Is deep Space deep?

[Jet2]

If yes, how deep?

[sanctus]

How do you define deep?

[Tormod]

Is a high mountain high? :doh:

[UncleAl]

13.7 billion lightyears deep (within 1%) - measured in any direction from any contained point. Science 315 59 (2007).

[Jet2]

Is a high mountain high? :doh:

 

Exactly.

[Pyrotex]

"You thought it was a far way to the corner druggist, but that's peanuts compared to space!" :doh:

[REASON]

The depth of space, while quantifiable, is virtually impossible for us to conceive, yet is still only a matter of perspective. :doh:

 

 

(I'm still trying to decide if the above statement even makes any sense. :))

[Jet2]

The depth of space, while quantifiable, is virtually impossible for us to conceive, yet is still only a matter of perspective. :)

 

 

(I'm still trying to decide if the above statement even makes any sense. :))

 

Me too.

 

May be Space shouldn't be measured or understood by Earth's standard?

But then how can we comprehen all the things around us?

 

Again, I don't know if the above questions make any sense...

[Ahmabeliever]

I must harken back to 1972 with Hawkwind and their classic space rock album, Doremi Fasol Latido.

 

Space Is Deep.

 

Space is dark, it is so endless

when you're lost it's so relentless

It is so big, it is so small

why does man try to act so tall

Is this the reason deep in our minds

 

It does not feel, it does not die

space is neither truth nor lie

Into the void we have to travel

to find the clue that will unravel

Is this the reason deep in our minds

 

The secrets lie with our tomorrow

in each of us a hidden sorrow

The path goes onward through the night

beyond the realms of ancient light

Is this the reason deep in our minds.

 

I think they not only imply the physical depth of space but the profound answers we find there.

[sanctus]

13.7 billion lightyears deep (within 1%) - measured in any direction from any contained point. Science 315 59 (2007).

 

Isn't that the size only of the visible universe? It is the distance light can have travelled from the beginning of time no?

 

So space might be bigger (or deeper if you want), we can only talk about the part of the universe which can have (or actually has since we see the early light) causal contact with us...

[Tormod]

The visible universe is possibly a sphere 92 billion lightyears across.

 

Check this for an enlightening read on the size of the observable universe:

Observable universe - Wikipedia, the free encyclopedia

[wddycus]

The Universe is still expanding so if you decide how deep it is today it will be

different tomorrow so this is a open ended question so their no correct answer.

So you are really need to ask a different question.

Dan

[UncleAl]

we can only talk about the part of the universe which can have (or actually has since we see the early light) causal contact with us

 

Exactly. Whatever exists outside our light cone is not accessible and doesn't matter - no cause and effect reationship. Go out on a clear night. Look at a galaxy on the horizon, look at another on the horizon 180 degrees away. More than likely they are not within the same lightcone so each doesn't exist for the other. So?

 

The universe has the same geometry as inside a black hole's event horizon. No path leads outward across the event horizon. "Outside" is not meaningful.

[Pyrotex]

Uncle Al is correct.

With the proviso that if you do his experiment, you will want to select two galaxies that are quite distant, say, just discernible in photos taken with the Hubble Space Telescope or some equivalently large ground-based telescope.

[LaurieAG]

Whatever exists outside our light cone is not accessible and doesn't matter - no cause and effect reationship. Go out on a clear night. Look at a galaxy on the horizon, look at another on the horizon 180 degrees away. More than likely they are not within the same lightcone so each doesn't exist for the other. So?.

 

Hi UncleAl,

 

I think you've made a slight error.

 

While the observer is always at the pointy end of a light cone, wherever they may be in the universe, the object that projects the photons towards the observer also projects photons in all directions, including 180 degrees away from any observer, unless something gets in its way.

[Moontanman]

If yes, how deep?

 

Deep , wide, and tall dude, deep, wide, and tall:hihi:

[LaurieAG]

Check this for an enlightening read on the size of the observable universe:

Observable universe - Wikipedia, the free encyclopedia

 

You're not wrong about that Tormod,

 

Many secondary sources have reported a wide variety of incorrect figures for the size of the visible universe. Some of these are listed below.

 

13.7 billion light-years. The age of the universe is about 13.7 billion years. While it is commonly understood that nothing travels faster than light, it is a common misconception that the radius of the observable universe must therefore amount to only 13.7 billion light-years. This reasoning only makes sense if the universe is the flat spacetime of special relativity; in the real universe, spacetime is highly curved on cosmological scales, which means that 3-space (which is roughly flat) is expanding, as evidenced by Hubble's law. Distances obtained as the speed of light times a cosmological time interval have no direct physical significance. [5]

15.8 billion light-years. This is obtained in the same way as the 13.7 billion light year figure, but starting from an incorrect age of the universe which was reported in the popular press in mid-2006[6] [7] [8]. For an analysis of this claim and the paper that prompted it, see [9].

27 billion light-years. This is a diameter obtained from the (incorrect) radius of 13.7 billion light-years.

78 billion light-years. This is a lower bound for the size of the whole universe, based on the estimated current distance between points that we can see on opposite sides of the cosmic microwave background radiation, so this figure represents the diameter of the sphere formed by the CMBR. If the whole universe is smaller than this sphere, then light has had time to circumnavigate it since the big bang, producing multiple images of distant points in the CMBR, which would show up as patterns of repeating circles.[10] Cornish et al looked for such an effect at scales of up to 24 gigaparsecs (78 billion light years) and failed to find it, and suggested that if they could extend their search to all possible orientations, they would then "be able to exclude the possibility that we live in a universe smaller than 24 Gpc in diameter". The authors also estimated that with "lower noise and higher resolution CMB maps (from WMAP's extended mission and from Planck), we will be able to search for smaller circles and extend the limit to ~28 Gpc."[2] This estimate of the maximum diameter of the CMBR sphere that will be visible in planned experiments corresponds to a radius of 14 gigaparsecs, the same number given in the previous section.

156 billion light-years. This figure was obtained by doubling 78 billion light-years on the assumption that it is a radius. Since 78 billion light-years is already a diameter, the doubled figure is incorrect. This figure was very widely reported.[11] [12] [13]

180 billion light-years. This estimate accompanied the age estimate of 15.8 billion years in some sources; it was obtained by incorrectly adding 15 percent to the incorrect figure of 156 billion light years.