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Finnforest 
Special Collaborator 
Honorary Collaborator Joined: February 03 2007 Location: The Heartland Status: Offline Points: 16913 |
 Posted: August 27 2013 at 19:40 |
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http://www.giantfreakinrobot.com/sci/quantumthruster-physics-key-warp-drives.html
I remain optimistic  Edited by Finnforest - August 27 2013 at 19:41 |
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: August 28 2013 at 14:02 |
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I remain an engineer.
Theoretically feasible does not mean practically realisable. There are more unasked questions regarding the Alcubierre drive than there are unanswered questions, not withstanding the negative energy required to produce it and the stability of unwarped bubble of space that rides this traversing wave of warped space, there are the physiological effects on the travellers.
It is theoretically feasible and practically realisable to produce a roller coaster that hits a terminal velocity of 220mph and exerts 10g on the passengers for 60 seconds, inducing cerebral hypoxia:
 The result is a euphoric death that makes the "Carrousel" of Logan's Run (film version) seem positively pedestrian.
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Finnforest
Special Collaborator
Honorary Collaborator Joined: February 03 2007 Location: The Heartland Status: Offline Points: 16913 |
Posted: August 28 2013 at 14:08 |
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 Would the inertial dampeners not take care of this effect? |
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: August 28 2013 at 14:16 |
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Gerinski
Prog Reviewer 
Joined: February 10 2010 Location: Barcelona Spain Status: Offline Points: 5154 |
Posted: August 30 2013 at 00:19 |
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Atavachron
Special Collaborator
Honorary Collaborator Joined: September 30 2006 Location: Pearland Status: Offline Points: 65152 |
Posted: August 30 2013 at 01:01 |
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Carrousel is a lie.
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: August 30 2013 at 01:18 |
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Gerinski
Prog Reviewer
Joined: February 10 2010 Location: Barcelona Spain Status: Offline Points: 5154 |
Posted: August 30 2013 at 06:01 |
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 Edited by Gerinski - August 30 2013 at 06:01 |
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Gerinski
Prog Reviewer
Joined: February 10 2010 Location: Barcelona Spain Status: Offline Points: 5154 |
Posted: August 30 2013 at 06:13 |
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Whether we will ever be able to master that energy or not and what might be the unforseen side effects of applying space expansion / contraction in smaller scales than those naturally occurring in the universe is of course speculation, but negating the posibility of achieving in the future technological feats which seem impossible today does not seem the expected state of mind from an engineer.
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: August 30 2013 at 06:31 |
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You did.
In order to take baby steps towards telepathy there needs to be a connection to telepathy. The carrier pigeon was not baby steps towards telegraphy. (A considerably more relevant example than Paul Dirac). Asking the person with the TV remote to change the channel is not telepathy, poking someone with a stick to get them to move is not telepathy, throwing rocks at them to trigger a prearranged action is not telepathy, calling someone on Skype and telling them to press the space bar on a computer is not telepathy. Telepathy is the medium (i.e. the conduit) not the message. The only reason the recipient's finger moved was because the TMS coil was carefully placed to directly stimulate the finger reflex, put the coil in a different place and a different response ensues regardless of what the sender is thinking - the sender could have been a poodle for all the difference it makes. It's a parlour trick performed in a lab, and for that it's no different to a Las Vegas magic show except without the scantily-clad showgirls. |
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: August 30 2013 at 06:53 |
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Theoretically feasible does not mean practically realisable. There are more unasked questions regarding the Alcubierre drive than there are unanswered questions, not withstanding the negative energy required to produce it and the stability of unwarped bubble of space that rides this traversing wave of warped space...
So we agree then. 
This is not something that seems impossible today, it is something that is impossible today. When both of these hyperthetical and as yet undiscovered exotic energies are fabricated and contained without annialating each other then the engineering feasibilities can be addressed.
I see no need to insult your professional credentials so I shall not be decending to your level of snarkiness. |
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Gerinski
Prog Reviewer
Joined: February 10 2010 Location: Barcelona Spain Status: Offline Points: 5154 |
Posted: August 30 2013 at 11:00 |
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^it was never the intention to insult, I apologize if it sounded that way. During this thread I have addressed a few times that technologies which are real today seemed impossible some time in the past so that I think that we should be excited and cautiously imaginative whenever science suggests potential paths to progress into new territories. This is my stance and I tend to disagree with people considering many things "impossible even in principle". Of course you are free to take a more conservative stance and that takes nothing away from your professionality as engineer, it just depicts a different stance towards the subject in question.
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: August 30 2013 at 15:18 |
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Technologies which are real today that seemed impossible some time in the past are technological developments not developments of fundamental science. Sure Einstein, Dirac, Schrödinger, Fermi, Heisenberg et al produced the fundamental foundation of semiconductor physics but the integrated circuits that power your computer, cell-phone, GPS, car engine management, washing machine, CFL light bulbs, credit cards, pacemaker, TV, internet connection, cruise missiles, the International Space Station and everything else in the 21st century are the same technology that Geoff Dummer proposed in 1952 and use the same field effect transistor technology that Julius Lilienfield patented in 1925. The cell-phone may have been one of those seemingly impossible things in the past of 1925 but the fundamental science that makes it work was not impossible in 1925 - the fundamental techniques and material sciences that make it all possible (growing crystals, photo-lithography, etching, etc.) are older still. Seeming impossible and being impossible are two different things, just as being theoretically feasible and being practically realisable are two completely different things. Things we cannot do because of the limitations of technology are not the same as things we cannot do because of the limitations of physical laws (ie scientifically impossible). The things that were scientifically impossible in 1925 are still impossible today. None of the seemingly impossible things we have today break the fundamental laws of physics - they don't break the 2nd Law of Thermodynamics, they don't defy Newton's Laws of Motion, or Euler's equations, or Gauss's law, or Boyles law or Ampère's law or Ohm's law. We can make digital watches today but could not make them in 1925 but we didn't change the laws of science to achieve that.
The Alcubierre drive is theoretically possible if we swallow a whole lot of hypothetical "what if" pills. We have yet to prove the existence of the speculatively hypothetical dark energy and that at least has a raison d'être, if it exists then it explains why the expansion of the Universe is accelerating and has been for the past 5 billion years, we have no reason to suspect the existence of anti-dark energy, or even speculate its existence. We don't even need it to speculate why the expansion of the Universe was decelerating prior to that - the gravity of dark matter and normal matter are sufficient for that so we have no reason to invert the sign of the cosmological constant even. To have anti-dark energy we need the negative energy density that negative mass provides, and that is more than just speculative. But even if negative mass were theoretically feasible that does not mean it and the Alcubierre drive will be practically realisable - it may be too difficult or just too dangerous. It is theoretically feasible to have a nuclear powered cell-phone, that does not mean I want one; 80 years ago it seemed like a good idea to paint children's toys using lead-based paint and to use radium to make luminous paint. The wiki entry for the Alcubierre drive lists more reasons why it won't make a practical FTL drive than reasons how it could - eternal optimism probably won't change that a great deal. Being unwilling to down a cocktail of "what if" pills does not make me conservative, it just makes me the bloke that doesn't get excited when someone extrapolates a tiny piece of hypothetical what if into a prediction of the future of space travel. (or a silly lab demonstration as research towards actual telepathy).
There are some fantastic (and fantastical) developments happening right now that are straight out of the pages of science fiction, none of them were ever impossible by my understanding of the word "impossible" - we can construct an inert substrate (extracellular matrices) that real human heart cells can grow on in a glass jar, we are reaching the stage where non-Newtonian liquids and nano-technology may have (at last) practical application, we are producing smart materials and even smarter tech and much of this is surprisingly low tech. There is plenty to get excited about without needing to re-write the laws of physics.
Anyway, I'm a child of the 50s and I'm still waiting on hover-boots and x-ray spectacles.
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Atavachron
Special Collaborator
Honorary Collaborator Joined: September 30 2006 Location: Pearland Status: Offline Points: 65152 |
Posted: August 30 2013 at 22:16 |
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Both horrific accidents waiting to happen, surely-- at least we got hover-boats. As I recall, the "X-ray Specs" advertised in the back of comic books created no more than a fuzzy halo around objects touted as an 'x-ray', and did not reveal any underwear of passing young ladies. Little b*stards. |
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: August 31 2013 at 04:09 |
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Why 8 year old boys would want to see the underwear of passing young ladies is a mystery, but they did. That (if it worked) they would also see the underwear of passing old ladies (and men) just illustrates that 8 year old boys seldom think things through.
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Gerinski
Prog Reviewer
Joined: February 10 2010 Location: Barcelona Spain Status: Offline Points: 5154 |
Posted: August 31 2013 at 04:26 |
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^^^ That current technological applications do not violate the currently known laws of physics is obvious, but our understanding of the laws of physics evolves. Besides, going back to 1925 to asses if anything revolutionary has happened or not is a rather short timespan, the 2 pillars of current science Relativity Theory and Quantum Mechanics were already formulated at least in its basic forms. But many if not most current technologies are based on physical "laws" which were not known in the middle ages so it would have been impossible for people of the time to even wonder if they might violate their "laws of physics" or not.
We are undoubtedly much closer to understanding "actual laws" (assuming that they exist in the way we assume them to be and that we will ever be able to fully comprehend them) but there's nothing saying that the laws as we understand them today are fundamental, on the contrary, we have every reason to suspect that they are limiting case approximations to some deeper laws.
The "laws" of General Relativity seem to imply a fundamental reality of 4-D spacetime and the limit of the speed of light, but for one thing even GR laws allow for the stretching and compressing of spacetime (which in principle can allow for FTL motion such as that confirmed to be ocurring between distant galaxies), and in any case most more recent approaches to quantum gravity theories, loop quantum gravity, spin-foam models, twistor theory, the many different versions of string theories, shape dynamics etc, while still theoretical and speculative, point to pictures where space and time are fundamentally quite different from the picture of GR (while of course they all must reduce to GR 4-D spacetime in limiting cases).
In some of them such as in shape dynamics theory, 3-D space is even not fundamental at all, but just an emerging observable phenomenon arising from the relational connections between the "shapes" of energy configurations in a fundamental time evolving universe. I have no intention to discuss any of this here, but my point is that for example in a theory such as shape dynamics, the "impossibility of FTL motion" suggested by GR is strongly put in question as a fundamental scientific principle, simply because in shape dynamics space is not fundamentally real. All this is not crackpot mambo-jumbo, many respectable scientists are working in these fields.
I am reasonably confident that future scientific and technological developments (not within a couple of decades) will make possible things which as of today we may believe violate the laws of physics as we understand them today. |
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Dean
Special Collaborator
Retired Admin and Amateur Layabout Joined: May 13 2007 Location: Europe Status: Offline Points: 37575 |
Posted: August 31 2013 at 06:22 |
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I dispute that. Semiconductors and semiconductor devices existed before GR and QM, after all it was the study of the photo-electric effect (in semiconductor materials such as selenium) that gave rise to them. The metal-semiconductor junction as a rectifier is a late 19th century discovery that predate GR and QM (selenium rectifiers and cat's whisker detectors) - they didn't know how they worked but they used the technology while science pondered they whys and wherefores - (Walter Schottky finally solved that one in 1938). GR and QM did not result in the invention of semiconductor technology, it merely provides us with the tools (aka Semiconductor Physics) to understand that technology and to do it better. For example the photoelectric effect (as electroluminessence) of a diode junction was known in 1906, use of gallium-arsenide to create red and infra-red light didn't employ any "science" in 1955 - it is only in recent times that we have used the physics of how this light is emitted to fine-tune the technology to emit different colours of light (that said, many modern coloured LEDs emit ultra-violet light and coloured phosphor to produce their coloured light).
For the most of history the science of why and how came after the discovery of an effect or a phenomenon and after that effect or phenomenon had been exploited technologically. Seemingly impossible in the middle ages was a limitation of the available technology, not the science, however, if 100 years is too short a timespan for you, 1,000 years is too long for me.
It is the central tenant of science that laws only valid while they work for all observations and can be superseded by better laws. General and Special Relativity did not replace Newton or Kepler's Laws, it simply refined the boundaries. While it is within the bounds of possibility that a more unified set of laws could render all three as obsolete, it is more likely that it would merely be more refinement of existing understanding. There is no time in the future where Newton's Laws of Motion will not accurately describe and predict the motion of a slow moving satellite orbiting Earth regardless of whatever new "fundamental" laws are devised.
Well. Not really. Stretching of space-time is only superluminal if comoving distance and cosmological time are used to calculate the velocity. Velocity calculated using comoving coordinates does not have any simple relation to velocity calculated locally. In the expanding Universe objects are not moving, that's kinda the point, only the space between them is expanding so you cannot use velocity in the same way as you would in local space or in a car journey to the shops..., if expansion occurred on a local level (which it sort of does but...) then the distance to the shops would be different each day. You said earlier that "distant galaxies recede from each other at superluminal speed", which isn't strictly true if those distant galaxies are in the same locale - they are moving away from us at apparent superluminal speed because they are not in the same relative locale. It only appears superluminal because the distance between us and the distant galaxies is so vast. The expansion of the Universe is uniform through-out the Universe (which is why dark energy, if it exists, is assumed to be homogeneous) - the space between us and a distant galaxy is expanding at the same rate as the space between us and Andromeda (or the Sun, or the Moon, or the village shop) BUT local gravitational attraction is far greater than the force that drives expansion so the neighbourhood sticks together. In the expanding Universe Earth does not get bigger. Wherever we are, and wherever we go, we will be part of that local space-time and thus limited by GR in that location regardless.
I have NEVER said any of this is crackpot mambo-jumbo, nor have I EVER been dismissive or derisory of any of it. What we have to be extremely careful of is cherry-picking the "good bits" out of conflicting and contradicting theories to make an "impossible" thing "possible" - these theoretical models cannot be mixed willy-nilly in the hope that "something wonderful happens".
I do not share your confidence simply because whatever theory "wins" will only describe what is, it will not change the nature of the Universe. Edited by Dean - August 31 2013 at 06:24 |
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Atavachron
Special Collaborator
Honorary Collaborator Joined: September 30 2006 Location: Pearland Status: Offline Points: 65152 |
Posted: August 31 2013 at 18:39 |
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It also illustrates a misunderstanding of X-ray, as the bones of a young lady would be no more appealing than anyone else's. I'll take a switchblade comb any day. |
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The Pessimist
Prog Reviewer
Joined: June 13 2007 Location: United Kingdom Status: Offline Points: 3834 |
Posted: August 31 2013 at 20:26 |
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I was going to say... X-rays pass right through clothes and skin don't they? As well as causing a small amount of radioactive damage to everyone within line of sight of the user, like a sh*ttier version of Cyclops in X Men.Edited by The Pessimist - August 31 2013 at 20:28 |
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"Market value is irrelevant to intrinsic value."
Arnold Schoenberg |
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Gerinski
Prog Reviewer
Joined: February 10 2010 Location: Barcelona Spain Status: Offline Points: 5154 |
Posted: September 01 2013 at 03:15 |
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Dean wrote: