4 ms·

Voids aren’t empty they just have less stuff in them. There’s galaxies and things in there.

galacticaactual 6y ago
Sometimes I wonder about the percentage of HN commenters who actually read the article. Literally a few paragraphs in: “The lack of radio sources means that there are no galaxies or clusters in that volume.”
- 6gvONxR4sf7o 6y ago
  This morning, on an article about 'fuck-you money' there was a discussion about where the term comes from. The 1990s? The 2000s? The first paragraph of the article dated it back to at least the 1920s.
- JoBrad 6y ago
  See, I was prepared to downvote the comment. But then you commented, and someone else did, too. So, they actually did spark conversation. Now I have to upvote, I guess. /s (just in case)
- mensetmanusman 6y ago
  I think it’s pretty low, but that’s because the comments are usually more interesting.
- edgyquant 6y ago
  I usually click on the comments, if an article seems interesting I’ll see if the comments say it’s bad etc before clicking but even articles I’m not interested in but have an interesting topic I’ll click through to read the comments. This one, for instance, I’ll admit I haven’t clicked through to the article. I’ve long been interested in these voids so I didn’t figure the article would relay any information I wasn’t aware of so I clicked through to see what people here had to say.
- wrwatson 6y ago
  I've considered if a discussion site like this would work solely based on the headline without actually needing TFA. Often it feels like people who comment just want to share their point of view about a particular topic rather than the article itself. Many people read the comments first (or exclusively). Perhaps Dang could get analytics on how many people viewed the comments and how many people clicked through to the article to answer your question.
- credit_guy 6y ago
  Well, literally one sentence before your quote says "They saw little or no radio sources in a volume ...".
- saagarjha 6y ago
  The parent commenter is correct, and you (despite your username) and the article are not. If you read the paper it notes a dip in radio sources, not a complete absence of them. An entirely empty void a billion light years across is essentially too improbable to exist. “Voids” are just areas with fewer galaxies, relatively, not places with a none of them. In fact, the Milky Way (and the entire Local Supercluster) itself is in a void called the “KBC Void”.
  - yesenadam 6y ago
    https://en.wikipedia.org/wiki/KBC_Void https://en.wikipedia.org/wiki/KBC_Void "an immense, comparatively empty region of space...proposed to be roughly spherical, approximately 2 billion light-years in diameter. As other voids, it is not completely empty but contains the Milky Way, the Local Group, and a larger part of the Laniakea Supercluster. The Milky Way is within a few hundred million light-years of the void's center." A void has by "working definition" "less than one tenth of the average density of matter abundance that is considered typical for the observable universe." https://en.wikipedia.org/wiki/Void_(astronomy) https://en.wikipedia.org/wiki/Void_(astronomy)
- raattgift 6y ago
  The article is dated 2007, and much more has been learned about the WMAP cold spot in the past almost fifteen years. Tracing out how the very earliest structures in the CMB compare with much more recent galaxy filaments (and the voids between the dense filaments) is an interesting area of research, and there will be open questions for many years to come as galaxy surveys at different redshifts produce observational data. (All the galaxies will be at a lower redshift than the CMB cold spot, and it is a good guess that the CMB cold spot reflects an arrangement of matter much closer to the hot big bang or cosmic inflation than that. Perhaps one day our descendants will be able to examine the cosmic neutrino background to see if it too has a comparable cold spot, and the same with primordial gravitational radiation; alternatively perhaps they will discover that later-time physics distorted the CMB very slightly. The latter hypotheses are in practice much easier to test with observational data, and of course one can exploit the many unknowns in the dark matter and dark energy sectors without colliding with constraints from known physics.) https://en.wikipedia.org/wiki/CMB_cold_spot https://en.wikipedia.org/wiki/CMB_cold_spot
- yesenadam 6y ago
  Please don't comment on whether someone read an article. "Did you even read the article? It mentions that" can be shortened to "The article mentions that." https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html

Sometimes I wonder about the percentage of HN commenters who actually read the article. Literally a few paragraphs in: “The lack of radio sources means that there are no galaxies or clusters in that volume.”

6gvONxR4sf7o 6y ago
This morning, on an article about 'fuck-you money' there was a discussion about where the term comes from. The 1990s? The 2000s? The first paragraph of the article dated it back to at least the 1920s.
JoBrad 6y ago
See, I was prepared to downvote the comment. But then you commented, and someone else did, too. So, they actually did spark conversation. Now I have to upvote, I guess. /s (just in case)
mensetmanusman 6y ago
I think it’s pretty low, but that’s because the comments are usually more interesting.
edgyquant 6y ago
I usually click on the comments, if an article seems interesting I’ll see if the comments say it’s bad etc before clicking but even articles I’m not interested in but have an interesting topic I’ll click through to read the comments. This one, for instance, I’ll admit I haven’t clicked through to the article. I’ve long been interested in these voids so I didn’t figure the article would relay any information I wasn’t aware of so I clicked through to see what people here had to say.
wrwatson 6y ago
I've considered if a discussion site like this would work solely based on the headline without actually needing TFA. Often it feels like people who comment just want to share their point of view about a particular topic rather than the article itself. Many people read the comments first (or exclusively). Perhaps Dang could get analytics on how many people viewed the comments and how many people clicked through to the article to answer your question.
credit_guy 6y ago
Well, literally one sentence before your quote says "They saw little or no radio sources in a volume ...".
saagarjha 6y ago
The parent commenter is correct, and you (despite your username) and the article are not. If you read the paper it notes a dip in radio sources, not a complete absence of them. An entirely empty void a billion light years across is essentially too improbable to exist. “Voids” are just areas with fewer galaxies, relatively, not places with a none of them. In fact, the Milky Way (and the entire Local Supercluster) itself is in a void called the “KBC Void”.
- yesenadam 6y ago
  https://en.wikipedia.org/wiki/KBC_Void https://en.wikipedia.org/wiki/KBC_Void "an immense, comparatively empty region of space...proposed to be roughly spherical, approximately 2 billion light-years in diameter. As other voids, it is not completely empty but contains the Milky Way, the Local Group, and a larger part of the Laniakea Supercluster. The Milky Way is within a few hundred million light-years of the void's center." A void has by "working definition" "less than one tenth of the average density of matter abundance that is considered typical for the observable universe." https://en.wikipedia.org/wiki/Void_(astronomy) https://en.wikipedia.org/wiki/Void_(astronomy)
raattgift 6y ago
The article is dated 2007, and much more has been learned about the WMAP cold spot in the past almost fifteen years. Tracing out how the very earliest structures in the CMB compare with much more recent galaxy filaments (and the voids between the dense filaments) is an interesting area of research, and there will be open questions for many years to come as galaxy surveys at different redshifts produce observational data. (All the galaxies will be at a lower redshift than the CMB cold spot, and it is a good guess that the CMB cold spot reflects an arrangement of matter much closer to the hot big bang or cosmic inflation than that. Perhaps one day our descendants will be able to examine the cosmic neutrino background to see if it too has a comparable cold spot, and the same with primordial gravitational radiation; alternatively perhaps they will discover that later-time physics distorted the CMB very slightly. The latter hypotheses are in practice much easier to test with observational data, and of course one can exploit the many unknowns in the dark matter and dark energy sectors without colliding with constraints from known physics.) https://en.wikipedia.org/wiki/CMB_cold_spot https://en.wikipedia.org/wiki/CMB_cold_spot
yesenadam 6y ago
Please don't comment on whether someone read an article. "Did you even read the article? It mentions that" can be shortened to "The article mentions that." https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html