How Far can our Telescopes see? The Edge of Cosmos?

I was just thinking about Einstein's prediction, about the 4 dimensional cosmos we live in. About how he said, that the universe had no bound, but yet it was finite.

Somehow like the surface of the Earth was border/boundless, but still it was not infinite.

So I asked to myself, could we discover the edge of our universe using telescopes? Can we really know the real age of the cosmos if we could find the edge of it? Is it even possible?

How would light behave, when it hit the egde of the cosmos? Is light a 4th dimensional entity, since it consistent speed (not bound in time)? Or is it a 3 dimensional entity, and because of it, it would always go along the spacetime fabrics, and thus no possible way for us to "see" the border of our cosmos?

But then, if this ought to be correct, if we can build a telescope, so powerfull, we can scan a very deep field image! Is it possible, could/might it be, if we can scan the sky so deep, that we can see PLANET EARTH in a distant far far away place??? All of this because of our 4 dimensional sphere of the cosmos we live in. So, that light will travel in a perfect circle, like if Chuck Norris could hit the backside of his own head, after encircling the Earth?!

But there is a 2nd question: if this is true, how could the astrophysicist predict the age of our cosmos, in the first place? If light could never reach the edge of the universe? Have we been LIED TO all this long?

So, there are 2 main questions in this thread:

1. Is it possible for us to see ourselves in a distant distance? Assuming, we are living in a 4D circular cosmos! (like Einstein predicted)

2. How do we define the age of the cosmos, really??? Does anyone know?

I want to know your opinions about this. Trolles, please keep out! Thank you!

P.S.: I dont know whether there was already a similar thread, asking the similar question. So, my pardon in the advance, folks.

First, I think the mankind (or womankind :-P ) is not advanced enough to truly grasp the secrets this universe holds. To try and wrap your brain around the concept of a 4d universe is a task that deserves weeks, months, maybe years.

Second.. Trying to grasp the concept is fun! and I suppose if we COULD find that 2nd future earth thing... we could determine how much further it is... based on the state of the planet.

And all of this reminds me of Futurama's famous "Smelliscope"

I wonder what Black Hole smells like? Heck.. what about a white hole?

Its somewhat discouraging that with all the tech out there, we can't even get a decent pic that shows mindblowing resolution from the moon's real estate.

We should be able to count the pebbles within a footprint on that piece of round fakeness, but strangely that capability lies beyond 'our' grasp and we only peck at altered crumbs that fall off the tables of those on higher levels.

Zoom zoom zoom.

reply to post by coyote66


using gravitational lensing we can see back in time
as you pointed out light takes time to travel places, so when we are looking through a grav lense,
we can see aprox 12.9 billion years ago and the same distence is also 12.9 billion years into the past
now when we see objects at that distence they are suprisingly like our "local" universe.
if we can see 12.9 billion LY in oposite directions and see similar things to what we see locally,

then we could say that to the furtherst thing we can see can see us and should be able to see the same distence in the oposite direction from us.
12.9 + 12.9 + 12.9 +12.9 billion LY = 51.6 billion LY
IN THEORY and not a glimpse of earths other side


xploder

Well, if its true that the universe is still expanding and its expanding at light speed, then we would never have the ability to see the edge of the universe, since it would be moving away at the same speed that the light from it (if any) would be coming towards us. Or am i completely off on this one?

IDK what he said UP there (post above me) but it sounded like a better explanation than mine, lol.

We can see far but only massive "objects' like nebulas and such. We can see light emitted from distant stars but cannot see planets past our solar system in any detail, as far as I remember reading.

According to our current understanding, the universe is expanding, and the expansion rate is increasing. This has as consequence that we live in a sort of a bubble. You can never see beyond this bubble, as everything outside this bubble is increasing in distance to earth at a rate that is larger than the speed of light. So light that travels towards us from outside that bubble never reaches us, its just too slow. In fact, that light will move away from us, even though its direction of movement is towards us. This "bubble" is called the cosmic event horizon, and has a radius of about 16 billion light years. However, since the expansion of space time is increasing, this distance decreases.

A tip for the OP, this, and also the age of the universe, is explained in rather great detail on Wikipedia.

reply to post by -PLB-


This boggles my mind. I am a believer that there is life SOMEWHERE out there... however, its unimaginable to me how life would end up being able to travel here. The theories of wormholes and ect. doesnt make it any easier to fathom.

I think about the possibility that the Universe is more than simply a bubble thats expanding. It reminds me of when the majority thought the Earth was flat. The Earth surely does FEEL flat because of the size, but perhaps this concept is at play on a much larger scale with the Universe.

Perhaps the Universe is comprised of something more than we have the abilities to detect or understand. I am still convinced that the blackness that actually makes up space has more to it.

Anyways, it's always fun to ponder the final frontiers of space... so mind boggling!

Originally posted by gypsychology909
Its somewhat discouraging that with all the tech out there, we can't even get a decent pic that shows mindblowing resolution from the moon's real estate.

We should be able to count the pebbles within a footprint on that piece of round fakeness, but strangely that capability lies beyond 'our' grasp and we only peck at altered crumbs that fall off the tables of those on higher levels.

Zoom zoom zoom.

Just taking a wild guess here...you aren't an astronomer, either professional or amateur, are you? I'm basing that guess on your post above...there are three basic reasons why "we" (defined, in this case, as "the subset of the human race with access to decent or better optical instruments") can't "count the pebbles within a footprint" on the moon. Tying this in with the original post here, those three reasons also set a practical limit on how far into the cosmos we can see with our telescopes.

First, there's the resolution of the optical system.
Definitions and math, for those so inclined

At some point, no matter how good your optical system, you will reach the point where light (whether emitted by or reflected from) adjacent objects succumbs to interference phenomena. That's not a product of some technology-suppressing conspiracy, it's a consequence of the way light propagates through space, and how it behaves within any system of mirrors and/or lenses. The better (or larger) your optical system, or the larger (or brighter) your target object is, the further you can see before objects start 'blending together', but eventually, it will happen, whether the objects are pebbles in a footprint, or stars at the far edge of the cosmos. To give a real-world example of this, Pluto (whether it's a planet or not) is a real *ahem* bear to spot, because it's fairly faint, and has an angular diameter of about 0.1 arc-seconds. It's roughly the same as spotting a ping-pong ball at a distance of 50 miles. Wrap your head around that, for a minute, then take a look at the European Extremely Large Telescope. When that monster is finally complete, it will have a maximum resolution of 0.001 arc-seconds. It could spot our theoretical ping-pong ball at 5,000 miles range. Big as it is, it can't see 'pebbles' on the moon.

Second, there's atmospheric aberration. The Earth's atmosphere isn't still...it's a very dynamic structure, with different layers having different temperatures, densities, and velocities. As light travels through those various layers, its path bends in all sorts of odd ways. Add in the scattering effect from suspended dust and / or ice particles, and you have serious problems with degraded images. That's why most observatories are on mountaintops and in out-of-the-way places...it's not that astronomers like to be cold, it's that they're trying to stay above the worst of the atmospheric problems. Some of them can also be fixed using adaptive optics, but not all.

Third is white-out, or image saturation. The further you want to look (or the smaller your target), the more light you're going to need to gather. Astronomical photography can use hours-long exposures and huge telescopes to gather as much as possible...but brighter objects can easily saturate an image with light, blotting out the smaller, fainter things you're actually looking for. This is why you can't see the stars in a daylight sky. They're up there, but the Sun is so bright, and scattering so much light into the atmosphere, that light from the relatively faint stars is simply swamped. Lunar photography has real problems with this, since the Moon is surprisingly reflective, making it really easy to saturate a long exposure.

Long story short (I know, too late!), there's no theoretical limit on how far a telescope can see (other than the physical size of the Universe), and no theoretical reason we can't see pebbles on the Moon...but in the real world, between resolution, aberration, and saturation, both small Lunar details and the most distant, faintest stars simply can't be recorded until we either go there, or put *much* larger instruments than the Hubble into orbit. *crosses fingers for that*

They say they can see galaxies 13billion years old,

BUT ... could it be half of that if they are looking across the center of the universe?

eg:
E = earth
G = the galaxy they see 13 billion light years away.


E___________________________________G
|________13 billion Light years ___________|


OR

E = earth
G = the galaxy they see 13 billion light years old.
B = point of the Big Bang where everything expanded from

E________________B__________________G
|_6.5 bn L/years ____||___6.5 bn L/years ____|

I understand about the tellescopes having image problems looking through our atmosphere, but why do they put satellites in close orbit arround the moon with cameras that can not take higher definition, and almost real colour pics. There always seems to be enough budget to do the experiments but they always skimp on the quality or ability of the cameras placed in them.

I wonder if the universe simply loops back in on itself.

if you zoomed out as far as you could from the endless galaxies we see,
\would they make up one molecule within infinite more molecules within infinite universes?

what is the point of a trillion galaxies if not to form something macroscopic?

like the trillion different cells that make up the human body

Did not even bother to read the whole post. The cosmos or the universe is infinite. That's it, there is no end and no beginning. It goes on forever. It does not matter that puny human brains that are subject to borders all there entire life don't understand infinite.

Originally posted by JPeveto4
Did not even bother to read the whole post. The cosmos or the universe is infinite. That's it, there is no end and no beginning. It goes on forever. It does not matter that puny human brains that are subject to borders all there entire life don't understand infinite.

Thanks for that uplifting tidbit.

Joking aside, how do you truly know it goes on for infinite?

There's no way to prove this as fact (maybe there I is... have any proof?)

Even if you didn't bother to read the entire post, I'm glad we got a few seconds of your time for your insight.

reply to post by gypsychology909


To see the flag on the moon, you will need a telescope with a mirror of about 200m in diameter!!!!! (and that is when we just look at the optics. When we add things like abberation, etc, it becomes even larger)

Hubble has a mirror of 2.4m. Keck has a 10m mirror. So, you will need a telescope 20 times larger than Keck just to see the flag on the moon.

here is a nice primer for you on telescopes : www.telescope-optics.net...

here is another (simpler one) : curious.astro.cornell.edu...

The light year concept, is it true?
Sure the speed should tell us how far in a year a light issued from an electron quantum
jump between atomic shells. That light is issued in all directions an does not lose power
if unencumbered. A big bunch of atoms make bigger lights from the stars.

The measure of distance came from special stars of known activity in time.
We may have gone past the time those stars can tell us the distance to further spots
in the universe. The Red Shift might be the new measure of distance for a star.

Well there's "infinite" and "potentially infinite". I think the consensus on our universe is the latter. That is it's currently finite but will grow forever. If we could take ourselves outside of time then it would no longer be potential but actual infinite.

reply to post by circlemaker


Well, there are theories out there that the universe will eventually run out of gas and die, taking all life along with it.
Everything that has a beginning has an end, Neo.

Dr Lineweaver said that the next step in the research is to out how close we are to maximum entropy, how much entropy is being produced and how much time we have left before the universe and all life in it dies in the inevitable heat death.

Link

A typical galaxy's star-making gas supplies last just 1-2 billion years. The growing darkness was so incremental Braun said it would be impossible to notice in a human lifetime, but were someone to live for one billion years they would "see things changing very dramatically" in the skies above. Without a reversal in the universe's dark energy-fuelled expansion -- the likelihood of which remains a great scientific puzzle -- Earth's inhabitants would very slowly but surely inch toward nights of deep darkness, he added

Link

Originally posted by myss427
I understand about the tellescopes having image problems looking through our atmosphere, but why do they put satellites in close orbit arround the moon with cameras that can not take higher definition, and almost real colour pics. There always seems to be enough budget to do the experiments but they always skimp on the quality or ability of the cameras placed in them.

Even today, you can get higher resolution with black and white images than with color, which is one reason that you see black and white cameras used on probes. The biggest limiting factor on any space mission, be it orbital, lunar, or long-duration probe, is weight...every pound of payload placed in orbit adds (if memory serves) eight to ten pounds of launch weight. That has a ripple effect throughout the entire design process of a probe...it would be nice to launch a bigger camera, but that ups the weight..and if we launch a bigger camera, taking bigger, higher resolution images, we'll need a faster communications system to transmit back the bigger images in a reasonable time frame...and that will mean more power, which means more solar panels / batteries / isotope generators, and you can see where this is going, can't you?

That said, it's not like the photographs we've gotten back from the latest generation of Lunar probes are exactly crap. The Lunar Module's landing gear had about a 30' span, but the actual body was about 14' square. That's not really a huge target to spot from several miles up...a 3' x 5' flag is an even harder target to spot. The only way to spot these things at any real resolution, using current technology, is to go up there and see them with the Mk 1 eyeball....a proposition I personally support wholeheartedly.

Originally posted by coyote66
I was just thinking about Einstein's prediction, about the 4 dimensional cosmos we live in. About how he said, that the universe had no bound, but yet it was finite.

Somehow like the surface of the Earth was border/boundless, but still it was not infinite.

So I asked to myself, could we discover the edge of our universe using telescopes? Can we really know the real age of the cosmos if we could find the edge of it? Is it even possible?

How would light behave, when it hit the egde of the cosmos? Is light a 4th dimensional entity, since it consistent speed (not bound in time)? Or is it a 3 dimensional entity, and because of it, it would always go along the spacetime fabrics, and thus no possible way for us to "see" the border of our cosmos?

But then, if this ought to be correct, if we can build a telescope, so powerfull, we can scan a very deep field image! Is it possible, could/might it be, if we can scan the sky so deep, that we can see PLANET EARTH in a distant far far away place??? All of this because of our 4 dimensional sphere of the cosmos we live in. So, that light will travel in a perfect circle, like if Chuck Norris could hit the backside of his own head, after encircling the Earth?!

But there is a 2nd question: if this is true, how could the astrophysicist predict the age of our cosmos, in the first place? If light could never reach the edge of the universe? Have we been LIED TO all this long?

So, there are 2 main questions in this thread:

1. Is it possible for us to see ourselves in a distant distance? Assuming, we are living in a 4D circular cosmos! (like Einstein predicted)

2. How do we define the age of the cosmos, really??? Does anyone know?

I want to know your opinions about this. Trolles, please keep out! Thank you!

P.S.: I dont know whether there was already a similar thread, asking the similar question. So, my pardon in the advance, folks.

edit on 11-4-2012 by coyote66 because: (no reason given)

edit on 11-4-2012 by coyote66 because: (no reason given)

Let me explain. All time that has and will occur from our frame of reference, the present, is the complete fourth dimension which we experience on slice at a time in 3D. We travel through time in 3D like crossing layers of an onion. Our frame of reference always being the present as it tunnels trough from the center of the onion. We can only see the tunnel of course which is the past, or record the existence of the past rather, but the future does exist just the same, and both are always as real as the present, but the tunnel through the onion of all time does not exist yet so we can't observe it, it's physically there, we just don't occupy its frame of references yet, its layers. So to answer "Is it possible for us to see ourselves in a distant distance?" Yes, as all our energy that makes up our atoms that make up our molecules that make us, us, are all layered like an onion like time as we are a product of time, or like a Russian doll set dating back to the Big Bang smaller and smaller to a very tiny dot of compressed energy that was that small due to it not only containing all energy that all matter in the Universe is comprised of, but also all of its gravity. Like a supercharged microscopic battery relative to the size of space and time now.

Regarding your other question, the age of the Universe is well documented in terms of past 3D in Earth years. If you are asking how old it is in 4D, it could be more than a googolplex.