# Antimatter-matter equality questions **URL:** \ **Category:** Factual Questions\ **Tags:** science-math\ **Created:** [July 16, 2025, 1:50pm UTC](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917 "2025-07-16T13:50:37Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [March 25, 2026, 9:07pm UTC](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917/21 "2026-03-25T21:07:40Z")
If you have Amazon Prime, is delivery free? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 25, 2026, 9:41pm UTC](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917/22 "2026-03-25T21:41:13Z")
You misspelled “Antizon”. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [March 25, 2026, 10:08pm UTC](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917/23 "2026-03-25T22:08:57Z")
I’m amazed that it takes a large truck the size of a moving van to transport 92 antiprotons. Much like some of my Amazon deliveries, it must be due to extremely bulky packaging! 😃 ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [March 25, 2026, 10:48pm UTC](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917/24 "2026-03-25T22:48:11Z")
Given observations of the current universe, and the physics models for its evolution, what are the constraints on the matter to anti-matter ratio in the past? What I’m wondering is, with the bias toward matter, how far back in time is a universe with a unity matter to anti-matter ratio consistent with observations of the current universe? For example, let’s start with a universe 1 sec after the Big Bang that’s equally balanced between matter and anti-matter. Could that universe evolve into our current universe? Or start with balance at 1 quecto-second after the Big Bang. Could that evolve into the current state? ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [March 25, 2026, 10:58pm UTC](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917/25 "2026-03-25T22:58:41Z")
> [@Pasta](#): > > The CMB and other windows into the early universe (_e.g._, light isotope abundances spanning many order of magnitudes) all point to a need for antimatter-matter asymmetry local to our observable universe already. That is: the problem isn’t that there is matter here and maybe antimatter somewhere else. If you try that, then there isn’t nearly enough matter here. You need the imbalance to play out in our observable universe itself. So, “hiding” the antimatter outside the observable universe doesn’t solve the problem and just makes new ones. If there were equal amounts of matter and antimatter in the beginning and 99.9% of them annihilated each other, the chances would likely be that surviving matter and antimatter would wind up on opposite sides of the universe??? ---
**Author:** ![Pasta](https://avatars.discourse-cdn.com/v4/letter/p/ecccb3/32.png) [@Pasta](https://boards.straightdope.com/u/Pasta)\ **Post date:** [March 25, 2026, 11:59pm UTC](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917/26 "2026-03-25T23:59:10Z")
> [@Pleonast](#): > > how far back in time is a universe with a unity matter to anti-matter ratio consistent with observations of the current universe? The asymmetry was spawned in the first tiniest fractions of a second. There are several viable pictures for how the asymmetry comes about. Some involve asymmetry-generating processes that are relevant only in the first 10-35 seconds while others include physics that comes in closer to 10-12 seconds. Beyond that point, the universe has cooled enough to pass the “electroweak symmetry breaking” scale, and relevant processes become inaccessible, if they weren’t already frozen out of equilibrium beforehand by the universe’s expansion. (Expansion and cooling both make it harder for things to happen since stuff is diluted more and the energetics are less favorable, respectively.) After that sort of time scale, the physics in play looks essentially like it does today. So, your quectosecond is more in the qualitative ballpark (though on an extreme end) than the relatively _very_ late one second. > [@HoneyBadgerDC](#): > > If there were equal amounts of matter and antimatter in the beginning and 99.9% of them annihilated each other, the chances would likely be that surviving matter and antimatter would wind up on opposite sides of the universe??? I’m not sure which way your question is being asked, but: The asymmetry develops everywhere in a violent soup. That is, it isn’t a blob and an anti-blob colliding and annihilating but rather a sea of reactions that are proceeding with slight imbalances in net matter and antimatter generation, and the imbalance we see today is the residual imbalance that is present everywhere after all that turmoil slows and stops. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [March 26, 2026, 3:25am UTC](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917/27 "2026-03-26T03:25:34Z")
I was thinking more like 2 bags of fine powder 1 black and 1 white that were peacefully mixed together until they reacted to something. Most being destroyed quickly and later on just occasional collisions ---
**Author:** ![dougrb](https://avatars.discourse-cdn.com/v4/letter/d/76d3ee/32.png) [@dougrb](https://boards.straightdope.com/u/dougrb)\ **Post date:** [April 6, 2026, 12:41am UTC](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917/28 "2026-04-06T00:41:15Z")
Here’s a cool veritasium video (1 hour) on how CERN is creating and capturing anti-matter. Current price is $1 billion/gram. [Why Is CERN Making Antimatter?](https://www.youtube.com/watch?v=jjp3WC8Unj8) ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [April 6, 2026, 12:56am UTC](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917/29 "2026-04-06T00:56:05Z")
The OP may find this video interesting (see below). It was only posted a few hours ago by the excellent YouTube channel Veritasium. While the whole video is not about what the OP asked a great deal of time in the video IS given to talking about exactly what the OP asked. Worth a watch I think. I’d summarize cuz I know some can’t or won’t watch videos but I am not sure where to start with this. [![](https://img.youtube.com/vi/jjp3WC8Unj8/maxresdefault.jpg "Why Is CERN Making Antimatter?") ](https://www.youtube.com/watch?v=jjp3WC8Unj8) [Previous page](https://boards.straightdope.com/t/antimatter-matter-equality-questions/1020917.md?page=1)