1. Hints of structure beyond the visible universe

Comment #191081 by Geraint on June 10, 2008 at 7:33 am

If you look at the original article, it's 10^100 (ten to the power of one hundred). Sub- and superscript formatting often seems to get killed.

2. Car dealership advert tells atheists to 'shut up'

Comment #185596 by Geraint on May 28, 2008 at 6:53 am

Atheists tell car dealership to 'grow up'.

3. Missing matter found in deep space

Comment #183395 by Geraint on May 22, 2008 at 3:18 am

JeremyH:
...large astrological bodies...

Russell Grant?

4. Missing matter found in deep space

Comment #183376 by Geraint on May 22, 2008 at 2:20 am

Rtambree: This doesn't explain the flat rotation curve of galaxies. Some reporter has misrepresented this.

This is not the matter you are looking for. You can go about your business. Move along.

Actually, I thought it was more carefully written than many science reports. It explicitly says that this is some of the previously undetected baryonic matter, and even contrasts it with the non-baryonic matter that draws the gas into the filaments where it shock-heats.

5. Missing matter found in deep space

Comment #182939 by Geraint on May 21, 2008 at 6:23 am

RickM: I've heard of the filament structure idea before as well. Is this stuff left over from old stars as the universe is "yanked" apart by expansion?

No, these filaments are on larger scales than that. As the denser parts of the Universe collapse, filaments are formed quite naturally, leading to a 'cosmic web' sort of structure.

Here's a picture of it from a simulation of dark matter:
http://www.mpa-garching.mpg.de/galform/millennium/seqB_063.jpg

Edit: I should add, that picture's about three billion light years on a side. We can actually see the filamentary structure in galaxy surveys, because the galaxies are strung out along the filaments. But it's very hard to see the other, diffuse gas in the filaments that hasn't collapsed into galaxies, and that's the point of this news article.

Incidentally, the reference to the 'backbone' is meant to conjure up an image of these filaments being the most important feature of the structure. It's not meant to imply there's one dominant structure somewhere in the Universe. You can see in the simulation that there is complex structure even though the picture is homogeneous on large scales.

6. Missing matter found in deep space

Comment #182830 by Geraint on May 21, 2008 at 2:54 am

rivetheretic: I'm surprised about the oxygen. Why oxygen? Hydrogen and helium I could understand, that's left over from the big bang. Iron or nickel I could understand; other elements tend toward iron and nickel in nuclear reactions because they are the most energetically favorable elements.

As other people have said, plenty of oxygen gets produced. There will be lots of hydrogen and helium in the filaments too, but it's also a matter of what you can detect. For gas at a given temperature, and using a given instrument, only certain species radiate strongly enough in the right wavelength range for the instrument to detect.

7. Discussion between Richard Dawkins and Paula Kirby

Comment #178306 by Geraint on May 11, 2008 at 6:04 am

Over on the forums, someone recently posted this link to a talk by John Maynard Smith related to that question:
http://atheistmedia.blogspot.com/2008/04/john-maynard-smith-royal-institution.html

I assume Dawkins' take would be similar: something to do with the presence of faithful replicators that can generate (near-)infinite variety. That does sound a bit of a strange definition until the rationale's explained, though. Even for someone who can describe the whole course of evolution in three minutes, it would be tough to explain quickly in response to a question after a talk.

8. Is religion a threat to rationality and science?

Comment #173918 by Geraint on May 1, 2008 at 11:04 am

NGC 6397 is over a billion light years away. I should not have used the word 'billions' [as it does imply two or more] in the sense of investigating SNR's within the Milky Way. My apologies.

No it's not. It's a nearby globular cluster.

9. Is religion a threat to rationality and science?

Comment #173880 by Geraint on May 1, 2008 at 10:13 am

We're talking billions of light years here, not accounting for unknown gravitational effects on the speed of light - though this does not affect the actual distance. Don't we think the law of averages would play out and create an even playing field no matter which direction we are looking?

Seeing them in galaxies other than our own would be even harder. We can see supernovae in distant galaxies, but only for a short time after the initial explosion, when they're at their brightest. Seeing old relics is a vastly different proposition. You seem to be trying to make an argument here without knowing even the most elementary things about the relevant astronomy.

10. Is religion a threat to rationality and science?

Comment #173848 by Geraint on May 1, 2008 at 9:41 am

So if we can not see the line [clearly] between phase two and phase three, why can we not see transitional evidence between the two? There should be thousands of SNR's in this transition phase of every flavor if the universe is billions of years old, no?

What I'm saying is that the whole thing is one big transition phase. There is no non-transition phase.

I think to make the argument you're making requires misunderstanding of both the physics and the observational problems. Supernovae happen in the plane of the galaxy, and you'd have to look for faint, diffuse emission against a dense background of literally millions of other point sources and sources of diffuse emission.

The whole argument's just a total non-starter.

11. Is religion a threat to rationality and science?

Comment #173817 by Geraint on May 1, 2008 at 9:10 am

The gist of the creationist's argument is right, observations of ongoing radioactive decay in supernova remnants can only date the very young ones.

My question - we can only 'date' very young ones or only observe very young ones?

We can only date very young ones. They meant what they said.

Similarly, the fact that you can't weigh an aircraft carrier with a set of kitchen scales doesn't mean that aircraft carriers don't exist.

There is no sharp dividing line between different phases in the development of an SNR, as you seem to imply. Different physical processes dominate at different times. As the remnant evolves it gets harder to observe until it blends into the background. This blending process is what introduced heavy elements into the gas that (for example) went on to form the solar system.

Of course, if you're going to use supernova models to date anything you'd need to explain all those neutron stars which are thought to be the relics of stars that went supernova, and the light from supernovae so distant that the light set off well over 100000 years ago.

But really, the whole idea that supernova frequencies are in conflict with cosmological models is just absurd.

12. Lying for Jesus?

Comment #156002 by Geraint on April 6, 2008 at 1:27 pm

Though it depends upon the various sects, most recognize the Humanist Manifesto as authoritative...

Never heard of it.

Is it too hard to imagine people who were just getting on with their lives, came across religious ideas, and thought they were silly?

There were religious bits and pieces at school, but I can't say I ever really thought anyone took them seriously.

Then I came across people who did take it seriously, considered the claims of the religious again, and they still just looked silly.

There's nothing more to it than that. No conspiracy. Just some people who want to get on with their lives without the silliness impinging.

13. Fleabytes

Comment #140418 by Geraint on March 7, 2008 at 9:24 am

mlearnedfriend:

Please learn how to use apostrophes. Cheers.

14. The Salamander's Tale

Comment #139550 by Geraint on March 6, 2008 at 4:26 am

wooter wootered:

If we go to a department store and just take look at the electronics department and see all kinds of equipment, tv, cd players, Mp3 phones, toasters etc,

You do realise none of these things reproduces, right? Maybe you don't; I can't honestly say that would surprise me.

15. Fleabytes

Comment #138520 by Geraint on March 4, 2008 at 1:19 pm

Steve Zara wrote:

Max Tegmark is fun. A bit "way out", but he comes up with exciting ideas.

I only realised this side of him after reading this forum. In fact he publishes a lot of good, solid science papers, and only allows himself one 'wacky' paper for every ten mainstream ones. More typical would be:

http://arxiv.org/abs/astro-ph/0608632

16. Fleabytes

Comment #138195 by Geraint on March 4, 2008 at 3:43 am

Thanks, MPhil. Good old wikipedia...

17. Fleabytes

Comment #138186 by Geraint on March 4, 2008 at 3:29 am

MPhil wrote:

And, he [Quine] has proven that the only abstract entities one needs to assume at minimum are sets.

Maybe I'm being dumb, but what does this even mean? Perhaps it's too technical to go into in a forum post. It's just that the way I understood it, the Russell paradox (which you mentioned above) compelled the development of category theory as a more general framework that avoided some of these contradictions.

18. Bill Maher on Larry King Live

Comment #127237 by Geraint on February 15, 2008 at 4:51 am

Well, fair enough, I haven't done the calculation for different decay paths. But you are extracting energy from the reaction at the end of the day. I just object to the idea of this idea of radioactivity as some sort of mysterious, infectious property spawned by power stations. Radioactivity doesn't come for free, it uses the energy stored in the binding energy of the nuclei.

19. Bill Maher on Larry King Live

Comment #127211 by Geraint on February 15, 2008 at 3:42 am

Nuclear power does create radioactivity, by fissioning relatively stable nucleii into more unstable (and so more radioactive) by-products.

Well, it creates it in the sense I described in the second half of that paragraph: the waste is more radioactive than the fuel, but with a shorter half-life, so is more dangerous in the short term. I still don't think I'd call it 'creating radioactivity', though. After all, Uranium-238 does spontaneously decay into other radioactive isotopes, but with a half life comparable to the age of the Earth. And its decay products have less energy available to produce radiation, else power stations wouldn't be producing power at all!

I suppose it's just a semantic issue, really.

20. Bill Maher on Larry King Live

Comment #127186 by Geraint on February 15, 2008 at 2:51 am

See, I think this is where you and I differ: I don't view radioactivity as harmless, ever. Even if one day the sun expands and envelops the earth, the radioactivity has already caused damage, to us, to other animals, to plants, to the earth. Just because radioactivity will one day (perhaps) be negated to zero, does not mean it is harmless. Difference in ethics perhaps?

Nuclear power doesn't create radioactivity. The fuel for power stations gets dug up out of the ground. What it does do is concentrate radioactive substances - fuel needs to be concentrated to produce useful energy - and produce isotopes that decay more quickly and so are more dangerous than longer-lived ones but for a shorter amount of time. So you can deal with this waste by putting it somewhere safe.

If it was radioactivity I was concerned about, I'd much rather live next to Yucca Mountain than a house in Cornwall built on granite. Naturally occurring radioactive argon is released from the granite, and can accumulate on poorly ventilated houses. I'd also make sure I stayed away from other people, who concentrate naturally occurring radioactive isotopes of potassium in their bodies.

21. Christopher Hitchens Debates Timothy Jackson

Comment #123524 by Geraint on February 7, 2008 at 10:03 am

1. Take the "multiverse" or "parallel universe" idea often quoted by these gentlemen. The idea that additional universes are created by the bazillions over time (past, present and future) requires a "universe generator" mechanism as a minimum. This leads to the question of what created the original universe generator? This is subject to exactly the same logical problems of infinite regression as a god creator.

I think multiverse hypotheses are meant to address the fine tuning problem rather than the question of why there's a universe at all. Explaining a mechanism that can generate any number of universes with various properties might turn out to be simpler than explaining one particular universe with a particular set of properties. Or it might not. I don't see a particular reason to rule a multiverse in or out given the current state of knowledge.

2. The current "big bang" theory, in order to properly explain the present state of the universe, requires an uneven rate of expansion. Most damning in this respect is that in the initial instants it requires expansion at hyper-light speed from what would have to be the largest black hole ever.

Why should the Universe expand at constant speed? It certainly shouldn't according to GR, unless it's empty. Really, I'm a bit puzzled what you're driving at.

Your point 3 is just wrong. Are you trying to claim you know of some observation inconsistent with GR? If so, let's see your calculation.

22. Letters: Theology has no place in a university

Comment #122344 by Geraint on February 5, 2008 at 7:51 am

And the big bang . . . POOF

The rest of that post contains such entertainingly ignorant nonsense that I can only assume anyone who'd bother to post it must be a troll.

23. Letters: Theology has no place in a university

Comment #116516 by Geraint on January 26, 2008 at 5:22 pm

By the way, I have an earned PhD.

I'm glad I didn't have to try to read your thesis.

24. God rest you merry atheist

Comment #99986 by Geraint on December 18, 2007 at 2:49 am

Comment #99915 by Dr Benway on December 17, 2007 at 8:33 pm
...
"Santa" with his jolly red suit and sleigh of eight flying reindeer was an invention of the Coke-Cola Bottling Co. If you don't like it, select another story for the kids.

http://www.snopes.com/cokelore/santa.asp

25. The Four Horsemen: on Christmas

Comment #99972 by Geraint on December 18, 2007 at 2:23 am

Comment #99869 by Ben Jennings on December 17, 2007 at 5:59 pm
Forget audio only, I wanna see more of Hitch's awesome house! ;)

Oddly enough, you can, about half way through his interview on 'In Depth':
http://www.richarddawkins.net/article,1655,In-Depth-Christopher-Hitchens,Book-TV-C-SPAN2

26. Jumbo shrimp, creationist astronomy

Comment #98723 by Geraint on December 14, 2007 at 6:25 am

Nonsense video. I just wanted to add my voice to the 'no Quicktime please' camp.

27. Why Christians should take Richard Dawkins seriously

Comment #76980 by Geraint on October 8, 2007 at 2:39 am

I mean you agree that there are objectively two particles out there (even though they share part of their quantum state), correct?

Well, I'm not quite sure what you mean. Isn't the nature of what's out there what we're trying to ascertain? You seem to be demanding before we start that the fundamental objects must be particles.

In any case, can you describe a model of a physical objective reality that accounts for Bell's test results and which remains coherent for observers in different frames of reference?

How about you tell me what happens in the reduction of a one-particle state first? This Bell's test stuff is all a red herring.

You seem to demand that an objective model of reality forgets about the results of QM (e.g. w.r.t. the nature of particles) and special relativity (simultaneity is observer-dependent). Demanding that physical reality is a tweaked version of Galilean classical mechanics won't work. I'm glad people are trying to understand it rather than writing it off as unknowable as you seem to.

28. Why Christians should take Richard Dawkins seriously

Comment #76816 by Geraint on October 7, 2007 at 11:18 am

Right, but I don't see how the change of wording affects my argument. Let's make away with the wording of "superluminal action" and use "shared quantum state" instead. That state does not exist before the first measurement is made, and the second measurement will always produce the same result as the first one. So epistemological coherence is violated again: The first observer will claim that measuring device A fixed the two particles' shared quantum state and that measuring device B only read that state anew, whereas the second observer will claim the opposite, namely that measuring device B fixed the two particles' shared quantum state and that measuring device A only read it anew. They can't be both right, and both base their claims on the same naturalistic logic (namely on the premise that the two particles objectively exist out there).

It seems to me you're creating a problem where none exists. The particles are always constrained to agree with respect to polarization measurements made in the same direction. You know that before either experimenter makes a measurement at all.

Talking about naturalistic logic implying that 'two particles objectively exist out there' makes it sound like you're still thinking of little bullets trundling along happily, until one gets measured and tells the other how to configure itself. It just doesn't work like that, and only our middle-world experience leads us to think that it should. There is an entangled two-particle quantum state.

29. Why Christians should take Richard Dawkins seriously

Comment #76229 by Geraint on October 5, 2007 at 6:30 am

Bell's test results appear to violate epistemological coherence and therefore to falsify all naturalistic ontologies (or at least all ontologies of scientific realism). The reason is that two observers in different frames of reference will observe different measurements first take place, and therefore will disagree about which measuring device superluminally affected the other. Which is analogous to two observers disagreeing about which tennis player first served the ball.

Only just got around to checking the thread, and I see Danielos will be away. Ah well.

The entanglement in a Bell test type experiment provides a constraint on the joint probabililty of the result of two measurements. The probability is the same in whichever order an observer sees the measurements take place.

This is the whole point about entanglement and non-locality. The two measurements are measurements of one entangled (non-local) quantum state, not two states that superluminally communicate.

30. Letters: Theology has no place in a university

Comment #75667 by Geraint on October 3, 2007 at 8:45 am

Well, the problem isn't the Oxford theology department per se, but the theological colleges which only admit students to read theology. Therefore their members spend all their time with other students also doing theology, and not experiencing the mix of different people and disciplines that an Oxford undergraduate usually experiences. Presumably this social and academic mix is felt to be more important to someone fresh out of school than to a mature student who will tend to be more narrowly concerned with the course offered by the university, rather than with the whole experience offered.

One can be a member of a 'normal' Oxford college and still study theology.

31. Why Christians should take Richard Dawkins seriously

Comment #75219 by Geraint on October 2, 2007 at 4:20 am

The Bell test results falsify all non-local naturalistic models,

Yes.

and, arguably, falsify all models of an objective and direct physical reality.

No, unless objective and direct means tiny billiard balls bouncing off each other. In which case I may as well take theism as requiring a man with a long, white beard sitting on a cloud.

The hard thing about an ontology of QM was and still is the measurement paradox. If anything, the Bell test makes the job easier by restricting the sorts of ontologies we might consider. But I know I should resist getting into this, since I managed to resist on the McGrath thread...

32. Why Christians should take Richard Dawkins seriously

Comment #75190 by Geraint on October 2, 2007 at 2:28 am

It's true that TGD was somewhat ambiguous on this point, perhaps deliberately since a rigorous treatment of complexity would massively increase the length and unreadability of the book.

Still, it's fairly clear Dawkins was talking about a macroscopic description of complexity. If you take two bodies of different temperatures and allow them to come into equilibrium, the entropy of the system will increase, and yet the description of their macroscopic state will become more concise. The level at which you 'coarse-grain' your description is important. Liouville's theorem and all that...

The problem is subtle. The early, nearly homogeneous Universe seems clearly to be of lower macroscopic complexity than the present one, and yet of lower entropy. One has to consider the gravitational degrees of freedom present in the early Universe; not something you normally have to think about in thermodynamics. Perhaps God sustained a massive increase in entropy in order to donate such low entropy to the early Universe. ;-)

If we were talking about the resources needed for a matrix-style simulation of reality then the information-theoretic definition of complexity applied to the smallest constituents of the simulation would be more relevant. But it seems somewhat tangential to this discussion.

33. Why Christians should take Richard Dawkins seriously

Comment #74390 by Geraint on September 28, 2007 at 11:48 am

Surely you see that such an ontology is ethically empowering, makes all of life appear more beautiful, and helps blunt any misfortune that may befall us.

Perhaps this is where many atheists part company with you. The point struck home with me on the McGrath thread when you mentioned that of course the distant galaxies we observe are not really there: God feeds our consciousness such that all observers have a consistent picture of these galaxies. Well, to me, such a picture is rather desolate. Perhaps the fact that my research concerns the early Universe colours that. To imagine it wasn't really there would make the whole process rather bleak and pointless. We're all little children given arbitrary, colourful toys to play with by God.

Isn't it more beautiful and ethically empowering to be part of a species forged by natural selection over billions of years, pulling itself up by its bootstraps and finally being able to explore and understand the Universe around it? Beating its own path rather than following a celestial study programme?

Whatever, my subjective experience of what I find satisfying isn't relevant to the truth of what's out there.

34. Why Christians should take Richard Dawkins seriously

Comment #74284 by Geraint on September 28, 2007 at 3:31 am

Maybe I've even misrepresented myself. Yes, one must make some assumptions. But they get you nowhere without data. Give me a sample of numbers and I can estimate some things about the population from which they were drawn; its mean, say. The estimates don't just depend on my assumptions about the sampling and so on: they depend on the assumptions and the data. The data don't follow from any assumptions; they're not a premise of my calculation in the way I understood the meaning of the term, but clearly I could be misusing it.

I just don't consider the statistical estimation of a mean, say, as a philosophical sort of argument in which you start from premises and end up with some logical conclusion, some number. Perhaps you do. But this is what I meant by saying that it seemed to me that the spirit of Dawkins' argument was more the estimation of a probability rather than a logical deduction.

35. Why Christians should take Richard Dawkins seriously

Comment #74264 by Geraint on September 28, 2007 at 2:10 am

Well, I don't see why I should rewrite someone else's book on an internet messageboard, or point out the flaws in any parody of its arguments that someone can come up with (and one could come up with unlimited numbers of such parodies).

I did read the Nagel and Orr reviews. They really attacked the argument only tangentially, Nagel claiming that other forms of argument are as valid for talking about God, and Orr essentially saying that more data would be nice. Well, as for the former claim, let's try using the tools that have worked before, bearing in mind we're not looking for 'proof'. As to the latter - well, it's always better to have more data. Sometimes you have to make do with what you've got.

Yes, the reviews said more than that, but I'm not required to find them convincing. I haven't read Plantinga, and I can't say I'm tempted. Life's too short. It's why I held off commenting on this board until this thread (except on some interesting astronomy articles where I could answer some questions), though I must say I was sorely tempted when it came to QM stuff in the McGrath thread.

36. Why Christians should take Richard Dawkins seriously

Comment #74032 by Geraint on September 27, 2007 at 5:19 am

Comment #74023 by epeeist

Hehe. There's a good reason Bacon's standing there next to Newton in Trinity College chapel.

37. Why Christians should take Richard Dawkins seriously

Comment #74021 by Geraint on September 27, 2007 at 4:53 am

What amazes me is how some of the philosophers who've reviewed TGD (Plantinga included, apparently) fail utterly to grasp the distinction between a logical deduction from premises and an inference from data. It seems to me that they want Dawkins to play their game of arguing from premises, when this seam of reasoning about gods has been pretty exhaustively mined out. They ignore the fact that Dawkins hasn't chosen to do this, and accuse him of doing what they think he wants to do incorrectly. Yes, we can see it all boils down to the premises you choose under their methods: nothing is proved, and Dawkins makes that point clearly. That's the reason for trying to make a statistical or probabilistic inference instead.

If one viewpoint requires the data we observe - say, that science works and that no miracles happen - while another merely allows those data, then that is evidence for the first viewpoint. Not proof, but as has been rehashed again and again, we can't expect proof. I don't think the existence of consciousness helps the argument for theism in this fashion, unless one can argue that conscious inhabitants are a necessary part of any theistic universe.

Statistical inference from data is something scientists do every day but which is unfamiliar to many other people, philosphers included, clearly. Maybe that's why Dawkins' argument is so often misunderstood.

38. Why Christians should take Richard Dawkins seriously

Comment #72817 by Geraint on September 23, 2007 at 3:33 am

Please stop replying to Dianelos Georgoudis - you're only encouraging him!!!!

OK, OK. I think on this occasion we've managed to reach a conclusion to this digression about the anthropic principle though, so I'd claim it was worth it. I'm not going to try and dispute the probabilities; I'd just be guessing.

I don't really like the practice of picking on isolated sentences from TGD and using them to claim a fallacy has been perpetrated. A lot of the time I think this just comes from Dawkins trying to write clearly within the framework of a whole chapter. Making each sentence stand alone would make the book unreadable, which would no doubt please some theists.

I can't say I found the Nagel or Orr reviews at all convincing. TGD isn't my favourite book of RD's either, but the subject matter is somewhat less inspiring than his others, so he can be forgiven.

Bringing the probabilistic argument to the table, outlining the other arguments made for and against gods, and managing to squeeze in nice insights such as the moth and the candle flame, and all in the usual clear prose, is enough to bring the book far above the mediocrity that DG is claiming for it.

39. Why Christians should take Richard Dawkins seriously

Comment #72663 by Geraint on September 22, 2007 at 6:22 am

Danielos:
Just a moment. We don't know whether life can or can't arise naturalistically on any planet, simply because we don't know whether life arose naturalistically in the first place, correct?

I don't know if you've just phrased this badly, but asking if life could have arisen naturalistically isn't the same as the question of whether or not it did.

Danielos again:
So how can the anthropic principle convince us that life did arise naturalistically, unless one begs the question by implicitly assuming that naturalism is true in which case by definition life did arise naturalistically?

It can't convince us that it did. No-one's saying it can. The argument from design, however, relies on saying that it couldn't. Otherwise, theists are reduced to saying that even given a good naturalistic theory for the origin of life, they choose a theistic one for essentially no good reason.

Danielos:
Of course there is no reason to believe that there is even a small minority of planets with just the right conditions for the naturalistic rise of life, unless one begs the question and assumes that naturalism is true. If conversely theism is true then there are zero planets where life can arise naturalistically. So Dawkins commits an obvious logical fallacy here.

But the anthropic principle isn't being used to decide whether or not it's possible for life to arise naturalistically. It's saying that if life can arise naturalistically, even if this is so unlikely that it may happen on only one planet in the entire Universe, then this is sufficient to debunk the argument from design. Otherwise, one might say, "Well, life can arise naturalistically, but it's so unlikely that it would have happened on our particular planet that it's reasonable to say that God did it instead." But if our planet wasn't the one on which it happened, we wouldn't be here to ask the question.

So, this means that if we can show that the probability of life arising naturalistically on any planet is such that we might be lucky enough to have one such planet in the entire Universe, then we have shown that a naturalistic theory of the origin of life is sufficient to explain life on Earth.

If I recall correctly, Dawkins then goes on to show just how unlikely the naturalistic appearance of life on any given planet would have to be in order that only one planet in the entire Universe might then harbour life.

All the anthropic principle does for us is change the probability that we must consider. We must consider the probability of life arising naturally on any planet in the Universe, not the probability that it arises on any given planet. You've confirmed to me that this is indeed the sense in which Dawkins uses the anthropic principle.

You must agree that it's valid to talk about the probability of life arising in a naturalistic Universe, since life at its most basic consists of replicators the behaviours of which can be explained naturalistically, and it would be possible (if improbable) for those to spontaneously form. Given that it is valid to talk about this probability, our question then moves to deciding what this probability is.

To say that a logical fallacy has been committed is to totally misunderstand the argument that Dawkins is making. He's making a probabilistic argument, not a deductive argument in axiomatic logic.

40. Why Christians should take Richard Dawkins seriously

Comment #72544 by Geraint on September 21, 2007 at 2:40 pm

I assume that Dawkins is aware of the problem but in TGD tries to hide it beneath the really harebrained device of the "anthropic principle", which in short is the completely irrelevant argument that assuming that life can originate on naturalistic principles given the right conditions it follows that our planet has had these right conditions. Of course the question is whether life's minimum required complexity can arise naturalistically in any planet, so here Dawkins is transparently begging the question.

Ironically, in making the statement that, "Of course the question is whether life's minimum required complexity can arise naturalistically in any planet..." (my emphasis) you've used the anthropic principle.

Without the anthropic principle, we might think that the probability that most concerns us regarding the origin of life on Earth is the probability of replicators arising on any given Earth-like planet. In fact, the relevant probability really is the chance that life will arise on any one of the Earth-like planets in the Universe, since we will only be here to ask the question if our planet was one of the lucky ones. This is the point at which the anthropic principle helps us out in deciding whether a naturalistic stance offers us a decent chance of accounting for life on Earth. I don't have TGD to hand so I don't know if this weak form of the anthropic principle is the one Dawkins employs in that particular argument.

In some ways it's a question of understanding conditional probability. Lots of people don't, and it's usually of more practical importance than their grasp of obscure logical fallacies.

41. Oxford's Christian colleges 'are not suitable for school-leavers'

Comment #71603 by Geraint on September 19, 2007 at 5:20 am

Certainly Dud Bug's post (#71580) chimes with what I knew of the people studying theology in Cambridge (some of whom even considered themselves agnostic) and the course itself, which seemed rather rigorous and wide-ranging.

Neither Oxford nor Cambridge needs 'theological colleges' as hangers-on.

42. The God of the Bible is No Delusion!

Comment #68965 by Geraint on September 9, 2007 at 10:03 am

A comment by David Deutsch - the Oxford quantum computing specialist - on his website at www.qubit.org (site is presently unresponsive, so I can't cite the exact link, sorry), notes a similarity that was observed, betwen the large-scale variations in the CMB, and the outline of the continents on the surface of Earth.

Continents? That's nothing. In the ILC map from the one year WMAP data, one can clearly see Stephen Hawking's initials; who's in charge now, eh?

In case you don't believe me, it's the topmost of the three images on this page:
CMB maps link.

You can see SH to the left of centre, just above the middle.

Your brain strains to make out familiar structure in random fields.

The 'axis of evil' is something of a curiosity. Even if it turns out not to be an effect of galactic foregrounds, as statistical flukes go the alignment isn't desperately unlikely. Certainly not likely enough to justify publishing the results under normal circumstances, but in this case collecting more data won't help (the statistical error is limited by the fact we only get to see one sky, not by the quality or quantity of the data), and there had already been some curious features of the low-l CMB noted (basically lower power than expected, leading people to wonder about non-trivial topology; again, the power deficit isn't that statistically significant).

I definitely wouldn't worry about those particular galaxy survey results yet either. As things stand, Steve's comments are essentially justified. One could argue that the mechanism of inflation, or whatever process does the same job, isn't yet known. The CMB results are consistent with inflation, but the current generation of results doesn't constrain the various inflation models particularly well, hence the continuing debate. It's somewhat like the case a few years ago with a proliferation of different cosmological models, most of which were eliminated by new data. A healthy situation.

43. Honest Mistakes or Willful Mendacity

Comment #68163 by Geraint on September 6, 2007 at 9:19 am

No doubt clunking sarcasm about a position your opposite number doesn't hold, like

Tell that to a teenager dying of cancer, and his family.

is what passes for featherlight footwork among theists.

44. A hole lot of nothing found by astronomers

Comment #66162 by Geraint on August 29, 2007 at 5:58 am

Ah, sorry for introducing jargon. The number of sigmas is just a measure of how confident you are that a detection isn't a statistical fluke. 2-sigma corresponds to about 95% confidence, 5-sigma to about 99.99994% confidence. I guess this board isn't a place to write an essay on statistics.

45. A hole lot of nothing found by astronomers

Comment #66079 by Geraint on August 28, 2007 at 11:39 am

Hi Lee,

As pissinintothewind has pointed out, you misattributed his comments to me.

There has already been some evidence of structures more extreme than we expect, notably a massive supercluster of galaxies seen in galaxy redshift surveys that would also have to be a statistical freak to fit in with current models. But statistical freaks do happen. That's why particle physicists need a 'five sigma' result to confirm the detection of new particles, or whatever. They do say that 95% of two-sigma results turn out to be wrong!

There are enough difficulties linking observations to theoretical models that a study of any single object won't make me lose sleep about whether the current standard model of cosmology is correct.

You also have to bear in mind that this model contains quite a few different parts: there's the matter/energy content of the Universe (how much dark matter, how many baryons, etc.); there's the initial conditions (what are the properties of the original 'seed' fluctuations within this matter?); and there are the physical laws and astrophysical processes themselves. A problem with the model could be within any one of those parts, rather than with the whole big bang paradigm.

In the standard model the initial perturbations are self-similar. I haven't had time to read Labini's papers so I don't know how what he's proposing is different. Certainly there are plenty of people studying the topology of large-scale structure, with better data than were available from the Labini papers I can find.

46. A hole lot of nothing found by astronomers

Comment #65865 by Geraint on August 27, 2007 at 6:58 am

Well, it has to be said the article was a bit misleading. The phrase "no stars, no galaxies, no black holes, no dark matter" is totally unjustified by the rest of the text (and by the original paper). Even the actual result is one where it's worth sitting back for a while and waiting for some confirmation.

47. A hole lot of nothing found by astronomers

Comment #65794 by Geraint on August 26, 2007 at 4:12 pm

What do Astrophysicists mean when they say "Nothing"?

On these scales, we trace the distribution of matter by looking at the distribution of galaxies. So when we talk about a 'void' it means a region of space where there are no galaxies large enough to be visible (or, as here, it can mean a region where the density of galaxies is a lot lower than average).

A void isn't an exotic phenomenon; if you plot the distribution of galaxies in 3D from various surveys, you see that galaxies tend to lie in clusters, filaments and walls (your eyes mainly pick out the filaments) with voids in between. Galaxies aren't dotted about randomly. In fact, this rather beautiful 'cosmic web' can be reproduced in simulations that just track the evolution of matter under gravity. Here is a slice through such a simulation (the box is approximately 6 billion light years on a side). The only special thing about the void mentioned in the article is that it seems to be especially large: larger than we typically see in the simulation I linked to, for example. It could just be a statistical fluke, or there could be some effect at work that's unaccounted for in simulations (or the cosmological parameters might be a bit different than appears from other experiments).

Of course, being devoid of galaxies doesn't mean the region is totally empty. A galaxy can only form at a sufficiently large, sufficiently dense concentration of mass. It's like looking at the night-side of the Earth from space, and using the lights from buildings to trace out where the people are. You can only really see the big cities, not individual farmhouses out in the countryside. But that doesn't mean there aren't people outside of the cities.

Black holes don't really have anything to do with it. And just to correct the following:

If I recall correctly, black holes' gravitational forces work relatively close range compared with other stellar bodies, otherwise wouldn't our solar system be quickly spiraling in towards the galactic core (super-massive black hole) of the Milky Way?

The gravitational force from a black hole falls off as an inverse square, identically to any other body. If you're some large distance from a black hole of 1000 solar masses, you feel just the same force as if you were at the same distance from a star cluster totalling 1000 solar masses. The difference with a black hole is that this mass is contained in a very small volume: when you get very close, the intense field leads to all of the black hole strangeness that people know about.

The only reason that the effect of the galaxy's supermassive black hole is only noticeable when you get close to it, is simply that the mass of the black hole is small compared to the mass of the rest of the galaxy.

48. New age therapies cause 'retreat from reason'

Comment #62220 by Geraint on August 9, 2007 at 12:49 am

Chance predicts success after about 5 goes (1 in 12 of getting it the first time + 1 in 11 the second time [unless they're blockheads who guess the same again] + 1 in 10 the third time + 1/9 + 1/8 = 0.51).

Not the correct way to do the calculation. You can see this if you carry on adding the fractions and get a probability >1 that they get it in nine tries.

49. The Panel

Comment #53427 by Geraint on July 1, 2007 at 12:21 pm

What on Earth was the 'answer' to the lightbulb question meant to be all about? Electrons visiting a power station and 'picking up energy'? Uh? The question was also vague.

I agree that it's the scientists' answers that are the most shocking. I can't imagine scientists trying to communicate with the public when they're all at sea outside their own little specialism.

I'm not surprised that Will Self did fairly well, especially compared to the other writers and broadcasters. I might even have expected better. But the others were just pathetic.