# How to have light move faster than C **URL:** \ **Category:** The BBQ Pit\ **Created:** [February 24, 2014, 9:53pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160 "2014-02-24T21:53:29Z")\ **Posts on this page:** 20\ **Page:** 25
**Author:** ![Itself](https://avatars.discourse-cdn.com/v4/letter/i/d07c76/32.png) [@Itself](https://boards.straightdope.com/u/Itself)\ **Post date:** [March 10, 2014, 7:40am UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/482 "2014-03-10T07:40:35Z")
> [@mythoughts](#): > > Your joke is closer to the truth than you may think. > > Einstein may have liked math, he said that once the mathematicians were done with his theory, HE DID NOT UNDERSTAND IT! > > As well as he understood his own theory and despite his excellent math skill, he was no longer able to be certain if the math related to reality in a coherent way. > > _Since the mathematicians have invaded the theory of relativity, I do not understand it myself anymore._ > Quoted in P A Schilpp, Albert Einstein, Philosopher-Scientist (Evanston 1949). You realize that Einstein was being facetious there, right? He wasn’t nearly as good at math as he was at physics, but his work in general relativity involves serious math: Riemannian geometry, vector bundles, tensor analysis, and so on. The Einstein field equations (which were actually Einstein’s), for example, involve reasonably sophisticated math. In any case, SR only involves high-school level math. There’s just no way to talk meaningfully about the theory without invoking math at even that level, as many people have to tried to explain to you already. ---
**Author:** ![Itself](https://avatars.discourse-cdn.com/v4/letter/i/d07c76/32.png) [@Itself](https://boards.straightdope.com/u/Itself)\ **Post date:** [March 10, 2014, 7:54am UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/483 "2014-03-10T07:54:20Z")
> [@mythoughts](#): > > The problems is that any transformation that would make light in one direction be C could not possibly help light going the other way be C. > If you make rulers shorter and clocks run slower, that only helps light with a subtracted velocity now appear to be back at C. That is utterly false: the Lorentz transformations, for example, do exactly that. After ten pages, have you not realized that lengths, time, etc. depend on a particular frame? They’re not getting ‘universally’ shorter or slower; measurements depend on the frame in which they’re computed. At this point, you’re just being obtuse. Stop whining about math, go read a special relativity textbook, and come back when you can understand the most basic concepts in the subject. You’re like a child asking why the sky is blue, who summarily ignores whatever answer he’s given and just asks another irrelevant question. ---
**Author:** ![mythoughts](https://avatars.discourse-cdn.com/v4/letter/m/7993a0/32.png) [@mythoughts](https://boards.straightdope.com/u/mythoughts)\ **Post date:** [March 10, 2014, 8:25am UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/484 "2014-03-10T08:25:49Z")
> [@Itself](#): > > This sort of thing— not knowing what Lorentz transformations or inertial frames are— is why people, including me, have been telling you that you don’t know what you’re talking about. This is very, very basic stuff and crucial to understanding the subject. What I thought an inertial frame was turned out to be correct. I had read about them long ago, but forgotten the details so when challenged I asked what they meant to that person. Both in the event I was mistaken (as the seemed to imply, incorrectly) and in the event their interpretation was incorrect. As for Lorentz contractions, I have understood this to encompass initially length contraction and then time was added by another physicist (not Lorentz or Einstein). But rather than be shown as wrong, and in order to again understand the other parties view I would rather reach a consensus rather than just assume that my understanding is both correct and shared by others. This is not the same thing as having no idea about these subjects. > [@](#): > > If you have two separate frames F and F’, then you have two corresponding coordinate systems. How do you map coordinates from one to the other? In the non-relativistic case, it’s easy: you just have a spatial translation (depending on time, if the (constant) relative velocity is nonzero), and the time is the same in both frames. In the relativistic case, it is not; the map between the two is given by a Lorentz transformation, which is a particular linear map. Fine. > [@](#): > > An ‘inertial’ frame is a non-accelerating one. Yes, this is what I thought it meant in the first place BTW. > [@](#): > > Again, this is exceedingly basic stuff. You should know this already if you’re trying to disprove relativity. This is the sort of thing that makes me and other conclude that you don’t know what you’re talking about. I do. > [@](#): > > You are confusing two questions: Why is the speed of light constant in every (inertial) frame That is just an assumption, an axiom. > [@](#): > > , and how does SR enforce that? Enforce? Let’s say explain. > [@](#): > > The first is because it’s confirmed by experiment. No, no it is not. Even the round trip speeds do not conform to C. And one way measurements are maybe even possible given SR’s logic game. > [@](#): > > We could have a completely non-relativistic, Newtonian universe; we just don’t. For the second, there are two possible approaches. One is to note that SR takes the speed of light invariance as an axiom Yes, which makes as much sense as having God as an axiom, or creation as an axiom, or a life force energy as an axiom. It doesn’t defend the position as based on logic. > [@](#): > > , and then works out coordinate systems have to transform in order for that to work. Coordinate systems that can’t be comprehended it seems. I understand time dilation and length contraction, and these do not explain the constancy of the speed of light, except in round trip measurements which they do just fine. But round trips do not make the speed of light to be C in each direction, in fact it pushes it further from C. > [@](#): > > The other is to just take those coordinate transformations as given and show that they make the speed of light invariant. Which is fine if you are happy to be taking things blindly on faith and engauge in magical thinking. > [@](#): > > Your assumption is incorrect. A Lorentz boost is the coordinate transformation corresponding to a frame moving at a constant velocity; it includes both a length contraction (in that direction of motion) and time dilation. Ok, so here is the thing. Length contraction and time dilation can’t make a photon appear to move slower! Both give a speed increase to photons going both ways. And this works just fine if what you want to do is bring the 2 way speed of light back to C. That is what I was able to establish (somewhat in reverse) from the thought experiment with Moe and Stacy that Kimble and I were able to show conformed to SR. > [@](#): > > (In general, a Lorentz transformation may also include a spatial rotation, but nothing interesting happens there.) This is, again, stuff covered in the first problem set of a introductory class on SR. > > If you want to make precise statements about the world, you have to use math. We do not need precise answers, if you can explain how a shorter ruler or slower clock can make a photon that would otherwise be above C now be moving at C, I’d like to hear it. But it can’t, these things will always make the speed seem higher. And while these DO fix the round trip time to be precisely C, they only further imbalance the one way trip time. > [@](#): > > If you had just asked something simple, like what happens in relativity if you’re travelling at a speed v \> 0 and then emit a photon, then we could have answered that easily and concisely. If you want to make the argument that math fails to describe the real world, then you’re a century too late: we already have electricity, GPS, particle accelerators, and all sorts of brilliant technology that happily work with math. None of those things backup SR. ---
**Author:** ![mythoughts](https://avatars.discourse-cdn.com/v4/letter/m/7993a0/32.png) [@mythoughts](https://boards.straightdope.com/u/mythoughts)\ **Post date:** [March 10, 2014, 8:34am UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/485 "2014-03-10T08:34:47Z")
> [@Itself](#): > > That is utterly false: the Lorentz transformations, for example, do exactly that. After ten pages, have you not realized that lengths, time, etc. depend on a particular frame? I know that SR claims they do. That is NOT the issue. The issue is that length contraction and time dilation can not make a superluminal photon be measured as moving at C once more. I would argue that 2 objects both having the fastest/slowest time while both are longer/shortest length might be impossibly paradoxical, but these are mu understanding of Lorentz transformations. It is you who has not tried to address how a photon could appear slowed by time dilation and length contraction. > [@](#): > > They’re not getting ‘universally’ shorter or slower; measurements depend on the frame in which they’re computed. Well D’oh. These are all things I have made clear in my posts. I know SR far far better than you are implying. > [@](#): > > At this point, you’re just being obtuse. Pot, kettle, black. > [@](#): > > Stop whining about math, go read a special relativity textbook, and come back when you can understand the most basic concepts in the subject. I do understand it very well it is you that has some obvious gaps at least in your ability to read. > [@](#): > > You’re like a child asking why the sky is blue, who summarily ignores whatever answer he’s given and just asks another irrelevant question. No, you are like the guy who reads none of the posts and then attacks a strawman by misrepresenting everything. ---
**Author:** ![mythoughts](https://avatars.discourse-cdn.com/v4/letter/m/7993a0/32.png) [@mythoughts](https://boards.straightdope.com/u/mythoughts)\ **Post date:** [March 10, 2014, 9:00am UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/486 "2014-03-10T09:00:52Z")
And one way measurements are maybe NOT even possible given SR’s logic game. ---
**Author:** ![Itself](https://avatars.discourse-cdn.com/v4/letter/i/d07c76/32.png) [@Itself](https://boards.straightdope.com/u/Itself)\ **Post date:** [March 10, 2014, 9:24am UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/487 "2014-03-10T09:24:18Z")
> [@mythoughts](#): > > It is you who has not tried to address how a photon could appear slowed by time dilation and length contraction. I’ve explained this to you several times already. You’ve responded by summarily ignoring it, screaming and whining about how my saying that you “refused” to consider an argument involving (oh no!) math was the worst injustice in the history of the universe, rambling about how _real_ physics shouldn’t involve math, or…well, whatever this nonsense is supposed to mean: > [@mythoughts](#): > > I would argue that 2 objects both having the fastest/slowest time while both are longer/shortest length might be impossibly paradoxical, but these are [my] understanding of Lorentz transformations. But sure, you obviously understand special relativity very well. ---
**Author:** ![Itself](https://avatars.discourse-cdn.com/v4/letter/i/d07c76/32.png) [@Itself](https://boards.straightdope.com/u/Itself)\ **Post date:** [March 10, 2014, 9:30am UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/488 "2014-03-10T09:30:27Z")
> [@Itself](#): > > But sure, you obviously understand special relativity very well. (Do I have to explain that that was sarcasm? That was sarcasm. **mythoughts** does not understand special relativity at all; he is a fucking idiot.) ---
**Author:** ![mythoughts](https://avatars.discourse-cdn.com/v4/letter/m/7993a0/32.png) [@mythoughts](https://boards.straightdope.com/u/mythoughts)\ **Post date:** [March 10, 2014, 9:57am UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/489 "2014-03-10T09:57:15Z")
> [@Itself](#): > > I’ve explained this to you several times already. > > You’ve responded by summarily ignoring it, screaming and whining about how my saying that you “refused” to consider an argument involving (oh no!) math was the worst injustice in the history of the universe, rambling about how _real_ physics shouldn’t involve math, or…well, whatever this nonsense is supposed to mean: > > But sure, you obviously understand special relativity very well. Saying I refused to do something was the height of gall when you knew I couldn’t. Saying I ignored it is no better, since I did not even know what was addressed. If it can explain reality, it should be able to be explained with a model of reality. It you can’t explain it, and if even Einstein can’t follow the math, then really this is just being taken on faith IMO. ---
**Author:** ![Itself](https://avatars.discourse-cdn.com/v4/letter/i/d07c76/32.png) [@Itself](https://boards.straightdope.com/u/Itself)\ **Post date:** [March 10, 2014, 10:11am UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/490 "2014-03-10T10:11:25Z")
It’s been ten pages without any progress and dwindling entertainment value. Mods, is it worth keeping this thread open? ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [March 10, 2014, 12:55pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/491 "2014-03-10T12:55:30Z")
> [@mythoughts](#): > > My understanding (and I have said that this is not my strength) This sums up the thread very nicely. ---
**Author:** ![pancakes3](https://avatars.discourse-cdn.com/v4/letter/p/ba9def/32.png) [@pancakes3](https://boards.straightdope.com/u/pancakes3)\ **Post date:** [March 10, 2014, 2:14pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/492 "2014-03-10T14:14:20Z")
> [@Try2B\_Comprehensive](#): > > nit: _prompts_ the question. [Begging the question](http://en.wikipedia.org/wiki/Begging_the_question) is something entirely different. My bad. > [@mythoughts](#): > > Saying I refused to do something was the height of gall when you knew I couldn’t. > Saying I ignored it is no better, since I did not even know what was addressed. You want to explain things with logic but not math because you don’t understand the math. The problem is that math IS logic. Setting an arbitrary cutoff point of saying “don’t use any math that’s algebra or higher because I don’t understand it” is basically asking someone to explain SR to a 5 year old. > [@](#): > > If it can explain reality, it should be able to be explained with a model of reality. SR explains reality nicely. Your aethered theory doesn’t - and I’m being generous granting your ravings “theory” status. > [@](#): > > It you can’t explain it, and if even Einstein can’t follow the math, then really this is just being taken on faith IMO. Who’s appealing to authority now? I really don’t know what you’re looking for here. If you indeed had a theory so obvious that it doesn’t even require picking up a pencil, then you’re sitting on historical immortality. Nothing would make people happier than to witness groundbreaking scientific breakthrough. The problem is you don’t have that. The frustration is that people try to tell you that you don’t have that and you lash out at those people. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [March 10, 2014, 2:48pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/493 "2014-03-10T14:48:59Z")
> [@mythoughts](#): > > If it can explain reality, it should be able to be explained with a model of reality. By “model of reality”, are you perhaps referring to [this?](http://modelofreality.org/cgi-bin/iet.cgi) ---
**Author:** ![Valgard](https://avatars.discourse-cdn.com/v4/letter/v/7feea3/32.png) [@Valgard](https://boards.straightdope.com/u/Valgard)\ **Post date:** [March 10, 2014, 3:55pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/494 "2014-03-10T15:55:00Z")
One of my co-workers told me something a few years ago that appears to be relevant here: “Argue with a fool and you can’t win. Argue with an idiot and you can’t stop.” ---
**Author:** ![JacobSwan](https://avatars.discourse-cdn.com/v4/letter/j/a6a055/32.png) [@JacobSwan](https://boards.straightdope.com/u/JacobSwan)\ **Post date:** [March 10, 2014, 4:29pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/495 "2014-03-10T16:29:18Z")
> [@Czarcasm](#): > > By “model of reality”, are you perhaps referring to [this?](http://modelofreality.org/cgi-bin/iet.cgi) Ouch! That site made my eyes hurt and brought back memories of AOL dial up access. He seriously studied under Wheeler? I’m not quite seeing how the EPR paradox would be solved by getting rid of photons. There’s still action at a distance and that still needs to be mediated by something. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [March 10, 2014, 4:41pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/496 "2014-03-10T16:41:08Z")
> [@JacobSwan](#): > > Ouch! That site made my eyes hurt and brought back memories of AOL dial up access. > He seriously studied under Wheeler? I’m not quite seeing how the EPR paradox would be solved by getting rid of photons. There’s still action at a distance and that still needs to be mediated by something. Just wait until you read the [the first post in his thread on the subject!](http://scienceforums.com/topic/11645-7-reasons-to-abandon-quantum-mechanics-and-embrace-this-new-theory/) ---
**Author:** ![Tangent](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tangent/32/3098_2.png) [@Tangent](https://boards.straightdope.com/u/Tangent)\ **Post date:** [March 10, 2014, 6:50pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/497 "2014-03-10T18:50:26Z")
> [@Itself](#): > > It’s been ten pages without any progress and dwindling entertainment value. Mods, is it worth keeping this thread open? Quit engaging him and the thread will die. It’s that simple. ---
**Author:** ![JacobSwan](https://avatars.discourse-cdn.com/v4/letter/j/a6a055/32.png) [@JacobSwan](https://boards.straightdope.com/u/JacobSwan)\ **Post date:** [March 10, 2014, 7:20pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/498 "2014-03-10T19:20:59Z")
> [@Czarcasm](#): > > Just wait until you read the [the first post in his thread on the subject!](http://scienceforums.com/topic/11645-7-reasons-to-abandon-quantum-mechanics-and-embrace-this-new-theory/) So the double slit experiment hasn’t been done with a single photon at a time due to the sensitivity of the film? So the work I did with a ccd camera some 20 years ago doesn’t count then? I certainly remember working out the s/n ratio to prove that it was detecting a single photon. (With maths!) And I’m sure it’s been done hundreds of times since. Just that part of his argument is enough to convince me that he’s a nutter. I have a lot of respect for Wheeler, so I’m not sure how this guy could have worked with him. ---
**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\ **Post date:** [March 10, 2014, 8:13pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/499 "2014-03-10T20:13:18Z")
> [@mythoughts](#): > > And one way measurements are maybe NOT even possible given SR’s logic game. One way measurements are difficult, because it would require synchronized stopwatches. Most practical measurements of the speed of light involve a round-trip. e.g., put a mirror on a distant mountaintop – or the moon – and then flash a light at it. However, there is an extant one-way measurement of the speed of light: observe the transits and eclipses of Jupiter’s Moons. Since Jupiter is closer to the earth at some times in our mutual orbits, and at other times it is farther away, we will observe given transits or eclipses at slightly different times. It takes light something like ten minutes longer to arrive at earth from Jupiter when Jupiter is farthest away. Since we know, to a very fine accuracy, when Jupiter’s moons will transit and become eclipsed, and since we have a very good measurement of the distance to Jupiter at any time, we can measure the speed of light in this way. It is a one-way measurement, and it’s reasonably accurate. ---
**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\ **Post date:** [March 10, 2014, 8:20pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/500 "2014-03-10T20:20:22Z")
> [@Itself](#): > > It’s been ten pages without any progress and dwindling entertainment value. Mods, is it worth keeping this thread open? Yeah… I’m still learning stuff! Really, the ideal compromise was when it got moved to the Pit. Those of us who haven’t burned out yet can engage with the amateur physicist – and even use opprobrious language for cathartic purposes – but it no longer clutters up the legitimate opinion and debate forums. FWIW, I’d never heard the phrase “Lorentz Boost” before either, so I am willing to forgive our illustrious correspondent for wondering what it meant. For not being willing to figure out how to use square roots, I find it much harder to forgive him. ---
**Author:** ![Shodan](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Shodan](https://boards.straightdope.com/u/Shodan)\ **Post date:** [March 10, 2014, 8:41pm UTC](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160/501 "2014-03-10T20:41:46Z")
[QUOTE=mythoughts] Lorentz invariance was used to explain the average speed of light being C while the one way speed of light was slower and faster than C. SR has never explained how Lorentz transformations can make the speed of light be C. [/QUOTE] No, the speed of light is never measurable as faster than c. IANAPhysicist, but the Lorentz transformations don’t make the speed of light c. They explain why it is never faster than c. It is an observed fact that light is never measurable as being greater than c. That never happens. Special relativity is the explanation of that fact. All of your “thought experiments”, to the extent that I can figure out what the hell you are talking about, seem to consist of saying “if we do thus-and-so, then light will go faster than c, and therefore special relativity is disproven”. And that is nonsense. Light will not go faster than c under the conditions you think you are describing. If you think that it will, then you actually have to do the experiment and show that it happens. You can’t do that, both because you don’t understand what you are saying, and because lots of other people have done the same, or very similar experiments, and without exception the speed of light never exceeds c. Regards, Shodan [Previous page](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160.md?page=24) [Next page](https://boards.straightdope.com/t/how-to-have-light-move-faster-than-c/682160.md?page=26)