Space
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Also, I have a question about "seeing" the Milky Way galaxy. Since that's our galaxy, how does one see it? The way I understand it, it would be like seeing earth. Since we're on planet earth, it wouldn't look like a sphere from here, right?
The galaxy is way less like a sphere than the Earth, it's closer to a dinner plate, but bulging in the middle. At least that's the current understanding. But it doesn't look like a circle from inside, it looks more like a thick line across the sky.
I've posted this before but it's probably useful right now. This is the Milky Way from Slate Peak in the North Cascades. The camera is more sensitive than the eye, so it's a little bit dimmer and it's less colorful too, when you're standing there.
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@PlaydohPants and @KeithMarcus
Let's go with a really basic analogy - but let's also stick with our space theme.
The sun is a star. It's not the biggest or the brightest start.
But it sure looks brighter than all the other stars.
Light comes from stars, and it goes in every direction, like this:
The closer you are to any light source, the more light will reach you. The further you are, the less light. Because tiny differences in angle get multiplied over distance. You can see how the beams spread out, they'll miss things that are far away.
You see light. Your eyes have lenses that gather it over a wide area and focus it onto a small area packed with light-sensitive cells.
A camera works the same way. But it's more sensitive - it "wastes" fewer incoming photons to inefficiency, so it requires fewer of them to recognize an image. The lenses people use for astrophotography are much larger (as a ratio of aperture width to optical length) than the eye, so they're able to gather more light.
People can do math, but we built calculators that can do it better. People can see, but we built cameras that can see better.3 -
I don't think I explained that very well at all. If you were able to make any sense of it, my hat's off to you.1
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astrophotography is a great hobby but gets expensive fast! my mount for my telescope cost me close to £1k and that was a cheap one!1
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Another thing, if anybody is interested in the physics of light and vision.
Here are some pictures of a 50 mm lens at different apertures:
You can plainly see that more light will pass through the lens at f/1.8 (first) than at f/22 (last). Smaller numbers mean a bigger opening, and more light gathering power - more brightness.
Your eyes work the same way. Your pupils dilate when it's dark, and when you're under the influence of certain drugs. They close down when it's bright out. That's why you can see well enough to walk under a full moon, or at noon at the beach. The lens in the pics above can open to f/1.8 and it can close to f/22, it can't get brighter or darker than that.
A 50 mm f/1.8 lens like this one costs about $100. A 50 mm f/1.4 lens is almost 2x brighter, weighs almost 2x as much, and costs $400. A 50 mm f/1.2 lens is brighter, heavier, and costs $1,500.
I don't know which one is most similar to human vision, but people can't go to the store and buy cat eyes. You sort of can do that with cameras. That's a huge part of why photos of the Milky Way look different than standing outside looking at it.1 -
LiftingLady5 wrote: »NorthCascades wrote: »I don't think I explained that very well at all. If you were able to make any sense of it, my hat's off to you.
Did you take advantage of a different kind of space last night Eeyore?
The snow must have frozen my brain, 'cause I'm not following?0 -
also most pictures of the MW will be significantly processed (stacking etc). atleast I'm my experience. A lot of photographers also play with hues0
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PlaydohPants wrote: »Right, the pictures are generally enhanced and I'm sure @NorthCascades can shed more light on how since I don't know much about photography. But when you look with the naked eye you can't pick up the dim light like a camera can. At least, it looks dim because it's so far away.
You'll never see a really good photo of the Milky Way that hasn't been edited. Probably more than a little. Mostly taken with a specialty lens, too, because there's only so much you can do in the computer.
I don't like the term enhanced at all, even though it's completely accurate.
The way people see is amazing, and it's pretty *kitten* relevant to us. But it's not "the" truth, it's "a" truth. Mantis shrimp can see colors we can't, because their brains process visual information differently from ours.
Really good cameras are designed to make dull photos. They're flat, and not especially colorful, because that's how they preserve the most data. Making them more contrasty means throwing data away, bringing darker values closer to 0 and brighter ones closer to 1, fewer values repeated more times. Exactly how much is a matter of taste, so best to just record everything. All of the same kind of stuff happens when film gets developed.
This is "Moonrise Over Hernandez, New Mexico" by Ansel Adams. He worked on the negative for ten years before he released a print!
People have this idea that photos are an objective record, or sometimes they're doctored. I think it's more fair to say it's a different way of processing visual information.0 -
I thought that's what you had to have meant, because whenever I'm confused I assume someone is talking dirty to me. But I wasn't sure.
I did!!
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NorthCascades wrote: »Also, I have a question about "seeing" the Milky Way galaxy. Since that's our galaxy, how does one see it? The way I understand it, it would be like seeing earth. Since we're on planet earth, it wouldn't look like a sphere from here, right?
The galaxy is way less like a sphere than the Earth, it's closer to a dinner plate, but bulging in the middle. At least that's the current understanding. But it doesn't look like a circle from inside, it looks more like a thick line across the sky.
I've posted this before but it's probably useful right now. This is the Milky Way from Slate Peak in the North Cascades. The camera is more sensitive than the eye, so it's a little bit dimmer and it's less colorful too, when you're standing there.
This is a really gorgeous picture, but I can't quite make out the dinner plate? Could you give me an idea what portion of it is captured in your picture? And thank you, you've been so patient with your explanations, and my questions are really elementary.0 -
LiftingLady5 wrote: »Luke_I_am_your_spotter wrote: »I captured this image of the November "Supermoon."
Beautiful pic!
Thank you!0 -
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John Glenn, American Hero of the Space Age, Dies at 95
A symbol of the space age as the first American to orbit Earth.
http://www.nytimes.com/2016/12/08/us/john-glenn-dies.html?_r=0
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RIP Brave John. Thank you for your service. You lived a long meaningful life that people dream of. And you really did it.
Motivation to be as fit as possible.
When many are still living on this planet, that has gone to kitten in sooo many respects, I'm going to move to Mars or any planet with possibility. (Edit: Mars is vicious.... Any better prospects planet wise??)
@Luke I love your pictures. Especially the Supermoon pic.
Incredible. 1 -
Luke_I_am_your_spotter wrote: »I took this pic of the Orion Nebula last winter.
Awesome.0 -
NorthCascades wrote: »Also, I have a question about "seeing" the Milky Way galaxy. Since that's our galaxy, how does one see it? The way I understand it, it would be like seeing earth. Since we're on planet earth, it wouldn't look like a sphere from here, right?
The galaxy is way less like a sphere than the Earth, it's closer to a dinner plate, but bulging in the middle. At least that's the current understanding. But it doesn't look like a circle from inside, it looks more like a thick line across the sky.
I've posted this before but it's probably useful right now. This is the Milky Way from Slate Peak in the North Cascades. The camera is more sensitive than the eye, so it's a little bit dimmer and it's less colorful too, when you're standing there.
This is a really gorgeous picture, but I can't quite make out the dinner plate? Could you give me an idea what portion of it is captured in your picture? And thank you, you've been so patient with your explanations, and my questions are really elementary.
Thanks!
I'm guessing that the center of the galaxy is down below the horizon, and the edge of the galaxy is up above the top of the frame. Just based on how bright it is. I could be wrong; I think it looks like two bands instead of one because giant dust clouds block a lot of star light.1 -
NorthCascades wrote: »NorthCascades wrote: »Also, I have a question about "seeing" the Milky Way galaxy. Since that's our galaxy, how does one see it? The way I understand it, it would be like seeing earth. Since we're on planet earth, it wouldn't look like a sphere from here, right?
The galaxy is way less like a sphere than the Earth, it's closer to a dinner plate, but bulging in the middle. At least that's the current understanding. But it doesn't look like a circle from inside, it looks more like a thick line across the sky.
I've posted this before but it's probably useful right now. This is the Milky Way from Slate Peak in the North Cascades. The camera is more sensitive than the eye, so it's a little bit dimmer and it's less colorful too, when you're standing there.
This is a really gorgeous picture, but I can't quite make out the dinner plate? Could you give me an idea what portion of it is captured in your picture? And thank you, you've been so patient with your explanations, and my questions are really elementary.
Thanks!
I'm guessing that the center of the galaxy is down below the horizon, and the edge of the galaxy is up above the top of the frame. Just based on how bright it is. I could be wrong; I think it looks like two bands instead of one because giant dust clouds block a lot of star light.
Awesome intro. I actually wound up squeezing in most of this 1.5 hour documentary on the Milky Way between commercials.
https://www.youtube.com/watch?v=ttz4Sr0tZFg&app=desktop
I thought it was interesting that most or all of the proof points to our galaxy being a spiral galaxy, but since we've not been able to travel outside of it to view it, we can't be 100% certain - or, at least we do not have a picture of it. That was the case when the documentary was made, anyway. Who knows now!
Finally remembered the chromecast plugged into the TV and I've since watched this and the 'Journey to the Center of the universe' one that came recommended after it. I just might continue doing this for a while rather than searching for ondemand TV shows whenever I have some down time. Good stuff!0 -
John Glenn, American Hero of the Space Age, Dies at 95
A symbol of the space age as the first American to orbit Earth.
http://www.nytimes.com/2016/12/08/us/john-glenn-dies.html?_r=0
RIP, John Glenn, American Hero.
You know, what I found so fascinating about this story is how this man basically made multiple careers from what some may consider passing interests. Oh, I just took flight lessons on the side. . That turns to a career as a military pilot and later an astronaut. Or, how being inspired by his high school civics teacher got him into a very successful political career.0
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