Why don't speed bubbles cause Doppler shift?

[Paracosmic_nomenclator]

So, I was rereading AoL, and came across the part where Khriss is wondering why Wayne's speed bubble doesn't cause a red shift. I think I might have an answer (though not necessarily the same one as Brandon).

As we learn from stories like The Emperor's Soul, and Mistborn: Secret History, an object's strength in the cognitive realm is proportional to the time it has been in its current form (i.e. If Stick had been a stick for decades, he would have been even harder to change into fire. Conversely, if he had only recently become a stick, Shallan would have been able to change him quite easily). Further, from several WoBs, which are covered more extensively on other pages, we know that a speed bubble's frame of reference is proportional to the most prominent feature in the cognitive realm around it (when you're on a train, the bubble moves with the train. When you're on the surface of a planet, the speed bubble moves with the planet itself.) These same WoBs imply that if a train barreled through a speed bubble anchored to Scadrial, the train (and its passengers) would remain relatively unaffected.

So?

The equation that serves as the foundation of special relativity states that as on object approaches the speed of light, time gets slower and slower for it (not really, but that's the best way our puny monkey brains can think of it). What, then, happens to an object traveling at the speed of light? It experiences no time from the perspective of an outside observer.

And?

If that's true, then photons would have no presence in the cognitive realm. The bubble would have no way of converting them to its reference frame, because they would not exist within the space the bubble operated in. They would simply pass through, unaffected.

But hold on. Aons glow, and Hoid can see inside the cognitive realm. That means that photons have to be able to exist in the cognitive realm in some form. How? My best guess: when photons are created, they inherit some basic the cognitive reference frame of the elctron that created them. What does that mean? If I'm right, it means that any light created within a bendalloy bubble would move faster then any light created outside the bubble. Big whoop. Except, if speed bubbles can't speed up photons, that means they can't slow them down either. Which means that light created within a bendalloy bubble would travel (with concentric bubbles, potentially hundreds of times) faster than light created outside of it. Forget subspace communicators, Scadrian starships can still use radio waves. Also, if you nested like seven cadmium bubbles, the light created within would travel at walking speed. Weird.

Now, due to the difficulty of explaining all this in a fantasy book, and some of the consequences it could spawn (tachyonic antitelephones), I doubt that this is the true reason why we don't see a Doppler shift. Do you like this idea? Have I missed an easier or better explanation? Let me know!

~Para

[Calderis]

The easy answer is magic. 

Quote

Questioner

I'm a creative myself but not really so much an authorial type but a systems designer type. And that's actually what attracted me to your books first, is that their systems are so... meticulous is not the right word. They're so hard.

Brandon Sanderson

Right, hard magic.

Questioner

And I'm not going to ask you to go over Sanderson's Laws but they add up to this magical materialism almost, which I think works really well with your storytelling. Do you have any particular method for meshing together the rules that you create for a system and creating a balance that allows you to tell a compelling story with it?

Brandon Sanderson

That's an excellent question because this is a really interesting give and take. Everything needs to be done in service to the story and the danger of these systems is doing the same sort of thing that an outline does to a story. Too rigid of an outline means you just don't have a good story in a lot of cases. Too rigid of a magic system can actually make certain stories just not work. And I don't think this is the only way you have to do it. For me, this is a lot of the fun but I have to let myself bend.

A good example of this, alright? I wanted to do speed bubbles... But one of the powers is these speed bubbles, right? You can slow down or speed up time around you in a bubble, right? So what I do is I say "Okay if we can do this, science-y people--" I go to my science-y people, that's the official term, I said "What's this going to do?" And they're like "Yeah, red shift. You're going to irradiate everybody." I'm like "Oh, right." *laughter* "Right, irradiating the room. A flashlight becomes a laser beam." Like stuff like this, I have-- What I do-- The difference between me and a science fiction writer is I say "I still want speed bubbles, so we will build into the magic system why the red shift doesn't happen and I will go with that. I will make a rule for it and I'll be consistent but I can make up a rule." And that is something I will recommend to fantasists versus science fiction writers is this thing. Remember the story is king. Be consistent once you've done something but go ahead and give yourself the wiggle room to build something that's going to become-- be for great storytelling. And that balance between being consistent and telling a great story is where you want to be.

So bubbles don't create those kinds of problems, because Brandon really wanted to have them. 

[+Extesian]

@Paracosmic_nomenclator calderis is right narratively but Brandon also seems to be trying to work it to his magical advantage. Here's a couple of WoBs you turn your mind to (as I don't have time to do more than link them)

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NECARION

One other speed bubble question. Is the speed of light the same inside and outside a speed bubble?

BRANDON SANDERSON

Um, yes. The speed of light is the same. Good question, you’re trying to figure out the FTL.

NECARION

Also, it would eliminate the redshift if the speed of light…

BRANDON SANDERSON

If the speed of light were similar . That’s one thing we considered, but it felt too non-intuitive, plus it’s just not how I imagined things working. So, no it is not, but that’s a good question. It is something we considered.

QUESTION

I just want to setup a lab in a speedbubble and do fun things.

FOOTNOTE

[Necarion’s note: there would be no redshift if the speed of light were directly proportional to the ‘speed of time’. Alas this theory doesn’t seem to be valid]

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Kurk: What exactly- When an object enters a time bubble, how exactly does it determine- how does it know how fast and which direction it's "really" going?

 

Brandon: It gets deflected a little bit when it enters, but then it adapts to the momentum that it would have going in.

 

Q: Like Spiritual bonds to something or other?

 

A: Riiight <sounds hesitant> it's- so... I can't explain that because it has relevance in the future. But in that moment when it passes [into the bubble], something is happening with conservation of momentum. The trick we have to do with it in order to keep from irradiating people.

 But your idea is quite interesting whether or not it has any truth to it. The main problem is the first WoB if i understood your reasoning

Edited September 28, 2017 by Extesian