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Physicists Confirm a Pear-Shaped Nucleus, and It Could Ruin Time Travel Forever (sciencealert.com)
An anonymous reader writes from a report via ScienceAlert: Physicists have confirmed the existence of pear-shaped nuclei, which challenges the fundamental theories of physics that explain our Universe. "We've found these nuclei literally point towards a direction in space. This relates to a direction in time, providing there's a well-defined direction in time and we will always travel from past to present," Marcus Scheck from the University of the West of Scotland told Kenneth MacDonald at BBC News. Until recently, it was generally accepted that nuclei of atoms could only be one of three shapes: spherical, discus, or rugby ball. The first discovery of a pear-shaped nucleus was back in 2013, when physicists at CERN discovered isotope Radium-224. Now, that find has been confirmed by a second study, which shows that the nucleus of the isotope Barium-144 is also asymmetrical and pear-shaped. In regard to time travel, Scheck says that this uneven distribution of mass and charge caused Barium-144's nucleus to "point" in a certain direction in spacetime, and this bias could explain why time seems to only want to go from past to present, and not backwards, even if the laws of physics don't care which way it goes.
Can you backup that statement? Oh wait... never mind.
the whole thing has gone pear-shaped.
Ideology: A tool used primarily to avoid the bother of thinking.
Time only "goes from" the past to the future because we define those terms by the way that time "goes", and time "goes" the way it does, from less-entropic to more-entropic states, because the process of memory formation, like all processes, necessitates an increase in entropy. Time isn't actually "going" anywhere, there are just different possible states of the universe, and the ones we we remember (or are otherwise recorded for us to gather information from) are necessarily more entropic, and we call the states we already remember (or otherwise has record of) "past" and the opposite direction in the configuration space "future".
What the hell could pear-shaped nuclei possible have to do with any of that?
-Forrest Cameranesi, Geek of all Trades
"I am Sam. Sam I am. I do not like trolls, flames, or spam."
Nice thought but no, there is no center as you're thinking, space itself expanded with the big bang so the big bang happened literally everywhere. At least as far as we know.
It's like the sysops are say, well, they're going to discover they're living in a simulation. Change the parameters so nuclei are pear shaped, and that ought to distract them for a little while.
--Jim (me)
How do we know time doesn't go backward? Maybe it does. We'd never know it if it did. (think about it.)
Perhaps in fact time goes back and forward all the time. This would be a nifty way to have things like spooky action at a distance. You run time forward till a correlated event happens, then run it backward and imbue the necessary future state. Instant hidden variables that you can't detect.
it doesn't matter how much time this time reversal takes since, you will never notice it happening.
Some drink at the fountain of knowledge. Others just gargle.
My DeLorean stocks just took a bigger hit than Brexit.
Table-ized A.I.
My body certainly has. Maybe the atoms examined simply reached middle-age. Time* to put the universe on a diet of neutrino shakes; but they are so bland and often just pass right through ya.
* No pun intended
Table-ized A.I.
If they point toward Mecca, I will be fully freaked out.
And, dammit, I just bought a bunch of Xmas decorations last year.
Table-ized A.I.
Points to direction of next quest.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
"And that, my lord, is how we know the Earth to be banana-shaped."
How do we know time doesn't go backward? Maybe it does. We'd never know it if it did. (think about it.)
Surprising as it seems we would actually know if time reversed because of what seems to be one of the most forgotten results of particle physics: the laws of physics do not work the same if time is reversed due to something called "T-violation": literally time-reversal symmetry violation. This is NOT the same thing as a glass falling off a table will not reassemble itself and flying back onto the same because this is an effect of entropy.
The first evidence for T-violation came from the CP-LEAR kaon experiment at CERN in 1998 [Phys. Lett. B 444 43 (1998)] and was confirmed in B-decays by Babar in 2012 (and as evidence that this result is always forgotten they forgot about the CP-LEAR measurement in this article!!). These experiments looked at how a particle oscillates back and forth between two possible states. What they found is that a particle in state A will oscillate into state B faster than one in state B will oscillate into state A. Hence the process prefers to go in one direction more than the other even though in this case the two states have identical entropy.
So if time were reversed you would be able to detect it by doing the same experiment and finding that now the particles would go from B to A faster than from A to B. Incidentally this symmetry is also closely related by special relativity to the symmetry between matter and anti-matter so reversing time would switch our universe into one which prefers anti-matter over matter and we could detect this flip again with particle physics experiments.
So amazing as it seems we could detect a flip in the direction of time and the article is just plain wrong when it says that the laws of physics don't care which way time goes: they do and we have evidence to show it!
I'm pretty sure Bill and Ted's Bogus Journey already ruined time travel forever.
You are welcome on my lawn.
Time travel has been over used and generally poorly done. Hopefully this kills it.
Several Sci-Fi genre relied on gravity not being bound by the speed of light. LIGO has killed that.
It will be interesting to see where the hard sci-fi authors go now.
Oddly enough Edgar Rice Burroughs is still sorta safe, since his Mars is in an alternate reality (other obvious failings aside).
even if the laws of physics don't care which way it goes.
Lacking access to a good intergalactic physics lawyer the Human race continues to make it up as they go along.
Imagine navigating the U.S. Justice system by trial and error the way science has been doing it.
The Volgons at least had a printed manual, in triplicate, read as poetry by some Volgons in self defense.
~ People that think they are better than anyone else for any reason are the cause of all the strife in the world.
Time only "goes from" the past to the future because we define those terms by the way that time "goes", and time "goes" the way it does, from less-entropic to more-entropic states
Actually that is not true because of something called T-violation which has been observed in kaon and B-meson oscillations (see my other reply to a post below for details but this is NOT an effect of entropy!).
What the hell could pear-shaped nuclei possible have to do with any of that?
This is harder to explain and you are absolutely correct that the article utterly fails to do so! We have three special symmetries in particle physics called C, P and T where T is time-reversal and C and P together, CP, is the symmetry between matter and anti-matter. What relativity tells us is that all three together, CPT, should be a perfect symmetry of nature. This means that CP (the matter-antimatter symmetry) and T (time reversal) are linked because if the T symmetry is violated then the CP symmetry must be violated in exactly the opposite way so that CPT altogether is conserved.
Now the pear shaped nucleus is interesting because the nucleus is bound together by the strong force and every test so far suggests that the strong force obeys C, P and T separately (and so of course also CPT together). The weird violation of T and CP is only seen in the weak force (which causes nuclear beta decay). Now if a nucleus has a non-symmetric shape it suggests that the strong force also violates P, called parity. If P is conserved then if you flip the direction of the x, y and z axes there is no change. However with a pear-shaped nucleus there would be a change and so parity is said to be violated and this means that CP would also be broken.
So, if true, this result would be interesting because we have never seen this effect in the strong force despite it being possible to add a term to do this and it has always been a mystery as to why this term appeared to be exactly zero - it is called the "strong CP problem". Since CP is tied to CPT by relativity this means that we would expect time reversal to be broken as well by the strong force. However despite the BBC's best effort to advertize Dr. Who this result says absolutely nothing about whether time travel is possible just that time seems to have a preferred direction...which we have known since 1998 thanks to the CP-LEAR experiment.
As for the "pointing in the same direction in space" I want to see that written in a journal before I give it any credence. Given there are several errors and mistakes elsewhere in the article I the journalism behind this story is seems appalling and I think they completely misunderstood the explanation given...which as you can see above is not exactly trivial!
Galaxies have centers, as does the known universe. Space expanding has no impact on this fact. Define the boundaries universe at any single point in time and you can define a center. (or at least the center of a bounding spheroid). That center may change as space boils and expands, but you can travel toward it and as you get closer, recalculate it.
... you make the rockin' world go round.
The boundaries of the known universe are what they are because of where the rest of universe is relative to us, i.e. we can observe things up to a certain distance in any direction. We will thus always observe ourselves to be the center of the known universe.
-Forrest Cameranesi, Geek of all Trades
"I am Sam. Sam I am. I do not like trolls, flames, or spam."
Instead of this being a CPT violation that requires all of physics to be "rewritten" there is another possibility that I hope they will look into.
Just like a finely balanced wind-vane (weather-vane) that can be moved around by the slightest breeze, might it not be the case that these particular isotopes (proton+neutron combinations) result in a unique very delicately balanced system that becomes "sensitive" to the movement and flow of other smaller matter/energy movements which can thus result in the apparent imbalance in shape?
For instance; if the nuclei of these isotopes are able to be influenced by the flow of a large enough number of neutrinos (for the sake of an example) traveling with sufficient energy then that could cause a wind-vane effect wherein the nuclei would be deformed in the direction of the neutrino flow, or perhaps the opposite? (btw: If this is the case then we now have the ability to build cheap neutrino detectors, or detectors of whatever is causing this.)
I sincerely hope that this idea is brought up with the scientists involved with these discoveries so that it can be investigated.
Hey Richard Feynman --- yeah I hear you laughing, we've been snookered again. It doesn't sound like a downer at all. If we're capable of perceiving that some of these things aren't just 'are' ... they are 'are' yet they are also 'oriented' ... that means we have been given a Signpost to follow ... and we must follow it.
Never mind that time travel blather. All fixation on 'practical time travel' in physics is a rollover from science fiction, in which it exists solely for humans to go back in time to fix::notmake their stupid mistakes and get the girl, this time. It's all about getting the girl. Modern girls don't want to be part of your strange loops, they prefer to get 'got' the first time around by guys who have just figured out the best way to get ''em.
Let's move on to the real question: what does this upset to physics imply, if anything,to the possibility of stable fusion containment...? Help, hinder, harness? That's the girl we want to get.
Finding asymmetric nuclei is like discovering that you can put batteries in a toy you got for Christmas. And it's July. So put 'em in and let's see what this thing really does.
<blink>down the rabbit hole</blink>
But if laws are not symmetric, then your brain will not work the same. You will un-learn and then un-do the experiments, so you will not be able to reach conclusions.
You are missing a few important details here. First, as far as we know, this time reversal asymmetry does not apply to the EM force which is how our brains work so they would not be affected. Second the effect is a tiny one only measurable with extremely precise experiments so you would not notice an effect without detailed experiments. Lastly though "unlearning", glasses leaping back onto tables etc will only happen if you rewind time, not just reverse the flow i.e. force everything to return to its precise, previous state rather than reverse time and let the universe evolve naturally under it's physical laws. The two are completely different questions.
Nothing but you have not reversed time you have rewound time and forced everything to go back into the precise state it was in just before. That is NOT the same as reversing the arrow of time. To reverse time you have to let the universe evolve naturally under its own physical laws just now with time counting down rather than up. Essentially all you do is put a minus sign in front of the time and ask whether everything will happen the same with time now going in reverse...and it will not.
Rewinding time is completely different because in that case the only physical law is that you must return to the fixed state you were in just prior to this one. This will erase all knowledge of what is now the past (because our current state has no knowledge of the future) and there are no real physical laws because everything is predetermined.
Ba, neutrino shakes. Only three tastes, and you can't even be sure it hasn't changed on your drive home from the store.
int main(void) {while(1) fork(); return 0;}
forget about expansion or relativity or anything like that
you suddenly pop into existence in the middle of a foggy field
your KNOWN universe is everything within a certain distance of you; beyond that, it's lost in the fog, and wherever the boundaries of the field may be, if there are any at all, they're lost in the distant fog.
the part of the field that you know of, that you have any experience of, appears to be centered on you, because the ability to know and experience it is a function of its distance from you.
if the TOTAL universe is finite, we don't know it, and we have no idea where its boundaries are. but the KNOWN universe, the boundaries of everything we have any information about, are a function of the distance of things from us, and consequently we find ourselves always at the center of that.
-Forrest Cameranesi, Geek of all Trades
"I am Sam. Sam I am. I do not like trolls, flames, or spam."