At the speed of light I lose my grasp on everything. The speed of absurdity.
What is space, change, time and interaction at the speed of light?
I'm not going to lie I've spent the best part of a month absolutely blown away by the concept of the speed of light. The more you think about it the less sense it makes and the more wonderful and mysterious it is.
At the speed of light, Time stops.
At the speed of light distance contracts to nothing.
So the "speed" of light doesnt appear to be a speed at all. At the speed of light the speed is zero because there is no distance to travel in no time at all. At not the speed of light the speed is 299 million and something meters/ second.
At the speed of light no interactions can occur forever. Everything is completely instantaneous because nothing is happening. Yet that same interactionless non-acting state hits a "slower" mass like a leaf and bam it's used to create sugar which we eat. What the hell.
At the speed of light there is no mass. No mass can travel at that rate. Then how did energy ever give rise to mass (e=mc2)? If it cannot do anything to itself in a state of pure timelessness then how did it just spontaneously slow down and get "heavy" with matter in the first place.
I'm not going to lie I've spent the best part of a month absolutely blown away by the concept of the speed of light. The more you think about it the less sense it makes and the more wonderful and mysterious it is.
At the speed of light, Time stops.
At the speed of light distance contracts to nothing.
So the "speed" of light doesnt appear to be a speed at all. At the speed of light the speed is zero because there is no distance to travel in no time at all. At not the speed of light the speed is 299 million and something meters/ second.
At the speed of light no interactions can occur forever. Everything is completely instantaneous because nothing is happening. Yet that same interactionless non-acting state hits a "slower" mass like a leaf and bam it's used to create sugar which we eat. What the hell.
At the speed of light there is no mass. No mass can travel at that rate. Then how did energy ever give rise to mass (e=mc2)? If it cannot do anything to itself in a state of pure timelessness then how did it just spontaneously slow down and get "heavy" with matter in the first place.
Comments (60)
That's Higgs theory; mass is a slowing down of energy. Mass and matter are not substances, they are processes.
Let's see, it takes a message from the Mars Rover about twenty minutes to reach Earth. So, nothing happens here while we are waiting. Sounds about right. :roll: :smile:
If you put a clock on that message (which you cant because of the mass of a clock) and it was sent at the speed of light from Mars to earth, and you had another clock here, the clock on earth would have elapsed 20 minutes while the clock returning at the speed of light would have barely ticked a second due to time dilation. From the perspective of the message the interval was instantaneous but to us it was 20 minutes. So yes nothing happened here while the message travelled (from the perspective of the message). No? Or am I getting relativity completely wrong
Hmm, I don't think I've heard of that description before, of the HIggs field absorbing things like quarks and stuff like that (and for that matter, I don't think that quarks are absorbed and produced either like force carriers are). I think you're mixing up two different explanations here, one for why light moves slower than c in a medium, which does involve photons being absorbed and re-emitted, and how some particles acquire mass through the Higgs field.
Imagine if you were a snail. At the speed of an elderly woman walking down Main Street with a cane, the same is true. In a way. Yes?
And here's a scary thought: what if the photon's perspective (no time, no distance) is the correct one? :o
Quoting Benj96
Because we get energy from two things: our mass and our momentum. Light is pure momentum: E=pc. A body at rest is pure mass: [math]E=mc^2[/math]. This leads to the interpretation that any restful body is not actually at rest but is moving through time at the speed of light. So in that sense everything moves through spacetime at velocity c, but photons can only move through space, hence no time passes for a photon.
Admittedly I am not a physicist, though I think @Kenosha Kid is, so maybe he can back me up. As I understand it, the Higgs mechanism involves massive "fundamental" particles like electrons actually being a kind of "blended" particle created when more fundamental particles rapidly interact with the Higgs field. In the case of the electron, IIRC, there is a particle that is mostly exactly the same as an electron, except it has no mass (and so moves at c), and a fixed spin, let's say left. Such a particle can't travel any notable distance at all though, without immediately smacking into the Higgs field, which converts it into a different particle with the opposite spin. That can't travel without immediately smacking into the Higgs field again, which converts it back to the first kind of particle. And so on, over and over, immeasurable rapidly, back and forth. The net result is what appears to be a single particle that's like both of those two, except it moves slower than light and has mass, and an indeterminate spin: the electron as we know it.
Likewise, all the other "fundamental" particles with mass, except IIRC the neutrinos, which don't couple with the Higgs field and so whose tiny mass is still unexplained (because in the Standard Model, all particles should by default be massless, unless interaction with some field is slowing them down and converting some of their kinetic energy to rest-mass, which was my main point).
I'm not a physicist either, so I am just going off of what I've heard on the topic as a layperson. The usual explanation describes the Higgs field as some kind of field of molasses which slows some particles down, and the fact that your description sounded similar to the explanation of why light travels more slowly in a medium is what gave me the idea that you're overlapping them. Perhaps you have a source that you can provide that can clear things up?
[video]https://www.youtube.com/watch?v=kixAljyfdqU[/video]
Another good (but more difficult) place to start would be Wikipedia's article on the Higgs mechanism, and possibly also their article on weak hypercharge (which is what e.g. the proto-electrons give and take from the Higgs field to convert between their two types).
Thanks for the links. I am still not sure where the absorption and emission aspect of your description comes in. What was described in the video was a particle being constantly bombarded by the Higgs field and converting into two distinct states. That is not the same as the reason why light moves slower in a medium.
Even physicists don’t usually speak so strictly though.
Even if I were to grant such a description, again I wouldn't call that the Higgs field "absorbing and re-emitting" fundamental particles like quarks, which was what I initially took issue with.
Oddly enough, apparently the Higgs Boson (which is also a fundamental particle) itself has mass that is not fully accounted for by the Higgs field, at least going off of this helpful source that I've been reading: https://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-known-apparently-elementary-particles/the-known-particles-if-the-higgs-field-were-zero/.
Quoting Mr Bee
Yes that's a good point, I had forgotten that that was also an exception.
And that article is one that I've seen before that helped me learn about this, too! I'm glad you found and shared it.
Sorry, it was bedtime here. I had to actually check the Feynman diagrams to see what Pfhorrest meant. A couple of clarifications.
The Higgs field is a weak-force (radioactivity and stuff), spin 0 (scalar) field: it does not couple to spin but weak isospin and to hypercharge. Weak isospin, annoyingly, is not a kind of spin but is so called because it behaves in a similar way to spin mathematically. It is the property that couples in electroweak (electomagnetic + weak) interactions along with hypercharge, which together comprise the conserved electric charge.
Both isospin and hypercharge can be flipped under interaction with the Higgs field, conserving charge. All quantum field theories are something called perturbation theories. If you imagine adding an electron to the universe, that electron will perturb space around it, and that perturbation will affect the electron, which in turn changes the perturbation, etc. Perturbation theory allows you to calculate e.g. the electron energy by cutting off this infinite series of interactions when the higher-order terms become negligible.
One of these terms correspond to what Pfhorrest said, which is the transformation of an electron from one isospin to another. As a Feynman diagram, it looks like [math]e_L + h[/math] becomes [math]e_R + h[/math], so it's valid to say that the electron in this term is destroyed and a new one with opposite isospin is created. However, individual terms (Feynman diagrams) in the series don't necessarily have a physical meaning. It is only the sum over an infinite number of terms that is physical. That said, it is usual to associate particular diagrams with a sort of approximation to a part of the physical process.
Quoting Kenosha Kid
Okay, I don't really take issue with that sort of description, but is it also valid to say that the Higgs field is absorbing and emitting things like electrons and quarks then? That was what I was hung up about earlier in our conversation.
It is valid within quantum field theory models, yes. Motion of particles themselves is formulated in terms of destroying a particle in one position and creating another in another. It depends on how slavishly you want to interpret the models. Plus, as I said, individual Feynman diagrams don't necessarily have physical meaning. These are really mathematical tools, not analogies to reality. When you work in QFT, it is helpful to think of these as physical processes, but that isn't guaranteed. Destroying a particle and creating an almost identical one is equivalent to the particle changing state. There are quite a few ontological degrees of freedom in quantum theory. That's where philosophers should come in :)
Okay that settles that then.
Quoting Kenosha Kid
Well, you can say that about any scientific theory really. Varying interpretations aren't just unique to quantum mechanics (though it is uniquely infamous for having alot of them). For instance relativity theory, contrary to popular opinion, is also open to interpretations which allow for an absolute time for instance (like the Lorentz ether theory that preceded special relativity), but of course those are less well known.
That is to say that there is no such thing as a purely scientific ontology of the world. If you want to attach a particular world view to a model you're gonna have to dip your toes in philosophy to a certain extent and make arguments that go beyond the science. That or you could shut up and calculate.
:up: That's me!
Do you actually though? I don't mean to say you have a standard philosophical position on the matter, but don't you have conceptual insight/imagination that you apply to the thing to interpret it? Like an imaginative background of the calculation.
Maybe off topic.
Shut-up-and-calculate is a sort of atheistic position on the interpretation of QM as a whole, which describes me well. There are some I find intriguing, some just plain wrong, but I think I have good reason to not adopt a premature position. The ball-rolling of interpreting QM comes from a time when there were only a few simple many-body states we could calculate, and yet intelligent people started generalising to cats rigged to particle detectors. My research group tended to be open to the idea that the maths would sort itself out and give us answers, which, to a limited extent, it has done. Experiment has also pointed in quite a different direction again. These have been far more insightful than adopting a position.
Concerning specific methods used, it is sometimes helpful to picture things as meaning something physical when you're learning, but beyond that short-term utility, it's more misleading than anything. Besides, these things tend to get their own terminology that's abstracted from any interpretation beyond "The Feynman diagram looks like a ladder/bubble/whatever." My particular research tended to live in quite abstract domains.
It's the results that are important. Those are what demand interpretation. I don't particularly question the underlying meaning of a hammer when putting pictures on my wall :rofl:
:up:
Thanks!
This is so cool
Can you clarify what "movement" means here? Certainly can't mean change in spatial location with respect to time since we are talking about "motion" through time. Of course one can define it in terms of a fifth dimension which objects move with respect to, but there are none beyond those of spacetime that I am aware. It seems like you're using it in a different sense than is normally used.
4D velocity is defined with respect to a different measure of time, rather than a different dimension. Within any given reference frame, a body's four-velocity is its rate of change of 4D position (x, y, z, t) with respect to the proper time of the body (t') which is time in that body's rest frame.
Like other physical four-vectors, this velocity is frame-independent even though its vector components are not. (In the body's rest frame or a comoving frame, all of the velocity is in the time component; in any other frame, some of it is spatial, i.e. the body is seen to move.) The magnitude of all 4D velocities is c, the speed of light.
Thanks, though from looking at the opinions of other physicists on the matter these past few hours, it doesn't seem like the whole concept of "speed through spacetime" is a popular way of describing things, with alot of people blaming Brian Greene for the concept.
It's older than that. The natural reaction to special relativity was to figure out what the invariant properties of objects were. Four-velocity is one of those invariants. It has good explanatory power, for instance in demonstrating why a reference frame change is a rotation and in simply describing time dilation. It encodes a lot of relativity. Beyond that, yeah, not a very useful quantity to work with.
Oh sorry, I wasn't saying that Greene introduced the concept of 4-velocity, but rather it's description as "speed through spacetime" (or at the very least he seemed to have popularized this way of understanding it). As you can probably tell through my own questions about it, it's can be pretty confusing to implicitly define a second concept of "motion" and apply that to things like time, and from what I can tell for physicists it's not very helpful as a description either. However as you can also tell from Benj96's comments, for the purposes of popularizing science it also sounds cool to describe things that way, sort of like how the Higgs Boson was described as the "God particle" that grants mass even though that isn't really the case.
Velocity generally is an unhelpful concept in modern physics. It is little-used in quantum mechanics for instance. Momentum is the useful quantity of motion. But any concept generalised to 4D is the same. If you accept time as a dimension different from but analogous to space, any temporal component of a four-vector will be likewise different from but analogous to the spatial components. The mixing of these components in frame transformations is testament to the validity of this interpretation. When you transform from a rest frame to a non-rest one, the result is a rotation of a 4D property from purely temporal into partially spatial. And vice versa.
I would argue relativity also harm science. For example, the pilot wave view which explains Quantum Mechanics in a very nice, non-mystical and deterministic way, it's not popular among scientists is because it is inconsistent with relativity.
Scientists have to accept that Einsten was at best a cool dude, but not a god, and he was simply wrong.
I think they need a stronger reason to than distaste. Relativity's predictions are numerous and empirically verified (black holes, gravity waves, Mercury's orbit...) and science is empirical. And it's not like they're not considering other options (string theory, for instance).
They have to be proposed and tested. Tmk no testable theory contests GR. A testable theory must a) explain everything Newtonian gravity explained, b) explain everything Einsteinian gravity explained, c) explain something unexplained by GR. When we have that, GR is dead. Science in a nutshell!
A good way to do science is to test your hypotheses. Belief is always optional :)
GR is based on the Equivalence Principle (gravity and acceleration are indistinguishable) and special relativity (SR) which decentres the observer and claims there are no special frames of reference. Quite the opposite to what you said.
Quoting Eugen
This is SR. If you wish to travel for 5 minutes to get to Mars for 9 am, you have to leave before 8:55 Martian time because of time dilation. Moving clocks run slow, as has been demonstrated by the velocity-dependence of particle decays.
I am sure it is a case where many mistakes bring you to the correct answer. It is simply illogic and against common sense and reality cannot be like this.
It is an exceedingly simple theory, derived exactly from two postulates:
1. The empirically-verified observer-independence of the speed of light;
2. The empirically-verified invariability of physical law to inertial motion.
Without finding a flaw in its postulates or its derivation, it is illogical to dismiss its conclusions.
Our tastes are our own, but taste is not a scientific criterion. The universe has no obligation to be intuitive; she may have her own rules as long as she sticks to them.
Pilot wave has no empirical flaws and it contradicts both GR and probabilistic QM.
Then it ought to yield testable predictions.
It's not relativistic by design btw. It is mathematically equivalent to non-relativistic quantum mechanics (i.e. the Schrödinger equation), which is an approximation to relativistic quantum mechanics (i.e. the Dirac equation).
Well, yes, it did. It predicted a sizeable electric dipole moment for hydrogen. This wasn't found, so Bohm went back and put the charge distribution inside the pilot wave instead of the particle, completely undermining the whole point of his own theory.
We are evolved to model everyday, human-scale phenomena. Limiting nature to be common sense is itself illogical. It is perfectly normal for scientific theories to evolves, spawn, die, succeed, etc. But common sense has nothing to do with it.
I think it has. Things function in this reality because it has.
I think we are at the begining, in that romantic infancy of the process when quarks move their positiom when we look at them, when things are in 2 places at one and when we curve time
Hmm. I'm not sure sure. This assumes the snails conscious perception of the passage of time is proportional to its size/distance travelled. But I dont believe it works that way because many small animals/insects travel vast distances within their short life which would be the equivalent to us travelling throughout our solar system proportionally.
A bee hurtling along on a wind current isnt going to experience time dilation or relativity just because it's small.
Yes but you're referring to things with mass. Things with mass such as a clock or two twins arent ever going to reach the speed of light. So no, for matter -time cannot stop it can only change relatively. But if you imagine a photon at the speed of light surrounded by other photons with the same velocity, the distance between them is negligible, the time it takes to go from their origin to their destination is also negligible so for a photon time doesnt occur.
Also if the universe has finite energy, it has a finite spectrum/scale of rate for which reactions and interactions can occur. A point of maximum change and a point of minimum change. I would imagine the minimum rate of chnage would be one whereby no information exchange occurs at all (no time).