11–20 of 28 posts
NASA is making a lot of "record-breaking" news in the past few weeks and it is increasingly difficult for me to think how these news affect me and my relationship to the Galaxy. I understood many of these discoveries translated to "current science could be wrong". But if counting stars isn't my hobby, what am I supposed to take a way from this and digest the meaning of 11.1B light years distance?
Earlier quoted context omitted.
Exactly right. Its exciting because we get new data and if it contradicts theory, it forces us to reconsider what we think is the correct answer. And in that reconsideration our understanding grows. It is unfortunate that we cannot image this object once a day for 5 years and then watch its changes over that time period in one 30 minute viewing. Telescope time is too valuable to "waste" but I wonder what it might sho…
Let's say our telescopes get better and better. Are there any hard limits for how well we can resolve the light from such a galaxy?
See https://en.wikipedia.org/wiki/Diffraction-limited_system for example.
I always wondered about these measurements. Excuse me if this is rookie astronomical information. I have read that we gauge the distance through brightness. That is we know how bright such an object should be at the source, and estimate the distance based on actual brightness at the instrument. How do we know it's not just brighter than we believe, instead of being as far away as we believe?
You're right in that there is sometimes debate about whether the "standard candles" as they're referred to are as bright as we expect, see: https://en.wikipedia.org/wiki/Cosmic_distance_ladder#Problem...
Earlier quoted context omitted.
Exactly right. Its exciting because we get new data and if it contradicts theory, it forces us to reconsider what we think is the correct answer. And in that reconsideration our understanding grows. It is unfortunate that we cannot image this object once a day for 5 years and then watch its changes over that time period in one 30 minute viewing. Telescope time is too valuable to "waste" but I wonder what it might sho…
Let's say our telescopes get better and better. Are there any hard limits for how well we can resolve the light from such a galaxy?
I suppose at some point quantum effects will take over, but I'm guessing the manufacturing requirements for perfect optics will be the limited factor long before then.
Earlier quoted context omitted.
Let's say our telescopes get better and better. Are there any hard limits for how well we can resolve the light from such a galaxy?
Practically, yes, telescopes are limited by the diffraction limit. This depends on ratio of the wavelength of the light being captured to the size of the optics. In theory one could make larger and larger perfect lenses/mirrors, but practically there is a limit somewhere. More information at https://en.wikipedia.org/wiki/Angular_resolution I suppose at some point quantum effects will take over, but I'm guessing the m…
(Space telescopes are diffraction-limited but have other constraints, like mass budget and cost, that keep them from being as large as ground based facilities.)
Earlier quoted context omitted.
When we have evidence to the contrary. Speculation about what we might find in the future doesn't change anything.
Exactly right. Its exciting because we get new data and if it contradicts theory, it forces us to reconsider what we think is the correct answer. And in that reconsideration our understanding grows. It is unfortunate that we cannot image this object once a day for 5 years and then watch its changes over that time period in one 30 minute viewing. Telescope time is too valuable to "waste" but I wonder what it might sho…
It would be great if we could build more of them. I'm hoping that the cheaper access to space coupled with some clever hacks will let us throw a few more up there.
NASA is making a lot of "record-breaking" news in the past few weeks and it is increasingly difficult for me to think how these news affect me and my relationship to the Galaxy. I understood many of these discoveries translated to "current science could be wrong". But if counting stars isn't my hobby, what am I supposed to take a way from this and digest the meaning of 11.1B light years distance?
The opening line tells it all for you: "A new record for the most distant galaxy cluster has been set". For reference: https://en.wikipedia.org/wiki/List_of_the_most_distant_astro...
https://en.wikipedia.org/wiki/Galaxy_cluster
We can't go there. Nothing from there will visit us.
If the big bang is even an actual thing, it still happened everywhere, whenever.
There are lots of galaxies, and they are old and far away.
I always wondered about these measurements. Excuse me if this is rookie astronomical information. I have read that we gauge the distance through brightness. That is we know how bright such an object should be at the source, and estimate the distance based on actual brightness at the instrument. How do we know it's not just brighter than we believe, instead of being as far away as we believe?
Earlier quoted context omitted.
The opening line tells it all for you: "A new record for the most distant galaxy cluster has been set". For reference: https://en.wikipedia.org/wiki/List_of_the_most_distant_astro...
At this scale of time and given the size, age and distance of galaxies, it doesn't really mean anything that will ever change our lives. https://en.wikipedia.org/wiki/Galaxy_cluster We can't go there. Nothing from there will visit us. If the big bang is even an actual thing, it still happened everywhere, whenever. There are lots of galaxies, and they are old and far away.
if this topic ain't for you, no problem, but it's extremely interesting to many others.