Why don't quantum effects occur in large objects? double slit experiment with tennis balls

The quantum physics of large things: Macro quantum effect. Why don’t tennis balls behave like quantum particles? What happens to a baseball in a double slit experiment? This experiment shows that atoms behave like waves of probability when not measured, and particles when measured. We also see that two quantum particles can be entangled, meaning that are connected through a sharing of one probability wave.

Why don’t we see these kinds of behavior in our everyday macro lives? At what point does the quantum behavior stop and classical behavior of everyday objects begin?

Scientists have shown quantum behavior through a double slit in particles as large as molecules containing thousands of atoms, but what about really large things like balls? Will we see the same kind of behavior that electrons or atoms have? No we will just see two patterns on the back wall. Why doesn’t the whole behave like the individual atoms it is made up of?

To answer this, we have to understand some of the basics of quantum mechanics. When we shine a Monochromatic light through a double, we see an interference pattern on the other side because as the waves spreads out, This should be no big mystery. This is not quantum mechanics, this is just a property of waves. It will happen with water waves too.

In the Copenhagen interpretation, these particles are not particles - they are like wave of probabilities. The waves become distinct like particles only when they are measured. At the point at which the probability wave becomes a distinct particle is called a collapse of the probability wave. What scientists have found is that when the which-path information of any particle is measured, its probability wave collapses. For the particles to remain probability waves, their path information must remain in absolute secrecy. If at any point any kind of measurement is made, whether it seen by anyone or not, the particles become distinct and do not display wave-like behavior.

A measurement always collapses the wave. A measurement is a formation of any physical record of which path the particle takes. It is such that a quantum forensic exam could establish which path the particle took. The particle has to be informationally isolated. The interference can only occur if it is impossible, even in principle, to find out which path the particle took.

Now what if throw really large particles that are composed of quintillions of atoms, like tennis balls at a double slit? Will be see an interference pattern? No, The reason is that large objects are nearly impossible to isolate informationally from the outside world. Let’s look and see what it would take to isolate a tennis ball informationally.

First we have to remove all the air and photons in the experiment - Because if a photon or air molecule bounces off the tennis ball, then it has potentially recorded the path of the tennis ball. The photon will do the same thing, if a photon reflects off of the ball, then that could be a measurement because the path of the photon would be changed and the bounced path of the photon has recorded the path information of the ball. Potentially, someone or the universe could examine the paths of all the photon in the room, find out how they were affected by the path of the tennis ball, and find out from that information, the path of the tennis ball.

We will also need to cool the baseball to near absolute zero, because the baseball that has a temperature will emit photons due to something called black body radiation. These emitted photons will have recorded information about the tennis ball, such that someone examining the photons could determine the path of the tennis ball.

We even have to worry about the small amount of gravitation that the tennis ball will have, because this gravitation will effect nearby atoms. This in principle can allow someone to determine the path the tennis ball took. So this ball will also somehow have to be isolated from that.

We have to completely isolate the tennis ball because any information that is leaked to the universe about its path will create a record. Even if this information is recorded in one atom, it is still information which has been captured in the universe, and the tennis ball will not be in superposition.
#macroquantumeffects

Macroscopic objects like this are very difficult if not impossible to isolate informationally. So in our everyday experience, we will not see quantum superposition or wave like behavior of macro objects. This is the reason, you and I and the cat in Schrodinger’s experiment are NOT in superposition. The cat is not dead and alive at the same time. That is a myth.

[KjV]

This is literally the only thing I've seen or read that actually defined what "measurement" means with regards, to the double-slit experiment. Such an important thing and nobody ever bothers explaining it - except you!

[FGj-xjrd]

Damn man! This is all inclusive.
1. It gives one of the best double slit experiment explanations, like ever.
2. Easily deals with the myth of the conscious observer.
3. Answers the main question very well.

[rclrd]

The use of the words “observation” and “measurement” in quantum mechanics is thoroughly misleading. Replace them by “interaction” and things become much clearer. A probability wave exists only while it’s _not interacting._ When an interaction takes place it collapses. An interaction is an _exchange of information._
Nice video - intuitively appealing and convincing.

[jadioj]

This is priceless content. Maybe this speaks to my stupidity but this is the only channel where I don't have to sort out confusion born out of the content I'm watching. Your videos make me feel like I moved slightly forward and leave me asking new questions. Thanks always!

[linusleonan]

This really sounds like a way a developer would optimize his code in a universe simulation (if no record is being made, then use the standard wave behavior) that is crazy to think about

[jb_]

I’ve never found such a succinct and graspable explanation. So well communicated, thanks!

[BomberDual]

Ive watched 6 or 7 videos explaining the double slit experiment. I happened to click on this one just for kicks to see if I missed anything. Im glad I did, the clarity of your explanation about information made many things click for me.

[brianegendorf]

My closest guess of why this is, is that every probability wave plays out on a field. You can't measure something on that field, without putting something else into that field to measure. The moment you do so, you change the shape of the field. Which changes the probabilistic outcome of deterministic processes that occur within that field.

[GothicKin]

Spoiler: he doesn't shoot ultra fast tennis balls

[willlaflam]

This may be the best explanation of quantum mechanics I’ve heard yet....thank you

[paulsammut]

I'm a not scientist nor a physicist, I have a basic school physics education from 55 years ago, which never covered atomic physics as it was called then. However, over the years, I have always been intrigued by the weirdness of the double slit results and the conclusion that followed from them, which formed the foundational explanation of the behaviour of light and quantum particles as understood now as quantum mechanics.

I have watched many videos on just this topic and formulated my own hypotheses which can explain all the results, including; the measurement observer problem, particle/wave duality, all without any weirdness, like waves and particles transmuting in to each other depending on if they are being observed or not.

I found your video very interesting and used your video expanation to test my hypotheses and I can explain all your results perfectly simply, using my hypotheses without any weirdness.

Because you are a physicist, I would love to discuss this hypotheses with you and for you to try your best to break it. I don't think my hypotheses changes the maths around QM, however it could give physicist a new way to look at things and like all good hypotheses, it makes predictions about things we do not yet know, which people like yourself can do the experiments to confirm if the hypotheses to be true or not.

Sorry for rambling on so long, thank you for your videos, very enjoyable!

[chrisroser]

Quantum superposition would definitely make sports more interesting if it did occur on large objects. Great video!

[MrMegarag]

I just can't believe I've found the best video ever explaining this matter. Thank you.

[Kairosx]

This might just be me, but I've NEVER heard someone give such a solid, succinct, and easy to grasp explanation for the whole "what could potentially be a measurement in quantum physics" thing. I've always kind of struggled to understand it before, but your explanation, combined with the examples about how hard it would be to -not- measure something like a tennis ball, made it all click for me. Thank you!

[Fregmazors]

Thank you! Finally, someone gets the dead/alive cat scenario right. I get so tired of people saying that 'the cat in the box is alive and dead', because they don't understand what a paradox is. It's very refreshing to have this explained properly.

[edwardjh]

BEST explanation, most basic I have ever heard and easy to understand. Based in theory and testing using the scientific method. Wonderful job.

[StefanReich]

NOW I understand why making a quantum computer is so hard - the superposition collapses from an event as trivial as the emittance of some blackbody radiation (which explains the extreme cooling).

[kensmith]

Even after all these years, quantum physics never fails to be weird

[CryptoNChill]

In order to "measure" the photons passing through the double slit experiment, wouldn't that entail some sort of physical external interaction with the photon? It makes much more sense that this action would materialize the wave function into a concrete phenomena as you've effective imparted external influence on it. I think a lot of people are thrown off by the use of the term "measurement"

[stevenglowacki]

It's interesting that the go-to example for this is tennis balls. In my Intro Physics textbook, the section on Quantum Mechanics does the same calculation of the De Broglie wavelength of a tennis ball and shows how its quantum behavior is entirely negligible, even if you were to work out a way to not have the wave function of the entire object collapse from interaction with its environment.

I've also seen the supposed diffraction pattern for molecules consisting of several dozen atoms, and it's barely discernible from a Gaussian. There's only a very slight dip in the probability off the center of the peak before it returns to the normally expected Gaussian.