that in mind when discussing scientific results.

[Ryan Thunder]

What the hell do you mean by "theoryladen"?

[SapphireFox]

This is what makes it something different from a 'direct video'. Devices such as telescopes are heavily theoryladen, and the results they produce can be highly abstract and indirect. It's important to keep that in mind when discussing scientific results.

Perhaps you should explain how the results of a telescope are abstract and indirect.

I second the question. "What the hell do you mean by "theoryladen"?"

[Witch]

Theory-ladenness of observation is a central topic in the philosophy of science (and
epistemology more generally). Roughly speaking, it is the idea that sensory
experience, observation reports and empirical data are inadvertently imbued with
theoretical prejudices. It presents a problem to the objectivity of knowledge by
motivating the view that observations are not neutral adjudicators in the testing of
theories. The aim of this course is to examine the merits, consequences and limits of
some of the most important types of theory-ladenness. Among other things, we will
be looking at how theory, broadly construed so as to include cognitive structures,
determines which observations to perform and how it affects the formation of
perceptions, the meaning of observational terms and the interpretation and assessment
of empirical data.

(Source I just looked up for quoting: http://www.votsis.org/PDF/Theory_Ladenness_Syllabus.pdf)

This is a very widely accepted notion in the philosophy of science, even though the extent to which it is accepted varies.

[SapphireFox]

A telescope produces images by direct observation either by a direct image, in the case of an optical telescope or an shifted or altered image, such as the case of radio and x-ray telescopes. In the cases of shifted/altered images the data is artificially shifted into the visible spectrum so we can perceive the image. That's why we have false color images like in the video.

[Surlethe]

Given the fact that stars don't actually look like that, I'm sceptical about this being a direct video. It's a model.

What do you mean, they don't look like that? If you mean they wouldn't look like that to the naked eye, sure. But that's kind of a pedantic point; IIRC, all of this high-res work is being done in infrared. See Dr Andrea Ghez's website.

[Gil Hamilton]

As Surlethe says, this is done in the IR and therefore that's a false color image. Most of those gorgeous pictures of nebulae and planets and other space objects that people take pictures of tend to be false color images too.

Incidently, look at the time scale in the corner. Those stars are BOOKING in terms of velocity. Damn.

[Surlethe]

Incidently, look at the time scale in the corner. Those stars are BOOKING in terms of velocity. Damn.

I read here that at the perihelia the closest stars get up to 0.04c.

[cosmicalstorm]

At what speed are those stars moving? A km/h figure would be very interesting, couldn't find one in the linked article.

Nevermind, saw the answer posted above me.

[starslayer]

Most of those gorgeous pictures of nebulae and planets and other space objects that people take pictures of tend to be false color images too.

Hubble's are false color (color coded by element, actually) for the most part, as are a lot of other professional works, even in the visible, but not all. The rest, including virtually all amateur astrophotos, are greatly enhanced color, not false color. All that us visual amateurs ever see at the eyepiece is gray, sometimes with a hint of ghostly lime-green, except for stars.

And telescope images are not abstract and theory laden, as others have already pointed out; the photons a CCD receives are the same as the ones my eyes do. And here, we simply can't see the stars in visible light (and even if we could, they'd be invisible to the naked eye); the dust in between blocks all of it, but lets IR and longer radiation through for the most part.

As for an awesome thing about astronomy, how about the fact that we will soon be able to detect Earth's twin around a Sun-like star, just by looking at how much it tugs a star back and forth over an object, with a velocity of only about a single meter per second? IOW, we will soon be able to detect stellar motions on the order of a normal walking pace.

[Witch]

And telescope images are not abstract and theory laden, as others have already pointed out; the photons a CCD receives are the same as the ones my eyes do. And here, we simply can't see the stars in visible light (and even if we could, they'd be invisible to the naked eye); the dust in between blocks all of it, but lets IR and longer radiation through for the most part.

This entire argument is absurd. You're invoking photons, highly theoretical particles that are invoked to explain light, in order to explain why what is seen by a telescope is the same as what is seen by a human eye, and yet you claim that telescopes aren't theoryladen. They're theoryladen precisely because they assume the existence of photons and the fact that they can observe them. This is parallel to the reason why Galileo's scientific opponents didn't accept the telescope as a valid instrument - they didn't agree that it wouldn't distort observation. There are many other ways in which perception, even without instruments, is theoryladen, but to go into that would probably take us too far.

I start about observation being theoryladen because somebody claimed that this is a 'direct video', that wasn't computer-generated. From what I can see, there was evident computer manipulation in the 'false color' techniques. Whenever a claim of a direct observation is made about such a highly theoretical science as contemporary astronomy, I grow skeptical. It's important to remember that while the sciences have brought us the most efficient models of nature to date, they are still just models.

[Formless]

"Just" models?

[Samuel]

in order to explain why what is seen by a telescope is the same as what is seen by a human eye,

Telescopes are just devices that focus light so that images to faint to be seen by the eye are visible. There is nothing to explain.

They're theoryladen precisely because they assume the existence of photons and the fact that they can observe them.

Even if light wasn't made of photons they would still be accurate- as long as they record the light being recieved they are as valid as the eye.

From what I can see, there was evident computer manipulation in the 'false color' techniques.

False color is to emphasis differences in images so we can tell them apart. It does not change the fact that it is direct observation.

[Witch]

Telescopes are just devices that focus light so that images to faint to be seen by the eye are visible. There is nothing to explain

Except for the fact that there are things to explain, and an entire field of physics is devoted to those things: optics.

I don't dispute the fact that telescopes allow us to make very accurate predictions; I dispute the fact that they can offer us some objective, direct perception of reality.

[Formless]

I don't dispute the fact that telescopes allow us to make very accurate predictions; I dispute the fact that they can offer us some objective, direct perception of reality.

The only way you can do that by your definition is to have telescopes for eyes.

One more reason to support transhumanist efforts?

[Witch]

Hey, observation with the human eye is theoryladen too. So that's not going to help. I highly recommend reading Kuhn (The Structure of Scientific Revolutions) for some background on this. It's very unlikely that any short discussion will convince you of this, but barrage after barrage of historical examples does the trick. (Although Kuhn is considered too radical by contemporary historians/philosophers of science, he's a very good writer, and much of what he writes still stands, while more recent accounts might be too technical or dull.)

[Formless]

What pragmatic reason do I have for accepting such a pedantically narrow definition of "direct observation"? If even observations made visually by the human eye don't count, what does? Do you not trust the accuracy of what your own two eyes see? This philosophy you are describing sounds dangerously like solipsism, and very much like a strawman of science.

[Crossroads Inc.]

I am sorry but "Philosophers of Science" is a non sequitur... "Philosophy" and "Science" are two things that should NEVER go together.

it basically sounds like Witch is saying "Well, if we can't see it with out own eyes ((IE the visible spectrum)) we don't really KNOW if that is whats happening!"
Which if true is absurd on so many fronts. Does it matter if lets say we "see" something invisible to us using X-Rays? If an object simply can not be see by a normal telescope, but you can plot it by the X-Rays it gives off, does that somehow make it less real?

Further more, I would liek to motion this conversion be split into its own group, since I can sense this argument shall soon get a life of its own.

[Surlethe]

I don't dispute the fact that telescopes allow us to make very accurate predictions; I dispute the fact that they can offer us some objective, direct perception of reality.

What's the difference?

[SapphireFox]

I don't dispute the fact that telescopes allow us to make very accurate predictions; I dispute the fact that they can offer us some objective, direct perception of reality.

Hey, observation with the human eye is theoryladen too. So that's not going to help.

So you say instruments don't have a direct perception of reality
And your own senses don't have a direct perception of reality

Therefor according to your "theroyladen" theory you can't directly perceive reality!

I submit that under this criteria that the "theroyladen" has effectively debunked itself and that any further discussion of this philosophy be moved into another thread so it can discussed or disproved more properly without further disruption of this thread.

[Shroom Man 777]

I don't dispute the fact that telescopes allow us to make very accurate predictions; I dispute the fact that they can offer us some objective, direct perception of reality.

What's the difference?

Yeah. How does that work? So if some pirate is up in the crow's nest of his boat and using his telescope to see some boat with booty that he's going to pillage for a bottle of rum, the thing that he's seeing with his telescope is not an objective, direct perception of reality?

Even if philosophical whatevers like this might be "true" in that human observations might not be truly "objective" in its "direct perception of reality", because human senses and human instruments are flawed and it's not really air we're breathing Neo take the red pill or the blue pill, why should it matter? Who gives a fuck?

The fact that the telescopes (and other things) make very accurate predictions would be sufficient enough - because, shit, if truly "objective, direct perception of reality" is impossible or something, then the next best thing should be good enough. It's workable, it's realistic, and it is sufficient for our scientific/whatever purposes and it is usable for us. That's that.

Thus, even if these observations are not perfectly "objective" in "direct perception of reality" or whatever, these space telescopes are still good enough for us to use in looking at the stars for astronomical purposes, and likewise bowel colonoscopes are still good enough for us to use in looking at the butts of people for gastronomical purposes.