840
submitted 8 months ago by some_guy@lemmy.sdf.org to c/news@lemmy.world
you are viewing a single comment's thread
view the rest of the comments
[-] arefx@lemmy.ml 10 points 8 months ago

Can someone give me the spark notes I started reading but I'll never get through that or probably even understand all of it

[-] machinin@lemmy.world 18 points 8 months ago

As I understand it, there are two measures of cosmic distance/expansion rate in which we are pretty confident.

One is using supernovas as a measure. Since one kind of supernova has very particular characteristics, it is easy to calculate the distance. It is like knowing that everyone has the same kind of candle, if you see a bunch of lights around you, you could make certain assumptions about how far they are from you by how bright they are. Also, with more precise measurements, we can use the doppler effect to know how fast they are moving. We have observed the area around or Galaxy and have come up with a very precise measurement for how fast the universe is expanding.

The other measurement is by looking at the cosmic wave background. This is the "first" thing we are able to see after the big bang. I don't really understand the details of this one, but scientists have also been able to calculate the expansion rate of the universe very accurately with this radiation.

As we have done more experiments to measure these two numbers, instead of converging on the same number, the results are actually diverging. Recent results have even made it so the error bars no longer overlap.

So, we have some big questions -

  1. Are our measurements wrong? There are no strong candidates for alternative understandings of how we measure things, so we don't really know how.
  2. Are the expansion rates at the beginning of the universe and current times different? Maybe, but again, we don't have any theories for why.
  3. Does the Universe expand at different rates in different places? Maybe, but again, we don't have any strong candidates that we can test.

All of this is called the Hubble Tension. It is probably one of the biggest questions in cosmology currently.

[-] arefx@lemmy.ml 6 points 8 months ago

Thanks this is both an uncomfortable and exciting thing to read.

[-] DadVolante@sh.itjust.works 7 points 8 months ago

Basically,

Everything you know is wrong.

Black is white, up is down, and short is long

[-] Apeman42@lemmy.world 13 points 8 months ago

And everything you thought was just so important doesn't matter. Everything you know is wrong. Just forget the words and sing along. All you need to understand is, everything you know is wrong.

[-] 4grams@awful.systems 1 points 8 months ago

I wish I had more upvotes for the random Yankovic!

[-] VirtualOdour@sh.itjust.works 2 points 8 months ago

It's simple, imagine you've got two smart friends that both have an opinion about a TV show you didn't watch - you can't tell who is right but the fact they disagree suggests they might be wrong when they say you can't have flying cars and time travel.

this post was submitted on 16 Mar 2024
840 points (98.8% liked)

News

23424 readers
1525 users here now

Welcome to the News community!

Rules:

1. Be civil


Attack the argument, not the person. No racism/sexism/bigotry. Good faith argumentation only. This includes accusing another user of being a bot or paid actor. Trolling is uncivil and is grounds for removal and/or a community ban. Do not respond to rule-breaking content; report it and move on.


2. All posts should contain a source (url) that is as reliable and unbiased as possible and must only contain one link.


Obvious right or left wing sources will be removed at the mods discretion. We have an actively updated blocklist, which you can see here: https://lemmy.world/post/2246130 if you feel like any website is missing, contact the mods. Supporting links can be added in comments or posted seperately but not to the post body.


3. No bots, spam or self-promotion.


Only approved bots, which follow the guidelines for bots set by the instance, are allowed.


4. Post titles should be the same as the article used as source.


Posts which titles don’t match the source won’t be removed, but the autoMod will notify you, and if your title misrepresents the original article, the post will be deleted. If the site changed their headline, the bot might still contact you, just ignore it, we won’t delete your post.


5. Only recent news is allowed.


Posts must be news from the most recent 30 days.


6. All posts must be news articles.


No opinion pieces, Listicles, editorials or celebrity gossip is allowed. All posts will be judged on a case-by-case basis.


7. No duplicate posts.


If a source you used was already posted by someone else, the autoMod will leave a message. Please remove your post if the autoMod is correct. If the post that matches your post is very old, we refer you to rule 5.


8. Misinformation is prohibited.


Misinformation / propaganda is strictly prohibited. Any comment or post containing or linking to misinformation will be removed. If you feel that your post has been removed in error, credible sources must be provided.


9. No link shorteners.


The auto mod will contact you if a link shortener is detected, please delete your post if they are right.


10. Don't copy entire article in your post body


For copyright reasons, you are not allowed to copy an entire article into your post body. This is an instance wide rule, that is strictly enforced in this community.

founded 1 year ago
MODERATORS