Do Cause and Effect Really Exist? (Big Picture Ep. 2/5)

Do Cause and Effect Really Exist? (Big Picture Ep. 2/5)


The idea that certain things, events or people
can “cause” other things to happen plays a huge role in human life. We constantly desire to know “why” things
happen, in science, love, sports, philosophy, and so on. But because the underlying laws of physics
don’t care about the direction of time, cause and effect don’t have the same meaning
at a fundamental level. It’s not that anything goes. The basic constituents of the universe — the
particles and forces of modern physics — behave in predictable ways according to the laws
of nature. In principle, you can just as easily know
their past paths as their future ones. The current momentum and position of a particle
determine its movement forward in the next second, but they also determine how it was
moving in the previous second. Neither is really a “cause” preceding
an “effect”, there’s just a pattern that particles follow. Kind of like how the integer after 42 is 43,
and the integer before it is 41, but 42 doesn’t “cause” 41 or 43 – there’s just a
pattern traced out by those numbers. At a fundamental, microscopic level, all we
can say is that there are patterns between events. The macroscopic, human-scale concepts of cause
and effect only emerge when you have larger collections of particles, like humans! As we know, time does have a direction for
larger-scale systems, and we can indeed talk about a spark causing oxygen and hydrogen
to turn into water and an explosion. “Spark plus oxygen plus hydrogen” and
then “water plus explosion” is a sequence the universe follows, and it only happens
in one direction. You never see a reverse explosion where water
spontaneously splits into oxygen and hydrogen gas and then at the very end emits a little
spark. One way of thinking about causes is that the
tiny spark has great “leverage” over the future. If you hadn’t lit the spark, we wouldn’t
have seen a giant explosion. It doesn’t work the other way: removing
or changing a tiny part of the giant explosion doesn’t imply that there wasn’t a preceding
spark. When a small change to the present implies
a big change to the future, the small thing we’re changing is generally thought of as
a “cause”. Leverage can also go the other way. Take this new pencil: the wood it’s made
of contains trace amounts of radioactive carbon-14, created by nuclear bomb testing. If the pencil didn’t contain that carbon-14,
that would imply that no nuclear bombs had been detonated in the last 80 years; while
if you removed a pencil-sized amount of one of the atomic bombs, this pencil would still
be basically the same. In this case, the fact that the pencil has
lots of carbon 14 means that it has a lot of “leverage” over the past. Instead of calling the carbon 14 in this pencil
a “cause” of the earlier detonation of hundreds of nuclear bombs, we call it a “record”
of the bombs. In general, when a small change to the present
would imply a big change to the past, the small thing we’re changing is thought of
as a “record” or a “memory”. So the distinctions between “cause” and
“effect”, “records” and “predictions”, aren’t fundamental to underlying physics
– they only really make sense on the large scale, because of the direction of time.

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  1. Can you do a video on the Hoyle state and beta decay? I understand that it happens but not really how. How does a neutron become a proton by spitting out an electron and a neutrino?

  2. You can look at almost anything in reverse with time going backwards, but that doesn't mean time can go that direction. It just means you're solving for cause, not effect. It feels like some elements of physics have become math without logic. Or at least that's what I think.

  3. Cause and effect only making sense at a macroscopic scale is all the more reason that time's arrow probably only exists at a macroscopic scale. It is not a fundamental property of nature – it is emergent (and I believe, symmetrical, although we are simply unable to "follow" anything going in time's opposite direction). If an "effect" ripples outward from its cause in every temporal direction at the quantum scale, this would easily explain entanglement.

  4. But in all actuality, we can't say the patterns exist either, because we can't observe everything single instance to know if the pattern actually is absolute. We can't observe the laws of physics, we can only observe their effects. While it's not based around a sequence of time, we are still postulating a cause and an effect relationship by saying these patterns cause the observations.

  5. All that can be stated is that the cause of these quantum events is unknown within the framework of the universe in which we live. It can not be said that there is absolutely no cause at all. Therefore, decisive evidence is still required in order to prove that there is no cause for quantum events, and this evidence is absent as long as there is no certainty that all existence is no more than our universe we live in. In fact, today, we have many theories of multiple universes with the possibility that they affect one another.

  6. The presence of the C14 in the pencil didn't CAUSE the atomic bombs to be tested and explode…

    But what if no one knew there was C14 or that the bombs had exploded?
    If you don't open the box, the cat is both dead and alive until you do. 🙂

  7. And there are energies that we are not discovered them yet and are involved in cause and effect. Like if your policy destroys one country or limits their capability of true life your country will be destroyed and will be limited. This is for teaching people to be sensitive to others and nature.

  8. cause = effect = an event

    There is no semantic difference for each of these terms standalone. Even in one time direction:

    … -> event A (cause and effect) -> event B (cause and effect) -> …

  9. But it does exist at a fundamental level! The laws of physics CAUSE the effect of particles behaving the way they do! …right?

  10. 1- the point he made about 42 not causing 43 is just absurd
    there is a logical cause and effect, but not necessarily an observable cause though
    why 43 ? because 42 is before it why 42 ? the same thing 41 !! ….. until why 1 ? because u started counting (:
    you cant go to B without passing through A (not having an observable cause & effect but because of the necessity of A, it's considered as a cause ) !!! those are just the basis of logic

    2- the second point about the pencil and nuclear bombs is also incoherent
    there was an obvious manipulation of words to convey the wanted idea !! instead of what he said it should be more like this;
    if there were no c14 (not like what he said a size of pencil c14, he manipulated the words between the general and the specific to convey an idea) in nuclear bombs there would simply be no pens. this was general. specifically if the same c14 in the pen didn't happen in the past then, the pen wouldn't exist as well. if u want to start with general keep talking generally, same for specifics.
    also if the effect (c14) ceased to exist !! that doesn't imply that this effect affected the cause and made the cause non-existent… that would be childish logic.
    if the effect ceased to exist !!! that means the cause ceased to exist first; which again made the effect cease to exist as well !!!
    for example : if the pencil is going to fade away, the c14 (cause or components) should fade away first so that the pencil (effect) can fade away as well !!!
    you start from the fading away (: the components (causes) of the pencil in order to make the pencil fade away! completely.
    i feel disgusted how the concepts are being manipulated by cheap techniques only to sound as someone pleases .

  11. But isnt time just counting even intervals? Doesnt that make it a verb? But you are using it as a noun.
    the direction of time?? you mean the direction you're counting?

  12. I've always thought about this, and never got an answer.
    You said that only in the macroscopic scale we can notice an arrow of time, but i think there's sort of an arrow of time microsopically. Basically, in our physics equations we put in all of the parameters and then we can figure out the future and also the past. For example, if a rock is in midair and you know its direction and velocity at that time, and you insert a bigger value of the time into the equations, you get where it is in the future. If the value you insert is smaller you get what happened in the past.
    But is it possible to create a different set of equations that if you insert a bigger value of the time you get what happened in the past, and if a smaller value you get what happens in the future?
    As far as i know, it's impossible, and that can mean that in the most fundemental level there's an arrow of time pointing to the future.

  13. 0:24 so if you had enough data (like a LOT cause there are so many atoms in the world or universe) and enough computing power (like a TON since figuring all the interactions are complex) you could THEORETICALLY figure out the future? And the EXACT past?

  14. At least half of carbon 14 in the pencil is due to the effects of cosmic rays. The other half from the atmospheric nuclear bomb tests.

  15. In Philosophy causes can exist without the element of time. Meaning that causes can be atemporal (indifferent to time) for e.g. the indentation in a pillow caused by a ball placed on it doesn't necessarily follow it chronologically but rather it occurs at the same time as the ball is placed on it yet we can safely label the placing of the ball as the cause to the effect (the indentation in the pillow). Consider this definition of cause " something that produces an effect" there is no time in this definition, also consider this proposition "every effect has a cause " this proposition is actually an axiom, arguing against it is tantamount to saying that something can come from nothing. Obviously this is an untenable position to take.

  16. Does this mean the grandfather paradox exists only in our mind? If you traveled back in time to kill your grandfather, your father would never be born, but you would not cease to exist?

  17. why is it that when you defy a law in physics, you go to Switzerland and get a Nobel prize but when you defy your parents' law, you go to your room cause you're grounded. I don't seem to understand how the universe works

  18. This is nonsense. The idea that cause and effect aren't fundamental to physics is idiotic and it is shameful that Carrol says that. Even in his examples he states cause and effect. In the case of C14 in pencils the nuclear test caused it.

  19. There is actually no 'cause' in cause & effect. We only see effects. Whatever you're calling a 'cause' is just the effect of a previous cause…. and so forth back through time. You can never catch up to the 'cause' part of the equation. Causation is a long string of effects.

  20. Time flows forward for a quantum reason. http://www.iflscience.com/physics/new-explanation-why-time-moves-forward/

  21. In the Wheeler's delayed-choice double slit experiment, the effect can happen BEFORE the cause. Potentially millions of years before. Quantum physics is a bit weird.

  22. Now i just want to remove a random pencil sized part from an hydrogen bomb. Just to see if it still worked.

  23. This seem somehow reasonable in a deterministic world or in a spacetime block. But what about, quantum mechanics, which has some inherent randomness? Even there there is a MWI (many worlds interpretation).
    The superposition of waves seems to generated the cause and effect phenomenon but these waves are already creates and other than the propagation it's seems there is no further cause and effect in a way. Even our consciousness, can it trigger some actions? It is just a simple system that evolves following the same pattern and free will seems more like an illusion. It's like a particle in a box that only bounces. You add more particles, the same rules apply, then add some more rules and more particle and you can create a clock that looks a bit more alive than the random particles. Then you make a more complicated thing like a life form with still the same rules, and magically it appears as having free will. But it's the same thing as the clock or the bouncing particle.

  24. Good grief! Don't get my brain all warped about how thermodynamics defines time again! In my—err—opinion? in applied(?) cases things only travel in one direction through time but at a very small scale they could follow the same trajectories in reversed time. This kind of confusion gets us warped around recursive paradoxes such as the big bang starting time except that it happened in some fraction of a second, but the fraction of a second wasn't there because the big bang had to happen to create time first.

  25. so…. I wanna know now why there is this question about cause and effect in the first place… is it simply to show that the idea of cause and effect is different in physics? now i'm feeling like i missed some kind of big question here lol

  26. Causality is just an illusion of stuff observed at the macroscopic level .. from science point of view, stuff just happens without any temporal relations ..

  27. If the universe is a causal chain, then it must recede infinitely (beyond the 'big bang') to avoid the paradox of a 'first cause'. Is this correct? Can there be a 'starting point' to cause and effect?

  28. from a certain point of view you just proved that cause and effect is very much real and gave a few examples too , in short , this was one of the worst and just a crappy word-play science video on the internet

  29. Sean Carroll is a really smart guy. But he is human and therefore not perfect. "Yes", Sean, "cause" and "effect" really exist. And the universe (or if you prefer "cosmos") had a cause. And that cause was NOT "itself". The cause was metaphysical since, by definition, the cosmos is ALL of the physical realm.

  30. LOL, this is "science", supposedly? Does he understand the difference between the notion of "Abstract Objects" and "Physical Objects"? Numbers do not exist the same as a rock, a planet or a person exists. Numbers are conceptual.
    We don't dig in caves and "discover" the number 2. Abstract objects do not have causal abilities, they are descriptors or aggregates.
    His argument that because the numbers 2,3,4 do not cause anything, that this means that nothing does, shows he needs to go study philosophy if that's what he's interested in instead of science.
    If I go kick a ball, I literally caused the ball to fly through the air. This has nothing whatsoever to do with the number 2 not causing the number 3.

  31. Assumption: "The underlying laws of physics don't care about the direction of time"
    That implies time symmetry holds which is not necessarily true

  32. So if i said that us knowing the position of a particle is the cause of an effect that is us knowing the previous particles position, aswell as its next position, would be false ? As without the position we would not know the previous or the next one. Secondly, lets take numbers 1 2 and 3. 1 is partial cause of an effect 2 and 2 is partial cause of an effect 3. Number 1 existing and the need for somethimg to follow after it is the pair of causes that in the end make an effect that is number 2… Same with number 3. Even patterns have causes and patterns are effects of the cause that is existance. If there was no number 1 we would not have number 2 if there was no current position of a particle then there is no next one nor a previous one. To my mind this videos first few minutes skip one crutial thing that is the cause of it all… existance.

  33. You need a more precise and detailed model that includes different categories of causes and conditions producing a result. For example, the material cause of an oak tree is the oak seed. But an oak seed cannot produce the result of an oak tree without supporting conditions, such as proper temperature, nutrients, water, freedom from being eaten, etc. Check out Buddhist Abhidharma for a much more detailed explanation, including the inevitable impermanence of all formations.

  34. I see so many comments complaining about the purpose of the video and that it is hard to understand. I'm not special at all and I understand, I just make some effort and repeat some parts and I get amazed by the knowledge. Let's try harder folks, it's completely understandable and logic

  35. Could 42 just be the explanation of the Universe,life,and it's meaning? Could it be God's age? Could it be the code of the Universe?

  36. But King Crimson erases the cause and leaves only the effect. An effect without cause. Take that physicians!

  37. I don't think this is an accurate explanation. Even if particles at the fundamental level can move freely at a certain velocity in the past or in the future without the Restriction of time, that doesn't imply that cause and effect mean anything anymore. Even if the particle was to Flow In Motion back into the past, that would still require the particle to go through a sequence cause and effect for anything to happen in general. I think this applies for the macroscopic and microscopic scale.

  38. i love you your so cool i want to meet you but i live in guam 116 carlos heights upper tumon guam thats my address will you pls meet me i want your markers and i love your drawing

  39. So there is no cause of this video.youtube made by nature so, Its an accident. Also my comment here is by accident, its not about the cause of my search .

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