With scientists having recently found the oldest known galaxy in our universe (13.1 billion years old, which disproves the Biblical creation story completely, new earth idiots!), it's painfully obvious to me that we are able to actually see back in time (if you could somehow zap yourself there in the blink of an eye by some kind of worm-hole means [you obviously can't race there faster than the speed of light, which would still take you billions of years], it means you could probably also time-travel technically). So my question is this: if we're seeing these 'infant galaxies' that formed billions of years ago as if it's happening right now, is it possible that if we developed technology to see even further into the universe (or 'further back in time' as it may be), that we may be able to witness the immediate aftereffects of its birth? The universe is 13.7 billion years old; 13.1 is awfully close to it. I'm just curious and wondering what our cosmology-savvy members have to say about our ability to someday witness the cosmic dawn.
Actually Genesis refers to a prior creation and the existing one.
"The earth became (was) void and without form" Was is an unfortunate rendering of the Hebrew"
This why everyone should read the scriptures in the orignal tongues as not to be misled by transliterational errors. Moreover scriptures allude to an unseen universe from which the seen one was made. "...that which appears was created from that which doesn't appear". This may be the first allusion to dark matter or someother nonbaryonic form.
Umm... apart from the mesmerizing tale Michael seems to tell in an earlier post, I want to say that there is actually a limit to where we can possibly see. There was some time after the expansion of our universe started when it was total darkness. Light could escape only after things cooled and slowed down a bit. Regardless of that, I think it's marvelous that we can see so far both in space and in time. It's quite awesome to think that all you need to do in order to see in the past is to look at the night's clear sky.
Also, about the witnessing of the beginning of this universe, maybe we won't be able to actually see it, but we can create a pretty clear picture of it through data collected from other forms of radiation and through mathematical models.
The thing about light is that it travels at the speed of light. ( physicists say it as it is ) So, based on that fact, light is carrying information with it. We use that information to form a picture.
is it possible that if we developed technology to see even further into the universe (or 'further back in time' as it may be)
It is possible but very, very, difficult. To bend space-time and create a wormhole to a certain point in time you would need the whole mass of Jupiter transformed into energy ( E = mc2 ). One gram of mass is equal to 1.5 Hiroshima bombs ( I've done the maths ).
Even if we could use all that energy, the amount alone could obliterate us, and even if we could control it, if we create a wormhole we couldn't figure out where it would take us, let alone steer it according to our will.
Theoretically, travel faster than light is possible, if you move the fabric of space-time ( and you remain motionless ). Matter has a speed limit. Space itself does not. A theoretical device is the Alcubierre Drive.
Possibilities are endless, and are limited to our resources/capacities, imagination and to the rules of the system in which we reside ( the laws of the universe )
Well, the way this basically works is that as we look back in time, the universe was hotter and denser. Go back far enough, and the universe was so hot, so dense, that it was a plasma. A plasma is an ionized gas. Here on Earth, we see this form of matter in lightning bolts and fire. The temperatures are just too low to keep plasma around. But the Sun is made up of plasma.
In a plasma, because the protons and the electrons are separated from one another, and since light tends to interact strongly with charged particles, light rays within a plasma just tend to bounce around. They don't get anywhere, and so the early universe was opaque.
About 300,000 years after the start of our region of the universe, this plasma cooled to a gas state. As a gas, like with our own atmosphere, it became transparent. The light that was bouncing around within this plasma was emitted. In fact, this light makes up over 99% of all the light that has ever been emitted in our universe. We see it today as the Cosmic Microwave Background, which gives us our most detailed look at the makeup of the early universe.
I don't even know if I know enough to discuss the topic intelligently. It always seems like no matter how far we can see back(or forward for that matter) we will eventually run up against the inherent limits of our human sensory apparatus. Regardless of whatever machinery we develop to increase it.
It's always seemed to me that trying to understand cosmology without the math is like trying to understand Beethoven without the music.
Well, it's not so much the limits of our sensory apparatus, but instead limitations imposed by the universe itself, such as the speed of light.
But yes, it's definitely the case that you can't really understand any of this without the math. It's unfortunate, but it's simply true that the only really accurate description of what is going on in cosmology (or most of physics) is mathematical by nature, and just doesn't have an exact translation into natural language. That said, a superficial understanding is in principle possible, but shouldn't ever be thought to be more than superficial.
Observation is passive. We can only see what is presented to us. That means we witness under the constraints of space/time. Although everything in the universe has a speed limit of 186,000 miles per second, the universe (space) itself can expand faster than this. I think the 13.1 billion-year limit on our hindsight will only decrease in the future. If I understand what I've read on this subject, the cosmic radiation background delimits the observable universe. No amount of passive observation techniques can improve this limit without breaking the known laws of physics.
But that's my amateur point of view. I'm sure my errors (if any) will be promptly corrected. :-)
75K Light years isn't all that far cosmologically. As far as I understand it, in a way it's where it always was, but it doesn't seem that way when we take a look. I believe it's the definition of "where" that keeps changing and how it relates to when. It's more than mind boggling, it makes mine want to crash. Every time a read another layman's guide to General Relativity, you think you get it for a second, then they go into the implications of it................it's like it won't register on the brain.
If you can find someone that can explain it without the math, let me in on it.
What does the Virgo Supercluster really look like at this instant?
I far as I've ever been able to figure, that's the wrong question. "This instant" is merely a convenient point of reference.
I'll bet the answer is still 42 though.
That view isn't actually consistent with relativity.
The basic problem is that if you take two spatially-separated points, different observers will make different choices for when the time on one point matches the time on the other point.
A classic example is this: let's imagine a train car moving at relativistic speed. We have sensors on either end of the train car, and when we flash a light in the center, we see when the light hits the sensors. So when this light is flashed in the center, to an observer on the car, the sensors are each hit at the same time.
However, an observer standing on the platform will not see this. As the backwards-moving light travels towards the back of the train car, the train car moves forward, so the distance traveled by the light is shorter and hits the back of the train before it hits the front.
So we have two simultaneous events to one observer which happen at different times to another observer. This is an indication that there is just no such thing as a global "now" that exists in any physical sense, which is an indication that the future and the past have to exist in the same way that the present exists.