Arrrggghhh - i KNOW some are there. But, let's zap together in a hypothetical future for a simple demonstration; what if the darn phenomenal & super-massive singularity gobbles up your exemplary galaxy that was roaming around when we observed it?
Where is it now?
No. Because said 'phenomenal & super-massive singularity' itself would be at the center of its own galaxy. And even if it weren't, and collided with another galaxy, it wouldn't just suck the whole galaxy up. The extreme pressures caused by a matter falling into black holes (LOTS of matter trying to get into the same place at the same time) cause the falling material to form an accretion disk (and large jets of matter that get catapulted out into space). If a single giant black hole tried to swallow a whole galaxy, that would make quite a spectacular accretion disk! However, such a large black hole is highly unlikely because it would probably evaporate faster than it could suck in more matter.
And, even if somehow such a massive giant black hole were wandering around without any surrounding matter, it would still be rather hard to miss - it would cause huge-scale gravitational lensing that would be hard to miss.
It was based on how far the farthest star is.
It is based on many observations - the cosmic background radiation, the earliest quasars, the first mature galaxies, the rate of expansion of the universe today and past rates, collisions in particle accelerators, elemental composition of the known universe. All of these observations were combined together to put together a theory of the evolution of our universe. This theory, combined with astronomical and experimental observations such as the above, were used to calculate an age of roughly 13.7 billion years.
It's my understanding that time is unique to the universe itself, the fourth dimension (width, heighth, depth and time). It is theorized that when the universe began there were actually many more dimensions that collapsed early in its life (something like fourteen i think). Here's the kicker, the physics we understand is also unique to our universe, therefore before the universe our concept of physics didn't exist. So there's really no telling what happened before the universe. Black holes are holes in the universe and as such, our concept of physics does not exist in the center where the "singularity" resides. The definition is: Astrophysics A point in space-time at which gravitational forces cause matter to have infinite density and infinitesimal volume, and space and time to become infinitely distorted.
I like that idea. I don't know if it's right, it could be, but it needn't be. I disagree with your idea that the physics of our universe doesn't apply inside black holes. It is blatantly obvious that physics as understood by humans at this time does not apply inside them, but there is one overwhelming piece of evidence that the same physics that applies in our universe must apply to the inside of black holes - there is two-way transfer of information and matter between the inside of black holes and the rest of the universe. People often think of black holes as giant vacuums that suck everything in and keep it there forever but it's not so - black holes actually evaporate! Through the wonders of quantum mechanics, matter is actually able to escape from black holes - it's called Hawking Radiation. If physics didn't apply inside black holes, then two-way transfer of information should be impossible or at least appear nonsensical to us, but that isn't the case.
It seems to me that since it generally takes energy to move anything from point A to point B, so wouldn't it also take energy to move from time A to time B, the amount of which is currently incomprehensible to our little human minds. Time also seems to be an peculiar and potentially unstable dimension, peculiar in that it moves in one "direction"(forward) and potentially unstable in that traveling backwards through it could cause major problems (i.e. Time Paradox, yikes!)
It doesn't necessarily take energy to move anything from Point A to point B. Objects follow the path of least resistance (in physics-speak, objects follow geodesics - straight lines generalized to curved spacetime). It only takes energy to move an object from A to B if A and B are not successive points on its current geodesic in spacetime. In curved space-time especially, you can't really speak about moving an object between two points in space [time] without also considering the time [space] component because the two are intricately and fundamentally connected.