observes your slit
Submitted 1 day ago by Deceptichum@quokk.au to science_memes@mander.xyz
https://quokk.au/static/media/posts/1Z/HN/1ZHNlkgK88lcJ5s.png
Comments
kruhmaster@sh.itjust.works 1 day ago
AppleTea@lemmy.zip 23 hours ago
gonna keep banging this drum every time this comes up:
When physicists say “observe”, they actually mean “measure”. And to measure a photon of light, you have to interact with it somehow, there is no passive way to do so.
The post’s header image implies that the interference pattern goes away just by looking at it. If that were the case, we would never see the interference pattern, never know it was there in the first place! In the actual experiment, they put a sensor at one or both of the slits. But to “sense” a single photon, you have to interact with it in some way. Otherwise you wouldn’t know it was there.
Again, this is where the language trips us up. Rather than “sensor”, would really be more accurate to say they put a photon-touch-er at the slits.
So, what we actually get is “Touching the photon changes the photon’s behavior.” The universe doesn’t magically infer when we happen to be looking at it, there is no spooky action-at-a-distance!
Amnesigenic@lemmy.ml 6 hours ago
Thank you for your service
kruhmaster@sh.itjust.works 22 hours ago
This guy observes.
partner_boat_slug@mander.xyz 1 day ago
The uncertainty principle has increased … my uncertainty.
spankinspinach@sh.itjust.works 1 day ago
I’m not sure about this
chuckleslord@lemmy.world 1 day ago
Whiskey_iicarus@lemmy.dbzer0.com 1 day ago
It feels like a very aggressive title for this post.
HakunaHafada@lemmy.dbzer0.com 1 day ago
JayDee@lemmy.sdf.org 15 hours ago
Anyone actually know what measurment devices are used to observe which slit the electron passes through? How do we know that a specific measuring tool isn’t changing the experiment significantly enough to cause issues with outcome and that the behavior change is abnormal?
VoterFrog@lemmy.world 6 hours ago
As far as I understand as a layman, the measurement tool doesn’t really matter. Any observer needs to interact with the photon in order to observe it and so even the best experiment will always cause this kind of behavior.
With no observer: the photon, acting as a wave, passes through both slits simultaneously and on the other side of the divider, starts to interfere with itself. Where the peaks or troughs of the wave combine is where the photon is most likely to hit the screen in the back. In order to actually see this interference pattern we need to send multiple photons through. Each photon essentially lands in a random location and the pattern only reveals itself as we repeat the experiment. This is important for the next part…
With an observer: the photon still passes through both slits. However, the interaction with the observer’s wave function causes the part of the photon’s wave function in that slit to offset in phase. In other words, the peaks and troughs are no longer in the same place. So now the interference pattern that the photon wave forms with itself still exists but, critically, it looks completely different.
Now we repeat with more photons. BUT each time you send a photon through it comes out with a different phase offset. Why? Because the outcome of the interaction with the observer is governed by quantum randommess. So every photon winds up with a different interference pattern which means that there’s no consistency in where they wind up on the screen. It just looks like random noise.
At least that’s what I recall from an episode of PBS Space Time.
bunchberry@lemmy.world 5 hours ago
The interference pattern disappears if anything becomes entangled with the which-way information at all. You can replace the entire measurement device with a single particle that interacts with the particles at the slits in such a way that it becomes perfectly correlated with the which-way information that the observer has no awareness of (such as if a moat of dust interacts with the particle because the experimenter did not isolate it well) and that is sufficient for the interference pattern to disappear.
starman2112@sh.itjust.works 10 hours ago
My understanding is that they use something like polarizing filters. Both slits have the same filter, they make a diffusion pattern as the waves interfere with each other. Both slits have different filters, there’s no wave interference and you get two slits.
Calling it an “observer” is maybe the most damaging name in the sciences since some douchebag decided to call the orthoganal number line “imaginary”
Fedizen@lemmy.world 14 hours ago
That’s actually the real lesson from the experiment. The detectors impart a small but real energy barrier and change the distribution pattern of the electron
Basically if you hold up a ruler to something human scale it doesn’t effect the thing your measuring much. But when you are trying to measure a basketball with something the size of a gymnasium you have to really launch that fucking basketball to open a door.
logicbomb@lemmy.world 1 day ago
I don’t get it. Don’t both top and bottom show interference patterns, or is this about something else?
sbeak@sopuli.xyz 1 day ago
top is interference patterns (like a wave) while bottom is as if it’s a particle (only two slits)
OpenStars@piefed.social 1 day ago
I see what you did there...
IndigoLarry@lemmy.world 1 day ago
Do you? Do you see it? The other dimensions!?
NO, IT’S IMPOSSIBLE… YOU CAN’T SEE IT.
… (long pause) … (longer pause) …
… (even longer pause) … (pause for dramatic effect) …
… (Pause with a capital P) … Can you?
OpenStars@piefed.social 1 day ago
Do you truly want to know?
Alrighty then, but don't say that I did not warn you:
...
...
...
Yes. Except after I peeked, it no longer exists. But the people - THOSE PEOPLE - they, haha, they hehe they claim that I am the ones who are (sic) crazy, the absolute fools! They refuse to know what I have seen!!
Quacksalber@sh.itjust.works 1 day ago
This reads like an order for the lemmings with the right body parts
MysticEdge@lemmy.world 1 day ago
I love this.
IndigoLarry@lemmy.world 1 day ago
Marry it, then.
ThrowawayPermanente@sh.itjust.works 1 day ago
Nice
tdawg@lemmy.world 1 day ago
It’s funny until you meet someone who actually believes that human eyes change quantum results
idiomaddict@lemmy.world 1 day ago
It’s a reasonable thing to think from the way it was described in my physics class, at least. I fault people a lot less for misunderstanding something that even scientists in the field don’t really understand than for something like thinking the earth is flat.
echodot@feddit.uk 23 hours ago
Its like punching a hole in folded paper to explain a wormhole. Hollywood science movies have a lot to answer for.
chocosoldier@lemmy.blahaj.zone 1 day ago
i fault them for doubling and tripling down when corrected, with sources, because they’d rather keep believing a fantastic lie.
bunchberry@lemmy.world 18 hours ago
They don’t even explain it in physics class. That is kind of the schtick of the Copenhagen interpretation. You just assume as a postulate that systems are in classical states when you look at them and in quantum states when you do not, and from those two assumptions you can prove using Gleason’s theorem that the only possible way the former can map onto the latter is through the Born rule. But there is no explanation given at all as to how or when or by what mechanism this transition actually takes place.
Many Worlds isn’t much better because they posit that the classical world does not even exist, yet that clearly contradicts with what we directly observe in experiments, so if that is true it necessarily means that the classical world is an illusion, and so then you still have to explain how the illusion comes about, which they do not. Dropping the postulate that there is indeed a classical world also disallows you from deriving the Born rule through Gleason’s theorem, and so it then becomes unclear how to do it at all without some arbitrary additional postulate, and the arbitrary nature of it means there are dozens of proposals of different postulates and no way to decide between them.
Modern physics is of the form (1) there is a classical state, (2) you look at it, (3) a miracle happens, (4) you perceive a quantum state, and then you are repeatedly gaslit into believing quantum mechanics is a complete theory of nature and it’s impossible for there to ever be anything more fundamental than it and any physicist who thinks there might be, even if they are literally Albert Einstein, is a crank crackpot.
tdawg@lemmy.world 1 day ago
I think I’ve meet too many charlatans to be that forgiving about it
skisnow@lemmy.ca 1 day ago
Yeah, those dumbasses. It’s obviously a monkey.
CannonFodder@lemmy.world 1 day ago
I thought it was some cat.
GreatTitEnthusiast@mander.xyz 1 day ago
The book The Quantum Magician makes this mistake
The protagonist has a quantum brain and to use it they have to turn off their consciousness in order to not collapse the superposition. I face palmed whenever they mentioned it
echodot@feddit.uk 23 hours ago
But other then that, totally scientifically accurate.