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Author Topic:   No Big Bang--Just gentle whisper
Son Goku
Member
Posts: 1153
From: Ireland
Joined: 07-16-2005


Message 46 of 100 (362467)
11-07-2006 5:04 PM
Reply to: Message 45 by nwr
11-07-2006 3:26 PM


The Singularity
Just to mention the singularity of most finite-past models of the universe is an artefact of GR, but usually isn't included in the Big Bang model.

This is to do with all our physical models based around fields being what we call effective theories. This is a far more prominent term in particle theory when used to discuss the quantum fields particle physics uses, however it also used by cosmologists to refer to classical GR.

Basically the theory is only taken to hold up to certain energies/distances with the higher level predications of the theory being literally cut off.

So the Big Bang works with this universe:

as opposed to:

The state of matter at the point were the cone gets truncated is modelled as a quark-gluon plasma along with a lepton plasma. The "real" Big Bang theory would be this quark-gluon and lepton plasmas living on a truncated cone model.

It starts by solving the GR field equations for an expanding universe, which gives you a universe with a singularity and cutting off the solution at a point in time when GR is a well defined theory and particle physics works according to the standard model. It then puts the plasmas of particles on the spacetime at this truncation point and using sensible initial conditions for the plasmas lets them evolve, giving predictions for observations today, thereby cutting off what we know to be a dubious extrapolation.


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 Message 45 by nwr, posted 11-07-2006 3:26 PM nwr has acknowledged this reply

  
RickJB
Member (Idle past 3373 days)
Posts: 917
From: London, UK
Joined: 04-14-2006


Message 47 of 100 (362478)
11-07-2006 5:45 PM
Reply to: Message 29 by Percy
10-31-2006 12:27 PM


Re: Time for Concluding Comments
Percy writes:

What's much more interesting is that here we have yet another example of a complete know-nothing, don't-want-to-know-nothing, coming here to make scientific declarations off the top of his head.

These are the threads in which I lurk the most due to their noted ability to extract lots of digestible information from those who ARE in the know. Frustrating at times? Yes. Useful nonetheless? Absolutely!


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Son Goku
Member
Posts: 1153
From: Ireland
Joined: 07-16-2005


Message 48 of 100 (362490)
11-07-2006 6:39 PM
Reply to: Message 39 by cavediver
11-07-2006 6:24 AM


Long time, no see.
Hey, SG! Been a while... working on anything suitably on-topic for this thread?

Unfortunately what I am working on (and will be working on much more next year) is always just slightly outside the scope of these threads. Kind of related to cosmology, but cosmological discussions never really need it.

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Percy
Member
Posts: 19240
From: New Hampshire
Joined: 12-23-2000
Member Rating: 3.3


Message 49 of 100 (362511)
11-07-2006 9:22 PM
Reply to: Message 45 by nwr
11-07-2006 3:26 PM


Re: BB skepticism
nwr writes:

I already explained why the objections you listed before are inadequate, ...

My objections are inadequate to persuade you. But I am not attempting to persuade you. It does not require any objections for me to decide for myself that I am not yet ready to commit to BB cosmology.

When I said inadequate I didn't mean inadequate for me to be persuaded. I meant inadequate to qualify as legitimate scientific criticism.

.. so bottom line: if you find BB theory dubious, why?

I have avoided saying that it is dubious.

You said you were questioning it because it was tentative. I pointed out that all science is tentative, leaving me with no choice but to assume you found something in the theory that caused you to doubt it more than other theories. Pick your own word if you don't like dubious, but you can't say, "I pick this theory to question and not others, but I don't have any scientific justification."

Now you've changed your answer from an argument about tentativity and Olber's paradox and are saying it is because it is an extrapolation. But when did extrapolation become questionable? You cite the singularity as a reason, but why not doubt electricity since half of electrical engineering is imaginary numbers. Quantum theory, which has been verified out the kazoo, is awash in infinities and has to go through a renormalization step that can't be justified other than to just say, "It works."

So what is it about the extrapolation of the BB that differs from extrapolations in other fields whose theories you find acceptable? If you can't name anything then this, too, is inadequate criticism.

So far your approach sounds a lot like the personal incredulity we see from creationists: lots of reasons and complaining, but no evidence. Not a single conflicting data point or failed prediction. What makes you think your personal incredulity is different from theirs?

--Percy


This message is a reply to:
 Message 45 by nwr, posted 11-07-2006 3:26 PM nwr has responded

Replies to this message:
 Message 50 by nwr, posted 11-07-2006 11:06 PM Percy has responded

  
nwr
Member
Posts: 5590
From: Geneva, Illinois
Joined: 08-08-2005


Message 50 of 100 (362525)
11-07-2006 11:06 PM
Reply to: Message 49 by Percy
11-07-2006 9:22 PM


Re: BB skepticism
When I said inadequate I didn't mean inadequate for me to be persuaded. I meant inadequate to qualify as legitimate scientific criticism.

Well, fair enough. I agree with that. But I haven't offered it as legitimate scientific criticism. I offered it, on your request, as an explanation of my personal skepticism.

You said you were questioning it because it was tentative.

No, that mischaracterizes what I said.

The relevant comment about tentativity is with respect to the relation between redshift and recessional velocity. That relationship is derived theoretically, based on the wave theory of light. The conventional wisdom says that we should use the photon theory of light rather than the wave theory. So where does that leave the theoretical derivation?

Granted, there is empirical support for the relation between redshift and recessional velocity. But the supporting experimental data is limited by the accuracy with which we can measure. You could account for the cosmological redshift with a discrepancy in that relation, where the amount of the discrepancy is far too small to be measured. And thus the empirical evidence is not, by itself, adequate to conclude that the cosmological redshift is due to recessional velocity.

Now you've changed your answer from an argument about tentativity and Olber's paradox and are saying it is because it is an extrapolation.

Wow! You have jumbled up everything.

My comment about Olber's paradox was to indicate why I don't consider the CMBR evidence sufficiently independent of the redshift evidence. If we could actually measure recessional velocity by triangulation, you would then have independent evidence that would provide far better support. However, we cannot triangulate with anywhere near the required accuracy.

My comment on tentativity was precisely because we are using a gross extrapolation.

But when did extrapolation become questionable?

Extrapolation has always been questionable. If you can dig up some 100 year old applied math textbooks, you will likely find warnings about the unreliability of extrapolation. Near extrapolation is generally reasonably reliable, but still riskier than interpolation. Far extrapolation is always risky. The gross extrapolation involved in BB theorizes is beyond what would be considered far extrapolation.

You cite the singularity as a reason, but why not doubt electricity since half of electrical engineering is imaginary numbers.

Sorry, that's quite silly. It is not even close to being analogous.

Quantum theory, which has been verified out the kazoo, is awash in infinities and has to go through a renormalization step that can't be justified other than to just say, "It works."

There is good experimental support. As indicated above, we don't have that kind of empirical support for the precision needed for the gross extrapolation used.

So what is it about the extrapolation of the BB that differs from extrapolations in other fields whose theories you find acceptable? If you can't name anything then this, too, is inadequate criticism.

I also reject the flat earth theory. And the flat earth theory is exactly what you get if you extrapolate from purely local considerations. Newtonian mechanics was an extrapolation from low velocity local conditions. The extrapolation was not completely successful, which is why Newton has been overturned in favor of Einstein.

So far your approach sounds a lot like the personal incredulity we see from creationists: lots of reasons and complaining, but no evidence. Not a single conflicting data point or failed prediction. What makes you think your personal incredulity is different from theirs?

Well, okay. Then I guess I will have to eat some crow here. Apparently the creationists have been right all along, in their accusation that science is a religion. You are now telling me that "all science is tentative" is merely an empty slogan, and that in reality science is a doctrine which one is compelled to believe.

And to think that, all along, I had made the mistake of assuming that I should evaluate the evidence for myself, and reach my own conclusions based on my own judgement.


This message is a reply to:
 Message 49 by Percy, posted 11-07-2006 9:22 PM Percy has responded

Replies to this message:
 Message 51 by Son Goku, posted 11-08-2006 3:11 AM nwr has acknowledged this reply
 Message 52 by Percy, posted 11-08-2006 7:07 AM nwr has responded

  
Son Goku
Member
Posts: 1153
From: Ireland
Joined: 07-16-2005


Message 51 of 100 (362548)
11-08-2006 3:11 AM
Reply to: Message 50 by nwr
11-07-2006 11:06 PM


Re: BB skepticism
The conventional wisdom says that we should use the photon theory of light rather than the wave theory. So where does that leave the theoretical derivation?

The average amplitude(energy) of light in the universe is far to high to require QED, so Maxwell's theory is sufficient. Even if you use QED you pretty much get things scattering into the width of the classical beam anyway, so it makes no difference.

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Percy
Member
Posts: 19240
From: New Hampshire
Joined: 12-23-2000
Member Rating: 3.3


Message 52 of 100 (362583)
11-08-2006 7:07 AM
Reply to: Message 50 by nwr
11-07-2006 11:06 PM


Re: BB skepticism
nwr writes:

The relevant comment about tentativity is with respect to the relation between redshift and recessional velocity. That relationship is derived theoretically, based on the wave theory of light. The conventional wisdom says that we should use the photon theory of light rather than the wave theory. So where does that leave the theoretical derivation?

Son Goku has save me the trouble of an explanation in his Message 51. You're approaching BB theory just like a creationist would. You are a priori skeptical of the theory due to personal incredulity, and now you're flailing about looking for reasons.

Granted, there is empirical support for the relation between redshift and recessional velocity. But the supporting experimental data is limited by the accuracy with which we can measure.

As is all science. Look, this is very simple. What is it about BB theory that is *different* from other theories that leads you to have more reservations about it than you do for the other theories? Criticizing BB theory for things that are true of all theories is silly.

It looks to me like you're not doing your homework. The likelihood is tiny that you're going to come up with meaningful criticisms of BB theory just sitting there in your armchair. You might at least start investigating the weaknesses that cosmologists themselves see in BB theory.

You could account for the cosmological redshift with a discrepancy in that relation, where the amount of the discrepancy is far too small to be measured. And thus the empirical evidence is not, by itself, adequate to conclude that the cosmological redshift is due to recessional velocity.

Uh, no.

If the discrepancy is too small to measure, then it could have no meaningful effect on our current measurements. Hubble's original measurements were off by a factor of at least two because our information about the brightness of certain star types wasn't as good back then, but even this factor of two revealed an expanding universe.

Now you've changed your answer from an argument about tentativity and Olber's paradox and are saying it is because it is an extrapolation.

Wow! You have jumbled up everything.

My comment about Olber's paradox was to indicate why I don't consider the CMBR evidence sufficiently independent of the redshift evidence.

Always possible that I've "jumbled up everything," but if you don't want me drawing my own conclusions about what you're thinking, then the next time I rebut your use of Olber's paradox I suggest you respond instead of ignoring for a message or two.

If we could actually measure recessional velocity by triangulation, you would then have independent evidence that would provide far better support. However, we cannot triangulate with anywhere near the required accuracy.

This is just like the creationist approach, general complaining about why they don't like something and no evidential support. Why don't you criticize something specific. This is from the Wikipedia article on the Cosmic Distance Ladder: "The cosmic distance ladder refers to the succession of methods by which astronomers determine the distances to celestial objects." Read the rest of the article and criticize that! Or something specific from somewhere at least.

My comment on tentativity was precisely because we are using a gross extrapolation.

But when did extrapolation become questionable?

Extrapolation has always been questionable.

Oh, get off it. You can misuse any method, including extrapolation. There's nothing inherently wrong with extrapolation. Creationists use recent sun data, extrapolate it, and claim the sun is shrinking at an extreme rate that would mean it was the size of the earth's orbit at the time of the dinosaurs. This extrapolation is as silly as making a couple measurements as the tide is coming in at La Jolla and calculating that within a few days the ocean will be lapping at the city limits of Phoenix.

So tell us what, specifically, is wrong with the extrapolation used in BB theory.

You cite the singularity as a reason, but why not doubt electricity since half of electrical engineering is imaginary numbers.

Sorry, that's quite silly. It is not even close to being analogous.

Not if you don't think about it, but infinitely dense matter isn't real, and neither are imaginary numbers.

Quantum theory, which has been verified out the kazoo, is awash in infinities and has to go through a renormalization step that can't be justified other than to just say, "It works."

There is good experimental support. As indicated above, we don't have that kind of empirical support for the precision needed for the gross extrapolation used.

More unspecific criticism.

Both QED and BB theory have extremely strong experimental *and* theoretical support. If there's some qualitative or quantitative flaw in BB theory that in character is not possessed by other theories like QED then please let us know what it is, but stop with all the unspecific disparagement. BB theory is tentative just like all theory. I'm not holding it up as an unchallengeable icon, but I am saying that if you're going to level criticism at it then at a minimum you must find criticism that possesses at least some semblance of the same scientific legitimacy as the supporting evidence.

I also reject the flat earth theory. And the flat earth theory is exactly what you get if you extrapolate from purely local considerations. Newtonian mechanics was an extrapolation from low velocity local conditions. The extrapolation was not completely successful, which is why Newton has been overturned in favor of Einstein.

Yeah, and I believe it was evidence that caused the challenge to Newtonianism. What evidence is causing your challenge to the BB? What anomalous data can you point to? What theoretical conundrums indicate problems?

Well, okay. Then I guess I will have to eat some crow here. Apparently the creationists have been right all along, in their accusation that science is a religion. You are now telling me that "all science is tentative" is merely an empty slogan, and that in reality science is a doctrine which one is compelled to believe.

And to think that, all along, I had made the mistake of assuming that I should evaluate the evidence for myself, and reach my own conclusions based on my own judgement.

Well, I see now I'm not only dealing with Ole Poor Buz, but also Ole Poor Nwr. I guess I have this effect on people. :D

Seriously, do I need to point out the inaccuracies in that characterization of my position on tentativity? Or can we just forget that tripe and move on.

--Percy

Edited by Percy, : Grammar.


This message is a reply to:
 Message 50 by nwr, posted 11-07-2006 11:06 PM nwr has responded

Replies to this message:
 Message 53 by cavediver, posted 11-08-2006 7:44 AM Percy has not yet responded
 Message 54 by cavediver, posted 11-08-2006 7:50 AM Percy has not yet responded
 Message 55 by nwr, posted 11-08-2006 6:07 PM Percy has responded

  
cavediver
Member (Idle past 2026 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 53 of 100 (362588)
11-08-2006 7:44 AM
Reply to: Message 52 by Percy
11-08-2006 7:07 AM


Re: BB skepticism
You might at least start investigating the weaknesses that cosmologists themselves see in BB theory.

:D :D :D

Sorry Percy, but I have been waiting for so so long for this to be said/recognised by a non-professional of the field here at EvC. Thank you.

There is of course the "slight" difficulty that understanding the problems meaningfully is often considerably more difficult than understanding the theory.

And of course, NWR's problems come from not appreciating the whole theory (as he himself admits) Such appreciation, as you are bored of hearing me say, only comes from working directly in the field under question. My fields are(were) general relativity, quantum gravity and string/M theory. Consequently, I am NOT an expert at BB cosmology.


This message is a reply to:
 Message 52 by Percy, posted 11-08-2006 7:07 AM Percy has not yet responded

  
cavediver
Member (Idle past 2026 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 54 of 100 (362590)
11-08-2006 7:50 AM
Reply to: Message 52 by Percy
11-08-2006 7:07 AM


Re: BB skepticism
Not if you don't think about it, but infinitely dense matter isn't real, and neither are imaginary numbers.

Just to pick up a possible new thread... imaginary numbers are not Real by definition, but what makes you so sure they are not real? The universe seems to rest upon the nature of complex numbers (via QM). Complex numbers are not apparent in our everyday world, but then neither are a 4 dimensional indefinite metric basis of space-time, Fermi-Dirac and Bose-Einstein statistics, etc.


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nwr
Member
Posts: 5590
From: Geneva, Illinois
Joined: 08-08-2005


Message 55 of 100 (362691)
11-08-2006 6:07 PM
Reply to: Message 52 by Percy
11-08-2006 7:07 AM


Re: BB skepticism
I'll start be rewording my response to a couple of points in Message 49.

Percy writes:

Quantum theory, which has been verified out the kazoo, is awash in infinities and has to go through a renormalization step that can't be justified other than to just say, "It works."


QM makes two kinds of claims. First, it asserts equations, and uses those equations to make predictions. I shall refer to those as epistemic claims. Secondly, it claims that certain particles exist (a variety of quarks, for example). I shall refer to that as a metaphysical claim.

The argument "it works" is fine for the epistemic claims. But it does not settle the metaphysical claims. It is my understanding that there are some quantum physicists who do not accept the metaphysical claims, yet do accept the epistemic claims. They take the entities as convenient fictions used as place holders in the equations.

In case you wonder, no I don't currently accept the metaphysical claims of QM.

..., but why not doubt electricity since half of electrical engineering is imaginary numbers.

The use of complex numbers in electrical engineering makes no metaphysical claims.

Getting back to BB, I have no problem with the epistemic claims. It is with respect to the metaphysical claims that I am not satisfied with the supporting evidence. When BB makes assertions about recessional velocity, I simply treat that as a place holder for terms in the equation, and I don't connect it to the actual (but unknown) velocity of the cosmic object.

Now back to the current message (Message 52).

Son Goku has save me the trouble of an explanation in his Message 51.

I have no problem with what Son Goku posted. I see it as supporting my point. But perhaps I was too cryptic.

There are two kinds of scientific law. Some are purely logical, while others are empirical. For the purely logical laws, deductive inference is sufficient. Moreover, we can usually take the purely logical laws as exact. For the empirical laws, we depend on empirical evidence as support, and we cannot expect these laws to be more accurate than the supporting empirical observations.

My comment about photons vs. wave theory was simply to make the point that we are talking about an empirical law rather than a purely logical law. I don't see Son Goku's post as contradicting that.

You are a priori skeptical of the theory due to personal incredulity, and now you're flailing about looking for reasons.

Please don't tell me what I believe. Your ability at reading minds is seriously flawed.

Granted, there is empirical support for the relation between redshift and recessional velocity. But the supporting experimental data is limited by the accuracy with which we can measure.

As is all science. Look, this is very simple. What is it about BB theory that is *different* from other theories that leads you to have more reservations about it than you do for the other theories? Criticizing BB theory for things that are true of all theories is silly.


I will take that as indicating that you failed to understand my point. I'll try to explain it in more detail.

From the empirical evidence, we can reasonably assert that
R = f(v) + g(s)
where R is the observed redshift (or blue shift, as the case may be), v is the recessional velocity and s is the distance of the object.

Lab testing gives us a formula for f, roughly the formula for Doppler shift but perhaps modified by relativistic considerations. Lab tests also tell us that g is too small to be measured.

The argument that cosmological redshift implies expansion is based on taking the function g to be zero. However, g could easily be too small to be measured in earth bound tests, yet be plenty large enough to fully account for the observed cosmological redshift.

You might at least start investigating the weaknesses that cosmologists themselves see in BB theory.

To do that would be to behave like a creationist, to assume that a minor flaw refutes the whole BB theory.

I'll repeat yet again, that I am not trying to "come up with meaningful criticisms of BB theory", although you are attempting to goad me into doing so. I have never asserted that BB is wrong. My assertion is that I don't currently find the supportive evidence sufficient to satisfy me.

Always possible that I've "jumbled up everything," but if you don't want me drawing my own conclusions about what you're thinking, then the next time I rebut your use of Olber's paradox I suggest you respond instead of ignoring for a message or two.

If you want to spend your time rebutting claims that I have never made, that's up to you. But I see no point in responding to such rebuttals.

If we could actually measure recessional velocity by triangulation, you would then have independent evidence that would provide far better support. However, we cannot triangulate with anywhere near the required accuracy.

This is just like the creationist approach, general complaining about why they don't like something and no evidential support. Why don't you criticize something specific. This is from the Wikipedia article on the Cosmic Distance Ladder: "The cosmic distance ladder refers to the succession of methods by which astronomers determine the distances to celestial objects." Read the rest of the article and criticize that! Or something specific from somewhere at least.


I happen to think the way distances are measured to be an example of excellent empirical method. That you ask me to criticize it only demonstrates your complete failure to understand my point. May I suggest more careful reading.

Note that my comment was not "general complaining". It was not any kind of complaining.

While our measurement of cosmological distances is based on careful use of a succession of methods, we have no comparable procedure for measuring velocity. Our ability to measure velocities is quite limited. My comment was simply that if we had better ways of determining velocity (as rate of change of distance), and if these corroborated claims from BB, that would go a long way toward satisfying me as to the correctness of the metaphysical claims of BB. That's not a complaint. That's an illustration of why I am not currently satisfied with the supporting evidence.

There's nothing inherently wrong with extrapolation.

Sorry to disagree, but extrapolation is inherently risky. Okay you are not a mathematician, so you might not be aware of this. It is certainly well known to mathematicians.

Often, when we use extrapolation, we have auxilliary evidence that allows us to estimate the likely error in the extrapolation. However, in the case of the velocity of distant objects, we lack that auxilliary evidence.

Seriously, do I need to point out the inaccuracies in that characterization of my position on tentativity?

Your behavior speaks louder than your words. You keep arguing with me. But I have not posted anything that warrants such arguing. As best I can tell, cavediver doesn't find my position nearly as troubling as you find it (see the last paragraph of Message 53). It is as if you are trying to coerce me into an orthodoxy.

What I have been discussing, is that the evidence I have seen does not satisfy me as sufficient for acceptance of BB theory. As I have clarified in this post, I am talking about the metaphysical claims of BB theory, not the epistemic claims (which I accept). I don't know why you expect me to accept your preferred metaphysics. It sure sounds as if you have made science into a religion.

Or maybe you haven't been reading what I have been posting.


This message is a reply to:
 Message 52 by Percy, posted 11-08-2006 7:07 AM Percy has responded

Replies to this message:
 Message 56 by Son Goku, posted 11-08-2006 7:56 PM nwr has responded
 Message 58 by Percy, posted 11-08-2006 9:35 PM nwr has responded

  
Son Goku
Member
Posts: 1153
From: Ireland
Joined: 07-16-2005


Message 56 of 100 (362715)
11-08-2006 7:56 PM
Reply to: Message 55 by nwr
11-08-2006 6:07 PM


Metaphysical claims
Perhaps to aid the discussion, what scientific theories do you see as having well justified metaphysical claims?

Also a small side question, what metaphysical claims of QM do you not accept? Is it just the existence of certain particles or is it other claims as well?
Do you only consider certain particles to be questionable, i.e. quarks are, but not electrons.

I think both these questions are important to see how you view any given physical theory.

Edited by Son Goku, : Grammar and spelling.


This message is a reply to:
 Message 55 by nwr, posted 11-08-2006 6:07 PM nwr has responded

Replies to this message:
 Message 57 by nwr, posted 11-08-2006 8:53 PM Son Goku has not yet responded

  
nwr
Member
Posts: 5590
From: Geneva, Illinois
Joined: 08-08-2005


Message 57 of 100 (362733)
11-08-2006 8:53 PM
Reply to: Message 56 by Son Goku
11-08-2006 7:56 PM


Re: Metaphysical claims
Perhaps to aid the discussion, what scientific theories do you see as having well justified metaphysical claims?

Good question. In one sense, I do tend to be generally skeptical of metaphysical claims. I guess I have a view something along the lines of Kant's idealism, although I probably disagree with much of what Kant wrote (or would disagree if I ever got around to reading it). Kant's view is that we cannot access the world in itself, all we can access is our perceptual experiences of the world.

From the Kantian perspective, we could say that all scientific entities are useful fictions, and in some sense I agree with that. However, the meaning of words is in their use, and we don't use "real" to talk about an inaccessible world in itself. There are lots of ordinary things that we ordinarily consider real, whether or not they are useful fictions. From that point of view, what makes something real is our familiarity with it. So electrons are real; I deal with electronics, so electrons are familiar. But I don't deal with quarks, so they are less familiar and less real.

To muddy the waters, I have no problem with the metaphysical claims of Newtonian mechanics. And I have no problem with at least some of the claims of GR, even though they contradict the Newtonian claims. Again, its a matter of familiarity. However, I am not so sure of black holes, so I have witheld full acceptance of them.


This message is a reply to:
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Percy
Member
Posts: 19240
From: New Hampshire
Joined: 12-23-2000
Member Rating: 3.3


Message 58 of 100 (362745)
11-08-2006 9:35 PM
Reply to: Message 55 by nwr
11-08-2006 6:07 PM


Re: BB skepticism
Hi Nwr,

What we've seen is that the requests for evidence pushed you further and further from factual considerations and into philosophical arguments. The bottom line is that you have no evidential or theoretical basis for being personally skeptical of BB theory.

You might find your philosophical arguments satisfying, but consider how you'd feel if a creationist used the same type of arguments to argue for flood theory. Radiometric dating requires extrapolation of decay rates over long periods of time, and how do we know that small unmeasurable differences don't become significant over a few thousand years. The geologists make both epistemic and metaphysical claims, and when they make claims about the way layers formed long ago, that's just a metaphysical claim with unsatisfying supporting evidence.

A wise philosopher once said (it was Crash, actually, Message 14), "If you're being asked to defend a scientific proposal or model, and you're referencing Popper instead of evidence, then what you're doing is nonsense." Sylas's reply was, "Spot on!"

Speaking of Sylas, he once said this about the Big Bang in Message 5:

Sylas writes:

The driving model for the big bang is general relativity. This is one of the most stringently tested models in science, and so far it has passed all tests will flying colors. A consequence of this model is an expanding spacetime; and this too is confirmed by observations. No other model makes sense of what we observe; and no other model is as thoroughly tested.

Cavediver had some excellent posts in the same thread, and maybe he'll spend some time on the issue here. I think my real problem is that your casual dismissal of BB theory as insufficiently supported is not made from a position of knowledge, and you conceded that at the outset. But it was a great opportunity to highlight the problems with challenging theory with only personal or philosophical skepticism, and I thank you for being an extremely challenging foil.

--Percy


This message is a reply to:
 Message 55 by nwr, posted 11-08-2006 6:07 PM nwr has responded

Replies to this message:
 Message 59 by nwr, posted 11-08-2006 11:25 PM Percy has responded

  
nwr
Member
Posts: 5590
From: Geneva, Illinois
Joined: 08-08-2005


Message 59 of 100 (362763)
11-08-2006 11:25 PM
Reply to: Message 58 by Percy
11-08-2006 9:35 PM


Re: BB skepticism
What we've seen is that the requests for evidence pushed you further and further from factual considerations and into philosophical arguments.

Nonsense.

Your repeated mischaracterization of what I have been saying has caused me to use philosophical terminology to see if you can understand that better than plain English. But I have not made any philosophical arguments.

The bottom line is that you have no evidential or theoretical basis for being personally skeptical of BB theory.

That's your opinion. I have repeatedly stated why I consider the evidence unsatisfying. That you don't accept my explanation is not my problem.

My last post, which you mischaracterize as "philosophical arguments", went into more detail than previous posts on why I am unsatisfied with the empirical evidence.

You might find your philosophical arguments satisfying, ...

Philosophy is bunk (paraphrasing Henry Ford).

..., but consider how you'd feel if a creationist used the same type of arguments to argue for flood theory.

If a creationist wants to personally believe flood theory, that's fine with me. If he tries to persuade others, I'll point out the problems.

May I remind you that I have not tried to persuade others. I only posted reasons for my skepticism because of your request. I have no interest in persuading others. Everybody should evaluate the evidence and come to his own decision. I'm offended that you want to deny me the right to make my own judgement of the evidence.

Radiometric dating requires extrapolation of decay rates over long periods of time, and how do we know that small unmeasurable differences don't become significant over a few thousand years.

Give it up, Percy. You still are missing the point entirely.

The radiometric scale has been well calibrated over the range being used. Therefore, it is interpolation within that range, and not extrapolation. Interpolation is quite robust. It does not suffer from the problems of extrapolation.

In the case of the velocity of distant objects, where velocity is measured as rate of change of distance, I doubt that we have any calibration points outside the solar system. It's as if we had calibrated radiometric dating up to 10 years ago, had no data points older than that, and then used it for ages 1 billion years ago.

I think my real problem is that your casual dismissal of BB theory as insufficiently supported is not made from a position of knowledge, and you conceded that at the outset.

Your "casual dismissal of BB theory" is another mischaracterization of my position. Firstly, my position is to postpone judgement until more evidence is available. I still consider it to be possibly correct, though not yet sufficient to persuade me. That's hardly a dismissal. Secondly, it is not casual. I have explained in some detail why I consider the evidence insufficient to satisfy me.

You are still treating science as a religion. You are demanding that we accept beliefs handed down from a high priesthood, instead of evaluating the evidence ourselves and making our own judgements. Science cannot work that way.


This message is a reply to:
 Message 58 by Percy, posted 11-08-2006 9:35 PM Percy has responded

Replies to this message:
 Message 60 by Son Goku, posted 11-09-2006 3:50 AM nwr has responded
 Message 61 by Percy, posted 11-09-2006 7:35 AM nwr has responded

  
Son Goku
Member
Posts: 1153
From: Ireland
Joined: 07-16-2005


Message 60 of 100 (362789)
11-09-2006 3:50 AM
Reply to: Message 59 by nwr
11-08-2006 11:25 PM


To invert the waters,.....
To muddy the waters, I have no problem with the metaphysical claims of Newtonian mechanics.

Funny, because as time has progressed, I have come to see momentum and force as useful fictions and come to see electrons, quarks and black holes as more real.

Anyway, I see you have strict requirements on justifying metaphysical claims. The fact that you extend this to the everyday is a good thing, as I think people are too harsh on things like electrons without being equally harsh on certain everyday concepts.

So let's take the epistemic road, how decent a theory is the big bang in this regard?
Would I be correct in saying you don't believe it is unique enough?
(i.e., that too many of its predictions and gross features can be replicated by other theories)


This message is a reply to:
 Message 59 by nwr, posted 11-08-2006 11:25 PM nwr has responded

Replies to this message:
 Message 64 by nwr, posted 11-09-2006 12:26 PM Son Goku has not yet responded

  
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