midtskogen wrote:

Source of the post highly relativistic travel?

By highly relativistic, do you mean luminal speeds (99.9% of c), or do you mean superluminal speeds (+c)?

midtskogen wrote:

Source of the post Yes, I realise that for a flat universe in that particular case, but for a network of wormholes it seems impossible to retain unless the configuration of the mouths exactly mirror each other, which would be less useful.  An if the network isn't properly planned from the beginning, there will easily be all kind of bending to bring new mouths together without breaking existing pairs.  It seems very hard to do this and maintain the flat shape, certainly from the paper analogy. 

From the paper analogy it seems obvious that we eventually strike a limit where we cannot add more wormholes wherever we want without stretching, tearing, self-intersecting, or some other violent action that changes the intrinsic geometry of the paper itself.

However, we have made a weak assumption.  Constructing wormholes in paper, we're folding up a 2D manifold in 3 dimensions.  Why only 3?  Well, we live in 3 dimensional space.  But if we allow wormholes to be made in an N dimensional space, and therefore assume there is a higher dimensional bulk, there's no reason to assume the bulk must be only N+1 dimensional.  It might as well be infinite dimensional!  In that case there is no limit to the number of connections we can make, or where we might make them.  And the intrinsic geometry of our manifold would still be unchanged with any number of those connections.  

Of course, if that bulk exists, bulklanders must still think our activities absurd.   

There is probably also no explanation anywhere for how all this extra-dimensional folding would actually work to make the wormholes where we want.  I don't know of anything in our universe that would allow us to manipulate how it is embedded in the bulk.  Gravitational wave measurements suggest that if the bulk even exists, then gravitational waves don't care.  Wild idea: maybe entanglement does.  That's essentially the basis of ER=EPR.

Watsisname wrote:

Source of the post Of course, if that bulk exists, bulklanders must still think our activities absurd.

Yes, there's the other problem with wormholes.  Imagine a call for proposal for a public transport connection between New York and Los Angeles.  Amongst the proposal we might find a regular railroad, maglev, and more fringe ideas like a hyperloop.  And then the lunatic proposal to bend and fold the entire continent so that New York and Los Angeles meet and travel between them can be done by a short elevator trip.

midtskogen wrote:

Source of the post And then the lunatic proposal to bend and fold the entire continent so that New York and Los Angeles meet and travel between them can be done by a short elevator trip.

This seems absurd only because of the analogy.  "Folding up the space" to form wormholes may just as well be trivial.  In ER=EPR for example, the connection is made automatically through entanglement.  The difficulty then isn't in how to fold up space, it's how to maintain entanglement between two large systems as you collapse them into a pair of black holes.

Watsisname wrote:

Source of the post In that case there is no limit to the number of connections we can make, or where we might make them

That seems reasonable.  In the sheet analogy we can easily make one wormhole and retain the flatness of the paper.  Now, if we want to make another wormhole and find it impossible to bend the paper in 3D and preserve the flatness, we instead make a simple flatness preserving 4D bend as we did in 3D.  And we can keep on going.
But, if we have the technology to fold N-dimensional space like this, we are also capable of detecting existing bending, right?  To preserve flatness we must also know how many dimensions it requires.  If we pick insufficient dimensions, flatness will not be preserved and we can notice the changed geometry.  So the detection method involves bending space and see what happens to geometry.  This is of course not very useful if what we wanted to find out in the first place was to know whether such bending could be possible and had been done.

Stellarator wrote:

Source of the post By highly relativistic, do you mean luminal speeds (99.9% of c), or do you mean superluminal speeds (+c)?

Near luminal.  Since time dilation could be countered by time travel.  And then you would effectively travel at superluminal speed.

Watsisname wrote:

Source of the post "Folding up the space" to form wormholes may just as well be trivial.

Well, perhaps in principle yes, but many things may be trivial at one scale and completely ridiculous at another.

Watsisname wrote:

Source of the post The difficulty then isn't in how to fold up space, it's how to maintain entanglement between two large systems as you collapse them into a pair of black holes.

Yes, we shouldn't forget that the old movie trope of the folded paper is an analogy, a good one maybe, but not indicative of reality in an objective sense.

midtskogen wrote:

Source of the post And then you would effectively travel at superluminal speed.

Only to outside observers, to the wormhole travelers their subjective time would pass 'normally' (at a rate of a year passing for every light year traveled). Really only outside observations done by observers far away would conflict with the timelines, and even then they are separated by space.  An outside observer would receive information (presumably by wormhole) that the travelers reached their destination, but if they looked at the destination with, say, a telescope, then they would not observe the travelers.

midtskogen wrote:

Source of the post Well, perhaps in principle yes, but many things may be trivial at one scale and completely ridiculous at another.

Absolutely.  Continuing with ER=EPR example, forming a large enough entangled system to make black holes out of which do not immediately evaporate, or even large enough for tidal effects not to ruin your day, and not ruin the entanglement in the process, seems absolutely ridiculous.  But I don't know that there is any law of physics that forbids it.  If there is, then it seems very non-obvious.  So I think we have worm-holed ourselves back to the idea that it isn't arguments of absurdity or difficulty that allow us to easily dismiss certain situations with wormholes.  It's rather what they would allow us to do if they existed.

Watsisname wrote:

Source of the post So I think we have worm-holed ourselves back to the idea that it isn't arguments of absurdity or difficulty that allow us to easily dismiss certain situations with wormholes. It's rather what they would allow us to do if they existed.

The truth is stranger then fiction. So typical for this amazing universe...

This is not a serious question, and is in the spirit of good fun.

In this sequence of numbers, what comes next: 5,6,3,?

If you can, what are the other numbers in this sequence? Before 5? After 3 and the mystery number?

Watsisname wrote:

midtskogen wrote:

Source of the post Yes, I realise that for a flat universe in that particular case, but for a network of wormholes it seems impossible to retain unless the configuration of the mouths exactly mirror each other, which would be less useful.  An if the network isn't properly planned from the beginning, there will easily be all kind of bending to bring new mouths together without breaking existing pairs.  It seems very hard to do this and maintain the flat shape, certainly from the paper analogy. 

From the paper analogy it seems obvious that we eventually strike a limit where we cannot add more wormholes wherever we want without stretching, tearing, self-intersecting, or some other violent action that changes the intrinsic geometry of the paper itself.

However, we have made a weak assumption.  Constructing wormholes in paper, we're folding up a 2D manifold in 3 dimensions.  Why only 3?  Well, we live in 3 dimensional space.  But if we allow wormholes to be made in an N dimensional space, and therefore assume there is a higher dimensional bulk, there's no reason to assume the bulk must be only N+1 dimensional.  It might as well be infinite dimensional!  In that case there is no limit to the number of connections we can make, or where we might make them.  And the intrinsic geometry of our manifold would still be unchanged with any number of those connections.  

Of course, if that bulk exists, bulklanders must still think our activities absurd.   

There is probably also no explanation anywhere for how all this extra-dimensional folding would actually work to make the wormholes where we want.  I don't know of anything in our universe that would allow us to manipulate how it is embedded in the bulk.  Gravitational wave measurements suggest that if the bulk even exists, then gravitational waves don't care.  Wild idea: maybe entanglement does.  That's essentially the basis of ER=EPR.

If string theory is correct, there can be universes of 4 and 6 dimensions (including time), would "the bulk" include all the dimensions in all the universes, or would it be a completely different layer with its own?
Either way, I like EP=EPR, in a way it provides a road to unifying relativity and quantum mechanics.  Wormholes are the macro version of quantum entanglement.

From what you're saying, if string theory or one of its variants is correct, it makes wormholes (artificial, traversable or otherwise) more likely, and would the existence of exotic matter also make them more likely?

A-L-E-X wrote:

Source of the post Have one of our big mass extinction events also been linked to a gamma ray burst?

That's hard to say. Attributing one cause (or a collection of related causes) to an extinction event in a incomplete geological record is a messy affair and not something we can assert any confidence in, especially the farther back one looks at the fossil record. There are other possible causes for the O-S Extinction, many of which are statistically more likely to occur then the solar-system happening across the path of a relatively rare and directionally focused event like a gamma-ray burst from a nearby hypernova. Certainly some evidence seems to point towards a gamma ray burst effecting Earth, and the results of which could be mixed in and mistaken with other events during that period, as the paper you linked to concluded.

A-L-E-X wrote:

Source of the post As far as the closest star that we know of that may go supernova in the future, that would be Betelgeuse, though the timescale of that happening is uncertain.  How bad would the effects be here if it did?

Given our lack of knowledge regarding the life cycles of supermassive late sequence stars like Betelgeuse and its exact mass and characteristics (despite studies attempting the contrary, many of which have yielded some amazing results - like the star rotating 150 time faster then expected and the fact that it may have eaten a companion solar-mass star) we don't know when Betelgeuse will go nova, but current theories suggest it will between ~500'000 to ~5 million years in the future approximately. Its effects on Earth will be very minor, since it's so far away that the charged particles accelerated unidirectionally will significantly lose their power when they reach our solar-system, and not even ionize our atmosphere. It would be quite a show for us astronomers though. Similar supernova were thought to have exploded no more then ~300 light-years away (half the distance between Sol and Betelgeuse), with no direct harm becoming of Earth's ecosystem during that time.

A-L-E-X wrote:

Source of the post About supervolcano eruptions, is there any connection between them and impact events?

Yes. It is well known that the impact of large asteroids can cause extreme weather patterns directly related to the impact event and in connection to disrupted atmospheric cycles, earthquakes and high volcanism due to crustal disturbances. I had a graph saved somewhere that showed the direct relation between the kilojoules of energy released per asteroid mass compared to the Richter scale of subsequent Earthquakes, but alas I have lost it. Suffice to say that there has been various studies linking the two: https://www.researchgate.net/publication/331282769_The_eruptive_tempo_of_Deccan_volcanism_in_relation_to_the_Cretaceous-Paleogene_boundary

A-L-E-X wrote:

Source of the post Some evidence for periodicity:

https://www.cambridge.org/core/journals ... 284E9CAA3F

https://arxiv.org/abs/1005.4393


https://arxiv.org/abs/1206.1804

https://www.nature.com/articles/nature03339

These are interesting, but as I have said earlier, it is difficult for us to state with scientific certainty that extinctions follow a tempo like this. The holes in the cyclic apocalypse theories include actual holes the geological record, in addition to those periods of Earth's history wherein we find without much doubt due to pristine preservation conditions that the predicted extinction did not occur, such during the Hauterivian stage of the Early Cretaceous ~130 million years ago, 60 million years before the K-T extinction, nor during the Sinemurian stage of the Early Jurassic 60 million years before then.

The fascinating thing is, one clearly single causal event cant be attributed to most of these mass extinction events, even the K-T event may have been accelerated by multiple events, including the Deccan Traps.  If any one of these events had occurred alone maybe it wouldn't have happened.

Getting back to this discussion about "the bulk" is the bulk necessary or can we just have universes nested inside each other without beginning or end (circularly) so that if you go up or down enough levels you'd eventually end up back where you started?

Also could we define mathematical functions to describe the number of dimensions in each layer using formulas like the Pythagorean Theorem and relate the number of dimensions to Pythagorean Triplets?

A-L-E-X wrote:

Source of the post The fascinating thing is, one clearly single causal event cant be attributed to most of these mass extinction events,

Many seemingly casual events can be linked to many seemingly miraculous ones. We fool ourselves into thinking there are patterns where there are none for the sake of satisfying esoteric preconceptions about life in this universe.

A thought while watching a video about quantum entanglement:
If quantum entanglements really exist, that is only possible in my opinion if space is not what we think.
If what we see as space is only an illusion, if what we see as distance does not exist in reality at all.