What is Special Relativity?

by Luke Muehlhauser on October 15, 2010 in Science

I keep saying that one reason I reject the Kalam Cosmological Argument is because it requires an A Theory of time, but most physicists reject the A Theory. Why? The first reason is special relativity. So last time, I claimed that you already understand relativity. Now I explain Einstein’s theory itself.1

One key idea in relativity theory is that of a reference frame. Your reference frame is, basically, everything that shares your state of motion. So if drive past and you measure my speed with radar, and you tell me my speed was 70mph, what you mean is that I was moving 70mph relative to your reference frame. You and the Earth and the radar were all in the same state of motion, and I was moving 70mph relative to your reference frame. But I may have been moving quite a bit faster relative to the reference frame of the Sun, for example.

Or if you’re traveling on a plane at 600mph and you say you’re going to walk down the aisle at 2mph, you don’t mean you’re going to walk at 2mph relative to the Earth. The Earth does not share your state of motion; you’re not in the same reference frame as the Earth at that time. Rather, the things that share your state of motion at that time are the plane, the other seated passengers, the luggage, and so on. So you’re saying you’re going to get out of your seat and walk down the aisle at 2mph relative to the plane, the seated passengers, and the luggage. You’re going to walk down the aisle at 2mph relative to your reference frame.

And as we discussed last time, the laws of motion are the same for any reference frame in uniform motion. You can play tennis on a planet traveling at 50 million mph (relative to Earth) just as well as you can on Earth.

Let there be light

Here’s another question: Are the laws of electromagnetism (Maxwell’s equations) the same for any reference frame in uniform motion?

Maxwell’s equations predict (correctly) that the speed of light is 671 million miles per hour. So an equivalent question is: Is the speed of light 671 million mph for any reference frame in uniform motion?

I’ll tell you what my intuition says. My intuition says that the speed of light depends on the speed of the observer.

Think about it. If you’re standing still and I drive toward you at 70mph and shoot you with a Nerf dart gun, that foam dart is going to hit you a lot faster than if I shoot you with the dart gun while standing next to you. Why? Because when I’m driving at you, your speed (relative to the Nerf dart) is the speed of the dart after it leaves the gun, plus the speed of the car.

Intuitively, it seems to me the same should be true of light. If light normally “fires” at 671 million mph, I would think that means it will come toward me at 671 million mph when sent from a light bulb that is stationary (relative to me). But if a distant star is moving toward me at 300 million mph, then the speed that its light is “fired” toward me should be 300 million mph + 671 million mph, right?

This is true of other kinds of waves. A sound wave travels at 768mph relative to the air it is disturbing, and the shock wave of an earthquake moves at a certain speed (let’s say, 400mph) relative to the rocks and dirt it is disturbing. So if I was in a spaceship and a volcanic moon was coming toward me at 200mph, and one of its volcanos suddenly erupted and sent out a shock wave at 400mph (relative to the moon), then the shock wave would approach me at 200mph + 400mph, or 600mph.

So this is true of electromagnetic waves like light, too, right?

Microwaves on another planet

Before we answer this, let’s first ask: what is it that electromagnetic waves are disturbing? Sound waves are disturbances of air, volcanic waves are disturbances of ground, water waves are disturbances of water. But light seems to travel through empty space.

Well, it must not be empty space, then. There must be a very light, invisible substance pervading all of space that light can be a disturbance of in order to move. Early physicists called this substance the “ether.”

But now, we have a weird difference between the laws of motion and the laws of electromagnetism. The laws of motion are the same for any reference frame in uniform motion. But the laws of electromagnetism are not, because they must always be the same relative to the ether. So if I’m moving 100mph relative to the either, and you’re moving 500mph relative to the ether, then electromagnetic waves are going to work differently for each of us.

But hold on a minute. Remember that you can play tennis on a planet in a distant galaxy that is moving at 80% the speed of light relative to Earth. That’s because the laws of motion work the same for any reference frame in uniform motion. So here’s another question: Can you successfully use a microwave oven on this distant planet?

Your intuition probably says “yes,” and you’d be right. You don’t have to adjust for your speed (relative to Earth) in order for the microwave to work properly. And yet the microwave is operating with electromagnetic waves!

So if you can use a microwave on this distant planet moving at 80% the speed of light relative to Earth, and if you can use a microwave on Earth while moving at 80% the speed of light relative to that distant planet, then the laws of electromagnetism must work the same for any reference frame in uniform motion, just like the laws of motion do.

And that’s all Einstein’s theory of special relativity says. Just like the laws of motion are the same for any reference frame in uniform motion, so too the laws of electromagnetism (and therefore, the speed of light) are the same for any reference frame in uniform motion.

Conflicting intuitions

So my intuition that the speed of light (relative to me) depends on the speed of the observer was wrong. The speed of light is the same for all reference frames in uniform motion. My second intuition – that I could use a microwave oven on a distant planet moving very fast relative to Earth – turned out to be correct. I just hadn’t noticed that these two intuitions were in conflict.

Now one might wonder: If all special relativity says is that I can use a microwave oven on a distant planet moving very fast relative to Earth, then why do people think it’s hard to understand special relativity?

The thing is, once you accept that you can use a microwave oven on that distant planet, then some very odd implications for space and time arise.

More on those, later.

  1. As before, I’m currently following along with Richard Wolfson’s course on relativity. []

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{ 54 comments… read them below or add one }

Luke Barnes October 15, 2010 at 5:52 am

“My intuition says that the speed of light (relative to me) depends on the speed of its source (relative to me) … This is true of other kinds of waves.”

You’ve slightly messed this up, I’m afraid. My SR lecturer spent most of the first lecture explaining this to us …

It isn’t true that the speed of a sound wave depends on the speed of the *source*. The speed of sound is relative to the rest frame of the medium it is moving through. I cannot make my shouts move faster by running towards their intended target. Once they leave my mouth, they move at 340m/s (mph … please), regardless. (The speed of a projectile, on the other hand, does depend on the speed of the source. Waves and particles … )

What is true is that the speed of a sound wave depends on the speed of the *observer*. If I run towards the shouter, then the sound waves arrive sooner, and thus appear to be moving faster. If I run away at the speed of sound, then the sound waves will travel with me – they appear stationary This is because I am moving relative to the medium that they are travelling through.

That’s where SR get’s weird – the speed of light is independent of the speed of the observer. Have a distant friend send you a light beam and measure its speed – its 300,000km/s. Now run at 99% of the speed of light toward your friend and measure the speed again – still 300,000km/s. Run in any direction you like, at any speed (up to c!) you like, and you will always measure the same speed.

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Silas October 15, 2010 at 6:14 am

Yeah, two beams of light approaching each other would still only approach each other at the speed of light. Two cars on the other hand, driving at 100mph, will approach each other at 200mph, of course. Counter-intuitive? Indeed.

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Michael October 15, 2010 at 7:09 am

Nice article. I think I would also edit/redo this part:

“So if I was in a spaceship and a volcanic moon was coming toward me at 200mph, and one of its volcanos suddenly erupted and sent out a shock wave at 400mph (relative to the moon), then the shock wave would approach me at 200mph + 400mph, or 600mph.”

What would the medium be between an erupting volcanic moon and a spaceship that an eruption shock wave would propagate through?

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Garren October 15, 2010 at 7:49 am

With you so far. I’m looking forward to hearing how Special Relativity implies an A Theory of time. Then I plan to do my best to not accept such a counter-intuitive theory.

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lukeprog October 15, 2010 at 7:51 am

Thanks again, Luke Barnes!

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lukeprog October 15, 2010 at 7:55 am

Michael,

The volcanic moon.

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Steve Maitzen October 15, 2010 at 9:04 am

I didn’t follow the “argument from the microwave oven.” Does it need the premise that the ether itself is always stationary with respect to a unique background frame? If it does, why accept that premise? (Does it follow from the definition of “ether”?) If it doesn’t need such a premise, why not? Thanks.

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RM October 15, 2010 at 9:18 am

Can someone please check my understanding of this (I think I’ve got it)?

I’m on a train of flatbed cars travelling east at 100 mph and throw a ball eastward. Someone on the train with a radar gun clocks my throw at 50 mph

Then

1) a person standing on the side of the track with a radar gun would clock the throw at 150 mph

2) a person on a train that is travelling eastward on a parallel track at 150 mph would clock the throw at 0 mph. The ball would appear to be standing still in space.

3)eastbound train at 250 mph would clock the throw at 100 mph but the ball would appear to be travelling in a westward direction

thanx

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lukeprog October 15, 2010 at 9:27 am

Steve,

The ether option was actually not a thought experiment but a whole scientific research program. In the late 19th century and early 20th century, the options for interpreting the ether hypothesis fell one at a time as new data contradicted each one. This is covered very nicely by Wolfram in Simply Einstein, but I’ve glossed over it entirely here.

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bossmanham October 15, 2010 at 9:34 am

The only way special relativity becomes incompatible with a tensed theory of time is if one adopts space-time realism, that the possibility of graphing points of space-time means that those measurements have an ontological reality. But just because we can graph relations doesn’t mean they’re real in that sense.

Furthermore, general relativity reintroduced absolute simultaneity into physics.

My second intuition – that I could use a microwave oven on a distant planet moving very fast relative to Earth – turned out to be correct.

Well earth relative to that planet is actually the one moving that fast on special relativity. So which one is actually moving? One would have to find a privileged reference frame. Perhaps this microwave radiation could be a privileged frame?

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Kyle October 15, 2010 at 9:42 am

At relativistic speeds total velocity does not equal the sum of the two speeds.

The equation
w = (u + v)/(1 + uv/c^2)
is a more accurate explanation of the speed from an outside stationary observer. If you are the person moving at velocity u and you throw, or shoot, something at velocity v it will appear to go at speed v from your point of reference.

Here’s a decent reference.
http://www.straightdope.com/columns/read/418/if-i-fire-a-gun-while-near-light-speed-will-the-bullet-exceed-light-speed

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Steve Maitzen October 15, 2010 at 9:43 am

The ether option was actually not a thought experiment but a whole scientific research program. In the late 19th century and early 20th century, the options for interpreting the ether hypothesis fell one at a time as new data contradicted each one. This is covered very nicely by Wolfram in Simply Einstein, but I’ve glossed over it entirely here.

Yeah, I’ve heard of Michelson-Morley and such. But the argument you gave seemed to need a premise asserting that the ether itself doesn’t move, and I was looking for a reason to accept that premise. If the argument is, instead, “Science has shown there isn’t an ether, so the speed of light is a constant,” I’m afraid I’d need that inference explained too.

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bossmanham October 15, 2010 at 9:49 am

Lorentz explained the Michelson-Morely experiment by pointing to the contraction of length that the measuring rods used in the experiment would experience. Whichever arm of their interferometer was parallel to the direction of movement would be contracted, thus giving the appearance that the earth is stationary within the aether (since the light had a shorter distance to travel when the arms were contracted). I don’t know what the justification is to posit that there is no aether based on that, though.

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Rob October 15, 2010 at 9:52 am

RM,

That was mostly right, except the ball would appear to be falling straight down from the POV of the other train. It would look like the thrower released the ball and then moved backwards at 50 mph. So no, the ball would not be standing still in space, it would be falling straight down.

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lukeprog October 15, 2010 at 10:42 am

Steve,

Yeah, I’ve skipped over that scientific story because I don’t have time to cover it. If you’re interested, check out Wolfram’s book. I’m trying to explain relativity, not defend it. But my explanation will not be anything like the full story, certainly!

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chroma October 15, 2010 at 10:58 am

Steve, the ether is presumed stationary relative to itself, no ‘background frame’ required. You don’t need to make it more complicated than it is.

That said, I suspect no simple illustration of non-Euclidean spacetime (the logical consequence of the invariance of physical laws to reference frames) of relativity will be forthcoming. Minkowski space isn’t technically curved – it’s totally flat – so the ‘curved space’ analogy falters. And it has one timelike dimension, which prevents the space from being realized as some kind of surface embedded in Euclidean space, which is generally a human being’s only mode of holistic spatial visualization. Moreover, enter general relativity, wherein spacetime’s curvature is not independent of its own contents, and the picture gets even more complicated.

But perhaps the implications for A- versus B-theories of time can still be made for a general audience.

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Reginald Selkirk October 15, 2010 at 11:09 am

Yeah, I’ve heard of Michelson-Morley and such…

This is my favourite example of why “science is built on assumptions or presuppositions too” is a bad argument. When it comes to assumptions, fewer is better. And even then, in science your assumptions are always open to reevaluation. Michelson & Morley did not set out to prove that the ether does not exist, the existence of ether was one of their starting assumptions. They were merely trying to determine its direction or frame of reference. M&M did their best to achieve experimental accuracy and reproducibility. But when all the cards were dealt, it was clear that the ether was not a player.

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Chip October 15, 2010 at 11:30 am

Furthermore, general relativity reintroduced absolute simultaneity into physics.

Really? I never heard that. I admit my GR is pretty weak[*]. However, GR reintroducing absolute simultaneity would be a pretty huge deal! In fact, my impression is rather the opposite: in GR, one cannot generally even tell which coordinate “should” be time, since space and time can be so thoroughly mixed under extreme circumstances!

Could you give a reference?

Chip

[*] Self-taught over 3 intensive weeks a few years ago, in order to pass our oral qualifiers which were on gravitational radiation that year.

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Hermes October 15, 2010 at 12:14 pm

Chip, I’m with you.

Bossmanham, do you have support for your claim that “… general relativity reintroduced absolute simultaneity into physics”?

Are you just talking about the practical convention of simultaneity for explaining things, or are you claiming that there is an actual simultaneity that either springs by necessity as a conclusion from general relativity or that GR relies on to make sense?

If it’s not just a convention, please provide references from modern physicists or physics who ideally specialize in GR.

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Steve Maitzen October 15, 2010 at 1:48 pm

Steve, the ether is presumed stationary relative to itself, no ‘background frame’ required. You don’t need to make it more complicated than it is.

Huh? Everything is stationary relative to itself. How can that “presumption” distinguish the ether from me? I think you’ve made it simpler than it needs to be.

I’ve asked for a defense of a required premise (“The ether is stationary”) or, if that premise isn’t required, then a defense of an inference (“Science has shown there isn’t an ether, so the speed of light is a constant”). All I’ve got so far is a tautology (“The ether is stationary with respect to itself”) and a metaphor (“But when all the cards were dealt, it was clear that the ether was not a player”).

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Rick B October 15, 2010 at 3:49 pm

Steve,

In exploring wave mechanics, physicists assumed the ether – it made sense because every other wave known – sound, ocean, pressure, etc. – was transmitted through a medium, without which there could be no wave motion. In exploring the primary direction of the ether – that which would have shown an interference in the Michelson-Morley experiment. But M-M showed there was no preferential direction, regardless of the orientation of the apparatus. Ergo, something else must be going on.

I don’t know what premise would be defended here: scientific experiments have shown that the facts are that the speed of light is constant irrespective of the ‘velocity’ of the observer, and that the wave mechanics of EM radiation work perfectly fine in a vacuum. In fact, the actual Maxwell equations in differential form can be interpreted to indicate that an EM wave is self-propogating, i.e. that the complementary parts of an EM wave – the changing electric field and the changing magnetic field – each give rise to the other. No ether required; thus it vanished as simply as epicycles did from orbital mechanics.

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Chip October 15, 2010 at 4:00 pm

Rick,

I will comment that Oleg Jefimenko (famous for the formulae giving the EM fields as explicit functions of the sources, and time) would disagree with that last part. On his view, the E and B fields are simply due to the effects of retardation combined with moving charges, and these fields do not “self-propagate”.

Sure, we often use the “source-free” equations, but no ontological statement is being made. We just use them because often, we don’t care about what the sources are doing; we’re only interested in the light.

I’m not sure whether I’d hold to this interpretation, but I find it handy to have both views in my arsenal of mental pictures.

This is a really obscure point, but I find it too awesome not to add it to the discussion :)

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Rick B October 15, 2010 at 4:24 pm

Chip,

Of course, I’d agree with the Jefimenko formulation; it must be so that every EM wave had a source, or started somewhen and somehow. Do we really care about tracking the source? Meh. But it’s still pretty awesome that the EM wave requires no medium in order to propagate!

Cheers!

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Chip October 15, 2010 at 5:23 pm

Agreed!

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bossmanham October 15, 2010 at 5:26 pm

Hermes,

Bossmanham, do you have support for your claim that “… general relativity reintroduced absolute simultaneity into physics”?

No, I just say things. Of course I do. William Lane Craig (theist) and Quentin Smith (atheist) point it out in their introduction to Einstein, relativity and absolute simultaneity. “The hypersurface of homogeneity and isotropy is the preferred hypersurface for the formulation of the laws of physics and the measurement of space and time” (Craig, William Lane and Quentin Smith. Einstein, Relativity, and Absolute Simultaneity. New York: Routledge, 2008. P 8). This frame is used to measure the age of the entire universe. So when people say the universe is 13.8 billion years old, they aren’t using an arbitrary frame of reference, such as their house, they are using this cosmic age of the universe.

I’m talking about actual simultaneity. This reference frame would be privileged.

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Hermes October 15, 2010 at 5:38 pm

Bossmanham, as I asked “Are you just talking about the practical convention of simultaneity for explaining things, or are you claiming that there is an actual simultaneity that either springs by necessity as a conclusion from general relativity or that GR relies on to make sense?”

Additionally, page 8 is part of the introduction, and as expected has no specific references. I’m not going to read ~300 pages just to go through their whole presentation. As I asked “If it’s not just a convention, please provide references from modern physicists or physics who ideally specialize in GR.”

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Silver Bullet October 15, 2010 at 8:07 pm

“It isn’t true that the speed of a sound wave depends on the speed of the *source*. The speed of sound is relative to the rest frame of the medium it is moving through. I cannot make my shouts move faster by running towards their intended target. Once they leave my mouth, they move at 340m/s (mph … please), regardless. (The speed of a projectile, on the other hand, does depend on the speed of the source. Waves and particles … ) … What is true is that the speed of a sound wave depends on the speed of the *observer*. If I run towards the shouter, then the sound waves arrive sooner, and thus appear to be moving faster. If I run away at the speed of sound, then the sound waves will travel with me – they appear stationary This is because I am moving relative to the medium that they are travelling through.”

I wonder if the above quote isn’t perhaps mixing up the constant speed of sound waves in a given medium, like air, with the doppler effect, which, to my knowledge, doesn’t require the speed of the waves travelling in the medium to vary, but leads to an apparent change in the frequency of the waves if either the shouter or the *observer* are moving relative to each other or the medium.

Here’s what Wikipedia had to say about the doppler effect: “For waves that propagate in a medium, such as sound waves, the velocity of the observer and of the source are relative to the medium in which the waves are transmitted. The total Doppler effect may therefore result from motion of the source, motion of the observer, or motion of the medium. Each of these effects is analyzed separately. For waves which do not require a medium, such as light or gravity in general relativity, only the relative difference in velocity between the observer and the source needs to be considered.”

Its been a long time since I studied physics. Plus my old brain isn’t what it used to be. But my reading of all this is that the actual velocity of the sound waves through the medium is constant. If either the shouter or the observer are moving towards each other, then the waves will appear to crowd, and the frequency will increase, so that the pitch will increase. Thus, the pitch of an ambulance siren increases whether you are driving towards the ambulance or it is driving towards you (and it diminishes as you move away from each other). In these cases though, the velocity of the soundwaves in air is constant.

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Josh October 15, 2010 at 10:32 pm

I don’t get all the confusion about special relativity. It just says that all the laws of physics are the same in all inertial reference frames. Maxwell’s equations are laws of physics, so they must be the same in all inertial reference frames. Maxwell’s equations predict the velocity of a wave that transmits the electric and magnetic fields, and it turns out that that is identical with light. Thus the velocity of light must be constant in all inertial reference frames.

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bossmanham October 15, 2010 at 11:52 pm

Hermes,

I ansered the question in italics. If there is a priviledged reference frame, as the “Hubble flow” (as it’s known) could be, or as God would be, then there actually is absolute simultaneity. It’d be silly to call it “absolute” and not mean it.

Second, what does it matter if the claim is on page 8? I’m pretty sure Smith and Craig, who have spent large portions of their careers studying relativity and the work behind it, aren’t going to be so silly as to state something that isn’t true in their introduction. Furthermore, arguments critiquing absolute simultaneity on both sides are found throughout the book.

Modern physicists aren’t always trained in philosophy, which means they may have certain presuppositions that they have picked up that are unjustified, such as the one I mentioned above about graphing space-time and thinking it therefore is an ontological reality. Why should we think that there is no aether? What was Einstein’s reasoning? It was pure verificationism. He gives no argument, he just discards it de facto. This is the problem with that interpretation, it presupposes this debunked positivistic mentality without justification.

Also, there are several things in physics that are good grounds for a privileged frame. The microwave background radiation (mentioned above) that permeates the entire universe, and is amazingly isotropic, and against which the speed of the earth has been measured (380 km/second in the direction of the constellation Leo). Why shouldn’t this be considered the aether against which we measure events? The quantum mechanical vacuum, which underlies all of reality, could be a privileged reference frame (as this article and this article mention), and has produced test data that supports absolute simultaneity. Why shouldn’t that be considered?

Not to mention you completely waved your hand at what was offered, while giving no counter argument. I consider that a weakness on your side of the argument.

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Michael October 16, 2010 at 12:15 am

@bossmanham

You are not using the term “preferred frame of reference” the way that physicists use it: a special frame of reference where the laws of physics are different than in other frames. You are instead using “preferred” in a common way to mean “given a choice, people would pick it”.

The quote you trot out is a cute way of saying that the frame of reference in which the cosmic background radiation is at rest is a preferred frame. Well, no competent physicist would make that claim: only a conman equivocating on “preferred” would write that. True, a frame of reference where the CMBR is at rest makes some measurements easier, but Special Relativity has absolutely no problem with that and that is not what physicists mean by “preferred frame of refefrence.”

Here, this is what Professor of Astrophysics Douglas Scott has to say on the subject.
( http://www.astro.ubc.ca/people/scott/faq_basic.html )

“How come we can tell what motion we have with respect to the CMB? Doesn’t this mean there’s an absolute frame of reference?

The theory of special relativity is based on the principle that there are no preferred reference frames. In other words, the whole of Einstein’s theory rests on the assumption that physics works the same irrespective of what speed and direction you have. So the fact that there is a frame of reference in which there is no motion through the CMB would appear to violate special relativity!

However, the crucial assumption of Einstein’s theory is not that there are no special frames, but that there are no special frames where the laws of physics are different. There clearly is a frame where the CMB is at rest, and so this is, in some sense, the rest frame of the Universe. But for doing any physics experiment, any other frame is as good as this one. So the only difference is that in the CMB rest frame you measure no velocity with respect to the CMB photons, but that does not imply any fundamental difference in the laws of physics.”

So… is the trickery yours or is it William Craig’s?

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Hermes October 16, 2010 at 5:02 am

Bossmanham: Not to mention you completely waved your hand at what was offered, while giving no counter argument. I consider that a weakness on your side of the argument.

Bossmanham, you made a claim that didn’t seem right to me. Because of that, I asked you to support that claim and requested you provide specific support for your claim from the relevant experts — physicists.

Instead, you gave an answer that was from philosophers, and then only from an introduction of a 300+ page book.

So, I re-asked my original questions.

Now you want to say that the act of me asking you to back up your claim requires that I choose sides in some argument you just made up.

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Hermes October 16, 2010 at 5:04 am

Michael, thanks for the clarification. Very informative.

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Muto October 16, 2010 at 9:17 am

Micheal, Ithink the trickery is done by Craig since I had a debate with another Craigling who did the exact same thing :(

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bossmanham October 16, 2010 at 1:42 pm

Michael,

You are not using the term “preferred frame of reference” the way that physicists use it: a special frame of reference where the laws of physics are different than in other frames. You are instead using “preferred” in a common way to mean “given a choice, people would pick it”.

I am saying it is a frame by which to measure the laws of physics and absolute simultaneity.

The quote you trot out is a cute way of saying that the frame of reference in which the cosmic background radiation is at rest is a preferred frame. Well, no competent physicist would make that claim: only a conman equivocating on “preferred” would write that. True, a frame of reference where the CMBR is at rest makes some measurements easier, but Special Relativity has absolutely no problem with that and that is not what physicists mean by “preferred frame of refefrence.”

Give me an argument for that, Michael. Why shouldn’t we consider it a privileged frame of reference? Because you prefer the status quo interpretation? The neo-Lorentzian interpretation I tend to think is far better grounded philosophically fits in perfectly with the mathematical core that makes up special relativity. All you’ve done here is say I’m wrong because you and this other physicist say so. WHY shouldn’t the background radiation be considered the frame that used to be called the aether? Why shouldn’t the quantum vacuum? There are physicists, such as John Field from CERN, who think it should. What makes their interpretation incorrect? This isn’t about the data or the measurements, it’s about how to interpret them.

The theory of special relativity is based on the principle that there are no preferred reference frames, In other words, the whole of Einstein’s theory rests on the assumption that physics works the same irrespective of what speed and direction you have. So the fact that there is a frame of reference in which there is no motion through the CMB would appear to violate special relativity!

Einstein and Murkowitz’s interpretations are based on that, yes. Einstein simply presupposed, without argument or justification, that there is no preferred reference frame (PRF). If you say there is no PRF because SR is based on it, you’re incorrect and begging the question. Einsteinian SR is based on that, Lorentzian isn’t. There are good arguments out there for the PRF’s I have suggested. You need to present an argument to the contrary that isn’t begging the question.

To repeat, all of the empirical data fits with either Einstein or Lorentz’s interpretations. Einstein based his interpretation off of a verificationist scheme, which is why many philosophers who study the arguments for relativity have come to reject his reasoning.

However, the crucial assumption of Einstein’s theory is not that there are no special frames, but that there are no special frames where the laws of physics are different.

Yes, which is what I am questioning. He really gave no argument to support that presupposition, yet you all just happily accept it and move along as if nothing’s happened.

Hermes,

I never claimed you had to choose sides in anything. All I said is I’d answered your question and gave even more reasons for why I would argue for this interpretation. I gotta wonder what’s wrong with me taking the words of two philosophers (and more who contributed to that collection of essays) on what they said about general relativity, when you seem to be taking the word of random atheist bloggers on the subject?

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bossmanham October 16, 2010 at 2:25 pm

Muto,

So all arguments you can’t understand are “trickery”? Craig isn’t the only one who makes this argument, as I’ve already pointed out that Quentin Smith, who Craig has famously debated, also argues along similar lines.

I think it’s about the intellectually weakest thing to do to accuse someone that you disagree with of trickery. You lose debates that way.

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Muto October 16, 2010 at 3:04 pm

Bossmanhan,

“Yes, which is what I am questioning. He really gave no argument to support that presupposition, yet you all just happily accept it and move along as if nothing’s happened.”

You do not need arguments, but experimental data. And all known forces behave the same in any experiment done so far, whether at rest with the CMBR ot at high relative speed.
And btw who is Murkowitz?

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Hermes October 16, 2010 at 3:13 pm

Bossmanham: I am saying it is a frame by which to measure the laws of physics and absolute simultaneity.

So, it’s a convention for explaining things not intended to be taken as a description of reality? If that is what you meant, I’m fine with that. You need explain nothing more.

As for you providing answers from two philosophers, there is also nothing wrong with that.

Except for one detail. I asked for modern physicists. Your reply ignored that, and answered as if you were addressing my question.

If you can back up your claim well, I consider that a win for me because I then learn something.

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Muto October 16, 2010 at 4:00 pm

Bossmanhan,
I am not sure, if I did accuse anyone of trickery or not. I stated:

“Ithink the trickery is done by Craig since I had a debate with another Craigling who did the exact same thing :( ”

In response to Mike’s:

“So… is the trickery yours or is it William Craig’s?”

I wanted to imply that Craig is the author of these arguments, only using the frase to make the context claer..
For the record I do not know whether Craig thinks his arguments are wrong or right for that matter, but I think they are very weak.

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Chip October 16, 2010 at 7:35 pm

bossmanham,

So what you mean is that cosmology has a preferred frame, not that general relativity does. The whole point of general relativity is to write the laws of physics in a way valid in all reference frames.

The CMB frame might be a good frame for cosmology, but it’s a lousy frame for, e.g., NASA calculating trajectories for satellites.

Do you think the laws of physics look any different in the “preferred” frame than any other? If so, then this contradicts general relativity, instead of being supported by it.

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bossmanham October 16, 2010 at 9:42 pm

Muto,

You do not need arguments, but experimental data

Experimental data is useless without arguments that explain the reasoning behind how to interpret it. Furthermore, the data is the same.

RE: trickeryYou accused Craig of trickery, and I’ve seen that several times from different people on this blog. Seems to me some people, when in a corner, are reduced to accusing their opponent-in-ideas of trickery, which is just bailing out of the argument.

Hermes,

So, it’s a convention for explaining things not intended to be taken as a description of reality? If that is what you meant, I’m fine with that. You need explain nothing more

No, I’m speaking of this as reality. I’m not sure where scientific anti-realism was even hinted at here. This is a frame that is coextensive with the universe and is isotropic (see here. That would be a universe-wide frame of reference. I’m not sure what else to say.

Except for one detail. I asked for modern physicists. Your reply ignored that, and answered as if you were addressing my question.

I ask you for modern physicists that explain why the burden of proof isn’t on them. I did mention a modern physicist who holds to a view like this. I just linked to a paper of more. One wonders what else I could offer before you just start looking hard-headed.

Chip,

So what you mean is that cosmology has a preferred frame, not that general relativity does. The whole point of general relativity is to write the laws of physics in a way valid in all reference frames.

The hypersurface of homogeneity and isotropy that is part of general relativity is said privileged reference frame. This is why we can refer to the entire universe as 14 billion years old without relying on the earth’s frame of reference.

The CMB frame might be a good frame for cosmology, but it’s a lousy frame for, e.g., NASA calculating trajectories for satellites.

So what? Then you use different reference frames for that stuff. Galilean and Lorentzian relativity would still be viable in this view. Besides, practicality != true.

Do you think the laws of physics look any different in the “preferred” frame than any other? If so, then this contradicts general relativity, instead of being supported by it.

I’m not sure what that means. I think the laws of physics are constant throughout the universe. I do think that from the priviledged frame, things would objectively experience length contraction and time dilation. Craig explains what an observer in the priviledged frame would observe here. Search for the paragraph that begins: “There are, after all, other physical interpretations of the Lorentz transformation equations that constitute the mathematical core of STR which are empirically equivalent to the received interpretation and which, if correct, would lead to completely different conclusions when applied metaphysically.”

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Muto October 17, 2010 at 2:32 am

Bossmanhan,

Regarding trickery: I explained myself, I think my explanation is reasonable. You seem to behave uncharitable.

Regarding more important stuff: Necessary for SR (or it’s interpretation, if you should insist) are two principles.

i, In every unaccelerated frame of reference the speed of light is constant: Observed by experiment.

ii, In every unaccelerated frame of reference, we observe no different forces, fundamental constants whatsoever: Observed by experiment.

I do not see where argument is needed.

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Hermes October 17, 2010 at 5:45 am

Bossmanhan: I ask you for modern physicists that explain why the burden of proof isn’t on them.

You made a claim. I asked for support from you of your claim from the relevant experts; physicists.

Why should anyone take your claim as the default? Are you a relevant expert?

You asking for physicists to explain why you aren’t right, and then pushing me to do that research is a clear shifting of burden.

Bossmanhan: I did mention a modern physicist who holds to a view like this. I just linked to a paper of more. One wonders what else I could offer before you just start looking hard-headed.

That snub was not effective. You can do it again if you want, or even go on a rant about my character. If you do, I encourage you to be creative and vigorous.

Back on topic…

What I — or anyone — would want to know about any claim — including your claim — are the facts available and the conclusions (if any) the relevant experts have drawn from those facts.

I’ll keep this practical and as simple as possible. In the case of your one physicist;

* Are they in the consensus among relevant experts (GM focused physicists)? (If so, provide some evidence that they are.)

* Is the conclusion you say they came to accepted as the most likely option or is it one of many? (If so, provide evidence that it is the consensus opinion relevant experts.)

You may consider this nit-picking, but from what you have said so far it looks like you are going with a philosophical presupposition based partly on Einstein, Relativity and
Absolute Simultaneity
not one that deals with all available evidence. As such, I am not inclined to put in effort to hunt down each variation of your claim that might pop up. It’s your claim, show me. I’m not against facts and evidence that are based in reality. I have no agenda in this as the conclusions on this one issue mean little to me, but seem to be critical to you.

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Hermes October 17, 2010 at 5:48 am

Note: If you reference something more recent, that would be good too. +35 years is a bit out there. If the authors of that one paper are still alive, they may not even say what you say the +35 year old paper said.

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Hermes October 19, 2010 at 5:38 am

Bossmanhan, I take it that your silence is due to you reconsidering the issues? If so, that is encouraging. Feel free to post your updated thoughts on this.

Note that I’m for reality. If that means I am shown to be currently mistaken, that’s great because I can stop being wrong about one or more details or an issue as a whole. I hope that you too are for reality and not holding to your preconceptions without considering they need to be updated or replaced.

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bossmanham October 20, 2010 at 11:03 am

Hermes,

You made a claim. I asked for support from you of your claim from the relevant experts; physicists.

I gave it.

Why should anyone take your claim as the default? Are you a relevant expert?

Because it’s never been supported with argument but is rather assumed. Arguments for a privileged frame have been given, and general relativity supports the contention. I’d say the burden of proof lies elsewhere.

You asking for physicists to explain why you aren’t right, and then pushing me to do that research is a clear shifting of burden.

No, I’m asking for an argument to simply assume that there is no privileged frame of reference in the universe. I’m aware that many physicists simply adopt the status quo.

Are they in the consensus among relevant experts (GM focused physicists)? (If so, provide some evidence that they are.)

This constant moving of the goalposts is somewhat amusing, and just adds to my impression that you’re just being hard-headed here. You keep changing and adding to the standard.

There’s rarely a consensus opinion on new and innovative interpretations of data. See Gallileo, Copernicus, Darwin. Consensus != good arguments or support. Furthermore, how many defunct theories enjoyed a huge consensus of agreement? Global warming, classical Newtonian physics, etc. Nothing would change if we always required a consensus view on things.

Is the conclusion you say they came to accepted as the most likely option or is it one of many? (If so, provide evidence that it is the consensus opinion relevant experts.)

It doesn’t matter if it’s the better argument. It is far better philosophically grounded, and meets up with all of the observational data, ergo it is the preferred theory. Certainly, it would basically make Luke’s assertion that the Kalam argument fails because the B-theory of time is correct just about null, since it doesn’t show anything of the sort.

If you reference something more recent, that would be good too. +35 years is a bit out there. If the authors of that one paper are still alive, they may not even say what you say the +35 year old paper said.

You do realize that Einstein’s work is from 1905, and it is still valid? Most of this stuff is based on years and years of research. Field’s stuff is within the past 10 years, and Smith, Tooley, and Craig’s stuff is also. This is recent work done by people who are unsatisfied with the verificationist assumptions of Einstein and the strange ontologizing of the Minkowskian interpretation.

Bossmanhan, I take it that your silence is due to you reconsidering the issues? If so, that is encouraging. Feel free to post your updated thoughts on this

Actually, it’s more due to me being too busy to get on Luke’s blog for a few days.

I haven’t really been given a reason to reconsider the conclusions I’ve been coming to since beginning my reading. I took physics a few years back and simply accepted the relativity taught there because I hadn’t read up on epistemology. Once I did, and then reconsidered Einstein’s assumptions and read the critiques by some philosophers like Craig, Smith and Tooley, and physicists like Field, I began to think that Einstein’s assumption is unjustified and that the neo-Lorentzian model is far better grounded. No scientific theory is too sacred to be reexamined and scrutinized. I’d think skeptics would appreciate that.

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Rick B October 20, 2010 at 11:51 am

bossmanham in my opinion is starting to sound trollish- he’s not arguing for his position and refuses to support it with evidence. He also rejects the evidence provided by others.

SR is supported by evidence; its implications mean that for all known frames of reference the laws of physics hold [excluding the well-known problem of quantum mech. disunity]. That this is so indicates there is no privileged frame of reference.

I don’t understand what argument you’re looking for, and I sure don’t understand why you keep stating without supplying supporting evidence that SR supports the view that indeed there is a privileged frame of reference.

Believe it or not, many physicists also are deeply aware of the philosophical implications of their work; but you’ve merely stated that other interpretations of the mathematics of the theories on question do not imply that there are no privileged frames of reference. You quoted philosophers. You didn’t show the philosophers are good enough at mathematics to dig through the physics; you didn’t use recent references; you didn’t prove anything.

Let’s say I wanted to do the same with heliocentrism. The mathematics admit that the earth could be the center of the universe, but become a little more complex in that case. It is not true that the Keplerian theory of elliptical orbits provides any argument against the heliocentric view. So why don’t we still find anyone advocating this view?

What you’re arguing is the same; that because the math and/or physics doesn’t provide an argument against your viewpoint, that your viewpoint must be considered and refuted before we can move on. To repeat Hermes, you’re pulling the classic burden shifting, and we’d like to believe we’re a little more sophisticated than that on this blog.

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Hermes October 20, 2010 at 12:44 pm

Rick B, thank you. It is hard to argue with your comments.

I was very willing and open to learn from Bossmanham if he had the best support for his point of view. Now, from his comments, I have to suspect that his agenda supersedes his rationality and ability to discern what is most likely true. Hopefully Bossmanham will correct this by actually supporting his conjectures using current relevant facts. If not, then I can’t trust what Bossmanham promotes as true. In the future, for this topic or some other topic, I’m now forced to spend extra time vetting what he claims instead of taking his word for any of it, or taking the easy road and just rejecting his claims as being from an unreliable source.

To re-emphasize: Bossmanham has the opportunity to show show that his claims are reliable by properly promoting them, and in that act promote himself as a reliable source of future claims. I am not blocking Bossmanham from doing that, and I encourage him to do that.

Treating me personally as a foe when I ask him relevant questions is not a way to encourage me to see him as an honest broker.

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bossmanham October 20, 2010 at 6:57 pm

Rick B,

bossmanham in my opinion is starting to sound trollish- he’s not arguing for his position and refuses to support it with evidence. He also rejects the evidence provided by others.

So then the arguments I’ve provided, and the evidence I’ve cited, aren’t arguments or evidence? You may want to read through the thread again, though I’ve found this tactic to be quite common when atheists don’t have an argument.

But, to summarize the discussion so far, for your exlusive benefit, Rick B:

Luke claims relativity theory proves the B theory of time.

I say it doesn’t, because there are interpretations that would support a Newtonian type of absolute time, and base it on neo-Lorentzian interpretations.

People ask for reasons.

I say that Einstein’s assumption that there is no privileged frame of reference is unfounded, and stems from positivism, which is a defunct philosophy.

People say that special relativity requires that assumption, so it’s necessary.

I point out that’s begging the question. Then give evidence from general relativity and quantum mechanics that there is a privileged frame.

People say to name some modern physicists who accept this. I did. People challenge me to link to articles. I did.

Not sure you’re up to date here, my friend.

SR is supported by evidence; its implications mean that for all known frames of reference the laws of physics hold [excluding the well-known problem of quantum mech. disunity]. That this is so indicates there is no privileged frame of reference.

SR, like all theories, is supported by certain assumptions. The neo-Lorentzian interpretation conforms to all of the same evidence, without making the same strange assumptions. And you’re just asserting that there is no privileged frame based on a theory that ASSUMES that there isn’t to work, which is textbook begging the question.

Believe it or not, many physicists also are deeply aware of the philosophical implications of their work; but you’ve merely stated that other interpretations of the mathematics of the theories on question do not imply that there are no privileged frames of reference. You quoted philosophers. You didn’t show the philosophers are good enough at mathematics to dig through the physics; you didn’t use recent references; you didn’t prove anything

Is it ironic that you’re doing what you accuse me of doing? First off, one doesn’t have to understand all of the relevant mathematics to understand what relativity theory says. Second, the interpretation of the mathematical core of the theory isn’t one in the same with the mathematical core of the theory. Neo-Lorentzian relativity relies on the same core evidences. Third, one doesn’t need to understand the mathematics to see the philosophical assumptions and their faults. Fourth, you assume that Craig, Smith, Tooley, and others don’t understand the math, but they cite it quite a bit and then expound on it in their essays and books. Fifth, there are physicists who have developed the neo-Lorentzian model.

Hermes,

Rick B, thank you. It is hard to argue with your comments.

Heh, cheer leading for the home team are we?

And until there is some wrangling with the things I have mentioned, I can’t do anything else for you. Again, the hard-headed impression is still pretty apparent.

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Hermes October 20, 2010 at 7:42 pm

Heh, cheer leading for the home team are we?

An honest assessment. One that I would be glad to give you each and every I thought you deserved it.

I’ve tried to make it clear that I don’t require that your claim is either right or wrong. If it were right, it would have no impact on me except that I have an opportunity to learn something new. Back your claims, and I’ll accept your claims. Don’t back your claims or do strange things like substituting old evidence for new, or philosophers for physicists and what does that leave me with? I’m with the evidence, not a team.

It’s your choice. You control the outcome if you are interested in reality, and you can show me that you have a firm grasp of what is real and not just speculation or presuppositions.

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Hermes October 20, 2010 at 7:53 pm

For reference, Michael posted some interesting comments on the philosophical and theological motivations of WLC’s emphasis of neo-Lorentzian interpretation;

http://commonsenseatheism.com/?p=11530#comment-70555

That said, I’m more interested in what the consensus of current relevant experts is and not the contorted arguments of philosophers.

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Rick B October 21, 2010 at 8:32 am

Bossmanham,

I’ve found this tactic to be quite common when atheists don’t have an argument.

Well, provide an argument for where I outed myself as an atheist and your argument here is still ad hominem.

Luke claims relativity theory proves the B theory of time.

Seems to me he set out to disprove that SR supports the A-theory of time. Maybe this is splitting hairs, but I’d like to stick to facts…

What I’d be interested in seeing is not only how the Neolorentzian interpretations differ in predictive capability, but what the implications are for the laws of physics for any inertial frame of reference. If they’re better, why isn’t the physics world using them instead of SR and GR? This is the same question you didn’t address above, from my analogy of heliocentrism and geocentrism. Which question you’ve so far dodged.

As far as making assumptions, what better assumption would you make in order to explain the MM experiments and account for the experimentally-verified invariance of physical law in any inertial reference frame?

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Rick B October 21, 2010 at 8:34 am

Please note: I’m interested in describing reality, not some philosophical might-be world which, because no one’s disproved its existence, must be considered at least possible so let’s talk about it ad nauseam.

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Chip October 21, 2010 at 7:11 pm

bossmanham,

You do realize that Einstein’s work is from 1905, and it is still valid?

Well, his special relativity stuff is, yes. But I thought you disagreed with that? You claim support from general relativity, which dates from 10 years later in 1915.

Of course, I’m nitpicking. :)

Anyway, I’m coming at this from the perspective of a physicist who thinks temporal becoming is real. I’m open to being shown otherwise (hence, I’m extremely interested in this post series), but I’d like to see a good reason to change my mind. Of course, I also subscribe to the “strange” ontologizing of spacetime, as you describe it (though I think what’s really strange is not ontologizing it). So I guess I’m a guy who looks at the A-theory vs. B-theory debate, and thinks… why can’t it be both? That’s where I’m coming from.

Here’s what I just don’t get: why do you want a preferred frame? Absolute simultaneity? A global “now”? What exactly does it “get” you? I don’t see a compelling advantage for any of them, from a theistic point of view or otherwise. And abandoning them lets you take Einstein’s perspective, which physicists adopt not due to some discredited positivistic philosophy, but merely because it’s the simplest and most natural interpretation.

I just started my new job this past Monday, so I doubt I’ll have much time for posting. Nevertheless, I hope we get a chance to explore each other’s point of view more fully. I plan to start a blog soon, and this is one issue I’m interested to discuss. I look forward to continuing our conversation.

Cheers,
Chip

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Hermes October 21, 2010 at 7:37 pm

Chip, as best as I can tell Bossmanham promotes A-theory so that he can use William Lane Craig’s arguments for theism because Craig’s arguments require A-theory.

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