[cross posted at uncommondescent: What Qualifies as Science in the Wonderful World of Disney]
The scientific enterprise entails:
1. observation
2. hypothesis
3. testing
Consider this passage from the class text of an introductory cosmology class I took once upon a time:
galaxies farther than 4300 megaparsecs from us are currently moving away from us at speeds greater than that of light. Cosmological innocents sometimes exclaim, “Gosh! Doesn’t this violate the law that massive objects can’t travel faster than the speed of light?” Actually, it doesn’t. The speed limit that states that massive objects must travel with v < c relative to each other is one of the results of special relativity, and refers to the relative motion of objects within a static space. In the context of general relativity, there is no objection to having two points moving away from each other at superluminal speed due to the expansion of space.
page 39
Introduction to Cosmology
by Barbara ryden
Let’s say for the sake or argument this is true, an agnostic, science-loving friend of mine expressed the following unease with this claim:
1. we can never observe these galaxies
2. thus we can therefore never test that they are moving faster than the speed of light from us
3. repeatability of the observation? Not even testable in principle
4. things moving faster than the speed of light? We can’t test that directly either!
5. if you add space between two attracting bodies, doesn’t that mean you increase potential energy out of nowhere?
I responded to point 5 by saying, “General Relativity might not implicitly assert the conservation of energy law”, but that didn’t seem to be reassuring to him. I then read this passage in the same book on page 17:
During the 1950s and 1960s, the Big Bang and Steady State models battled for supremacy. Critics of Steady State model pointed out that the continuous creation of matter violates mass-energy conservation. Supporters of the Steady State model pointed out that the continuous creation of matter is no more absurd than the instantaneous creation of the entire universe in a single “Big Bang”.
My agnostic friend just about fell out his chair laughing. We both laughed.
The scenario of faster-than-speed-of light motion can be fit into the Friedmann-LeMaitre-Robertson-Walker solution to Einstein’s field equations of General Relativity, but does that make it true?
Consider Newton’s 2nd law. Suppose we are dealing with a force of 5 Newtons, what are the some of the mathematical (not necessarily physical) solutions to an equation constrained by the assumption that the force is 5 Newtons?
F = ma where F = 5 Newtons
Solution 1:
mass = 5 kg
acceleration = 1 meter/ sec^2Solution 2
mass = -5 kg
acceleration = -1 meter/sec^2etc.
Astute readers will notice solution 2, though mathematically consistent with the equation F=ma, is not physically real (in classical or most physics anyway) since it invokes negative mass.
I recall when studying General Relativity the professor assigning us an exercise to analyze geodesic trajectories through a particular solution to the Einstein field equations. This solution yielded incredible possibilities, and I thought to myself, “wow, where can I find such a place in the universe to observe this?”
And then reviewing the solution in class, the professor said something to the effect, “I didn’t tell you, but the solution I gave you describes a wormhole, but I’m not sure wormholes are possible since you need negative mass! This was more an exercise in math.” I and my fellow students had a small laugh, especially after having endured this mathematical exercise. The point being however, just because something is a mathematical solution to an equation of physics doesn’t mean it’s for real.
So with respect to those galaxies which we can’t see, which we will never see, that move faster than the speed of light, we can only postulate their existence as fact via inference. We can’t do it by observation, not by repeatable measurement or direct testing. So is the claim of these unseen entities a scientific claim? It does not accord with 2 of the 3 elements listed above that describe the scientific enterprise. The positivists among us will assert, “well if we can’t see it, we won’t believe it.”
So I would respond, “Ok, so do you believe the unseen galaxies predicted by the Big Bang. You can’t see them, you won’t see them, you can’t verify them, but supposedly they exist, they have properties as galaxies, and to top it off they move faster than the speed of light even though in the lab or anywhere we have access to, we haven’t clocked anything moving faster than the speed of light?”
So is the claim of unseen, unobservable, untestable, unverifiable galaxies a scientific claim? Eh, I leave that to the philosophers of science to decide, but it seems to me if one will admit as scientific the unseen, untestable, unknowable, unobservable, unverifiable entities as existing and having certain properties via inference and without direct evidence, then — well uh — couldn’t we hypothesize all sorts of unseen, untestable, unobservable, unknowable, unverifiable entities as being real via inference, and hence call that hypothesis science? I provided one example of such an entity in the thread: Quantum Enigma of Consciousness and the Identity of the Designer where Richard Conn Henry (a professor at no minor school) argued that Quantum Mechanics suggests God exists. Richard Conn Henry argued God is a permissible construct within accepted physics, and so is consciousness. Whether God is ultimately real is a separate question, but science doesn’t preclude His existence.
Getting back to cosmology, I learned of Alan Guth who speculated the universe expanded briefly at around 1000 times the speed of light in a process called inflation. In fact Andrei Linde speculated Guth understated the inflation speed by a factor of 10^1,000,000. If Guth claims the universe was inflationary, Linde claims it was hyperinflationary. Yikes!
What wasn’t presented in our cosmology class was Guth’s other speculation, which I learned of in a taboo book by William C. Mitchell
Guth is reported to have said, “in fact, our own universe might have been started in somebody’s basement.” Overbye has reported that, Guth and another MIT professor, Ed Fahri, found that, “If you could compress 25 pounds of matter into 10^-24 centimeters, making a mass 10^75 times the density of water…a bubble of false vacuum, or what Guth called a ‘child universe’ would be formed. From outside it would look like a black hole. From the inside it would look like an inflating universe.”
page 229
Bye Bye Big Bang, Hello Reality
by William C. Mitchell
Mitchell further commented of Guth, “can you believe such garbage?” I withhold making such a judgment since Guth is a smart guy, but it seems to me if we admit the possiblity of the universe being created by some tinkerer in a basement, we can surely admit intelligent design of the universe.
On a marginally more serious note, there are a minority of dissenting voices that share some of the reservations about modern cosmology that I’ve hinted of in this thread. One of them is a respected cosmologist by the name of Michael Disney. He argues we have too little data to really form a cosmological model.
Here is an excerpt from Modern Cosmology Science or Folktale
Where Do We Stand Today?
Big Bang cosmology is not a single theory; rather, it is five separate theories constructed on top of one another. The ground floor is a theory, historically but not fundamentally rooted in general relativity, to explain the redshifts—this is Expansion, which happily also accounts for the cosmic background radiation. The second floor is Inflation—needed to solve the horizon and “flatness” problems of the Big Bang. The third floor is the Dark Matter hypothesis required to explain the existence of contemporary visible structures, such as galaxies and clusters, which otherwise would never condense within the expanding fireball. The fourth floor is some kind of description for the “seeds” from which such structure is to grow. And the fifth and topmost floor is the mysterious Dark Energy, needed to allow for the recent acceleration of cosmic expansion indicated by the supernova observations. Thus Dark Energy could crumble, leaving the rest of the building intact. But if the Expansion floor collapsed, the entire edifice above it would come crashing down. Expansion is a moderately well-supported hypothesis, consistent with the cosmic background radiation, with the helium abundance and with the ages inferred for the oldest stars and star clusters in our neighborhood. However, finding more direct evidence for Expansion must be of paramount importance.
In the 1930s, Richard Tolman proposed such a test, really good data for which are only now becoming available. Tolman calculated that the surface brightness (the apparent brightness per unit area) of receding galaxies should fall off in a particularly dramatic way with redshift—indeed, so dramatically that those of us building the first cameras for the Hubble Space Telescope in the 1980s were told by cosmologists not to worry about distant galaxies, because we simply wouldn’t see them. Imagine our surprise therefore when every deep Hubble image turned out to have hundreds of apparently distant galaxies scattered all over it (as seen in the first image in this piece). Contemporary cosmologists mutter about “galaxy evolution,” but the omens do not necessarily look good for the Tolman test of Expansion at high redshift.
In its original form, an expanding Einstein model had an attractive, economic elegance. Alas, it has since run into serious difficulties, which have been cured only by sticking on some ugly bandages: inflation to cover horizon and flatness problems; overwhelming amounts of dark matter to provide internal structure; and dark energy, whatever that might be, to explain the seemingly recent acceleration. A skeptic is entitled to feel that a negative significance, after so much time, effort and trimming, is nothing more than one would expect of a folktale constantly re-edited to fit inconvenient new observations.
Ah, the wonderful world of Disney. Disney wrote a more technical article in The Case Against Cosmology published in the Journal General Relativity and Gravitation..
It should be noted, there is a forgotten article in the Discovery Institute archives by David Berlinski: Was There a Big Bang
Is the big bang model correct? One of my professors, James Trefil, gave his estimate that its about half way confirmed, but he has still some skepticism as he articulated in his book The Dark Side of the Universe.
The answer to the question of the Big Bang is way above my pay grade, but I posted this thread mostly to point out that if we pass off certain unverifiable, unseen, unknowable, unobservable claims as science, by what standard is ID disqualified? After all, according to Richard Conn Henry, quantum mechanics suggests God exists, and if so (though he won’t go so far as I would), imho, ID can then be admitted into to the realms of scientific hypotheses since now we have a theoretical entity with a sufficient skill set to design life.
And finally, with respect to the question of ID being science, in light of considerations above, this passage by Bill Dembski comes to mind:
Thus, a scientist may view design and its appeal to a designer as simply a fruitful device for understanding the world, not attaching any significance to questions such as whether a theory of design is in some ultimate sense true or whether the designer actually exists. Philosophers of science would call this a constructive empiricist approach to design. Scientists in the business of manufacturing theoretical entities like quarks, strings, and cold dark matter could therefore view the designer as just one more theoretical entity to be added to the list. I follow here Ludwig Wittgenstein, who wrote, “What a Copernicus or a Darwin really achieved was not the discovery of a true theory but of a fertile new point of view.”
Recent observations suggest that the universe’s expansion rate is increasing. Doesn’t this imply that distant galaxies, as the rate they are receding increases, should vanish from sight because the light they emit can’t travel fast enough to overcome the expansion rate, and will “lose ground” on the way to us?
Of course, we might not notice this for some millions of years, since “old light” is close enough to us to exceed the expansion rate between us and its current position…
Q.E.D.
That’s my understanding, but I don’t think we’ve reached that point.
The part of the big bang we can’t see is prior to star formation and generation of light.
“That reflects a serious misunderstanding of general relativity. GR doesn’t forbid galaxies from moving faster than light relative to each other;”
Where did I say otherwise KeithS? You were right on one point before (about the 46 billion light years), but now you’re over reaching. I specifically cited:
” In the context of general relativity, there is no objection to having two points moving away from each other at superluminal speed due to the expansion of space.”
I only pointed out there no lab experiments to confirm expanding space. It’s all predicated on the assumption FLRW is the correct explanation for red shifts.
JetBlack claims:
“4. things moving faster than the speed of light? We can’t test that directly either!
except we can and we do.
”
Provide a lab experiment where this is done. I seem to recall a recent scandal:
http://www.wired.com/wiredscience/2012/06/neutrinos-cant-beat-light/
That said, glad to see TSZ critics advocating superluminal velocities. Superluminal velocities are heartwarming to YECs. Thanks a bunch!
Going up against general relativity is a good way to score crank points. You seem to have a problem with consilience.
“Going up against general relativity is a good way to score crank points. You seem to have a problem with consilience.”
FLRW is only one solution to GR, there are an infinite number of solutions to GR just like there are an infinite number of solutions to this famous equation:
F = ma
Thus your insinuation that I’m necessarily criticizing GR by criticizing FLRW is baseless and wrong.
Here are some other solutions to GR:
https://en.wikipedia.org/wiki/Schwarzschild_metric
or
http://arxiv.org/abs/0710.4474
Your insinuation that criticizing FLRW implies criticism of GR is an error, and KeithS and Mike Elzinga should pounce on you for your basic misunderstanding of the relationship of FLRW to GR. They won’t, because I’m a creationist and you’re not.
Comment cross-posted from UD:
Sal,
You quoted Ryden’s explanation in order to disagree with it:
If space doesn’t expand, then general relativity is wrong. Yet general relativity is one of the best-tested theories in the history of science. As petrushka pointed out, you’re really veering into crank territory when you start contesting GR.
Relative to each other in expanding space? Sure. But that doesn’t solve the distant starlight problem, and it doesn’t help YEC.
Look, Sal — I understand that you’re embarrassed to be wrong on such a basic point of general relativity, but just admit it and move on. Trying to cover up your mistake is only going to draw more attention to it.
Sal, I’m no physicist, but think about this:
How do you define a velocity?
How do you define space?
The answers to this will tell you that the galaxies are not receding at superluminal velocities when considered within our own space-time framework. It is space itself that is expanding.
You consider a research group publishing its results and inviting others to critique and correct them to be a scandal?
Interesting.
I nominate Sal’s OP and subsequent comments for Most Embarrassingly Desperate Creationist Gambit of the month.
Those kinds of relative velocities won’t help the YEC, Sal. YECs need light to go faster than light relative to the space being traversed. GR still precludes that, even if galaxies (or any two entities) are moving with respect to each other faster than c due to expansion of space.
As an aside, having read your original post’s comments from a while ago at UD, don’t you find the “lights are on” factor a bit disturbing between UD and TSZ? I can understand the “besieged” mentality you might develop, but isn’t it telling to you that what UD’s ID proponents had to offer was 40 pages of the usual BA77 dreck and Eric Anderson looking for quotes that support the idea that “Jesus == The Big Bang”?
Say what you want about your “persecution” over here. Don’t you want something more than a collective stupor with Joe’s middle finger waving around behind it? Take a read of the comments you got on that thread until keiths jumped in with his comment today.
Very funny, and quite accurate.
Sal is engaging in taunting and the Gish Gallop. All wannabe ID/creationist leaders do this.
The point is that Sal cannot do even basic high school science and math; not one, I repeat, not one ID/creationist can. Their “PhDs” are irrelevant.
Sal continues to avoid addressing the previous issues he ran away from, as well as the high school level calculations. He gets called on it over and over; but he still Gish Gallops.
It is classic ID/creationist behavior ever since Morris and Gish started it back in the 1970s.
Sal has become a boring robot who has never had the self-dicipline to learn. He doesn’t know the science; and he doesn’t give a damn. He is not doing this to learn science; he is doing it to practice “debating.” He will never do any science; so nobody should waste time even thinking about trying to teach him anything. His only responses are to “refute” by copy/pasting quote mines he doesn’t comprehend.
Serious real students don’t waste time learning this way; they engage reality from the beginning.
I think any claim that is made and then later shown to be incorrect gives them hope that those other claims, the ones that prevent their viewpoint being true, may also fall.
Perhaps stcordova views it as a scandal because the claim itself was quite out there (as are YEC claims) and it got a somewhat skeptical response despite there being evidence for the claims.
stcordova probably thinks he has evidence for his claims too, and views it as a scandal that those views are met with a, well, unsympathetic reading at best. Well, they are at tsz, at UD not so much.
Guys, it’s tough to be the pilee in a pile on.
Check out the site rules and address Sal’s post, not Sal.
thanks 🙂
You are accusing them of dishonesty — a violation of the forum rules. There have been a number of corrections on this thread and not just corrections of your errors.
But you are wrong on many counts. Despite the faster than light expansion of the universe, the “beginning” has not yet slipped beyond the horizon. We can still see everything back to first light.
I had noticed that.
But I have generally had a policy of not letting ID/creationists ride on my back. I know where it always ends up. I observe ID/creationist misconceptions and tactics instead.
There are plenty of good special and general relativity textbooks out there that are easy to find. I have a shelf full of some of the best, and I have found these to be very useful over the years.
There are also some very good introductory physics textbooks as well; even at the high school level. 😉
There are even more good math books.
This is ridiculous. Empirical measurements of red shift vs. distance—based on standard candles (supernovae type Ia)—show that the FLRW metric is a good model of the Universe on large scales.
You are making it sounds like the Schwarzschild metric is a competing solution to FLRW’s. It isn’t. They apply to entirely different situations. The former is a solution for empty space surrounding a point mass. The latter is for a Universe filled uniformly with matter. It’s not like cosmologists have the Schwarzschild solution waiting in the wings in case FLRW doesn’t work out.
I should add that the main idea of the OP is based on a dumbed-down interpretation of the cosmological red shift as the Doppler effect. It works at small distances between objects, but not for large ones (a fact glosed over in popular books and freshman textbooks). Here is a brief description of the problem at John Baez’s website: What Causes the Hubble Redshift? Are the light waves “stretched” as the universe expands, or is the light doppler-shifted because distant galaxies are moving away from us?
And lastly, F=ma does have infinitely many different solutions, but not in the manner you describe in the OP. They correspond to different initial conditions (position and velocity). Not to the silly example of a negative mass.
It looks like all that physics education didn’t help much.
The main difference, in this context, is that ID doesn’t provide any indications of what ought to be found in an embryo at which state of development, and evolution… does provide such guidance. The guidance provided by ToE is of course less than 150% perfect and less than 150% complete, but that beats the flat-out nothing whatsoever which is the ‘guidance’ provided by ID.
Thanks for this! I remember thinking it was strange that red shift would even happen if light speed was constant, and that it must mean something different from the change in pitch from a passing train siren.
And that it must mean that the light waves were stretched, rather than the peaks arriving delayed.
Which made sense to my lay understanding of spacetime.
Looks like I wasn’t wrong.
*has no training in physics beyond HS year 11*
As has already been pointed out, if an object has a red shift of greater than 1.4, that object is receeding superluminally. There is absolutely no problem with this, as it is all the space in between us and the object that is expanding (like the balloon analogy). We can measure the red shift by noting the distance between the emission/absorption lines of things like atomic hydrogen, which are very well known. So we can measure whether something is going faster than light and we do. This has nothing to do with neutrinos or local velocity.
And that is a perfectly reasonable assumption to make, up there with assuming that the gravitational constant and charge on an electron are the same in these places. We can make relativistic red and blue shift measurements of large numbers of objects from rotating objects to objects with peculiar motion, which can be cross-correlated in a number of ways. Red shift is also fundamentally linked to time dilation (frequency) and length contraction, and these effects can readily be seen both in labs on earth as well as in space from the frame dragging experiments of Gravity Probe B, through to the decay of neutron star orbits. Furthermore, the red shifts not only apply to optical measurements involving the various electron transitions within atoms, but also to nuclear processes and so on. If you have any reasonable justification as to why relativistic red shift is wrong, do let us know, and also let us in on any alternative models you might have.
so essentially the form of the argument is: we don’t know everything about the Big Bang and cosmology, therefore Intelligent Design is ok.
I seem to have overlooked the questioning of redshift. I tend to assume some mimimum level of competence. Redshift denial gets you into TimeCube territory.
Ditto! But I don’t think the Doppler effect is inapplicable to light, simply that it is insufficient to account for the cosmological observations. The Doppler effect is due to change in the arrival rate of the wave peaks at the observer, not change in the velocity of the wave relative to the observer. You can shorten or lengthen the apparent wavelength by motion towards or away from the source, even if the waves always appear to be moving at the same speed. If you flung a torch away at speed, its light would be redshifted but its velocity the same as that from the torch you kept in your other hand. If you did the same with radios, the sound from the moving radio would appear to travel more slowly than that from the other, but you are Doppler-surfing the wave peaks in both cases.
Ignoring relativity, (Observed wavelength – Rest wavelength)/(Rest wavelength) = (v/c). Where v is not <<c, you have to adjust for the distortion of distance at relativistic speeds. [a word of warning – never type “<<” into the WP Post Reply Editor in Firefox using the keyboard symbol – it hangs and you have to type the whole dang thing in again! But you can get << in if you edit the comment after posting.]
This is germane to the side-discussion I had with keiths above: even if space were not expanding, you would still observe redshift (and potentially achieve superluminal recession velocities) if two galaxies had been propelled apart at an appreciable fraction of c.
See 3.1 here http://www.marmet.org/cosmology/redshift/mechanisms.pdf
[IANAP! Awaits correction! :)]
Red shift still happens, but here we are looking at two different phenomena – one is redshift due to peculiar motion and the other is due to the expansion of space.
Since you’re happy with the idea that the speed of light in vacuum is the same for all observers, it follows mathematically that you’re also happy with the concept of time dilation and that ‘moving clocks run slowly’. Now if I’m on a train with a hydrogen gas source, an electron decays from an excited state to its ground state, and the frequency is given by E=hf, where h is planck’s constant. frequency is just oscillations per second, so it can be treated like a clock, but you, on the station platform, see my clock running slowly, and therefore of lower frequency or redder light – the light is red shifted. The funny thing is that this still works even if we ignore the speed of light boundary for massive objects and I am travelling at 2c or 3c – you still see the light emitted from my lamp, it’s just more red shifted. So even if we ignore the limit of massive objects not being able to travel faster than the speed of light in vacuum, sal is still wrong, because the speed of light in vacuum is constant for all observers – we would be able to observe those galaxies.
Can you explain ToE predicts what will you found in embryo development? specifically how ToE predicts the hourglass model?
I think that there is a more deep question there. If modern science is
1. observation
2. hypothesis
3. testing
The big bang theory can´t fullfill point 3,
Keiths explicit that
“keiths on June 27, 2013 at 6:11 pm said:
“We see galaxies in every direction, nearly to the edge of the observable universe, and beyond them the cosmic microwave background. The parsimonious assumption is that the pattern continues beyond the cosmic horizon. Option.”
“ Far more likely that there is mass out there, that we are not at the center of the universe, and that our cosmological models are on the right track.”
“Someone might argue that while there is mass beyond the cosmic horizon, it may not be in the form of galaxies, but that also seems like an unparsimonious assumption.””
no matter on that is considered science. Why ID no? Lizzie aknowledge that and said:
“Lizzie on June 27, 2013 at 1:02 pm said:
“And yes, that means that ID hypotheses can be perfectly scientific.””
Usually people add , and Lizzie does, the comment that that hypothesis make “predictions”. But that is only partially true. Usually to fit the predictions that hypothesis needs to be “adjusted” a litle and end beeing “postdictions”.
Also people add, and Lizzie does, that ID cannot make “predictions”, I am not and ID but I read some ID “postdictions” equivalents t the ToE.
Lizzie, as many others, also stated that ToE help his work on actual biology and ID do not, but I never
get an answer as how the differences work.
Nothing wrong, scientist cannot know the future, new observations led to new hypothesis but It is that science? Maybe, but it is not modern science, we are back to age of ancient greeks when they made observations and get “conclusions” about the universe without testing. And also that is fine as far as everybody knows that that “conclusions” are only models that maybe completely wrong. Usually materialist know this:
“davehooke on June 27, 2013 at 6:59 pm said:
Believes? Probably not.
Takes seriously because it is a consequence of inflation (and string theory)? Yes.”
“Allan Miller on June 27, 2013 at 7:40 pm said:
Not me (I’m insufficient of a cosmologist to understand the demand for them by extension from known measurements). I’d accept as plausible (regardless of the relation to inflation) that there has been more than one Big Bang in the history of … uh … everything. I also think there’s life on other planets, but doubt we will ever know. But ‘believe’ … nah.”
The problem as I see it is that they put this hypothesis at the same level of tested hypothesis. Calling science only step 2 and 3, ancient greeks speculations science confuses the values.
Blas,
The Big Bang theory fulfills point 3. why shouldn’t it? Remember that the CMB as a prediction came long after the original suggestion of the BB model, and it was also found at about the same time that it was predicted. That was a test right there and it was passed with flying colours. There should also be a CNB which will take a bit more detecting.
You can test the Big Bang. You try and determine what you would expect to find if your model were true. You look for it. You get a positive or negative or ambiguous result and scratch your head some more. You don’t need to make a Big Bang to test the hypothesis, nor do you need to make a giraffe to test a theory on its origin. Unique history can still be tested, just as repeatable regularities can.
Indeed. I could have a hypothesis that I am adopted. I do not need to get my parents to produce billions more children until they produce another me in order to test this hypothesis (i.e. repeat the original event) – and the same is true for the big bang. There are ramifications of the initial event that have knock on effects in the present day, and we can test for those.
You do not understand what testing is. The CMB is another observation and didn´t fit to the original Big bang theory, it was corrected in order to make the CMB a “postdict”.
That it is not testing. For unique history the only thing you can do is add observations.
The CMB was predicted as far back as 1948 by the likes of Dicke and Gamow based on the Big Bang Model and was not measured until 1964 after Penzias and Wilson had discounted a white electrolytic substance as the cause of the uniform microwave signal they were picking up. In short the CMB was expected based on the BB model before it was detected. It was a test of the BB model, not a postdict.
you’re equivocating “test” and “experiment” (in the Baconian sense). One can test one’s hypothesis by comparing it to observation, regardless of whether the observation is that of a controlled experiment, natural experiment or observational study.
And a few others. History of the cosmic microwave background radiation.
Well, maybe if you want. But the difference between modern science and ancient greeks speculations is testing as experiment. You can call testing adding observations that fits, or make it fit, and also call that science. But there are differences, and everybody should be aware.
Interesting your quote show exactly that the CMB was a postdict, as seven years before the temperature of the space were measured.
… and those observations tell you something. They increase, decrease or are neutral in regard to your confidence in your hypothesis, by being variously consistent with or in opposition to predictions.your hypothesis makes. This is not difficult material to grasp, Blas.
I do not agree, new observations fits or do not fit your hipothesis. The visions that many observations that fits add the some value to the hypothesis as the experimentation is an illusion and science stopper. Because no matter how many observations fits the next observation can do not fit and all your hypothesis should be wasted.
how does that differ at all from a controlled experiment? As I say, you are just equivocating here between test and observation. Whether it is a controlled test, uncontrolled test or observational study, it is an observation of the way that nature behaves, and that observation has to fit the model or the model is wrong. If the observation fits the model, then the model might be right (unless there are other observations which do not fit the model). That’s how it always is.
Blas: All conclusions are provisional. Your apparent suggestion that data gathering in support of this or that cosmological model is a ‘science stopper’ is risible. Science marches on by throwing its hands in the air when faced with unrepeatable events?
You don’t have to do the shouting to pick up an echo.
Maybe I do not said it correctly. What I said is science stopper it is not the data gathering, but the idea that more data that fits adds value to the hypothesis.
Allan Miller:
Science marches on by throwing its hands in the air when faced with unrepeatable events?
I don´t think in that way litterally, but I think that any theory of unrepeatable events should be taken with a bit of irony.
Postdict? Seven years prior to the measurement?
Evidence for the big bang:
– The CMBR, cold radiation in all directions in space. Discovered by Penzias and Wilson. Predicted by the Big Bang model and NO OTHER THEORY.
– That the CMBR is black body radiation. Confirmed by COBE to 400 sigma.
– How much of each of the light elements there are.
– Large scale structure.
Maybe I do not said it correctly. What I said is science stopper it is not the data gathering, but the idea that more data that fits adds value to the hypothesis.
To test how wrong this idea is, consider what would happen to law enforcement if it were true.
Lizzie,
Your instincts were correct.
In general relativity, we are dealing with a space-time geometry. As experimentalists, we are embedded in that space-time making measurements of events taking place within that space-time.
What is more, that space-time has a geometry that needs to be determined from within that space-time, and that geometry is affected locally and globally by the concentrations of matter and energy.
This means translating what the universe looks like as viewed from “outside” that four-dimensional manifold to what observers see when embedded in that manifold.
It is a difficult leap for students to make that transition; and they typically fall back on their familiarity with Newtonian physics. Sal doesn’t even understand the basics. His “education” is a hodge-podge of memorized formulas and facts cobbled together in order to get through exams. He has not really thought about any of the basic concepts.
It is not unusual for inexperienced students to want to jump immediately into advanced topics because they want to be “sophisticated’ in their conversations with others. When they do this without laying the groundwork in the basics, they frequently end up being extremely confused with their cobbled-together mess.
If there is an ideological motivation to constantly bend and break concepts to fit preconceived beliefs, one ends up with a thoroughly rationalized pseudoscience that is extremely difficult to dislodge. American fundamentalist evangelicals are particularly prone to this; but other preconceptions can cause problems also.
Nonetheless … Lizzie seems to be saying that the Doppler effect can’t be in operation on light because of the constancy of c for all observers. I don’t think that’s correct (but am perfectly happy to be wrong). The expansion of space between galaxies produces a redshift, but that does not have to happen for a recessional redshift to be observed … does it? Surely a photon emitted by a receding particle 20 yards away could be redshifted depending on its approach to c, when the expansion of space across such a region is pretty close to nonexistent?