Everything We Know About Time Bubbles

[Satsuoni he/him]

This is pretty complicated stuff.  You really can't understand GR without a solid grounding in SR, and while SR is not mathematically complex, it turns our intuition into a bloody mess.  GR just makes it worse.

I know this is offtopic (and maybe I should have used PM system), but as QFT practitioner, can you (or somebody) explain the difference between vectors/matrices/tensors with subscript indices and superscript indices? Like f_ijk and f^ijk? Apparently it is so basic that nobody ever bothers explaining it (in the articles that I've read, wiki included) XD It drives me nuts XD

 

Back to the bubbles - as usual, with gravity the border of the bubble seems to have discontinuity which is rather hard for me to handwave. The time/gravity/space shear there should be rather huge, as far as I can tell. And a simple experiment can show that the energy values (as we understand energy, anyway, which is a different topic entirely) do change - a solar battery/ induction based charger inside a bendalloy bubble would produce more energy, possibly even more than actually went into emitting the light in the first place, if efficiency is above timechange percentage (around 12.5% for 8x bubble, that is). This is not unusual for realmatic interactions per se (see - Feruchemical iron perpetuum mobile).

[happyman he/him]

I know this is offtopic (and maybe I should have used PM system), but as QFT practitioner, can you (or somebody) explain the difference between vectors/matrices/tensors with subscript indices and superscript indices? Like f_ijk and f^ijk? Apparently it is so basic that nobody ever bothers explaining it (in the articles that I've read, wiki included) XD It drives me nuts XD

 

Back to the bubbles - as usual, with gravity the border of the bubble seems to have discontinuity which is rather hard for me to handwave. The time/gravity/space shear there should be rather huge, as far as I can tell. And a simple experiment can show that the energy values (as we understand energy, anyway, which is a different topic entirely) do change - a solar battery/ induction based charger inside a bendalloy bubble would produce more energy, possibly even more than actually went into emitting the light in the first place, if efficiency is above timechange percentage (around 12.5% for 8x bubble, that is). This is not unusual for realmatic interactions per se (see - Feruchemical iron perpetuum mobile).

 

For the first part, I believe the differences between upper and lower indices are between covariant and contra-variant tensors.  I'm mostly just repeating words here, though.  If I am right, the reason this is hard to explain is because in Euclidean space there is very little practical difference between the two types of indices; they are most useful in curved spaces.  Our intuition is much worse at grasping curved spaces.

 

As for the second part of your post, that's an example of the kind of non-conservation of energy which GR can produce, although I also suspect handwavium must be burned to get the details right.

[Satsuoni he/him]

For the first part, I believe the differences between upper and lower indices are between covariant and contra-variant tensors.  I'm mostly just repeating words here, though.  If I am right, the reason this is hard to explain is because in Euclidean space there is very little practical difference between the two types of indices; they are most useful in curved spaces.  Our intuition is much worse at grasping curved spaces.

 

As for the second part of your post, that's an example of the kind of non-conservation of energy which GR can produce, although I also suspect handwavium must be burned to get the details right.

Thank you! (Reads up on contravariance) The vectors are not what I thought they are (which was an ordered collection of number-things, btw, that cannot be any-variant) Another question then - is multiplication of co and contravariant vectors (vectors, not tensors) commutative? Because in school I learned that depending on order  of column/row vectors you get inner or outer product, respectively XD And what is the difference between a tensor and particularly multidimensional matrix?

 

Back to relativistic bubbles

IIRC (I am very unsure) that energy variation is what blue/redshift is all about - for me, as a dabbling layman, lowering frequency is in many ways the same thing as making light slower, or stretching space a bit. When light exits gravitational well, it sheds energy, and with it, frequency, until, in case of black hole, it falls back down

Hmm, that actually makes sense, in  a way - entering a bendalloy bubble is like falling down the grav well - you gain speed, and light gains intensity instead of frequency, resulting in the same energy gain... hmmm... Or does it gain frequency as far as outside world is concerned, but intensity compensation as far as the bubble itself is concerned? I've mentioned before that the way something perceives light kind of depends on the "speed" of its own interactions with said light - so they light might be blueshifted, but if you are sped up, you won't notice it. This can be made to fit a lot of things... except the air pressure thing   At least I don't see how. ... I need to go to sleep NOW.

[happyman he/him]

Thank you! (Reads up on contravariance) The vectors are not what I thought they are (which was an ordered collection of number-things, btw, that cannot be any-variant) Another question then - is multiplication of co and contravariant vectors (vectors, not tensors) commutative? Because in school I learned that depending on order  of column/row vectors you get inner or outer product, respectively XD And what is the difference between a tensor and particularly multidimensional matrix?

 

Back to relativistic bubbles

IIRC (I am very unsure) that energy variation is what blue/redshift is all about - for me, as a dabbling layman, lowering frequency is in many ways the same thing as making light slower, or stretching space a bit. When light exits gravitational well, it sheds energy, and with it, frequency, until, in case of black hole, it falls back down

Hmm, that actually makes sense, in  a way - entering a bendalloy bubble is like falling down the grav well - you gain speed, and light gains intensity instead of frequency, resulting in the same energy gain... hmmm... Or does it gain frequency as far as outside world is concerned, but intensity compensation as far as the bubble itself is concerned? I've mentioned before that the way something perceives light kind of depends on the "speed" of its own interactions with said light - so they light might be blueshifted, but if you are sped up, you won't notice it. This can be made to fit a lot of things... except the air pressure thing   At least I don't see how. ... I need to go to sleep NOW.

 

I actually know the answer to the first part of your question.  Look up Einstein Notation for understanding how to tell what type of product you are seeing.  The short description is that if an index name is duplicated somewhere in a term, there is an implicit sum over that index.  If an index stands alone, then the expression implicitly stands for all possible choices of that index, i.e. that is one of the indices into the resulting tensor.  Then the expression a_i b^i is a dot-product between two vectors and a scalar, and a^i b_j is second-order tensor (e.g. matrix)

 

It's not a trivial bit of math, but its better than all the other notations we've come up with.

 

As for the second part, well, in the real world, when light falls down a gravitational well, it's frequency changes just like we talked about in the previous time-bubble thread, so handwavium is still vital to not kill everybody.

[Satsuoni he/him]

I actually know the answer to the first part of your question.  Look up Einstein Notation for understanding how to tell what type of product you are seeing. [..]

(Reads up) Ok, that makes sense, I guess. I'll just follow the links from there Thank you.

Now, as for the bubbles, Ive realized too late that bottom end of the gravitational well corresponds to chromium bubble -slower time. So the effect for the light entering the bubble is to increase energy (as perceived by people in the bubble. Seriously, definitions of kinetic energy in even simple moving reference frames start to baffle me. Add to this SR, and, well... XD I kinda wonder what the world looks like from, say, neutrino POV, which seems to be always moving at almost the speed of light. Ahem.) So anything at the border that would drain energy from the, say, bullet, can be applied to light, therefore avoiding blueshift. Hmm... Maybe I'll think about it some more.

[happyman he/him]

(Reads up) Ok, that makes sense, I guess. I'll just follow the links from there Thank you.

Now, as for the bubbles, Ive realized too late that bottom end of the gravitational well corresponds to chromium bubble -slower time. So the effect for the light entering the bubble is to increase energy (as perceived by people in the bubble. Seriously, definitions of kinetic energy in even simple moving reference frames start to baffle me. Add to this SR, and, well... XD I kinda wonder what the world looks like from, say, neutrino POV, which seems to be always moving at almost the speed of light. Ahem.) So anything at the border that would drain energy from the, say, bullet, can be applied to light, therefore avoiding blueshift. Hmm... Maybe I'll think about it some more.

 

In special relativity, kinetic energy and momentum are best understood as the time- and space-like aspects, respectively, of a single quantity, the energy-momentum four-vector.  This means that you can't transform kinetic energy without including momentum.  However, speed bubbles change both energy and momentum, so this is OK!

[Jo and the Bush all/any]

Wayne burns Bendalloy and makes a Speed bubble...

1. And there's a seeker outside the bubble. Could the Seeker sense the Bendalloy burning? Or is it to fast?
2. And there's a seeker inside the bubble. Could the Seeker sense metals burning outside the Bubble? Or are they slow/distorted to the point that you can't sense them?
3. And there's a powerful Smoker inside the Bubble. Can the coppercloud leave the Bubble?
4. And there's a powerful Smoker outside he bubble. Can the Coppercloud Enter the Bubble?

[Kurkistan he/him]

@Joe

 

I don't know. Such questions have been discussed before, though, if you'd like to see some thoughts on it.

 

Also, as a rule, if a question is hard enough that you feel the need to put it directly to Brandon, I probably can't answer it.

 

@Physics people

 

 

 

 

 

 

 

@Happyman

 

Soooo... one question...

 

Looking at how I model bubbles and relative motion in the OP, is this anything at all like how the effects of a moving field of gravitational time dilation as (I think...) you've been discussing would work?

Edited July 2, 2014 by Kurkistan

[Jo and the Bush all/any]

 I just wanted your take on it, Because those questions aren't going to get asked for a long time.

[Pathfinder]

If a mistborn put up a speed bubble, and then flared eletrum, would he see the shadows of himself moving outside the bubble, or would the limits of the bubble end the effect?

[Kurkistan he/him]

Added a new WoB to the OP; looks like mechallomancy may well be involved.
 
Merger of magic and technology for FTL:

[Leinton]: Can you use hemalurgy to power machinery?
Brandon: He was initially confused as to what I meant, so I said I got the idea from thinking about FTL travel, and he said that it was a RAFO, but that I was thinking along the right lines, there needs to be a merger between magic and technology.

[Ynax he/him]

I know it's a little late but regarding Sliders bubble: If you have several sliders make a bubble inside each other you would essentially make it move so slowly the 0 degree kelvin would be just some nano, or even lesser, degrees away, and interesting things could be done. This made me also think that your body would probably freeze if you put up several cadmium bubbles (if I understand it correctly). 

[Kurkistan he/him]

I think you're talking about Pulsers here (the one's with bubbles that slow things down), but as for the point itself: maaaaaybe? Probably not?

 

Heat and light are of those set of things that are weird/possibly-handwaved with time bubbles. You'd have to hunt down some of Satsuoni's old posts if you really wanted to get into it, but you can also pile air pressure on top of it if you really want to have some fun with the difficulties/counterintuitivities (totally a word) involved.

 

The thing is, it looks like a fair amount of this stuff that should really change (temperature, light intensity/wavelength, pressure) inside the bubble if you really picture a part of space-time where everything happens faster/slower than everything around it doesn't do what it "should". Temperature is one of the less-counter-intuitive ones, though.

 

So you're saying that, since temperature is essentially a measure of how fast things are moving/vibrating (by my poor-science-understanding understanding), and since things in a slow-bubble are moving slower, then they're cooler?

 

On the barest level this makes sense. Assuming some exemption from time-bubble-weirdness for the sake of science, it's my understanding that a laser thermometer pointed into a slow-bubble should return a significantly lower temperature than a mercury thermometer that's within the bubble. But that mercury thermometer is the thing. We've seen no sign that the people/things on the inside, relative to each other and the time/space they are inhabiting, have slowed at all. It would follow from this that we really shouldn't expect any change in temperature from their perspective.

 

This does raise the question of how these objects should interact with one-another across the boundary of the bubble. For awhile there I'd dismissed the question because we have that whole "you're either all the way in or all the way out" WoB. But then I got the punching WoB (the one that says that your arm can be distinctly outside of the bubble but still affected by it), and things get a bit weird. Because if your arm really is "moving", say, 10x faster than the rest of the world, won't it be 10x hotter? I'd suspect that this isn't how it works in practice because reasonability, but it's another thing to be explained/explored.

 

--

 

The sciency question ontop of all of this, of course, is the question of radiative heat. Someone inside a speed bubble should be getting an order of magnitude more heat from the sun, fires, etc. per-second versus those outside of it, and so cook in short order. To a lesser extent those inside slow-bubbles will be getting less heat per second, while it seems that light is leaving the bubble at the "ordinary" real-world-fast rate. It's odd.

[Ynax he/him]

Oh yea sorry for that, it should obviously be the Pulser.

 

One thing that disproves my theory I think is that time bubbles compress time, not speed, so the speed of the things inside

the bubble would be the same as they would be outside. I wrongly thought speed was a factor, but it's actually only time that is different. 

 

Then we come to the question about radiative heat, which conflicts in matters we are not yet aware of...

Edited January 27, 2015 by Ynax

[Kurkistan he/him]

Well you say that about speed not being directly affected and it sounds like the kind of thing that should make sense, but then we get into frame of reference issues. Also, I think even in the naive case that doesn't examine frame of reference we end up with speed being affected, since it's a function of movement over time, and time is being affected.

[Ynax he/him]

Yes time is being affected, but not the time in which the objects move, since time bubbles doesn't make you go faster, or slower. So heat should not be affected inside the bubbles if we exclude solar rays and such.

[Kurkistan he/him]

I think I get what you're saying? So your saying that, relative to the time bubble, the speeds of objects aren't affected?

[Ynax he/him]

Yes, because, well, time bubbles only affect time (which I didn't think of in my first post in this topic). 

[Kurkistan he/him]

Well it seems you've got the gist of it right, then, though the finicky thing about it is that time bubbles really don't just affect time, they also look like they likely affect motion in somewhat oblique ways, as I cover in the OP regarding frame of reference.

[Ynax he/him]

Haha, yeah I read that but my mind can't really take in that right now... Well thanks anyways! 

[Kurkistan he/him]

Added another "FTL involves magitech" WoB to the OP:

 

Contemporary trilogy tech hints at FTL:

QUESTION

If you were to use Allomancy to fly faster than light, would it be like the Navigators in Dune, where you pick out the best possible route through the stars?

 

BRANDON SANDERSON

No, good question though! That's not quite the way, I haven't given you the tools to figure it out, because I feel that the tools you need to figure it out, I couldn't give them to the characters. I wanted it to progress with the technological progress, so hints are only really brief in the story. You will not see a lot of this until the contemporary trilogy, when they are starting to figure out the technology for how this might plausible work out in the future.

[Vessyr]

I  just barely read The Alloy of Law and only skimmed through this thread about time bubbles. So if what I mention has been discussed elsewhere, I am sorry.

 

Why are these 'time' bubbles being taken at the face value of time?

 

These remind me of how Sazed moved when storing and using speed. What if these bubbles are extreme forms of that? Cognitive and all other bodily functions sped up to the point that it appears like everyone else is standing still? Atium showed the future movement of objects and provided the cognitive capacity to understand what they were seeing. So these bubbles could be providing The Flash type super speed to everyone inside the bubbles while reducing air and water density to help facilitate the increase in movement.

 

If this theory has any merit. Then objects exiting the bubble would have increased air resistance upon leaving and hitting the denser air. This would slow the bullets down and throw them off course. If one side of a bullet hit the denser air first, it would slow down causing the bullet to turn for the deflection. The only way to avoid the deflection would be to shoot on a perfect line that originated from the middle of the sphere so that each side of the bullet exited at the same time.

 

I feel like if it were really time and not just their perception of time. Then either Wax or Wayne would have had to adjust their pocket watch to the correct time. With all the banter between them, it seems like a simple thing that should have been there with Wax blaming Wayne for it being wrong. Wayne is always using 'time' bubbles to change disguises so his watch would frequently be wrong, yet he still checks it. Maybe I am putting way too much thought into that not being in the book helping lead me to my theory.

 

Sorry if this should have been somewhere else. I didn't see another recent thing about time bubbles in my quick search.

[Kurkistan he/him]

An interesting theory, but I doubt that's how it works.

 

For one, the initial formulation for time bubbles as written in the books, before Peter got all "science says not to do that, Brandon", included time bubbles causing red/blue-shift, implying rather strongly an actual effect on time.

 

So far as "jostling" goes, it is a bit of an open question exactly how it works. But we've got two different quotes in the OP that both talk very directly about momentum/energy being lost when you transition out of a speed bubble. I suppose you could model this as a secondary effect of the pressure change, but it seems less likely.

 

Sorry if this should have been somewhere else. I didn't see another recent thing about time bubbles in my quick search.

 

You'd probably just have been better off posting a new topic to ask/theorize your questions, but this is something of a catch-all thread, so I don't exactly blame you.

[18th Shard he/him]

What is up with the ricocheting caused by exiting a time bubble (from the quote Kurk should have payed attention to )? I think this might be the key to at least part of FTL, if something inside the bubble is ricocheted back because the arm outside of the bubble is slower than the arm moving inside, so it ricochets. can we ask for clarification?

[Plaeggs he/him]

So I didn't read the entire shamoozle, but i think that an object moving through a bubble has its velocity "refracted" such that it would be possible to calculate where an object (a bullet, perhaps?) will go. Now, of course this entire theory would be absolutely and irrevocably debunked if indeed there is WoB about the randomness of objects moving through bubbles. Now I have another idea, stemming from my previous one: depending on the exact limitations of a zinc ferring, or a sparker, (which at this point in time I do not care to debate) one could possibly predict this change in velocity. Anyways, feedback is appreciated.