Posted: Dec 01, 2020 11:50 pm
Of course, one of the reasons science is such hard work, is that the data point refuting a hypothesis may only appear after many years of diligent search, among a sea of other data points that lend support thereto. The transition from Newtonian physics to General Relativity is an educational case in point. For 250 years, scientists were presented, in their experiments, with a veritable tsunami of confirmatory data points upholding the Newtonian world view. Only when through application of that world view, they developed the technology allowing them to observe data points that did not fit the Newtonian world view, was it possible to move on to a better set of postulates.
But of course, there's another reason science is hard work. Finding the contradictory data point is merely the beginning of the hard work. Once that data point is found, the real hard work begins, of devising a hypothesis that not only encompasses the new, contradictory data point, but all of the past data points as well. Which is why Einstein's ideas prevailed, because they not only provided an explanation for the contradictory data points, but for all the other data points that appeared to support Newton's ideas as well.
In addition, Einstein's ideas provided an explanation for why those other data points appeared to support Newton's ideas so well - namely, that Newton's ideas are a very good approximation to General Relativity in the cases of low velocities and weak gravity fields, within which the error is too small to be measurable by the means available to late 19th century physicists. That error only starts appearing when you have the means to measure quantities to 15 decimal places - indeed, doing so is expensive and difficult even today. For example, measuring time dilation at everyday velocities requires atomic clocks with £10 million or more price tags attached, and intricate experimental logistics. Logistics that in some cases involves large aircraft with in-flight refuelling, and the attendant expense.
Finding the contradictory data points that lead to new, better and more illuminating hypotheses is a particularly acute problem in particle physics, where one is attempting to find those data points amid quadrillions of other events, and one has to spend colossal sums of money on gigantic particle accelerators simply in order to generate any data in the first place.
An illustrative example is the graviton. This is a hypothesised boson responsible for the force of gravity. There are numerous sound theoretical reasons why such a particle should exist, and indeed, the Standard Model provides a nice list of properties that said particle is likely to possess (though with the caveats attached that arose from experience with the W and Z particles, of course). Trouble is, until someone actually finds a particle with the requisite properties in an accelerator experiment (and some physicists have good reasons for suspecting this will be difficult, to put it mildly), the graviton will remain to a certain extent speculative, even though the Standard Model has room for it, and even though the aforementioned sound theoretical reasons are still present.
However, the good news on the graviton front is this - even though detecting one in an accelerator experiment is likely to be difficult, it has, if it genuinely exists, one feature that will make it stand out from the crowd - namely, it will be a spin-2 particle, while all the other bosons are either spin-1 (photon, W, Z) or spin-0 (Higgs). Furthermore, according to those sound theoretical reasons I mentioned the existence of above, there is room for only one spin-2 particle in the Standard Model. Even if one moves into the world of supersymmetry theory, the superpartner of the graviton - the gravitino - isn't a boson, but a fermion with spin 3/2. Consequently, if any spin-2 particle turns up at the LHC in future experiments, this will be sufficient to add the graviton to our list of observables.
Though there's a few problems to address here with respect to the graviton, such as the fact that in order for gravity to be a long-range force (which it observably is), the graviton has to be massless, and a massless particle shouldn't require much energy to synthesise in a particle accelerator. But no spin-2 particle has been reliably observed in the entire history of particle accelerator experiments to date. Why this is so is an unsolved puzzle for the moment.
However, I'll add here the fact that theories of gravity that are either extensions of, or complete ground-up alternatives to, General Relativity, are numerous if one peruses the literature, and quite simply, the number of unresolved issues extant in fundamental gravity research are sufficient to keep the requisite theorists employed for a very long time.
The fun part of all this, of course, is that the state of the art in that field is such, that scientists have yet to acquire sufficient data for selection or confirmation bias to be an issue. Furthermore, that field is likely to contain some intricate subtleties of such a nature, that once we have some data to work with, it's possible that an entire new class of data-related biases may sneak up upon the scientists unawares.
It's indicative of the manner in which gravity has been exercising world class minds (along with a good few crackpots, I hasten to add), that James Blish made the whole business of finding a workable gravity theory a central plot device in the Cities in Flight novels.
Quite simply, if you want a first class education on the subject of biases and how to avoid them, particle physics and its attempted unification with gravity will provide one, and a roller coaster ride to boot.
But of course, there's another reason science is hard work. Finding the contradictory data point is merely the beginning of the hard work. Once that data point is found, the real hard work begins, of devising a hypothesis that not only encompasses the new, contradictory data point, but all of the past data points as well. Which is why Einstein's ideas prevailed, because they not only provided an explanation for the contradictory data points, but for all the other data points that appeared to support Newton's ideas as well.
In addition, Einstein's ideas provided an explanation for why those other data points appeared to support Newton's ideas so well - namely, that Newton's ideas are a very good approximation to General Relativity in the cases of low velocities and weak gravity fields, within which the error is too small to be measurable by the means available to late 19th century physicists. That error only starts appearing when you have the means to measure quantities to 15 decimal places - indeed, doing so is expensive and difficult even today. For example, measuring time dilation at everyday velocities requires atomic clocks with £10 million or more price tags attached, and intricate experimental logistics. Logistics that in some cases involves large aircraft with in-flight refuelling, and the attendant expense.
Finding the contradictory data points that lead to new, better and more illuminating hypotheses is a particularly acute problem in particle physics, where one is attempting to find those data points amid quadrillions of other events, and one has to spend colossal sums of money on gigantic particle accelerators simply in order to generate any data in the first place.
An illustrative example is the graviton. This is a hypothesised boson responsible for the force of gravity. There are numerous sound theoretical reasons why such a particle should exist, and indeed, the Standard Model provides a nice list of properties that said particle is likely to possess (though with the caveats attached that arose from experience with the W and Z particles, of course). Trouble is, until someone actually finds a particle with the requisite properties in an accelerator experiment (and some physicists have good reasons for suspecting this will be difficult, to put it mildly), the graviton will remain to a certain extent speculative, even though the Standard Model has room for it, and even though the aforementioned sound theoretical reasons are still present.
However, the good news on the graviton front is this - even though detecting one in an accelerator experiment is likely to be difficult, it has, if it genuinely exists, one feature that will make it stand out from the crowd - namely, it will be a spin-2 particle, while all the other bosons are either spin-1 (photon, W, Z) or spin-0 (Higgs). Furthermore, according to those sound theoretical reasons I mentioned the existence of above, there is room for only one spin-2 particle in the Standard Model. Even if one moves into the world of supersymmetry theory, the superpartner of the graviton - the gravitino - isn't a boson, but a fermion with spin 3/2. Consequently, if any spin-2 particle turns up at the LHC in future experiments, this will be sufficient to add the graviton to our list of observables.
Though there's a few problems to address here with respect to the graviton, such as the fact that in order for gravity to be a long-range force (which it observably is), the graviton has to be massless, and a massless particle shouldn't require much energy to synthesise in a particle accelerator. But no spin-2 particle has been reliably observed in the entire history of particle accelerator experiments to date. Why this is so is an unsolved puzzle for the moment.
However, I'll add here the fact that theories of gravity that are either extensions of, or complete ground-up alternatives to, General Relativity, are numerous if one peruses the literature, and quite simply, the number of unresolved issues extant in fundamental gravity research are sufficient to keep the requisite theorists employed for a very long time.
The fun part of all this, of course, is that the state of the art in that field is such, that scientists have yet to acquire sufficient data for selection or confirmation bias to be an issue. Furthermore, that field is likely to contain some intricate subtleties of such a nature, that once we have some data to work with, it's possible that an entire new class of data-related biases may sneak up upon the scientists unawares.
It's indicative of the manner in which gravity has been exercising world class minds (along with a good few crackpots, I hasten to add), that James Blish made the whole business of finding a workable gravity theory a central plot device in the Cities in Flight novels.
Quite simply, if you want a first class education on the subject of biases and how to avoid them, particle physics and its attempted unification with gravity will provide one, and a roller coaster ride to boot.