Things are kinda weird. We had a reasonable notion of "now", as in... a photo. Came 1905 relat. and that blows the idea up, there is no more a consensual concept of "now". But though not consensual, the photo definition, even if dependent on the observer, is still there. One thing that an earlier documentary on the Webb experiment impressed on me is that with that "now" so defined, the farther the things I see are the earlier, so it is legit that we are seeing big bang "now" (modulo some shit occluding). It is geometrically also weird. We can look around 2D in 360 degrees and see bbang photons coming from everywhere, look 3D spherically around every direction receiving bbang photons. Yet all photons are sourced in a single point-like event (bbang, or post bbang "first light" in fortunate ESA terms). Photons came to us from behind in spacetime from our causal past light-cone, but that cone joins base with the forward oriented bbang causal future light cone, so any valid signal one gets must be inside that region of joined cones. The pic has to be the same as in "suspension" in topology wiki page.
The finite speed of light was known before 1905. It was known by 1676.
Second, we see "big bang photons" in the CMB, but we're not seeing the big bang. We're seeing the glow from stuff at the time when the universe became transparent, that is, no longer a plasma.
I saw this at the Museum of Science in Cambridge, MA, in all its IMAX glory. The images are profoundly beautiful, and the ideas about seeing so far back in time are a real trip (even for the relatively well-informed layperson). Also, the telescope's creation, how close it came to being scrapped, the long-shot odds and multiple SPoFs that it survived... makes for a really engaging story.
The finite speed of light was known before 1905. It was known by 1676.
Second, we see "big bang photons" in the CMB, but we're not seeing the big bang. We're seeing the glow from stuff at the time when the universe became transparent, that is, no longer a plasma.
hell yes I'm watching this. I need to find a 'download' button to watch it at 1.5x tho
edit: actually, right click the video player when it's playing and there are speed controls
Do they mention that it runs javascript?