Just to revisit, for the sake of illustration of my earlier point, the Alcubierre drive which assumes negative mass. When we assume negative mass we're violating general relativity.
Alcubierre drive enthusiasts claim they're just adding this 'one' little assumption (i.e. negative mass) but by doing so they happen to violate energy conditions in general relativity which predict extremely successfully observations across the universe. Even the Casimir effect, which was thought to violate certain energy conditions, can satisfy an appropriately defined energy condition (i.e. averaged null energy condition).
In other words, conveniently 'tweaking' a highly successful general theory of physics to satisfy an alien spacecraft hypothesis in order to explain a modest set of low quality UAP data is bad science at best, pure science fiction pretending as science at worst.
Whilst general relativity surely has its limitations, to seriously even entertain an alternative theory without energy conditions, this alternative must be able not only to predict negative mass observations which do not comfortably satisfy relativity, but to also account for all the observations which relativity predicts with amazing accuracy across the universe. For an alien hypothesis for a particular fuzzy video blob to be seriously considered as a scientific one, it must take on the formidable burden to prove an alternative general theory to Einstein's relativity which is more successful in its predictions. Now that's quite a tall order.
Until such a serious well-formulated scientific theory, all talk of negative mass is science fiction rather than science. Which is fun. As long a we don't put too much stock on it.
<< Every scientific discovery has always added limits to what can possibly be done >>
This is a remarkable statement and I dare say, if I may, that no scientist would make such a statement.
2 counter-examples :
1) Before the discovery of Hubble's law and the discovery of galaxies, the bound of known universe was significantly smaller. Science helped expand that horizon to a current observable universe to 93 billion light years (yes it is expanding horizons and not what can be done)
2) Superconductivity - electrical resistance drops to zero below a certain critical value
Is this a counter-rebuttal? A generic and totally unsubtsantiated appeal to authority and two more examples of the same stuff you're going on and on to list, misguidedly thinking it can support your thesis when in fact it just does the opposite?
- The discovery of Hubble's law has made (intergalactic) distances even more difficult to navigate that they were before. My thesis scores a point (again), yours scores zero (again).
- Superconductivity: it expanded what can be done in practice (and a good deal) without adding any new theoretical limits, but notice it did not remove any also (there was no phyiscal law saying 'resistance is always greater than zero', go figure, resistance can even be negative). My thesis scores zero point (woops!), but your thesis scores zero as well (again).
But just to steel-man my argument, I'll reword it as such:
Every scientific discovery has always added theoretical limits to what can possibly be done (*) (**), there's no reason to expect anything different for future discoveries. More discoveries = even more limits, most probably.
(*) while at the same time has expanded what can actually be done
(**) Or (to be picky), at best it did not add any new limit nor removed a previous one.
Now, please, refrain from posting yet more boring 'examples' 'supposedly' supporting your thesis. It's getting annoying (I'm tempted to cry "Gish gallop" at this point).
Is this a counter-rebuttal? A generic and totally unsubtsantiated appeal to authority and two more examples of the same stuff you're going on and on to list, misguidedly thinking it can support your thesis when in fact it just does the opposite?
- The discovery of Hubble's law has made (intergalactic) distances even more difficult to navigate that they were before. My thesis scores a point (again), yours scores zero (again).
- Superconductivity: it expanded what can be done in practice (and a good deal) without adding any new theoretical limits, but notice it did not remove any also (there was no phyiscal law saying 'resistance is always greater than zero', go figure, resistance can even be negative). My thesis scores zero point (woops!), but your thesis scores zero as well (again).
But just to steel-man my argument, I'll reword it as such:
Every scientific discovery has always added theoretical limits to what can possibly be done (*) (**), there's no reason to expect anything different for future discoveries. More discoveries = even more limits, most probably.
(*) while at the same time has expanded what can actually be done
(**) Or (to be picky), at best it did not add any new limit nor removed a previous one.
Now, please, refrain from posting yet more boring 'examples' 'supposedly' supporting your thesis. It's getting annoying (I'm tempted to cry "Gish gallop" at this point).
- Superconductivity : does it limit or expand what is possible?
- theory and application of aerodynamic lift : does it limit or make manned flight possible?
- theory of germs and bacteria and viruses : does it limit us or make diseases more diagnosable and treatable?
Theoretically they all limit the catalogue of logical possibilities. You're conflating what's logically possible with what's technologically possible which are separate discussions.
Like I said, theoretically every new piece of knowledge about reality renders its alternative claims untrue and hence rules them out (i.e. adds limits to possibilities) from the realm of knowables.
Superconductivity, aerodynamic lift and microbiological organisms limit theoretical possibilities of physical entities to such that must be consistent with the existence of the foregoing as well as with the laws of physics that impact the properties and behaviours of the foregoing.
Agree that the Sun and its properties have been observed for long
We also have to agree that the sources of the sun's energy (gravitational collapse, stellar nucleosynthesis) was not known till the 1920s onwards - obviously, as atomic theory of elements had to be invented before that (and electrons, protons and neutrons had to be discovered before that)
Hence, new physics had to be discovered to explain the sun's energy source
New physics such as quantum mechanics, orbital theory, fusion, nuclear forces etc
All backed by hard experimental evidence - no speculation and no science fiction
These marked a significant departure from what was known earlier and paved the way for modern cosmology including the big bang and understanding of the early universe (which again was verified empirically by experimental observation such as cosmic microwave bavkgroujd radiation - homogenous and isotropic
Hence, it is expected that new physics would also be discovered 100, 200 or 500 years from now
That's not expected at all, because we simply cannot say. Logistic curves look temptingly like exponential curves when you're only half way up. And some researchers have implied that perhaps we're already more than half way up, and we've started to level off. For example, it has been said that the scientific advances we've been making in the last few decades have been less impactful than in the half-century before that. E.g.:
Papers and patents are becoming less disruptive over time
Michael Park ORCID: orcid.org/0000-0001-8373-54801, Erin Leahey2 & Russell J. Funk ORCID: orcid.org/0000-0001-6670-49811
Nature volume 613, pages 138–144 (2023)
Theories of scientific and technological change view discovery and invention as endogenous processes1,2, wherein previous accumulated knowledge enables future progress by allowing researchers to, in Newton’s words, ‘stand on the shoulders of giants’3,4,5,6,7. Recent decades have witnessed exponential growth in the volume of new scientific and technological knowledge, thereby creating conditions that should be ripe for major advances8,9. Yet contrary to this view, studies suggest that progress is slowing in several major fields10,11. Here, we analyse these claims at scale across six decades, using data on 45 million papers and 3.9 million patents from six large-scale datasets, together with a new quantitative metric—the CD index12—that characterizes how papers and patents change networks of citations in science and technology. We find that papers and patents are increasingly less likely to break with the past in ways that push science and technology in new directions. This pattern holds universally across fields and is robust across multiple different citation- and text-based metrics1,13,14,15,16,17. Subsequently, we link this decline in disruptiveness to a narrowing in the use of previous knowledge, allowing us to reconcile the patterns we observe with the ‘shoulders of giants’ view. We find that the observed declines are unlikely to be driven by changes in the quality of published science, citation practices or field-specific factors. Overall, our results suggest that slowing rates of disruption may reflect a fundamental shift in the nature of science and technology.
Other scientists have questioned their analysis, but one particularly critical counter to it, Macher et al., Research Policy 52 (2024) /Is there a secular decline in disruptive patents? Correcting for measurement bias/ found a methodological error, redrew the curves, and concluded the opposite. However, it's possible to interpret the new graphs as still showing a decline. The debate still continues - there's plenty of opportunity to publish papers on this subject!
Of course, a truly disruptive advance might exist that could kickstart a whole new run of innovative research and technology, but there's no reason for one to exist. There were far better reasons for the previous advances we made to exist, as there were glaring inexplainables staring us right in the face. Giving us sunburn. We didn't know that the sun was mostly hydrogen until Cecilia Payne proposed that in 1925, and due to the state of science at the time, we still didn't know it after she'd discovered it, we had to wait for a man to discover it:
Payne was able to accurately relate the spectral classes of stars to their actual temperatures by applying Indian physicist Meghnad Saha's ionization theory. She showed that the great variation in stellar absorption lines was due to differing amounts of ionization at different temperatures, not to different amounts of elements. She found that silicon, carbon, and other common metals seen in the Sun's spectrum were present in about the same relative amounts as on Earth, in agreement with the accepted belief of the time, which held that the stars had approximately the same elemental composition as the Earth. However, she found that helium and particularly hydrogen were vastly more abundant (for hydrogen, by a factor of about one million).[13] Her thesis concluded that hydrogen was the overwhelming constituent of stars, making it the most abundant element in the Universe.[14]
However, when Payne's dissertation was reviewed, astronomer Henry Norris Russell, who stood by the theories of American physicist Henry Rowland, dissuaded her from concluding that the composition of the Sun was predominantly hydrogen because it would contradict the scientific consensus of the time that the elemental composition of the Sun and the Earth were similar.[15] In 1914, he had written in an academic article:
The agreement of the solar and terrestrial lists is such as to confirm very strongly Rowland's opinion that, if the Earth's crust should be raised to the temperature of the Sun's atmosphere, it would give a very similar absorption spectrum. The spectra of the Sun and other stars were similar, so it appeared that the relative abundance of elements in the universe was like that in Earth's crust.[16]
Payne consequently described her results as "spurious".[12]: 186 [14] A few years later, astronomer Otto Struve described her work as "the most brilliant PhD thesis ever written in astronomy".[17] Russell also realized she was correct when he derived the same results by different means. In 1929, he published his findings in a paper that briefly acknowledged Payne's earlier work and discovery, including the mention that "[t]he most important previous determination of the abundance of the elements by astrophysical means is that by Miss Payne [...]".[18] Nevertheless, he was generally credited for the conclusions she had reached four years prior.[19][20][21]
It seems absurd now that something that behaves in such an un-earthlike way as the sun was considered as just a very hot very large earth. We already knew it was highly energetic and active - flinging out vast plumes of helium, whose spectral lines do stand out against the background black body spectrum. What made the very large earth so very hot? We knew from the gas giants that mere size is not enough to prevent you cooling down over countless millennia[*]. The prevailing theories, containing no endogenous heat generation, were thoroughly inadequate to explain what we saw every day. We knew there was a gap to fill.
What's our current gap?
- The muon's anomalous g-2, aμ = 0.00116592059(22) is 5.1 sigma from standard model predictions? What kind of solution to that enigma would be a source of energy or propulsion?
- dark matter and sterile neutrinos don't fit in the standard ? How would fitting them in enable us to store or harness the energy they posess - the whole point of them is that they don't interact with us except gravitationally.
- our positive vacuum energy might be only a local minimum, so potentially there's zero point energy available? No, as such a drop would trip the rest of the universe into the lower energy state at the speed of light; it's not harnessable at all, it's basically the end of the universe as we know it.
- name your gap, I'll see if I can address it. (Unless it's "what if particles with property X exist?", because those aren't gaps that need explaining, that's just science fiction you wish to be true.)
None of the gaps we currently have - and there are of course hundreds of them - point to being able to solve the real world problems that would be needed to make interstellar travel practical, or even useful.
[* Pointless linguistic aside: I so wanted to use the word "billennia", but it's more cute than meaningful; it's not actually following a sensible pattern, if anything, it's breaking one.]
Theoretically they all limit the catalogue of logical possibilities. You're conflating what's logically possible with what's technologically possible which are separate discussions.
Like I said, theoretically every new piece of knowledge about reality renders its alternative claims untrue and hence rules them out (i.e. adds limits to possibilities) from the realm of knowables.
Superconductivity, aerodynamic lift and microbiological organisms limit theoretical possibilities of physical entities to such that must be consistent with the existence of the foregoing as well as with the laws of physics that impact the properties and behaviours of the foregoing.
That's not expected at all, because we simply cannot say. Logistic curves look temptingly like exponential curves when you're only half way up. And some researchers have implied that perhaps we're already more than half way up, and we've started to level off. For example, it has been said that the scientific advances we've been making in the last few decades have been less impactful than in the half-century before that. E.g.:
Papers and patents are becoming less disruptive over time
Michael Park ORCID: orcid.org/0000-0001-8373-54801, Erin Leahey2 & Russell J. Funk ORCID: orcid.org/0000-0001-6670-49811
Nature volume 613, pages 138–144 (2023)
Theories of scientific and technological change view discovery and invention as endogenous processes1,2, wherein previous accumulated knowledge enables future progress by allowing researchers to, in Newton’s words, ‘stand on the shoulders of giants’3,4,5,6,7. Recent decades have witnessed exponential growth in the volume of new scientific and technological knowledge, thereby creating conditions that should be ripe for major advances8,9. Yet contrary to this view, studies suggest that progress is slowing in several major fields10,11. Here, we analyse these claims at scale across six decades, using data on 45 million papers and 3.9 million patents from six large-scale datasets, together with a new quantitative metric—the CD index12—that characterizes how papers and patents change networks of citations in science and technology. We find that papers and patents are increasingly less likely to break with the past in ways that push science and technology in new directions. This pattern holds universally across fields and is robust across multiple different citation- and text-based metrics1,13,14,15,16,17. Subsequently, we link this decline in disruptiveness to a narrowing in the use of previous knowledge, allowing us to reconcile the patterns we observe with the ‘shoulders of giants’ view. We find that the observed declines are unlikely to be driven by changes in the quality of published science, citation practices or field-specific factors. Overall, our results suggest that slowing rates of disruption may reflect a fundamental shift in the nature of science and technology.
Other scientists have questioned their analysis, but one particularly critical counter to it, Macher et al., Research Policy 52 (2024) /Is there a secular decline in disruptive patents? Correcting for measurement bias/ found a methodological error, redrew the curves, and concluded the opposite. However, it's possible to interpret the new graphs as still showing a decline. The debate still continues - there's plenty of opportunity to publish papers on this subject!
Of course, a truly disruptive advance might exist that could kickstart a whole new run of innovative research and technology, but there's no reason for one to exist. There were far better reasons for the previous advances we made to exist, as there were glaring inexplainables staring us right in the face. Giving us sunburn. We didn't know that the sun was mostly hydrogen until Cecilia Payne proposed that in 1925, and due to the state of science at the time, we still didn't know it after she'd discovered it, we had to wait for a man to discover it:
Payne was able to accurately relate the spectral classes of stars to their actual temperatures by applying Indian physicist Meghnad Saha's ionization theory. She showed that the great variation in stellar absorption lines was due to differing amounts of ionization at different temperatures, not to different amounts of elements. She found that silicon, carbon, and other common metals seen in the Sun's spectrum were present in about the same relative amounts as on Earth, in agreement with the accepted belief of the time, which held that the stars had approximately the same elemental composition as the Earth. However, she found that helium and particularly hydrogen were vastly more abundant (for hydrogen, by a factor of about one million).[13] Her thesis concluded that hydrogen was the overwhelming constituent of stars, making it the most abundant element in the Universe.[14]
However, when Payne's dissertation was reviewed, astronomer Henry Norris Russell, who stood by the theories of American physicist Henry Rowland, dissuaded her from concluding that the composition of the Sun was predominantly hydrogen because it would contradict the scientific consensus of the time that the elemental composition of the Sun and the Earth were similar.[15] In 1914, he had written in an academic article:
The agreement of the solar and terrestrial lists is such as to confirm very strongly Rowland's opinion that, if the Earth's crust should be raised to the temperature of the Sun's atmosphere, it would give a very similar absorption spectrum. The spectra of the Sun and other stars were similar, so it appeared that the relative abundance of elements in the universe was like that in Earth's crust.[16]
Payne consequently described her results as "spurious".[12]: 186 [14] A few years later, astronomer Otto Struve described her work as "the most brilliant PhD thesis ever written in astronomy".[17] Russell also realized she was correct when he derived the same results by different means. In 1929, he published his findings in a paper that briefly acknowledged Payne's earlier work and discovery, including the mention that "[t]he most important previous determination of the abundance of the elements by astrophysical means is that by Miss Payne [...]".[18] Nevertheless, he was generally credited for the conclusions she had reached four years prior.[19][20][21]
It seems absurd now that something that behaves in such an un-earthlike way as the sun was considered as just a very hot very large earth. We already knew it was highly energetic and active - flinging out vast plumes of helium, whose spectral lines do stand out against the background black body spectrum. What made the very large earth so very hot? We knew from the gas giants that mere size is not enough to prevent you cooling down over countless millennia[*]. The prevailing theories, containing no endogenous heat generation, were thoroughly inadequate to explain what we saw every day. We knew there was a gap to fill.
What's our current gap?
- The muon's anomalous g-2, aμ = 0.00116592059(22) is 5.1 sigma from standard model predictions? What kind of solution to that enigma would be a source of energy or propulsion?
- dark matter and sterile neutrinos don't fit in the standard ? How would fitting them in enable us to store or harness the energy they posess - the whole point of them is that they don't interact with us except gravitationally.
- our positive vacuum energy might be only a local minimum, so potentially there's zero point energy available? No, as such a drop would trip the rest of the universe into the lower energy state at the speed of light; it's not harnessable at all, it's basically the end of the universe as we know it.
- name your gap, I'll see if I can address it. (Unless it's "what if particles with property X exist?", because those aren't gaps that need explaining, that's just science fiction you wish to be true.)
None of the gaps we currently have - and there are of course hundreds of them - point to being able to solve the real world problems that would be needed to make interstellar travel practical, or even useful.
[* Pointless linguistic aside: I so wanted to use the word "billennia", but it's more cute than meaningful; it's not actually following a sensible pattern, if anything, it's breaking one.]
Fair point - I have a few areas but the point is that we do not and cannot (strong word) know what we will discover
It may well be, as per your citation, that disruptive innovations are reducing. We definitely havent had the kind of worldview-changing discoveries like Quantum Mechanics or GR in the last few decades.
Then again, the 1st half of the 20th century, at least for physics, was far far beyond what humanity has managed to discover for hundreds of years. So...
A few areas which may or may not yield results :
- investigating (maybe harnessing) the enormous energies around black holes (technological challenges would be daunting as per our current capabilities plus we are very far from black holes so far discovered)
- deeper probe towards identification of fundamental constituents of matter beyond quarks ; discovery of the strong nuclear force gave us fission and fusion, who knows what this may give us in terms of energy output?
- investigating (maybe harnessing) the enormous energies around black holes (technological challenges would be daunting as per our current capabilities plus we are very far from black holes so far discovered)
- deeper probe towards identification of fundamental constituents of matter beyond quarks ; discovery of the strong nuclear force gave us fission and fusion, who knows what this may give us in terms of energy output?
But to freely paraphrase Nima Arkani-Hamed's paradox on the theoretical limits of experimental physics: In order to study the energies around black holes you need to harness the energy-levels of black holes which would have had to be studied before harnessing. A vicious cycle.
Theoretically they all limit the catalogue of logical possibilities. You're conflating what's logically possible with what's technologically possible which are separate discussions.
Like I said, theoretically every new piece of knowledge about reality renders its alternative claims untrue and hence rules them out (i.e. adds limits to possibilities) from the realm of knowables.
Superconductivity, aerodynamic lift and microbiological organisms limit theoretical possibilities of physical entities to such that must be consistent with the existence of the foregoing as well as with the laws of physics that impact the properties and behaviours of the foregoing.
But to freely paraphrase Nima Arkani-Hamed's paradox on the theoretical limits of experimental physics: In order to study the energies around black holes you need to harness the energy-levels of black holes which would have had to be studied before harnessing. A vicious cycle.
Nah. I'm sure you agree that the difficulty of an argument doesn't qualify as grounds for ignoring it.
But let me try and put it more intelligibly:
If some amazing technology is a physical one operating in the physical universe, it must follow laws of physics. Many of those laws of physics we already know as real rather than being unknowns or mere subjective opinions bandied about by stupid humans subject to rebuttal by some new discoveries made by smarter beings.
The false historical narrative of science (gravity as a case in point):
Einstein's gravity of spacetime curvature around matter refuted Newton's gravitational force between bodies of mass. New science uprooted and changed old science, so don't nobody put too much stock in current science.
Facts:
According to Newton's gravitational theory, particles in the universe attract other particles, independent of observers.
According to John Wheeler's famous encapsulation of Einstein's relativity: Spacetime tells matter how to move; matter tells spacetime how to curve.
This, too, happens independent of human observers and acts as a kind of a law or a force. Matter sort of attracts spacetime to curve around it.
Did Einstein refute and rebut Newton? No. In fact he (1) confirmed there's a kind of an attractive force in the universe we can call gravity but which is more accurately and universally describable with a tensor equation involving four physical dimensions, and (2) preserved Newton's gravitational constant.
The new successful theory was built on the successful foundations of the old whilst throwing out the unnecessary generalizations. Science evolved. And the story continues in the same manner.
The false historical narrative of science (gravity as a case in point):
Einstein's gravity of spacetime curvature around matter refuted Newton's gravitational force between bodies of mass. New science uprooted and changed old science, so don't nobody put too much stock in current science.
Facts:
According to Newton's gravitational theory, particles in the universe attract other particles, independent of observers.
According to John Wheeler's famous encapsulation of Einstein's relativity: Spacetime tells matter how to move; matter tells spacetime how to curve.
This, too, happens independent of human observers and acts as a kind of a law or a force. Matter sort of attracts spacetime to curve around it.
Did Einstein refute and rebut Newton? No. In fact he (1) confirmed there's a kind of an attractive force in the universe we can call gravity but which is more accurately and universally describable with a tensor equation involving four physical dimensions, and (2) preserved Newton's gravitational constant.
The new successful theory was built on the successful foundations of the old whilst throwing out the unnecessary generalizations. Science evolved. And the story continues in the same manner.
Definitely some theories complete and extend theories that precede it - so that the previous theory becomes a special case of the new theory (GR and Newtonian gravity)
This often happens, but not always
There are theories which demonstrate that the existing theory was incorrect and replaces it altogether.
Case in point - asteroid impact theory of dinosaur extinction
As always, evidence decides which theory is correct
We have to consider the potential difficulties involved in interstellar travel based on what we know now, not what we might know in the future.
Our future knowledge might make practical interstellar travel seem even more difficult than it currently appears.
If we base our assessments of what is possible on the assumption that there are no real physical constants that can't be overcome or altered with sufficiently advanced technology- that "physical constant" is merely a label we apply to entities that aren't understood/ manipulable yet- then literally anything can be possible.
Claims about what science might achieve in the future become unfalsifiable.
Definitely some theories complete and extend theories that precede it - so that the previous theory becomes a special case of the new theory (GR and Newtonian gravity)
This often happens, but not always
There are theories which demonstrate that the existing theory was incorrect and replaces it altogether.
Not 'altogether' if the existing theory had proved scientifically successful by yielding great predictions and useful technologies (e.g. Newton's gravitational theory).
A scientific theory refuting a purely speculative or faith-based one (your asteroid impact example) that's been widely believed is not a counter-example nor does it demonstrate evolution of successfulscientific theories from more basic towards more advanced.
To repeat myself: "The new successful theory was built on the successful foundations of the old whilst throwing out the unnecessary generalizations. Science evolved."
The point we're debating here is whether existing successful theories are going to be proven altogether wrong by some amazing new discoveries or theories. The history of science says: No.
Not 'altogether' if the existing theory had proved scientifically successful by yielding great predictions and useful technologies (e.g. Newton's gravitational theory).
A scientific theory refuting a purely speculative or faith-based one (your asteroid impact example) that's been widely believed is not a counter-example nor does it demonstrate evolution of successfulscientific theories from more basic towards more advanced.
To repeat myself: "The new successful theory was built on the successful foundations of the old whilst throwing out the unnecessary generalizations. Science evolved."
The point we're debating here is whether existing successful theories are going to be proven altogether wrong by some amazing new discoveries or theories. The history of science says: No.
The asteroid impact theory has been broadly accepted against the theory of volcanism ( in the Deccan Traps). It is neither faith-based nor speculative. There is evidence for both theories, probably broad scientific consensus favours the asteroid impact theory as of now.
Another live example is the possible causes ofnthe Younger Dryas Impact hypothesis (occurred c. 12800 years ago). One group (Firestone, Powell etc) believes that a large comet or asteroid broke up over parts of N America or impacted the Laurentide ice sheet leading to large scale extinction of megafauna, extinction ofnthe Clovis culture and global climate impact. There is some evidence for this theory.
The other group (Mark Boslough etc) believe that it is related to changes in oceanic circulation and possibly overhunting of megafauna. There is some evidence for this as well.
As of today, it is a significant scientific debate.
Another recent example is the debate between the steady-state universe theory (Fred Hoyle and Chandra Wickremasinghe) vs the expansing universe theory (de Sitter etc) which was definitively settled by the evidence of galaxies receding from us and the discovery of Hubble's law (simplifying here)
There are plenty of such examples
The asteroid impact theory has been broadly accepted against the theory of volcanism ( in the Deccan Traps). It is neither faith-based nor speculative. There is evidence for both theories, probably broad scientific consensus favours the asteroid impact theory as of now.
Another live example is the possible causes ofnthe Younger Dryas Impact hypothesis (occurred c. 12800 years ago). One group (Firestone, Powell etc) believes that a large comet or asteroid broke up over parts of N America or impacted the Laurentide ice sheet leading to large scale extinction of megafauna, extinction ofnthe Clovis culture and global climate impact. There is some evidence for this theory.
The other group (Mark Boslough etc) believe that it is related to changes in oceanic circulation and possibly overhunting of megafauna. There is some evidence for this as well.
As of today, it is a significant scientific debate.
Another recent example is the debate between the steady-state universe theory (Fred Hoyle and Chandra Wickremasinghe) vs the expansing universe theory (de Sitter etc) which was definitively settled by the evidence of galaxies receding from us and the discovery of Hubble's law (simplifying here)
There are plenty of such examples
None of these are counter-examples of successful theories (as defined earlier) being entirely replaced. Just more speculative hypotheses being replaced by others that are more consistent with facts.
Comparing them to Newton and Einstein is a false equivalence, nor do they refute the main contention about the evolution of successful theories that was made.
Also, broader scientific theories (say GR) and specific hypotheses (say, what killed the dinosaurs) are not epistemically equivalent scientific pursuits.
None of these are counter-examples of successful theories (as defined earlier) being entirely replaced. Just more speculative hypotheses being replaced by others that are more consistent with facts.
Comparing them to Newton and Einstein is a false equivalence, nor do they refute the main contention about the evolution of successful theories that was made.
Also, broader scientific theories (say GR) and specific hypotheses (say, what killed the dinosaurs) are not epistemically equivalent scientific pursuits.
Steady State universe , Volcanism and YDIH impact competing hypotheses are hypotheses all right, but not speculative by any stretch of the imagination.
Steady State universe , Volcanism and YDIH impact competing hypotheses are hypotheses all right, but not speculative by any stretch of the imagination.
Yes they are in the sense of not yielding great predictions whilst theories like Newton's gravitational theory did. You're arguing past the point and hence we fail to make progress. Nobody's arguing there are no theories in science that have failed. There are no successful theories that have altogether failed.
Yes they are in the sense of not yielding great predictions whilst theories like Newton's gravitational theory did. You're arguing past the point and hence we fail to make progress. Nobody's arguing there are no theories in science that have failed. There are no successful theories that have altogether failed.
If I may (at the risk of bias), restate the argument being made by some on this forum
1) Interstellar travel is hard because of constraints of physical laws, biology and state of human technological progress - no argument
2) Fundamental changes ( in how some physical laws operate and impact interstellar travel ) are not likely to occur in the forseeable future. Also, any human technogical progress will inevitably come up against the limitations of kaws such as :
1) Impossibility of superluminal velocity of objects
2) Impact of high acceleration on humans
3) Amount of fuel to be carried for interstellar travel
4) Potential destructive impact of even small dust grains at high fraction-c velocities etc
These are powerful arguments and my (admittedly long) counter argument is that forecasting technological and scientific progress is quite difficult on timescales beyond a few decades as it is contingent on many factors.
1) to 4) may or may not get resolved through our progress as we have solved various challenges so far as a civilization (not all)
Can we say definitely that they wont get solved?
If I may (at the risk of bias), restate the argument being made by some on this forum
1) Interstellar travel is hard because of constraints of physical laws, biology and state of human technological progress - no argument
2) Fundamental changes ( in how some physical laws operate and impact interstellar travel ) are not likely to occur in the forseeable future. Also, any human technogical progress will inevitably come up against the limitations of kaws such as :
1) Impossibility of superluminal velocity of objects
2) Impact of high acceleration on humans
3) Amount of fuel to be carried for interstellar travel
4) Potential destructive impact of even small dust grains at high fraction-c velocities etc
These are powerful arguments and my (admittedly long) counter argument is that forecasting technological and scientific progress is quite difficult on timescales beyond a few decades as it is contingent on many factors.
1) to 4) may or may not get resolved through our progress as we have solved various challenges so far as a civilization (not all)
Can we say definitely that they wont get solved?
Out of your 4 only 2.1 is a physical 'law' which is amply evidenced by all accumulated observations on matter from time immemorial till the present moment using all manner of detectors ranging from low to high tech. The rest (2-4) are technological challenges which, however unlikely they may seem at present to overcome, are not imho in the same neighbourhood of improbability as an object with a mass travelling at superluminal speed. If we know already that only something with zero rest mass can travel at light speed, how is it physically even possible for anything with a mass to travel faster?
But can we say anything in science definitively? You'd be hard pressed to find anyone here who'd say 'yes'.
Nah. I'm sure you agree that the difficulty of an argument doesn't qualify as grounds for ignoring it.
But let me try and put it more intelligibly:
If some amazing technology is a physical one operating in the physical universe, it must follow laws of physics. Many of those laws of physics we already know as real rather than being unknowns or mere subjective opinions bandied about by stupid humans subject to rebuttal by some new discoveries made by smarter beings.
That's a definite improvement, thank you - you even lost me with V1!
One of the problems with quantum mechanics weirding the world (and I'm very much with Feynman on that) is that people extrapolate along all axes of possibility simultaniously, not realising that some of the possibilities exclude each other, often guided by only superficial understanding of heisenberg's uncertainly principle. Worse is the lack of appreciation of how steeply probabilities die away, clinging to a belief that a p=1/googolplex event could be detected, and still be the best explanation of what happened to whatever was doing that detection, despite us bathing in a shower of cosmic rays. One instance of that mistake is to map the microscopic effects that are certainly possible through the macroscopic analogies used to make them understandable to a belief that the same kind of thing can happen in the macroscopic scale, and even worse, a belief that because somthing is mathematically possible, it's controllable or harnessable. That's not how quantum mechanics works - yes, you do have a 1/googolplex chance of tunnelling through that barrier, but that doesn't mean you can teleport through the barrier (I genuinely envisioned that scene from /The Men Who Stare at Goats/ as I typed that, it's quite an enduring image), because if you try, you will fail (1-1/googolplex)*100% of the time. There is no possible appeal to "but what if we could control the probabilities, or control which branch was taken?", because the response to that is quite simple: "in that case, you're no longer doing Quantum Mechanics - you may not use anything we've proved about our theory in order to support your alternative, as they are different incompatible theories". Physics isn't mix and match.
You don't kneed high accelerations to achieve relativistic speeds within a "reasonable" mission time.
If a ship is using 1 g constant acceleration, it will appear to get near the speed of light in about a year, and have travelled about half a light year in distance.
(...) As a rule of thumb, for a constant acceleration at 1 g (Earth gravity), the journey time, as measured on Earth, will be the distance in light years to the destination, plus 1 year. This rule of thumb will give answers that are slightly shorter than the exact calculated answer, but reasonably accurate.
You don't kneed high accelerations to achieve relativistic speeds within a "reasonable" mission time.
If a ship is using 1 g constant acceleration, it will appear to get near the speed of light in about a year, and have travelled about half a light year in distance.
(...) As a rule of thumb, for a constant acceleration at 1 g (Earth gravity), the journey time, as measured on Earth, will be the distance in light years to the destination, plus 1 year. This rule of thumb will give answers that are slightly shorter than the exact calculated answer, but reasonably accurate.
Equally, rapid acceleration to a significant fraction of c also requires enormous amounts of energy, to the point that we don't really have any good ideas about how this might be done.
Equally, rapid acceleration to a significant fraction of c also requires enormous amounts of energy, to the point that we don't really have any good ideas about how this might be done.
This holds for slow acceleration too, even infinitesimally slow . The amount of energy is always enormous, no matter the time it takes to reach the desired speed.
In reference to ET coming to visit, I don't think it's possible in reality. They couldn't live long enough to get here. You really do have to invoke magic in order to justify the view that Aliens are visiting and many people do but then you have the folks that make the case they've been here and they hide in mountains or the oceans. Total hogwash.
In reference to ET coming to visit, I don't think it's possible in reality. They couldn't live long enough to get here. You really do have to invoke magic in order to justify the view that Aliens are visiting and many people do but then you have the folks that make the case they've been here and they hide in mountains or the oceans. Total hogwash.
Specifically, the magic is often the abolition of the conservation of momentum. And thanks to the work of Emmy Noether we know that's inviolable (because if you shifted all the participants in a closed system to one side, the system behaviour wouldn't change apart from it just now being a bit to the side, it's "invariant under translation"). WIth conservation of momentum, you need to send high speed, high energy, particules in our direction in order to decelerate from interstellar speeds down to basically stationary - that requires the release of an enormous amount of energy.
If you don't think about it too deeply, you can create a mothership/drone narrative that attempts to work around this to some extent, but those two craft will never meet up with each other again, it's a one-way mission to each planet they visit, and if you do think about it deeply, the mothership needs to be solar-system-sized (a very fluffy measure, deliberately) because the drone needs to be accelerated by it - along its length - for a very long time, something comparable to the time it took the mothership to speed up in the first place. Those who think too deeply will realise that this workaround is possibly setting up a mass density high enough to create a black hole. Ooops.
However, sometimes the magic is just good old-fashioned woo too, a salad of words with no clear meanings, rather than pretending to address the laws of physics.
However, sometimes the magic is just good old-fashioned woo too, a salad of words with no clear meanings, rather than pretending to address the laws of physics.
Pretending indeed, as well as perpetrating what I'd call the Ufologistic Fallacy, which is related to the idea of advanced technology being indistinguishable from magic:
The Ufologistic Fallacy
Superintelligence implies supernatural powers.
The fallacy essentially makes the following illogical inference: 'If there are beings and civilizations in the universe that are smarter than us, then the laws of physics that we stupid beings think apply to the universe might be completely off the mark.'
The contrary position being: 'Even us stupid humans can know stuff about the universe that would affect every physical entity no matter how smart.'
Voles and bunny wabbits are generally (albeit imperfectly) aware of the ground beneath them and also when the ground suddenly ends at a cliffside, which impels them to stop and turn around. (Sheep and lemmings do occasionally follow their 'leader' to their deaths down a gorge, but that's a slightly different -- social -- phenomenon, which inspired an addictive 1980s computer game 'Lemmings'.)
Stupider beings (yes, I said it) are thereby demonstrably aware of something that seriously affects us smarty pants hoomans too when we aren't airborne.
Voles and bunny wabbits are generally (albeit imperfectly) aware of the ground beneath them and also when the ground suddenly ends at a cliffside, which impels them to stop and turn around. (Sheep and lemmings do occasionally follow their 'leader' to their deaths down a gorge, but that's a slightly different -- social -- phenomenon, which inspired an addictive 1980s computer game 'Lemmings'.)
(Plus Disney intervention, of course, in the lemming case.)
Not quite on the same lines, but close enough to overlap from certain angles, there's an apocryphal tale, probably mangled almost to unrecognisability in my head over the decades, of a physics professor seeing a dog catch a frisbee in the park, and exclaiming "wow, dogs can solve differential equations!". (That exclamation has beceme one of the shortcuts I use in conversation with my g/f when discussing current scientific affairs, it's remarkable how often it's pertinent.)
Absurdists twists are possible, the prof could have exclaimed "wow, that dog's invented time travel, as frisbees won't be invented for another few decades".
(Plus Disney intervention, of course, in the lemming case.)
Not quite on the same lines, but close enough to overlap from certain angles, there's an apocryphal tale, probably mangled almost to unrecognisability in my head over the decades, of a physics professor seeing a dog catch a frisbee in the park, and exclaiming "wow, dogs can solve differential equations!". (That exclamation has beceme one of the shortcuts I use in conversation with my g/f when discussing current scientific affairs, it's remarkable how often it's pertinent.)
Absurdists twists are possible, the prof could have exclaimed "wow, that dog's invented time travel, as frisbees won't be invented for another few decades".
In the same vein, the instinctive grasp of aerodynamics by the albatross, the peregrine falcon or just the common ol' swallow is nothing short of astounding. Even the best hand-glider pros are comparatively amateurs whilst scoring more than a notch or two higher on the IQ test than a gull.
I've never been clear on what another dimension would even BE, but if they were to exist, whatever they are, I would suggest that the conservation of energy would just need to be tweaked to include "within the multiverse of dimensions" as opposed to just within "this" universe.
You'd be on dodgy ground there, as you are now allowing mystery stuff to creep in from other dimensions....effectively from nowhere. Seance mediums are gonna love you. Long lost Auntie Maud can slip in from dimension X, wave a table about, and then slip back again. Auntie Maud is why scientists don't allow inter-dimensional exchange. It is precisely why the many worlds theory does not allow the split off branches to interact again.
You'd be on dodgy ground there, as you are now allowing mystery stuff to creep in from other dimensions....effectively from nowhere. Seance mediums are gonna love you. Long lost Auntie Maud can slip in from dimension X, wave a table about, and then slip back again. Auntie Maud is why scientists don't allow inter-dimensional exchange. It is precisely why the many worlds theory does not allow the split off branches to interact again.
So you sound skeptical about powering an interstellar drive with ghosts, then? Surely the spirits will occupy little space, so all we need to do is generate sufficiently powerful exorcisms. Option 2 would be to use angels, because we'd only need the head of a pin to hold all we need.
On a more serious note, one argument above seems to be that any arriving interstellar visitors would have to be decelerating energetically and in the modern era we'd have at least passively detected a radiation source approaching and arriving in the solar system. For which I guess the believer response would be that the visitors arrived before modern radio astronomy -- the CMB was identified in 1965 -- and/or used a mechanism that decelerates without any emissions.
I'm dubious that you can have any of the proposed hand-wavy, fuel's-no-problem interstellar drives and arrive unnoticed. Though the current "woo" argument on reddit seems to be that something could have arrived at some point and begun synthesizing bodies and vessels in some now-giant undersea facility that also remains undetectable. The proof being on 4chan, much like the girlfriend being in Canada.
It is interesting, when we posit that progress in Science is plateauing, it is self-limiting and is fundamentally incremental in that it is a further tweak on earlier known Science, one should not forget Quantum Mechanics.
QM was/is not incremental at all, marked a significant departure from the deterministic description of the world till that point and moved physics in a completely different direction. And its experimental predictions have been repeatedly verified experimentally over many many years.
Similar step changes in other branches of physics followed - QED, QCD, modern cosmology, elementary particle physics, chaos and complexity to name a few.
Granted that the last 30-40 years or the 20th century and the first 23 years have hardly been that revolutionary as far as fundamental discoveries in physics are concerned.
Lets see what the next 50, 100, 200 years will bring
It is interesting, when we posit that progress in Science is plateauing, it is self-limiting and is fundamentally incremental in that it is a further tweak on earlier known Science, one should not forget Quantum Mechanics.
QM was/is not incremental at all, marked a significant departure from the deterministic description of the world till that point and moved physics in a completely different direction. And its experimental predictions have been repeatedly verified experimentally over many many years.
So what? Quantum mechanics destroyed the idea we can get a perfect knowledge of the behaviour of the universe, which dated back to Leibniz at least: https://www.jstor.org/stable/2022829
Before Quantum Mechanics one could dream of determining 'God's equation' and to be able to make measurements precise enough to determine the future behaviour of the whole Universe, while after Quantum mechanics we can't even say when a single unstable atom will precisely decay [did I already say chaos theory then delivered an even more fundamental blow to Leibniz's dream?]
C'mon, stop putting forth self-defeating arguments, have mercy on yourself, if not on us.
But only if there ARE other dimensions, whatever that means. IF there are, it's not my fault, I didn't create 'em, and I'm not to blame for dodgy stuff creeping in!
I merely proposed a simple tweak of conservation laws to cover an expanded definition of universe(s) IF they are shown to exist and IF stuff can leave one and appear in another.
I'll take all the love I can get, but I can promise you I won't be the one discovering the existence of other dimensions (timelines? universes?) unless they tend to manifest on kite fields, nor am I proposing that any such things exist.
So what? Quantum mechanics destroyed the idea we can get a perfect knowledge of the behaviour of the universe, which dated back to Leibniz at least: https://www.jstor.org/stable/2022829
Before Quantum Mechanics one could dream of determining 'God's equation' and to be able to make measurements precise enough to determine the future behaviour of the whole Universe, while after Quantum mechanics we can't even say when a single unstable atom will precisely decay [did I already say chaos theory then delivered an even more fundamental blow to Leibniz's dream?]
C'mon, stop putting forth self-defeating arguments, have mercy on yourself, if not on us.
"The quality of mercy is not strain'd
It droppeth as the gentle rain from heaven...."
Seriously, all one is saying is that QM was a discontinuous (not incremental) scientific paradigm shift. It's hardly an earth-shaking or controversial statement
Point taken!
