The distance between the Earth and the center of our galaxy, the Milky Way, is estimated to be around 27,000 light-years. However, this does not imply that we are waiting to learn about a potential galactic explosion that occurred 26,000 years ago. Here's why:
Speed of light: When we observe distant objects in space, we see them as they were in the past because light takes time to travel to us. For example, when we look at a star that is 1,000 light-years away, we see it as it appeared 1,000 years ago. Similarly, if our galaxy were to explode, we would observe that event only after the light from the explosion reaches us. So, if an explosion occurred 26,000 years ago, we would have already seen the effects of it by now.
Galactic timescales: The Milky Way is a massive structure, consisting of billions of stars, gas, and dust. It has a long lifespan measured in billions of years. The likelihood of the entire galaxy undergoing a sudden and catastrophic explosion is extremely low. Galactic events such as supernovae (explosions of individual stars) or mergers with other galaxies occur over longer timescales, and their effects can be observed and studied.
Continuous observations: Scientists constantly observe the night sky using various telescopes and instruments. They study the behavior of galaxies, including our own, and look for any signs of significant changes or disturbances. If a galactic explosion of the scale you mentioned were to occur, it would likely leave observable traces such as high-energy radiation, shockwaves, or other detectable phenomena. Scientists would have noticed and investigated such an event by now.
In summary, based on our current understanding, there is no evidence to suggest that our galaxy exploded 26,000 years ago and we are awaiting information about it. Galactic-scale explosions are highly unlikely and would have been observable through our continuous monitoring of the cosmos.