astro123

8 ms·

31.
by astro123 7y ago
I don't know why this is downvoted (maybe I'm missing a bad joke)? But this is exactly why people are excited about this. Either, a) we have a systematic in our measurement and our model is right and eventually we'll work thi
32.
by astro123 7y ago
Nope, that's total garbage. H0 is defined as the rate of expansion now.
33.
by astro123 7y ago
Yeah, I'll second what others have said that designing (good) telescopes is not a quick/easy thing. Also, any telescope that is easy to slap together is probably so many orders of magnitudes worse that existing ones that you don&#
34.
by astro123 7y ago
I think that [1] is the paper that this is based on. I don't work on dynamics and I found it pretty readable. Most of what is in the article is in sections 3.2, section 4 (discussion) and section 5 (conclusions). [1] https:/&#x2F
35.
by astro123 7y ago
Not to go into much detail, but these author's views are not shared broadly in the cosmology community. There was a recent paper [1] put on the arxiv that talked a bit about this. I'm not an expert on supernova cosmology (I work o
36.
by astro123 7y ago
The paper is https://arxiv.org/pdf/1903.12097.pdf for anyone interested. The results aren't actually that interesting. The posterior on H0 (the rate that the universe is expanding) is not at all competitive with t
37.
by astro123 7y ago
This is exactly the sort of thing that blinding is there to prevent. It is the same reason we in cosmology blind our data - to prevent us from biasing ourselves towards what other experiments have found. Also, the charge of the electron exp
38.
by astro123 7y ago
With the caveat that I have nothing to do with ligo and so don't know much... I think that during this ligo run (it just turned back on in April-ish) they expect to find roughly 1 event per week. So this will be fairly common! [1] is
39.
by astro123 7y ago
Here's a statement [1] by one of the largest upcoming surveys, LSST. At least for them, this isn't going to be too much of a problem as, 1) Exposures are fairly short and frequent and so pixels contaminated by these satellites can
40.
by astro123 7y ago
As the article mentions, this is most likely due to the rotation of the cluster. Throwing some numbers out there: The Virgo cluster is 60Mly away which is ~20Mpc (mega parsecs). Hubble's law [1] (v = Hd) tells us that for every 1Mpc aw
41.
by astro123 7y ago
The full story is actually (I think) more interesting than the headline suggests. Really what we have here are two methods of calculating the age of the universe that disagree. And we are getting to a stage where the disagreement (or "
42.
by astro123 7y ago
I was maybe a bit too cavalier here. I think I understand what the author means - the data that they gather is understood in the context of the model that we think is best. But, it isn't as if cosmologists are rigidly holding to the mo
43.
by astro123 7y ago
For some reason edits are silently failing, but an addendum to > Big bang was only the accepted paradigm from the 60s (post CMB observations). We have had DE since Einstein in 1917 and DM since Zwicky in the 30s. Admittedly the DE from E
44.
by astro123 7y ago
I'm a grad student working on cosmology, and while I agree there is a lot of work still to do (we don't know what 95% of the matter that makes up the universe is!), I disagree with a lot of what the author says. > Another recen