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posted by mrpg on Thursday September 20 2018, @07:00AM   Printer-friendly
from the what-are-we-waiting-for? dept.

Mars trips may involve less radiation exposure than previously thought:

There's no question that the first human mission to Mars will be extremely dangerous. Some studies have suggested that the radiation levels would exceed the maximum career dose for a given astronaut, greatly increasing the risk of cancer and other illnesses. It might not be quite so bad as it sounds, though. Newly presented ESA ExoMars orbiter data indicates that astronauts would receive "at least" 60 percent of their maximum recommended career radiation exposure on a round trip to Mars that takes six months both ways. That's still several times what ISS crew members receive, but it's relatively gentle compared to what some had feared.


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  • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @06:12PM (22 children)

    by Anonymous Coward on Thursday September 20 2018, @06:12PM (#737631)

    Its fine to have a working hypothesis or rough estimate, but something is wrong if that becomes what you believe... until the next thing youll switch to believing

  • (Score: 2) by Immerman on Thursday September 20 2018, @06:50PM (21 children)

    by Immerman (3985) on Thursday September 20 2018, @06:50PM (#737657)

    So, you would have scientists believe *nothing*? That's extremely non-productive - you need a foundation to build further.

    The important thing for scientists, and anyone else really, is to not get emotionally attached to your beliefs. So that when new evidence conclusively proves one of them is wrong you can discard it and move on.

    Moreover, scientists tend to use the word "belief" a bit differently than most are accustomed to thinking about it. If a scientist says they "think" or "believe" something, they are declaring varying degrees of uncertainty. To say that you believe something is to acknowledge that you are accepting something as truth despite a lack conclusive evidence. If you had such evidence, you would *know* it, and wouldn't have to believe. And thus scientific beliefs are things that are specifically acknowledged to be conjecture waiting to be confirmed or contradicted evidence.

    It not really that different than how most people use the term when you get right down to it. People may believe in the God, or the inherent value of human life - but they don't believe in cars and houses. Cars and houses simply *are* - you *know* they exist, belief is unnecessary.

    • (Score: 2) by Immerman on Thursday September 20 2018, @06:59PM (20 children)

      by Immerman (3985) on Thursday September 20 2018, @06:59PM (#737663)

      It's worth noting as well that the entire basis of science is that *nothing* is sacred. f=mv? e=mc^2? These are things that every experiment to date has confirmed. But the entire history of science, the entire foundation upon which it's built, is the acknowledgement that *anything* and *everything* you believe could be proven wrong tomorrow. It's happened numerous times already, and will hopefully happen many, many more. You can't function without *knowing* things, but the entire point of science is to destroy what you know and replace it with a more accurate aproximation of reality.

      There is no Truth in science - only successively more accurate approximations. It's even been logically proven that, if we ever truly achieve the ultimate, perfectly accurate description of the universe, it will be impossible to prove that we have done so.

      • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @07:18PM (19 children)

        by Anonymous Coward on Thursday September 20 2018, @07:18PM (#737673)

        Im pretty sure scientists really do believe some stuff, eg its colder in outer space than on earth at the equator. I doubt they really believed there was x amount of radiation exposure before and now really believe there is y amount of radiation exposure. But if they do, they have some kind of mental problem and we shouldnt listen to them.

        So rather than say "than previously thought", just say "radiation exposure estimates have been lowered based on new data".

        • (Score: 2) by Immerman on Thursday September 20 2018, @07:28PM (18 children)

          by Immerman (3985) on Thursday September 20 2018, @07:28PM (#737677)

          >Im pretty sure scientists really do believe some stuff, eg its colder in outer space than on earth at the equator.
          No, they *know* that, because they've collected data from a variety of sources (given sufficiently specific definition of "outer space" - the region around the sun is MUCH hotter, even than the sun itself, for unknown reasons)
          Again - in the face of knowledge, belief is unnecessary. Data is known. Theories are believed. Long-standing well-tested theories are often presumed to be known, with the rational understanding that they are still subject to revision.

          >I doubt they really believed there was x amount of radiation exposure before and now really believe there is y amount of radiation exposure

          Why not? A great deal of exploratory research is "current evidence suggests X" i.e. "we think X" or "X is the most reasonable assumption in the face of current data" - then they work taking that assumption as probably true until it gets revised in the face of further evidence. That's not a mental problem - that's dealing with the realities of working in a realm where your data is woefully incomplete.

          • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @07:47PM (17 children)

            by Anonymous Coward on Thursday September 20 2018, @07:47PM (#737685)

            Data could be cherry picked etc, so i dont see how it can be any more known than a theory.

            The rest of the post is you claiming that scientists have just redefined the word belief. What possible purpose could this serve? It can only work to confuse people...

            • (Score: 2) by Immerman on Thursday September 20 2018, @08:07PM (16 children)

              by Immerman (3985) on Thursday September 20 2018, @08:07PM (#737705)

              Cherry-picking isn't about the data, it's about the interpretation. Which is back in belief territory.

              Only the raw data is known. And even that knowledge is contingent on possible flaws in the measuring equipment.

              And no, they haven't redefined the word - they just use it with more awareness of its implications.

              Do you "believe" in the existence of houses, or that the sky is blue? Or do you simply know it to be true from personal experience?

              • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @08:22PM (15 children)

                by Anonymous Coward on Thursday September 20 2018, @08:22PM (#737715)

                I believe houses exist and the sky is blue. In the latter case I have to take peoples word for it...

                • (Score: 2) by Immerman on Thursday September 20 2018, @08:51PM (14 children)

                  by Immerman (3985) on Thursday September 20 2018, @08:51PM (#737727)

                  Then you have my condolences:

                  Belief is the state of mind in which a person thinks something to be the case with or without there being empirical evidence to prove that something is the case with factual certainty. https://en.wikipedia.org/wiki/Belief [wikipedia.org]

                  • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @09:07PM (12 children)

                    by Anonymous Coward on Thursday September 20 2018, @09:07PM (#737737)

                    That definition supports what I said that you are saying scientists have redefined belief. The term applies to believing something based on evidence... and "thinking something to be the case". A working hypothesis or rough estimate is not a time scientists think it is actually the case.

                    • (Score: 2) by Immerman on Thursday September 20 2018, @09:35PM (5 children)

                      by Immerman (3985) on Thursday September 20 2018, @09:35PM (#737747)

                      It also applies to believing something *without* evidence. The distinction is extremely important to scientists, and there's not really a term specific to "belief without evidence" (faith has far too many other implications)

                      Look at the Venn diagram on the page if you need clarification. Belief has no relationship with facts. If you want to say something is "true", saying that you believe it is irrelevant. Knowledge has supporting evidence, belief is... just belief. It's a statement about your personal framework, not about the universe.

                      Or to put it another way,
                      Saying that you know something means you believe it *and* have solid evidence to support that belief.
                      Saying you believe it is a much weaker statement which, by virtue of not making the stronger claim, implies that you *don't* have solid supporting evidence.

                      • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @09:46PM (4 children)

                        by Anonymous Coward on Thursday September 20 2018, @09:46PM (#737755)

                        How do you know you arent living in a simulation, etc and everything is an illusion? You don't know for sure, some people think its 1 billion to one odds this isnt a simulation:

                        Some of the world’s richest and most powerful people are convinced that we are living in a computer simulation. And now they’re trying to do something about it.

                        At least two of Silicon Valley’s tech billionaires are pouring money into efforts to break humans out of the simulation that they believe that it is living in, according to a new report.

                        [...]

                        That has led some tech billionaires to speculate that the chances we are not living in such a simulation is “billions to one”. Even Bank of America analysts wrote last month that the chances we are living in a Matrix-style fictional world is as high as 50 per cent.

                        https://www.independent.co.uk/life-style/gadgets-and-tech/news/computer-simulation-world-matrix-scientists-elon-musk-artificial-intelligence-ai-a7347526.html [independent.co.uk]

                        We never "know" anything for sure, there is only belief.

                        • (Score: 2) by Immerman on Thursday September 20 2018, @10:07PM (3 children)

                          by Immerman (3985) on Thursday September 20 2018, @10:07PM (#737774)

                          Sure, which makes the question irrelevant. That's philosophy, and the philosophers can sit around mutually mentally masturbating over the issue until they all crumble to dust. I wish them much satisfaction of it, but unanswerable questions are explicitly outside the realm of science. It's not even a new idea - just a rehashing of Descartes Evil Demon Hypothesis from almost 400 years ago, with flashy new cyberpunk paint job. Or Plato's Allegory of the Cave, from almost 2000 years before that. That's the problem with unanswerable questions - you can keep rehashing them over and over again for, literally, thousands of years, and get not one iota closer to an answer.

                          Do we have evidence that this *isn't* a simulation? No - just like we don't have any evidence that there *isn't* an giant invisible teapot orbiting the moon. It is logically impossible to disprove the existence of something. But in the absence of evidence in support of such a conjecture "the universe is as it appears to be" is the default, useful, assumption. And science is all about practical, confirmable results. It's not trying to reveal the ultimate nature of reality - it's trying to fully, accurately describe how the natural universe behaves.

                          • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @10:19PM (2 children)

                            by Anonymous Coward on Thursday September 20 2018, @10:19PM (#737788)

                            The point was that there is nothing you actually "know", so no one should even use that term except in a religious context.

                            • (Score: 2) by Immerman on Thursday September 20 2018, @10:48PM (1 child)

                              by Immerman (3985) on Thursday September 20 2018, @10:48PM (#737805)

                              You absolutely should *not* use the term in religious contexts - by and large there are no facts to support religious assertions, it's pure faith. And without testable facts, you have only belief, not knowledge.

                              Facts meanwhile are the raw data about which everyone (intellectually honest) can agree upon. Everyone can agree that rocks are hard - if you deny the evidence of your senses (aka the natural universe) then you have no basis for building knowledge at all. You'll be in the grip of Descartes radical doubt, and cogito ergo sum is the *only* thing you can ever know. Even he could not endure that and jumped down a series of very questionable assumptions to escape back to a belief in the natural universe.

                              • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @10:59PM

                                by Anonymous Coward on Thursday September 20 2018, @10:59PM (#737816)

                                Everyone can agree that rocks are hard - if you deny the evidence of your senses (aka the natural universe) then you have no basis for building knowledge at all.

                                So you "know" we don't live in a simulation then? If billionaires and scientists are trying to "break out of the simulation", it doesn't sound like a self defeating belief to me...

                    • (Score: 2) by Immerman on Thursday September 20 2018, @09:50PM (5 children)

                      by Immerman (3985) on Thursday September 20 2018, @09:50PM (#737756)

                      ...And I suppose that does support your claim that scientists have, to a certain extent, redefined the word. As happens to pretty much every common-usage word used in within technical fields - those fields require extreme specificity to communicate effectively, and concepts closely related to existing terms tend to get... refined a bit.

                      Two concepts, both of which are relevant to the field, and one of which is a subset of the other. Either you coin a third term that nobody else will understand at all, or you use the superset term as "everything commonly understood to mean *except* the subset that has it's own name - because if I meant the subset I would use *that* term instead.

                      Sort of like if we were talking about animals. If I say something is a dog - it's because it's a dog. If I say it's a wolf, it's because it's a wolf. If I say it's a canine - it's because I either don't know what kind it is, or that information isn't relevant to the conversation.

                      • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @10:03PM (4 children)

                        by Anonymous Coward on Thursday September 20 2018, @10:03PM (#737769)

                        In the definition it says belief requires "thinking something to be the case".

                        Just because you come up with a theory or make a rough estimate does not mean you "think it to be the case". Once you start making more and more careful measurements and deriving hypotheses to test that work out then you may come to "think it to be the case".

                        • (Score: 2) by Immerman on Thursday September 20 2018, @10:41PM (3 children)

                          by Immerman (3985) on Thursday September 20 2018, @10:41PM (#737798)

                          Careful - "theory" is one of those words scientists have redefined. A Theory is the final stage of scientific knowledge - a hypothesis that's been so thoroughly tested, and gathered such a solid body of evidence and widespread agreement over its validity that it is accepted as being reliable knowledge.

                          There is some debate about the distinction between a Theory and a Law - the best guideline I've encountered is that a Law is the mathematical formula describing *how* some aspect of the universe behaves, while a Theory is the conceptual interpretation of *why* the universe behaves in that fashion. But the use of Law also seems to be going out of style, perhaps in deference to the fact that it suggests an absolute truth, while pretty much all the famous ones have been disproven. Newton's Six Laws of Motion for example, though the three still-famous ones remain useful enough under almost all "normal" conditions to still be widely taught and used.

                          The word you're looking for is speculation, or perhaps conjecture. Which, depending on the field may take many years of refinement before it reaches the point where a testable hypothesis can even be formulated, and you may very likely start believing it along the way - the same way parents believe their children are especially smart and attractive. Eventually you reach the point where you can meaningfully formulate a series of testable hypothesis and start collecting evidence. And then, if you collect enough evidence to convince the scientific community of the validity of your conjecture, it will join the ranks of other Theories as being accepted "truth" - a.k.a. a more accurate approximate description of how (and why) the universe behaves than what came before.

                          • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @11:08PM (2 children)

                            by Anonymous Coward on Thursday September 20 2018, @11:08PM (#737826)

                            I don't know any scientists who actually use the word 'theory" in the way you describe. Theory/model/hypothesis are all interchangeable terms.

                            Also, the way you describe the scientific method sounds idealistic. It seems more like what Lakatos described: http://www.lse.ac.uk/philosophy/science-and-pseudoscience-overview-and-transcript/ [lse.ac.uk]

                            Science advances by coming up with theories that make otherwise surprising predictions that turn out correct. Degenerating theories are those that keep needing ad hoc additions to deal with the new data that comes in (the theory lags the data). Its never possible to prove or disprove anything, so there is no concern with facts/truth/etc.

                            • (Score: 2) by Immerman on Friday September 21 2018, @12:23AM (1 child)

                              by Immerman (3985) on Friday September 21 2018, @12:23AM (#737887)

                              Theory of Relativity
                              Quantum Mechanical Theory

                              the two most thoroughly tested and broadly accepeted models ever conceived

                              They also use theory a lot in less well established contexts, but probably shouldn't when laymen can hear them. Or should come up with a better term for "theories most everyone believes".

                              • (Score: 0) by Anonymous Coward on Friday September 21 2018, @12:54AM

                                by Anonymous Coward on Friday September 21 2018, @12:54AM (#737906)

                                I don't know about QM, but general relativity predicts the wrong thing all the time. They came up with the ad hoc theory of "dark matter" and "dark energy" to save it, and now 90% (or whatever) of the universe is made of stuff that can only be "detected" as deviations from the predictions of GR. So, yea its a perfect example of a degenerating theory.

                  • (Score: 0) by Anonymous Coward on Thursday September 20 2018, @09:13PM

                    by Anonymous Coward on Thursday September 20 2018, @09:13PM (#737739)

                    Also, I didnt mean to imply I was blind, only "color frustrated".