Two questions about space (Earth, stars, light, Sun)

[trevor0101]

I had a couple of thoughts, and I'd love to C-D's resident smart people to weigh in:

1. Are there areas of space where light is so lacking that I could not see my hand in front of my face? Perhaps in interstellar space? What about in the far reaches of our solar system?

2. Is it possible to be a "still" object within a solar system, and not orbit the dominant star? Taken to the practical, were I to somehow be between Earth, and Mars and just stopped my spacecraft there relative to the Sun at a point in time, would I begin to orbit something eventually? Or would I always be orbiting the Sun without knowing it? I am aware this is a more complex question that I have the ability to state in a useful way, but I am sure someone can understand what I mean

TIA!

[rjshae]

1. I think you've already answered your question. It can also be quite dark in the shadow of an airless body such as the Moon, when the Earth isn't visible.
2. Do you mean stationary relative to the background stars? Well you'd start to accelerate according to the pull of gravity, unless you are using a solar sail or some other form of propulsion to counter it.

[Diesel23]

1. Space is extremely clear. In a Bok Globule it is extremely dark and cold, but Bok's Globules are relatively dense clouds of dust and gas. I would think that your hand in front of your face would just get dimmer and dimmer, say in the space between galaxies.

2. To orbit a body in space is to be in free fall around that body. We will leave out the phenomena of Frame Dragging. Speed over comes gravity and a circle or eccentric is drawn with imaginary lines. Everything spins, sometimes in multiple planes simultaneously; stars, planets, galaxies, moons, dust, gas clouds. The universe itself seems to not spin, go figure. Galaxies and individual stars are moving towards Sol or away, so to stay still relative to other objects inside or outside the solar system, you would have to be moving.

Clear as mud? LOL!

[Milky Way Resident]

Originally Posted by trevor0101

I had a couple of thoughts, and I'd love to C-D's resident smart people to weigh in:

1. Are there areas of space where light is so lacking that I could not see my hand in front of my face? Perhaps in interstellar space? What about in the far reaches of our solar system?

I think you'd still be able to see your hands in interstellar space, as there would be tons of stars in a galaxy. In intergalactic space (space between galaxies that are part of the same group), you would probably see such galaxies , but not individual stars.

In the middle of a cosmic void, it would be so dark that you wouldn't see a thing. The nearest galaxy would be at least millions of light years away. I'm talking about things like the Bootes Void or the Eridanus Supervoid, which still do have some galaxies in them.

Someone correct me if I'm wrong.

[Dapper Zoom]

Originally Posted by trevor0101

1. Are there areas of space where light is so lacking that I could not see my hand in front of my face?

In almost all of space you wouldn't be able to see your hand in front of your face. You wouldn't be able to see anything whatsoever. Even if the star closest to you went supernova in the direction you were looking you wouldn't see it. It'd be just you and a few helium and hydrogen molecules. And your laptop, so you could read this answer to your post.

This may seem unintuitive, but the Universe is vast and most space is intergalactic space.

[Milky Way Resident]

Originally Posted by Dapper Zoom

In almost all of space you wouldn't be able to see your hand in front of your face. You wouldn't be able to see anything whatsoever. Even if the star closest to you went supernova in the direction you were looking you wouldn't see it. It'd be just you and a few helium and hydrogen molecules. And your laptop, so you could read this answer to your post.

This may seem unintuitive, but the Universe is vast and most space is intergalactic space.

Is that really the case though? Why wouldn't you be able to see your hands in interstellar space? I agree about intergalactic space though.

[Dapper Zoom]

Originally Posted by Milky Way Resident

Is that really the case though? Why wouldn't you be able to see your hands in interstellar space? I agree about intergalactic space though.

Almost all space is intergalactic space, so interstellar space is extraordinarily atypical. As far as interstellar space is concerned, there are regions where you could actually see your hand, and others where you could only see silhouette of your hand as you held it up and it blocked out the distant stars.

[tnff]

For your two questions, let's reduce them to practical rather than absolute answers.

a. There will be lots of places in space where the number of photons (amount of visible light) is lower than what your eye can detect. In practical terms, you wouldn't be able to see your hand in front of your face.

b. Again, in practical terms, Lagrange points would be places where you would stay in the same place relative to the sun and another body. Technically you're still orbiting, but we're talking practical usefulness, not the complete mathematics of the solar system.

[Milky Way Resident]

Originally Posted by Dapper Zoom

Almost all space is intergalactic space, so interstellar space is extraordinarily atypical. As far as interstellar space is concerned, there are regions where you could actually see your hand, and others where you could only see silhouette of your hand as you held it up and it blocked out the distant stars.

When you put it that way, it makes a lot of sense. I was more looking at each region individually, where you have interplanetary, interstellar and intergalactic space and not considering which one occupies the largest volume.