FTL and Violating Causality

[Douglas]

From Y's point of view, nothing can exit X for no apparent reason because X isn't there yet. This was what I was trying to get at with the "simultaneously 2 different lengths" thing.

What are you talking about? Of course X is there already.

From X's point of view, Y is moving right and is compressed:

XL          XR
YL    YR

The message emerges from Y at L. Then some time later:

XL          XR
      YL    YR

The message is sent through Y at R.

From Y's point of view, X is moving left and is compressed:

      XL    XR
YL          YR

The message emerges from X at R. Then some time later:

XL    XR
YL          YR

The message is sent through X at L.

Both of these views are valid, and both are correct. At the same time.

Then could you fix your example so that you aren't comparing lengths of time in perspective X with lengths of time in perspective Y? It makes it hard to see how that's not screwing things up when it is literally the crux of the issue. If it doesn't matter what perspective you pick, use only perspective L.

That would be a rather significant overhaul of the math, because I omitted time dilation (in the sense of speed of time passing) entirely for the sake of simplicity. For the purpose of the example as I wrote it, "2 years pass in frame X" is exactly the same as "2 years pass in frame Y". I am, therefore, comparing lengths of time in the same perspective already because there is no difference in the rate of time passing. In the actual full theory of Relativity this is not correct and would throw my numbers off a bit, but it would not change the conclusion of time travel happening.

The point that really matters here, with regard to picking one frame or another, is "which frame's definition of 'now' does travel through a wormhole use?" For my example, I used "the rest frame of the wormhole." The other obvious possibility is "the rest frame of the message," but going with that would just mean I could drop wormhole Y entirely and send the return message inscribed on a rock that's moving at .5 c instead. The end result is the same.

[exelsisxax]

Well that forced me to clear up a bunch of my confusion about lorentz contraction, It gave me a new idea for FTL at the end of this post.

So in your original example:

The ends of wormhole Y reach L and R simultaneously in wormhole Y's rest frame.

This is incorrect. L and R are in the same frame as X, and are going to be contracted along with it, which your contraction diagrams and my previous self did not take into account. So i'll reconstruct the timeline to resolve that:

From X:
wormholes sync at R. Knowing the speed of Y, L sends message M early in order for M to exit X at this exact time, the origin. Presumably-instant response: R sends a laser through space and messages Mx and My through corresponding wormholes.
L receives Mx - but not My. From X perspective, Y is not in proximity to L and has not been for quite a bit. L instead receives My after a duration, and then later the laser from R.
In this case, Y's contraction has placed YL much closer to R than XL is, resulting in transmission delay.

From Y:
wormholes sync at R. Knowing the speed of Y, L sends message M early in order for M to exit X at this exact time, the origin. Presumably-instant response: R sends a laser through space and messages Mx and My through corresponding wormholes.
My exits Y - on the wrong side of L, the same distance as YL is from X's perspective(from the POV of My)
L receives Mx - but not My. From Y perspective, Y is not in proximity to L and won't be for a while. L instead receives My after a duration from side opposite R, and then later the laser from R.

No problem except L getting 2 messages at once, which is something of hugely a problem. No time travel though, because L and R are contracted along with X - not independent and somehow uncontracted despite Y's relative movement.


So couldn't you use contraction to communicate at any distance, using a pair of objects oscillating together or not in order to compress/expand space for an infinite distance along the line of parallel movement? If contraction is detectable, and everything leads me to believe that it is, you can transmit out infinitely far. Unless contraction actually propagates at C, which I have not been led to believe.

[Anymage]

So couldn't you use contraction to communicate at any distance, using a pair of objects oscillating together or not in order to compress/expand space for an infinite distance along the line of parallel movement? If contraction is detectable, and everything leads me to believe that it is, you can transmit out infinitely far. Unless contraction actually propagates at C, which I have not been led to believe.

Depends on whose perspective. A photon, for instance, sees every journey as covering zero distance and taking zero time. We massive creatures still only see photons moving at c.

In general, though, no effects can create causes outside their light cone. (It might be easier to picture as a light bubble. A sphere radiating out from a given point at c. Only things inside the bubble can have been influenced by that fact.) If I could magically create an infinite mass black hole, it would indeed swallow the entire universe. (infinite mass = infinite gravity = everything reachable getting sucked in.) The far side of the galaxy, about 100,000 light years, would be safe and content (and indeed, completely oblivious) for 100,000 years before they started getting sucked in.

[Max_Killjoy]

Depends on whose perspective. A photon, for instance, sees every journey as covering zero distance and taking zero time. We massive creatures still only see photons moving at c.

In general, though, no effects can create causes outside their light cone. (It might be easier to picture as a light bubble. A sphere radiating out from a given point at c. Only things inside the bubble can have been influenced by that fact.) If I could magically create an infinite mass black hole, it would indeed swallow the entire universe. (infinite mass = infinite gravity = everything reachable getting sucked in.) The far side of the galaxy, about 100,000 light years, would be safe and content (and indeed, completely oblivious) for 100,000 years before they started getting sucked in.

Wait... do gravitational forces actually propagate at the speed of light?

[Anymage]

Wait... do gravitational forces actually propagate at the speed of light?

Yup. Otherwise you could manipulate massive objects to send gravity messages at faster than c. They even talked about this back when gravity waves were news, how the black hole merger happened about a billion years ago, but it happened about a billion light years away, so we only saw signs of it when the gravity waves finally traveled to us.

[exelsisxax]

Wait... do gravitational forces actually propagate at the speed of light?

Yep, as far as we can tell. That's what the whole gravity wave thing(approximately) is, lightspeed crests and troughs of gravitational distortion.

This is why anymage's infinite black hole would not consume the universe instantly, just at the speed of light.

[Max_Killjoy]

up. Otherwise you could manipulate massive objects to send gravity messages at faster than c. They even talked about this back when gravity waves were news, how the black hole merger happened about a billion years ago, but it happened about a billion light years away, so we only saw signs of it when the gravity waves finally traveled to us.

Yep, as far as we can tell. That's what the whole gravity wave thing(approximately) is, lightspeed crests and troughs of gravitational distortion.

This is why anymage's infinite black hole would not consume the universe instantly, just at the speed of light.

I thought gravity was actually a distortion of spacetime caused by mass.

And that theoretical warp drives were supposed to work by distorting space such that the vessel would move less than c local to itself, but the distortion would move through the surrounding space faster than c.

[Yuki Akuma]

I thought gravity was actually a distortion of spacetime caused by mass.

It is! And it propagates at the speed of light.

[Max_Killjoy]

It is! And it propagates at the speed of light.

But regarding the second half of my post, for that to be theoretically possible then some distortions of spacetime have to be able to move through space faster than the speed of light.

So I wasn't automatically assuming that the distortion involved with gravity would be limited to the speed of light, and I had to stop and make sure I was reading it right when someone said it was a speed-of-light propagation.

[exelsisxax]

I thought gravity was actually a distortion of spacetime caused by mass.

And that theoretical warp drives were supposed to work by distorting space such that the vessel would move less than c local to itself, but the distortion would move through the surrounding space faster than c.

Yeah, that's how warp/alcubierre drives are supposed to work. But the distortion in those cases isn't generated by gravity, but some thing on the vessel, so the idea is that by riding the wave the vessel can shove its own distortion faster than C because of the compression of space in front and expansion behind it. The wave propogates from the ship at C, but we're cheating because the whole frame of reference is already moving faster than that.

[Anymage]

To make things weirder, there are things we already know are moving away from us at faster than c. Read up on the particle horizon. In short, space is expanding everywhere, and due to that expansion happening everywhere there are places rushing away from us so fast that light from them will never be able to reach us. Likewise, in the earliest moments of the big bang, our best models assume a short growth spurt when the universe itself grew faster than light could travel. Gravity in particular is stuck at the cosmic speed limit, but the fabric of spacetime can grow or shrink at whatever rate.

(If you want to be convinced that the universe is just out to mess with us, also look up the delayed choice quantum eraser. It's up there with quantum entanglement for things that shouldn't happen, but do. For some reason none of those oddities can be used to send information backwards or FTL, but non information carrying effects seem perfectly happy to ignore the rules.)

[Douglas]

Well that forced me to clear up a bunch of my confusion about lorentz contraction, It gave me a new idea for FTL at the end of this post.

So in your original example:

This is incorrect. L and R are in the same frame as X, and are going to be contracted along with it, which your contraction diagrams and my previous self did not take into account. So i'll reconstruct the timeline to resolve that:

From X:
wormholes sync at R. Knowing the speed of Y, L sends message M early in order for M to exit X at this exact time, the origin. Presumably-instant response: R sends a laser through space and messages Mx and My through corresponding wormholes.
L receives Mx - but not My. From X perspective, Y is not in proximity to L and has not been for quite a bit. L instead receives My after a duration, and then later the laser from R.
In this case, Y's contraction has placed YL much closer to R than XL is, resulting in transmission delay.

From Y:
wormholes sync at R. Knowing the speed of Y, L sends message M early in order for M to exit X at this exact time, the origin. Presumably-instant response: R sends a laser through space and messages Mx and My through corresponding wormholes.
My exits Y - on the wrong side of L, the same distance as YL is from X's perspective(from the POV of My)
L receives Mx - but not My. From Y perspective, Y is not in proximity to L and won't be for a while. L instead receives My after a duration from side opposite R, and then later the laser from R.

No problem except L getting 2 messages at once, which is something of hugely a problem. No time travel though, because L and R are contracted along with X - not independent and somehow uncontracted despite Y's relative movement.


So couldn't you use contraction to communicate at any distance, using a pair of objects oscillating together or not in order to compress/expand space for an infinite distance along the line of parallel movement? If contraction is detectable, and everything leads me to believe that it is, you can transmit out infinitely far. Unless contraction actually propagates at C, which I have not been led to believe.

There are quite a few aspects of Relativity that I left out of the example, and length contraction was one of them. Poking at that really just brings up the point that all the parts of Relativity are required to prevent inconsistencies from popping up. If I leave anything out to try to simplify the example, then if you analyze it thoroughly enough you'll find something that doesn't fit right. In each case, there will be one or another aspect of Relativity that was left out and would resolve it.

To really provide an ironclad example that can't have some legitimate problem picked out of it, I'd have to spend a fair bit of time refreshing my knowledge of the finer details of Relativity, and likely learn a few completely new things too. And if I did that and then tried writing it up the simple way, I'd be using equations without explaining why they work and it could easily end up looking like a circular argument.

To write up a really solid example that explains the derivation every step of the way, like my current example does, I'd have to spend way more time on it than I'm willing to devote to a random Internet argument, and to some extent I'd be attempting to duplicate something that people routinely take actual classes to learn.

Suffice it to say, the critical point is that different frames have different definitions of "now", and if there are two wormholes/teleporters that use different frames then their different definitions of "now" can be exploited to produce time travel. The example I gave illustrates the concept of how and why, even if its numbers are wrong because it is overly simplified. If that's not enough for you, maybe give those website explanations other people have linked a try. The discussion of light cones, etc., may be a bit abstract and have less obvious foundations, but it is fully correct to a far greater extent than anything I'm willing to spend the time and effort to produce.

[Yuki Akuma]

But regarding the second half of my post, for that to be theoretically possible then some distortions of spacetime have to be able to move through space faster than the speed of light.

So I wasn't automatically assuming that the distortion involved with gravity would be limited to the speed of light, and I had to stop and make sure I was reading it right when someone said it was a speed-of-light propagation.

Gravity specifically propagates at the speed of light, but spacetime itself appears to be able to "move" faster than light. 'Warp drives' obviously use some other mechanism to bend space, rather than using gravity.

[Douglas]

On a related note, years ago I came across an educational game for Relativity, Velocity Raptor. The guy who made it went to the trouble of implementing I think all of Special Relativity in the game, and you can actually see how things change as you move around and change speed and direction. It introduces concepts one at a time as you progress through the levels, and the changing definition of "now" is one of them.

It also has two display modes, one for what information you would see from light that has actually reached you (where you can make clocks dramatically slow down but no more than that) and one for what's going on "now" (where you can make distant clocks run backwards by accelerating to change your reference frame). If you consider the latter view as showing information received through FTL messages (sent in your current rest frame, whatever that frame is at the moment), it may help grasp what's going on with the FTL time travel issue.

[exelsisxax]

There are quite a few aspects of Relativity that I left out of the example, and length contraction was one of them. Poking at that really just brings up the point that all the parts of Relativity are required to prevent inconsistencies from popping up. If I leave anything out to try to simplify the example, then if you analyze it thoroughly enough you'll find something that doesn't fit right. In each case, there will be one or another aspect of Relativity that was left out and would resolve it.

To really provide an ironclad example that can't have some legitimate problem picked out of it, I'd have to spend a fair bit of time refreshing my knowledge of the finer details of Relativity, and likely learn a few completely new things too. And if I did that and then tried writing it up the simple way, I'd be using equations without explaining why they work and it could easily end up looking like a circular argument.

To write up a really solid example that explains the derivation every step of the way, like my current example does, I'd have to spend way more time on it than I'm willing to devote to a random Internet argument, and to some extent I'd be attempting to duplicate something that people routinely take actual classes to learn.

Suffice it to say, the critical point is that different frames have different definitions of "now", and if there are two wormholes/teleporters that use different frames then their different definitions of "now" can be exploited to produce time travel. The example I gave illustrates the concept of how and why, even if its numbers are wrong because it is overly simplified. If that's not enough for you, maybe give those website explanations other people have linked a try. The discussion of light cones, etc., may be a bit abstract and have less obvious foundations, but it is fully correct to a far greater extent than anything I'm willing to spend the time and effort to produce.

And so we reach the inevitable breaking point.

You understand why this is fundamentally unconvincing, right? Your position might be the right one, but if nobody can demonstrate it to something without a minimum of a BS in physics then it is no surprise that people are not convinced. I gave those other links a try, I think you did a better job of it than they did(although being able to directly ask you questions is a big bias there). Eventually, this just turns into argument from authority or "trust me", which are unreasonable for a person to accept.

In contrast, evolution requires no math in order to explain it and unless you've basically never been outside you already know everything needed in order to understand it other than heredity. There are satisfying answers to every question and speak directly to human experience.

There's just such a huge gulf between this whole argument and "here's a catalogue of tens of thousands of human and ancestral remains illustrating every step of the transition between our common ancestor with chimpanzees and modern homo sapiens, corroborated with chromosomal and mitochondrial DNA research" But I am a squishy science person at heart.

[Chen]

You understand why this is fundamentally unconvincing, right? Your position might be the right one, but if nobody can demonstrate it to something without a minimum of a BS in physics then it is no surprise that people are not convinced. I gave those other links a try, I think you did a better job of it than they did(although being able to directly ask you questions is a big bias there). Eventually, this just turns into argument from authority or "trust me", which are unreasonable for a person to accept.

Arguments from authority that are verified by other, independent authorities should generally be considered convincing. The arrogance that for some reason all those other people are wrong and you're right, when you don't have the experience/education/training in the subject matter is just foolish.

Some things can't be simplified down, especially if people are insisting on pulling at every little thread in the simplified explanation. If you're going to nitpick just ask for the full explanation, math and all included and if you can't understand that, well it's on you to enhance your understanding of the subject matter. This is particular true with abstract things like mathematics, relativity or quantum mechanics. Things like the double slit experiment are massively counter-intuitive, as are things like length contraction and time dilation. We have no experience with these things in everyday life because the scenarios that produce these effects are done in conditions we wouldn't normally experience. Trying to extrapolate our intuitive understanding of something to that is not appropriate and causes people to reach the wrong conclusions.

[jayem]

And so we reach the inevitable breaking point.

You understand why this is fundamentally unconvincing, right? Your position might be the right one, but if nobody can demonstrate it to something without a minimum of a BS in physics then it is no surprise that people are not convinced. I gave those other links a try, I think you did a better job of it than they did(although being able to directly ask you questions is a big bias there). Eventually, this just turns into argument from authority or "trust me", which are unreasonable for a person to accept.

In contrast, evolution requires no math in order to explain it and unless you've basically never been outside you already know everything needed in order to understand it other than heredity. There are satisfying answers to every question and speak directly to human experience.

There's just such a huge gulf between this whole argument and "here's a catalogue of tens of thousands of human and ancestral remains illustrating every step of the transition between our common ancestor with chimpanzees and modern homo sapiens, corroborated with chromosomal and mitochondrial DNA research" But I am a squishy science person at heart.

Evolution is quite often misunderstood, e.g. taking the Darwin Award level of event as being the typical extremes of selection. To understand properly (without making ridiculously naive misjudgments) you need a level of Probability roughly equivalent to the basic maths to understand 'Galileon-Relativity '.

Special Relativity takes place at the limit, an outcome of the culmination of 2 key [mathsy] disciplines in Physics (Dynamics and Electromagnetics) and is intimately connected to two others just reaching maturity (Astro and Nuclear). And as such should probably be compared with more complex Evolutionary aspects (by definition above my understanding) but perhaps say where Lamarkian effects reappear (or something else).

That said it isn't that complex.
The (then) current rules of Dynamic's say that the laws of physics should every apply in inertial frame. If I put 'everything' on a big enough boat then it wouldn't matter how fast the boat was moving (things are different if I miss something off, like the air). It's newly been shown by (Hamilton) that if things are different then there is basically no such thing as 'energy' or 'momentum' (You can apply the fudge factors for say an electric field, that is outside the boat.)

The rules of Electrostatics say that if I accelerate an electric charge then a magnetic force occurs and vice versa (if our understanding of Gravity were better, and we could turn mass on and off the same would be true). It's newly been shown (by Maxwell) that a wave propagates at a specific speed (dependent on the medium). This speed does not depend on the motion of our box.

This is a problem, two disciplines have reached their peak and contradict themselves. One says all inertial frames are equivalent, one says light travels through vacuum at a specific speed in some frame.
Option 1) There is a specific frame that is special (we must be pretty close to it, although it could change a bit but then...). However (unless the Sun goes round the earth), we are in a frame that changes and the difference should be opposite in Summer and Winter. Cue Michelson Morely
Option 1b/2a) Cue Lorenz (who plays a bit of a Copernian role), even if we don't know what we're doing compared to 'the absolute frame', what happens if we try and force the two together. Lets guess there is a way to change co-ordinates, well if there is and it's simple like x2=g(v)x1 t1=g(v)t2...then g(v) has to be, but this then does our brief. So if instead of 'real' distance we used this we get something that works. If we convert our distances into this, we can do our calculations a lot easier (or in other words, the sun moves round the earth in a complicated pattern that is easier to work out if you assume the earth went round the sun)
Option 2b) Cue Einstein (apparently independently), why are we pretending that's not how things work. In addition what happens to our 'energy' (this turns out to have implications).

Consequences:
Cue Einstein, what happens in accelerating frames, and with Gravity, this theory only applies in Special cases, I need a more General one
Cue Dirac if I apply this to QM the energy levels are slightly different and 'antimatter'
Cue Astronomer's, Mercury isn't behaving right does it behave right if I apply (General) relativity
Cue Particle physicists, our slow moving Muon has a very short life, while those fast moving ones almost last a millisecond. Oh wait...
(also of course relevant in Cern)

[Douglas]

And so we reach the inevitable breaking point.

You understand why this is fundamentally unconvincing, right? Your position might be the right one, but if nobody can demonstrate it to something without a minimum of a BS in physics then it is no surprise that people are not convinced. I gave those other links a try, I think you did a better job of it than they did(although being able to directly ask you questions is a big bias there). Eventually, this just turns into argument from authority or "trust me", which are unreasonable for a person to accept.

In contrast, evolution requires no math in order to explain it and unless you've basically never been outside you already know everything needed in order to understand it other than heredity. There are satisfying answers to every question and speak directly to human experience.

There's just such a huge gulf between this whole argument and "here's a catalogue of tens of thousands of human and ancestral remains illustrating every step of the transition between our common ancestor with chimpanzees and modern homo sapiens, corroborated with chromosomal and mitochondrial DNA research" But I am a squishy science person at heart.

On second thought, maybe I actually will go to the effort of writing up the full, numerically accurate, derivation. It will be interesting to see if I can get the formulas right without looking them up first. I think the only factors I will actually have to add are length contraction and time dilation. There are a lot of more complicated things I still won't be addressing, but they all involve things like non-parallel motion, acceleration, and rotation, which I deliberately set up the example to not have.

I'm not doing it right now, but maybe in the next week or so.

[Lord Torath]

I think one of the things that makes Relativity and Causality really hard to understand is the concept of "Now". I have a "Now", and it's pretty darn close to your "Now", because our reference frames are pretty darn close to each other (even if we're on opposite sides of the planet). It's easy to imagine that everyone, regardless of reference frame, can have a simultaneous "Now", even if time is flowing past each of us at a different rate. It's very hard to accept that something that happened just before my "Now" hasn't yet happened in someone else's "Now". You'd think that if we had FTL communications, we could all synchronize our watches at a T₀ and agree that "Now" is "Now", even if our watches would disagree with each other almost instantly. We live so far from visible effects of Relativity* in our daily lives, that its stranger effects are very hard to understand.

* Or at least situations where Relativity differs noticeably from Newton's Laws

[Max_Killjoy]

I think one of the things that makes Relativity and Causality really hard to understand is the concept of "Now". I have a "Now", and it's pretty darn close to your "Now", because our reference frames are pretty darn close to each other (even if we're on opposite sides of the planet). It's easy to imagine that everyone, regardless of reference frame, can have a simultaneous "Now", even if time is flowing past each of us at a different rate. It's very hard to accept that something that happened just before my "Now" hasn't yet happened in someone else's "Now". You'd think that if we had FTL communications, we could all synchronize our watches at a T₀ and agree that "Now" is "Now", even if our watches would disagree with each other almost instantly. We live so far from visible effects of Relativity* in our daily lives, that its stranger effects are very hard to understand.

* Or at least situations where Relativity differs noticeably from Newton's Laws

With apologies to the serious subject... I couldn't resist.

[Gray Mage]

Minutephysics is beggining a series on special relativity. They usually are very good at explaining physics concepts in an accessible manner, so I think it'll be worth to keep tabs on it.

[Bohandas]

A discussion in the Roleplaying forum got into FTL travel/communications and how it violates causality. Those of you who are experts in this field, can you explain how something like this could happen by allowing FTL communications?

For example, Person A sees Saceship B explode Planet C, then transmits this information instantaneously to Spaceship D traveling at Speed Ec, enabling someone on the spaceship to prevent the exploding. Assuming the light from the shooting reaches Person A before it reaches Spaceship D, of course.

Under some formulations it may not be possible even with ftl and/or wormholes. Physicist Igor Novikov postulated that self contradictory timelines would necessarily cancel thems3lves out

[Bohandas]

Yeah, that's how warp/alcubierre drives are supposed to work. But the distortion in those cases isn't generated by gravity, but some thing on the vessel, so the idea is that by riding the wave the vessel can shove its own distortion faster than C because of the compression of space in front and expansion behind it. The wave propogates from the ship at C, but we're cheating because the whole frame of reference is already moving faster than that.

Does anyone else find it ironic that the only sci-fi program that actually gets this right is wacky old Futurama?

Edit:
and I guess also Dune, sort of

[Anymage]

Alcubierre's original idea, like many conceptual leaps, came from trying to find realistically doable versions of things that happened on Star Trek. (I remember hearing that one of Google's long term plans was to build up to something that's literally Trek's computer.)

Futurama getting it right wasn't coincidence, though. The showwriters are a bunch of geeks, and Alcubierre came out with his idea well before the show came out. It's a reference, not a prediction.

[Knaight]

You understand why this is fundamentally unconvincing, right? Your position might be the right one, but if nobody can demonstrate it to something without a minimum of a BS in physics then it is no surprise that people are not convinced. I gave those other links a try, I think you did a better job of it than they did(although being able to directly ask you questions is a big bias there). Eventually, this just turns into argument from authority or "trust me", which are unreasonable for a person to accept.

It's not unreasonable to treat the scientific consensus as your personal null hypothesis, and rejecting a theory just because you can't personally understand it is a terrible epistemological practice.

In contrast, evolution requires no math in order to explain it and unless you've basically never been outside you already know everything needed in order to understand it other than heredity. There are satisfying answers to every question and speak directly to human experience.

Theoretical evolutionary genetics is an absolutely brutal field in terms of required math, and it's basically required to explain why genetic diversity doesn't display regression to the mean, which would be a death knell for evolutionary theory. On top of that any understanding that isn't total garbage requires being able to think of population level statistical distributions, which usually means either doing the math and trusting it or being able to intuitively think in graphs (which I'm given to understand is rare, weirdly enough).

[exelsisxax]

It's not unreasonable to treat the scientific consensus as your personal null hypothesis, and rejecting a theory just because you can't personally understand it is a terrible epistemological practice.

It is the only reasonable position to have in this case. If you cannot understand X, you cannot know X. You may be convinced that it is the most reliable model yet produced, but if you don't know what an elephant is you cannot be reasonable in claiming that you see one. They are two different things.

Theoretical evolutionary genetics is an absolutely brutal field in terms of required math, and it's basically required to explain why genetic diversity doesn't display regression to the mean, which would be a death knell for evolutionary theory. On top of that any understanding that isn't total garbage requires being able to think of population level statistical distributions, which usually means either doing the math and trusting it or being able to intuitively think in graphs (which I'm given to understand is rare, weirdly enough).

And a 4-body gravitational system also fights back in trying to solve it. That doesn't make it difficult to explain that gravity is a mutual force between two objects and not a vacuum emitted from one mass. You are confusing the forest for the trees.

Just as you don't need to understand how to correct clocks for gravity-induced time dilation to understand that gravity is a thing, you don't need to understand protein synthesis to be able to understand evolution. You don't need to know every facet of a thing to know how it works in general.

Also, what do you mean it's hard to explain why genetic diversity doesn't mean-regress? It's extremely easy to explain the general reasons: mutations constantly arise, and selection is independent of the mean. That's a pretty low bar.

And even if both of those were not the case, evolution would still be able to explain everything. You'd just have much less explaining to do. I don't know where you're getting the death knell idea from.

[Knaight]

Also, what do you mean it's hard to explain why genetic diversity doesn't mean-regress? It's extremely easy to explain the general reasons: mutations constantly arise, and selection is independent of the mean. That's a pretty low bar.

And even if both of those were not the case, evolution would still be able to explain everything. You'd just have much less explaining to do. I don't know where you're getting the death knell idea from.

Those aren't the general reasons - absent any mutation at all the existence of replicated distinct genes will maintain genetic variability in a population instead of the gradual move towards an average. It's Mendelian segregation, not mutation, and it can be a bit mathy.

As for where I'm getting the idea that it would be the death knell if that weren't the case, that would be every theoretical evolutionary genetics textbook I've ever read. The discovery of genes by Mendel nicely solved a prior criticism of evolution regarding its behavior under simpler phenotype merging with mutations assumptions, and this is usually covered shortly after the introduction.

The minimum knowledge here is thus a decent understanding of basic genetics and enough math to be able to follow a variety of cases involving generational tracking of populations under different conditions, which involves being fairly decent at discrete math once you start dropping simplifying assumptions.

It's similar to relativity here - neither subject can be really understood without digging into the math a bit, and if you don't understand the math you probably shouldn't be trying to argue that it's all nonsense (if you do understand the math you still shouldn't, but it's at least somewhat less grating).

[exelsisxax]

Those aren't the general reasons - absent any mutation at all the existence of replicated distinct genes will maintain genetic variability in a population instead of the gradual move towards an average. It's Mendelian segregation, not mutation, and it can be a bit mathy.

As for where I'm getting the idea that it would be the death knell if that weren't the case, that would be every theoretical evolutionary genetics textbook I've ever read. The discovery of genes by Mendel nicely solved a prior criticism of evolution regarding its behavior under simpler phenotype merging with mutations assumptions, and this is usually covered shortly after the introduction.

The minimum knowledge here is thus a decent understanding of basic genetics and enough math to be able to follow a variety of cases involving generational tracking of populations under different conditions, which involves being fairly decent at discrete math once you start dropping simplifying assumptions.

It's similar to relativity here - neither subject can be really understood without digging into the math a bit, and if you don't understand the math you probably shouldn't be trying to argue that it's all nonsense (if you do understand the math you still shouldn't, but it's at least somewhat less grating).

Absent distinct genes, mutations and natural selection still guarantee diversity in a population. Without them, every population will eventually homogenize into a flat gene pool governed by drift. Segregation doesn't matter to that problem. I feel like you are not using genetic diversity correctly. It's like you are referring to the literal existence of discrete genetic components.

In any case, that isn't a death knell at all. Get better textbooks. There isn't a list of thing that must be true for evolution to occur beyond the existence of self-replicators, there's a list of things that need to be true for it to NOT occur and most of them are impossibilities. The models we currently use would be useless, but evolutionary theory would not be shaken.

Again, you don't need to understand everything about a thing to understand basics. You can know about cells before being introduced to protein synthesis.

I've never said the math was nonsense(I have yet to be presented with any to examine). I've said the argument from authority is fallacious nonsense.

[Grey_Wolf_c]

I've never said the math was nonsense(I have yet to be presented with any to examine).

You have been presented with the math multiple times since thread start (here, for example). You rejected it out of hand. But it was presented to you. Pretending it wasn't presented is quite dishonest.

GW

[exelsisxax]

You have been presented with the math multiple times since thread start (here, for example). You rejected it out of hand. But it was presented to you. Pretending it wasn't presented is quite dishonest.

GW

That post contains no mathematical proof or demonstration on any level. It uses mathematical concepts as illustrative device. They are different things. Again, those concepts are not nonsense, just the lack of demonstration of the conclusion.