Delve into the infinite cosmos. What's the furthest we compare into the past? Light our cosmic messenger travels at a set speed so when we gaze upon distant celestial bodies, we're actually seeing them as they were in the past. The Hubble Space Telescope has glimpsed galaxies over 13 billion light years away. Imagine that's viewing the universe as it was just 400 million years after the Big Bang. But there's a limit. The cosmic microwave background or CMB is a relic from when the cosmos was a mere 380,000 years old. Beyond that, it's all speculation and theory. So in essence, our cosmic vision is a grand time machine, witnessing the universe's infancy. Fascinating, isn't it? This is the power of cosmology.