Antimatter falls down, not up: CERN experiment confirms theory
Antimatter falls down, not up: CERN experiment confirms theory
Observing this simple phenomenon had eluded physicists for decades.
Antimatter still has a positive mass. It's not some exotic negative mass matter.
87Well, yes, as far as our theories go. But we also "knew" that light was a wave that traveled through the luminiferous aether, which permiated all of space... Until we tested that theory with the Michelson-Morely experiment, and it turned out our theories were completely wrong and physics as we knew it was completely upended.
Point being, it's important to actually test our theories instead of assuming they're completely correct just because most of their predictions are accurate.
104Science advances by testing the limit cases. You do it and you do it until one day you get an unexpected result. That result, and the subsequent understanding of why it happens, is what leads to Nobel Prizes.
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I'm pretty sure every physicist in existence knows that. It's just a simple principle that's really hard to test, so actually testing it is pretty cool. Like dropping a steel ball and a feather on the Moon.
49It has a positive mass, and in every other way it acts just like normal matter going backwards in time (cpt inversion).
If, despite its positive mass, it was pushed back by gravity, then it would have given even more weight to the theory that antimatter is just matter moving backwards.
Since gravity is such a wonky interaction, I'm not even sure this result disproves the time-reversal theory entirely!
3Why would inverting charge make particles go backwards in time? Electrons have opposite charge to protons and they don't seem to. Positrons have the opposite charge to electrons and as far as I know they don't go backwards?
I think you're misinterpreting cpt reversal symmetry, which is if you mirrored the universe in terms of charge, time and parity it would essentially evolve the same
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I have a basic understanding of CERN, but if it comes down to it, everything they do there still blows my mind.
Like, imagine being the person who designed that experiment.
“Here is a CERN. Find out how antimatter falls.”
And some one/team was like ok I got this. And then they showed up one day & did it.
“Down. It goes down.”
I know it was much more complex than that, but still…imagine having the brain that stores the information required to do this. It’s so fucking cool.
50What you don't see is the hundreds of people and countless hours of work that went into stuff like this. None of it is one person just showing up and making it happen. Everyone has their specific skill set and role in the project, no one knows everything. We see the result, but the day to day of this work would look mind numbingly boring to most people. It's not about geniuses having inspiration strike and figuring out something amazing, it's about months and years of staring at spreadsheets, analyzing data, fixing your mistakes, double checking, running the test again. It's about not giving up not being wicked smart, though the people working on it are definitely smart. Also this is the expected result. We were sure it fell down not up already, this was a confirmation of that.
37This is pretty accurate. I was part of a detector group that did a beam test at Cern this summer. Everyone there is super helpful and humble because they know it takes grit more than anything at the end of the day.
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Reading stuff like this is super funny when you have absolutely no idea how any of this stuff works.
"Wow, antimatter falls down! Gravity sure do be like that!"
42It confirms what pretty much everyone already assumed would happen, but it's one of those things that should be tested just in case. Plenty of times tests have been performed and unexpected results appeared, leading to advancements in science. So if (on the very off chance) it didn't interact with gravity as expected, that might have led to improvements in our understanding of general relativity and/or quantum mechanics, since gravity is one of the big problems we have in trying to marry the two theories
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My understanding of CERN comes explicitly from Neon Genesis Evangelion (1995) and Steins Gate (2011)
I do not have the gumption to mess with shadow companies jimmies.
26Steins gate was introduction to CERN for me. And it scared the shit out of me. No, thank you. You do you.
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Well, it’s antimatter, not anti-gravity.
21I've heard hypothecies that antimatter was normal matter going back in time. But this disproves it since it would have been going in reverse in gravity.
9Unless antimatter is also antigravity and the two cancel each other out, making it look normal to us.
5In many instances it is very convenient to think of antimatter as normal matter going back in time. This is what makes Feynman diagrams so easy to use and powerful.
Furthermore, CPT symmetry is a necessary condition for basically all scientific theories. This means that reversing time is literally identical to reversing 'charge' and 'parity' together - and in this context, reversing charge means swapping all matter for anti-matter and visa-versa. Reversing 'parity' roughly means swapping left and right across the whole universe.
... Anyway, CPT doesn't directly tell us that anti-matter particles are normal matter going back in time, but it does imply that that isn't a bad way of thinking about it.
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Correct, but negative matter might in theory work that way
Either way, they still do these tests just to check that their theories remain consistent across a variety of edge cases
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If you think this is cool, there is a !boinc@sopuli.xyz project for the LHC (worlds largest particle accelerator) run by CERN. You can donate your computer's spare computational power and maybe find a new subatomic particle! I've been running it for years, very fun project to be involved in, no PhD required.
18A side note, with the announcement of the raspberry pi 5, there's a lot of chatter about how the pi boards are big contributors to boinc.
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So, they put all the antiatoms in a tin can, put it up high, then opened the top and the bottom of the can and saw which end they came out of. I love it.
14Unsurprising really. It seems fairly apparent that gravity merely influences the geometry of the substrate in which all known forms of matter & fundamental forces operate within. Something would have to seriously be fucky for antimatter to act counter to that geometry given it is comprised of similar particles with opposite charge. I'd assume astrophysicists know this, but wanted experimental proof for what seems to be straightforward logic from things we have experimentally confirmed.
The real question is what form does this geometry use to exert influence on the matter operating within curved spacetime? How is that information carried and how does gravity interface with that?
11Antimatter is not just matter with an opposite charge. It's matter with every type of charges (electromagnetic, strong and weak nuclear charges) inverted, as well as the "parity", that is the relative direction of its spin compared to its propagation direction, are all inverted.
If you look for "CPT symmetry", you'll find better explanations than this.
It basically boils down to this: invert the flow of time, and every particle will look like antimatter, while antimatter will look like normal matter.
It would have been very likely that antimatter moved backwards in gravity of it was normal matter moving backwards in time!
4No offense, but nothing you wrote here makes any sense. You're right (if I'm 'translating' this correctly), but you're mix-and-matching various concepts here.
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🙃
10🙂 actually.
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what if our arrow of time is actually going left and not right and we were the antimatter all along
9Maybe the real antimatter were the friends we made along the way
8In my next life I want to live my life backwards. You start out dead and get that out of the way. Then you wake up in an old people's home feeling better every day. You get kicked out for being too healthy, go collect your pension, and then when you start work, you get a gold watch and a party on your first day. You work for 40 years until you're young enough to enjoy your retirement. You party, drink alcohol, and are generally promiscuous, then you are ready for high school. You then go to primary school, you become a kid, you play. You have no responsibilities, you become a baby until you are born. And then you spend your last 9 months floating in luxurious spa-like conditions with central heating and room service on tap, larger quarters every day and then Voila! You finish off as an orgasm!
6Everything was good until the last one 💀
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Oh. That's weird.
1Well that puts some validity in the "antimatter is matter going back in time" camp.EDIT: Lol I misread. This actually disproves it.
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