Longer answer: It’s actually light diffracting around the four arms (called spider legs) holding up the secondary mirror of a telescope! For the stars above it’s four spider legs from the stars because the Hubble Space Telescope took these images and its secondary mirror has four arms holding the secondary – for other telescopes the diffraction could be different depending on how the secondary mirror is held up.
Here’s apicture of the Hubble’s secondary mirror design:
Three of the four “spider arms” are visible and I drew red lines next to them so you could see what they look like.
(Image credit: NASA and ESA
)
While they’re at it, they could point out that almost all the colors in space photos are faked too
“Faked” is a huge simplification of that. Actually most of the space images you see are detections of colors the human eye can’t see… like x-ray, gamma or radio wave light. By converting these colors into pictures visible to the human eye we aren’t lying… we are allowing ourselves to actually see and study the universe – not to mention make a massive fraction of the invisible reality totally visible to the average person. Uh, you’re welcome? 😉 😛
It’s even more complicated than that. Some of the images are not “true color” even though they are actually taken in visible light. Let me explain with an image I made:
This is an image of M101. It *looks* like a true color image, but it’s not. That is because it is a composite of these two images:
The top one is an exposure taken through a B (”blue”) filter while the bottom one is taken through a “V” (”visible”) filter. The B band is centered on 445nm or blue wavelengths whereas the V band is centered on 551 nm or yellow/green wavelengths. These two images when overlaid would not make an easily viewable image, so I made the V image orange so they became complementary colors.
But! It gets more complicated still. You see, when you take an image through a telescope, the CCD (your “camera”) always produces an output in greyscale. The greyscale image’s appearance can be further altered by changing the way the counts on the CCD are displayed as values on your computer screen.
This here is a linear stretch. It would look very different with a histogram equalization stretch, while still actually being the same image.
You can only get color images by combining two or three different greyscale images, and dyeing them different colors. Sometimes, you take an image through a red, green, and a blue filter, and then when you combine them, it roughly approximates a “true color” image. However, as you have control over the intensity and contrast of each component color, the resulting image can be made to look differently.
Two ways of making a composite.
Sometimes you want to combine images taken through filters that focus in on specific spectral lines. Sometimes these spectral lines are in the same region of the color spectrum. For example, the famous Hubble “pillars of creation” image actually contains two red spectral line components, one due to hydrogen, and one due to sulfur. To make the composite image easier to read, one of these red wavelengths was recolored blue.
The image would basically be mostly red if they didn’t do this.
And of course, as @antikythera-astronomy said, there are always false-color images of light wavelengths we cannot see, such as this radio image of mine:
So, what does this all mean for images being faked or not?
The Answer: None of the images of space taken by telescopes are what they would look like to your eyes, but that’s okay, because what is the point of a telescope if it just mimics what your eyes see?
The human eye cannot distinguish colors at all for low surface brightness objects such as galaxies or nebulae. If you ever look through a personal telescope at a galaxy, what you see is a faint smudge. That first galaxy whose image I posted? I’ve seen it with my own eyes, and it looked like a blurry grey blob with faint grey spokes. Even if you were in a spacecraft blazing your way through the Orion Nebula, you wouldn’t be able to see its colors. The surface brightness is just too faint.
Even though none of these images is a “true color” image, none of them are faked either, because each is actually visualization of a scientific measurement. They are merely ways we can use our computers to present to us the results of measurements of photon counts, wavelengths, and position on the sky, it’s like changing the scale on a graph, or a map. It’s not fake, just…different.
It’s when a body of water has fresh AND salt water. The salt water is very dense and thus heavy, remaining on the bottom while the fresh water is on top. It results in a body of water (ocean, lake, etc) having water underwater.
The salt water is so dense that it looks like very foggy water when viewed at from the fresh water part.
Halocline is actually very dangerous, if divers go down into the salty part. Some forget (or are unaware, as in caves for examples) of the Halocline, emerge from the foggy salt water and believe they are OUT OF WATER, resulting in them taking off their helmets, only to drown.
But it is super interesting and really beautiful.
EXTRA: I don’t know for absolute certain, but I am quite sure that the “magic underwater water” in the videogame ABZÛ is also Halocline, since it looks very much like that
yo scientists what good is gonna come from making this
y’all are so hung up on that but you know she had said more things, right?
“I foresee massive and unimaginable change in the future,” she said. “Either creativity will rain on us, inventing machines spiraling into transcendental super intelligence or civilization collapses. There are only two options and which one will happen is not determined. Which one were you striving for?”
I remember first learning that you can cry from any emotion, that emotions are chemical levels in your brain and your body is constantly trying to maintain equilibrium. so if one emotion sky rockets, that chemical becomes flagged and signals the tear duct to open as an exit to release that emotion packaged neatly within a tear. Everything made sense after learning that. That sudden stability of your emotions after crying. How crying is often accompanied by the inability to feel any other emotion in that precise moment. And it is especially beautiful knowing that it is even possible to experience so much beauty or love or happiness that your body literally can’t hold on to all of it. So what I’ve learned is that crying signifies that you are feeling as much as humanely possible and that is living to the fullest extent. So keep feeling and cry often and as much as needed
SHIT WHAT
Also let yourself cry. It really is a biochemical release valve to dump out all the chemicals that make you feel stuff.
I honestly think one reason men in western culture have so many problems is that we don’t let them cry, and literally their brains get stuffed with all this crap that doesn’t have a release valve. Men, please cry. You’ll feel better. It’s ok. You are not lesser for taking care of your health.
This is why tears from different emotions look different under an electron microscope. They’re literally made up of different things.
Happy tears are structurally different than sad tears than angry tears than overwhelmed tears etc.
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