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bio website none.seriously
location Switzerland
age 29
visits member for 3 years, 5 months
seen 34 mins ago

Physicist.


Mar
20
comment How would we tell antimatter galaxies apart?
@endolith Good question - I can't answer it though, maybe it's worth a new question here. From my limited understanding of cosmology I'd suspect that might reduce the amounts of dark matter and dark energy required to explain the universe, and maybe also inflation. But I'm really only speculating... This answer to my strongly related question gives some sources that may be helpful, but I didn't fully read them to be honest...
Mar
5
comment Is there something similar to Noether's theorem for discrete symmetries?
I'm afraid you're mixing up symmetry and conserved quantity here
Feb
27
comment Is there any way to annihilate matter without the use of anti-matter?
It's probably "cheating", but there probably exist virtual states where this happens. It's just not a finished process, i.e. while this contributes to some probabilities it won't be actually observable... Then again you could claim $p + e^- + \gamma \to n + \nu$ made the proton vanish without any anti-matter involved...
Feb
16
comment Is it fair to judge this speedskating race by only 3 thousands of a second?
"And it's a dead heat! They're checking the electron microscope. And the winner is...number 3, in a quantum finish." "No fair! You changed the outcome by measuring it."
Nov
6
accepted Are there models/simulations of antigravitational antimatter-galaxies?
Nov
6
comment Are there models/simulations of antigravitational antimatter-galaxies?
Thanks for your exhaustive answer! So in short, aside from arXiv publications (which are fine, but still not as peer-reviewed as one of "The Big Journals") with very theoretical considerations, not much has happened yet and is unlikely to happen until enough antimatter has been produced on Earth to "once and for all" settle the question of antigravitating antimatter...
Nov
6
comment Are there models/simulations of antigravitational antimatter-galaxies?
@GeorgeE.Smith Do you have ANY evidence of ANY "pro"-gravitation observations of antimatter? ;) I only rule out the impossible, not the improbable. Whether you consider that SciFi, specualtion, or a model (hey, have you seen any strings or superparticles so far?) is up to you, but it has not succinctly been proven impossible so far, so I do at least want to consider the possiblity
Nov
4
comment How would we tell antimatter galaxies apart?
An interesting idea would be negative-mass antimatter, such that galaxies consisting out of antimatter would repel ordinary matter, drastically reducing the likelihood of such boundary annihilations...
Nov
4
comment How would we tell antimatter galaxies apart?
An antigalaxy could have negative gravitational mass in theory - leading the question whether that has been modelled/simulated somewhere
Nov
4
revised Are there models/simulations of antigravitational antimatter-galaxies?
deleted 99 characters in body
Nov
4
comment Are there models/simulations of antigravitational antimatter-galaxies?
@KyleKanos Thanks! Then I'll edit that one out here
Nov
4
comment Does antimatter curve spacetime in the opposite direction as matter?
Well, consider alternating "shells" of galaxies and anti-galaxies (or clusters etc), would the neighbouring shells' repulsion be countered by the next-to-neighbour ones' attraction? Anyway, I think this should be discussed in a separate question...
Nov
4
asked Are there models/simulations of antigravitational antimatter-galaxies?
Nov
4
comment Does antimatter curve spacetime in the opposite direction as matter?
Neat - so we could theoretically have "antigalaxies" that are repulsed by "progalaxies", which might yield a contribution to the universe's inflation... I wonder if there are simulations/models of this
Nov
4
revised Does antimatter curve spacetime in the opposite direction as matter?
making the paragraph more consistent
Nov
4
suggested suggested edit on Does antimatter curve spacetime in the opposite direction as matter?
Nov
4
comment Does antimatter curve spacetime in the opposite direction as matter?
thanks - I'd also be surprised by this, though negative gravitational mass would at least be an explanation for the lack of antimatter in our galaxy (hm, would it be too far a shot to claim that other, sufficiently isolated, galaxies consisted of antimatter)
Nov
4
comment Does antimatter curve spacetime in the opposite direction as matter?
I'd reformulate that first sentence into "Currently there is no reason to believe/require antimatter has negative mass", since to date it cannot not really be excluded due to the low amount generated so far, as Sklivvz' answer hints at
Nov
2
awarded  Yearling
Oct
16
comment Are Stephen Crothers' claims legitimate?
@dj_mummy That may actual be one reason that chap got so much attention to start with. Basically sounds like a Science Troll to me - but to be honest, I didn't bother to read even a single one of these papers, so you may call me wrong in a century or two...