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[Vattic]

From what I understand astronomical objects appear black and white through small telescopes because their isn't enough light trigger our colour receptors, but then why does Mars appear red/orange to the naked eye?

[Il Palazzo]

If you mean to say that Mars is black&white in a telescope, then it isn't. It's nice reddish-orange, even in a pair of binoculars.

It's only those diffuse objects like galaxies and nebulae, which give off too little light (per unit area) to look anything like those fabulous pictures you get from long-exposure photography.

To recapitulate, if something looks red/white/blue/whatever to the naked eye, it will look at least that in a telescope.

[Knit tie]

Yeah, I've always wondered if we somehow manage to increase the light sensitivity of the human eye, could we possibly see the night sky like the long exposure photos show it to us?

[MetalSlimeHunt]

Possibly, but you'd have to also alter the brain to interpret this data and deal with all greater light being blindingly overwhelming. 

[10ebbor10]

Also, find a way to zoom in. I mean, a small colored pixel or a small white pixel isn't much difference.

[alway]

Yeah, I've always wondered if we somehow manage to increase the light sensitivity of the human eye, could we possibly see the night sky like the long exposure photos show it to us?

Nope. The problem comes down to simple math and the fact that photons are discrete. The relation between the emitting surface area and the surface area at a given distance is the inverse square. So if you get 1,000,000 photons passing by an area per unit of time, if you double your distance to the object, that drops to 250,000 photons. Just above the surface of our sun, you would get around 200-ish times as many photons as on earth. And earth gets about 900 times as many as Pluto, measured on a basis of 'photons passing through a given area in a given time unit. Alpha Centauri would have approximately 1 photon from the sun per square meter for every 169 million photons seen per square meter on earth. And this is all assuming no dust, atmosphere, ect in the way. This is why those deep space images require a long exposure combined with a receiving surface dozens of meters across. They are capturing photons which have traveled unimaginably vast distances, decreasing in density by 3/4 for every doubling of their distance.

[Vattic]

If you mean to say that Mars is black&white in a telescope, then it isn't. It's nice reddish-orange, even in a pair of binoculars.

It's only those diffuse objects like galaxies and nebulae, which give off too little light (per unit area) to look anything like those fabulous pictures you get from long-exposure photography.

To recapitulate, if something looks red/white/blue/whatever to the naked eye, it will look at least that in a telescope.

Makes sense. The question stems from seeing someone on television with a load of black and white images of planets, nebulae, and galaxies. It was explained that the images were black and white because of what I mentioned in my previous post, but they must not have meant to include their images of Mars in that explanation.

[alway]

If you mean to say that Mars is black&white in a telescope, then it isn't. It's nice reddish-orange, even in a pair of binoculars.

It's only those diffuse objects like galaxies and nebulae, which give off too little light (per unit area) to look anything like those fabulous pictures you get from long-exposure photography.

To recapitulate, if something looks red/white/blue/whatever to the naked eye, it will look at least that in a telescope.

Makes sense. The question stems from seeing someone on television with a load of black and white images of planets, nebulae, and galaxies. It was explained that the images were black and white because of what I mentioned in my previous post, but they must not have meant to include their images of Mars in that explanation.

Color is really just a representation of the data. A lot of telescopes focus on specific wavelengths or wavelengths outside of the visible spectrum. Whether or not you take the results and interpret them as color is simply personal preference and artistic vision.

The Hubble Ultra Deep Field image for example isn't actually a single image. It was a composition of hundreds of exposures over a half year period, taken with different wavelength detections. Sort of like how you print a newspaper one color at a time. A large majority of 'images' would thus be black & white if you just looked at the data from a telescope; color only becomes relevant when you have multiple color channels. Sure, they could interpret the color they detected from mars as 'red,' but displaying the image as such would be highly misleading simply because, in lacking the other color channels, it would be a misrepresentation of what it actually looked like.

[Vattic]

Back when I found that out about Hubble I was both impressed and kind of disappointed.

Cheers for clearing up my confusion. Wish the television presenters had been clearer to begin with.

[Knit tie]

Yeah, I've always wondered if we somehow manage to increase the light sensitivity of the human eye, could we possibly see the night sky like the long exposure photos show it to us?

Nope. The problem comes down to simple math and the fact that photons are discrete. The relation between the emitting surface area and the surface area at a given distance is the inverse square. So if you get 1,000,000 photons passing by an area per unit of time, if you double your distance to the object, that drops to 250,000 photons. Just above the surface of our sun, you would get around 200-ish times as many photons as on earth. And earth gets about 900 times as many as Pluto, measured on a basis of 'photons passing through a given area in a given time unit. Alpha Centauri would have approximately 1 photon from the sun per square meter for every 169 million photons seen per square meter on earth. And this is all assuming no dust, atmosphere, ect in the way. This is why those deep space images require a long exposure combined with a receiving surface dozens of meters across. They are capturing photons which have traveled unimaginably vast distances, decreasing in density by 3/4 for every doubling of their distance.

Is a huge recieving surface strictly necessary? I remember seeing a documentary about a man who takes long exposure photos of the night sky with a very fancy but still quite small camera.

[palsch]

Is a huge recieving surface strictly necessary? I remember seeing a documentary about a man who takes long exposure photos of the night sky with a very fancy but still quite small camera.

It is for resolution. If you are taking a photo of something very faint then extending the exposure will give you a better image. However, the object won't be any sharper, just clearer.

If I wanted to, say, take a photo of a moon in orbit around a planet then no matter how long an exposure I use, I will need a camera with a certain resolution, and resolution translates into area.

Simple case and some expansion here.

You can get some dazzling images and videos of the night sky using fairly simple and small cameras, but you are taking images of point light sources where angular resolution isn't that important. Arguably you don't mind having stars smeared out or blurred together in such photos because it just makes the sky look even more populated and you are aiming for overall impact rather than scientific accuracy.

There is a second group of night sky photographers who take far less immediately stunning shots, but who focus on resolution. They get shots like this.

[Knit tie]

Thank you very much. I was asking this because I wanted to know if it's theoretically possible to have some sort of nifty little "star-gazing" camera that will be like a pair of binoculars except with the explicit purpose of showing the user extremely faint objects like nebulae. Of course, it will electronically process the data, but it won't need to have good resolution as it'll be used primarily for entertainment.

[palsch]

Ooh, reminds me. There is a Coursera course on image processing that may be slightly relevant that just closed. Obviously can't get a grade from it any more (and I think the free temporary Matlab offer has expired), but the video lectures and materials can still be downloaded for future study (I recommend DownloadThemAll pointed at the lectures page set to videos and documents plus typing 'subtitles' in the filter box; gives you subtitled lectures plus pdf notes).

Image and video processing: From Mars to Hollywood with a stop at the hospital

As far as a rig like that goes, google around some astrophotography sites. Most people use telescope rigs, but there might be some cheaper basic setups that could work out.

[scrdest]

Apparently, some scientists managed to grew working muscle cells. Tested on mice, would contract and regenerate normally.

[Knit tie]

Apparently, some scientists managed to grew working muscle cells. Tested on mice, would contract and regenerate normally.

I believe they grew muscle cells earlier with that steak, but didn't manage to get them to contract.