[jschwartzi]

Isn't the Big Bang only observable as the Cosmic Microwave Background? The Big Bang is the oldest event we can observe, but that doesn't mean nothing was happening before it. It just means we can't observe what was happening.

The travel time for light from that event doesn't seem to tell us very much about how old the Universe is as an n-dimensional space. It only tells us how far back we can observe. We can choose t_0 to be the point in time at which that farthest emitted light was emitted. That doesn't mean there isn't a t_-1, it only means that our axis of positive time starts there because that's all we can observe right now. We know some event happened and before that event we can make no observations, while after that event we can make observations. So everything observable follows from that event. But absence of observations is not evidence of absence.

It's actually sensible to ask what's north of the North Pole because it reveals something about the geometry of the coordinate space. You're considering the North Pole as a fixed boundary where all lines end, whereas the asker considers it as a point that all lines pass through(this is a more correct interpretation). In our polar coordinate system going to that point would result in being somewhere south of north but on the other half of the semicircle. Whether it's sensible to ask that about the universe seems like an open question to me.

The sensible thing to me is to wonder at the question while recognizing that we aren't currently able to answer it sensibly. Maybe we never do.

[saagarjha]

We can’t observe things before recombination, a couple hundred thousand years after the Big Bang, when electrons bound to nuclei and photons stopped being constantly scattered.

[sunstone]

I believe there's some hope they may be able to see past this point using the new gravitational astronomy.

[jschwartzi]

That makes sense. Observation implies that matter and energy have to be in a form familiar to the observer.