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Patrick Elliott wrote:
> if the universe isn't logically consistent than science
> would have to be wrong on a huge scale,
I don't think so.
> You would need to.. have an inconsistent universe, which
> never the less, managed to be consistent on the large scale only. Like..
> statistically stable, but completely unstable on the basic level.
We have that already. It's called quantum mechanics. :-)
> Mind, this wouldn't preclude it being consistent, it would only mean
> that events where not predictable on the smallest scale, but that the
> law of averages/big numbers both made it consistent once you had enough
> events to look at.
Again. :-)
--
Darren New, San Diego CA, USA (PST)
Serving Suggestion:
"Don't serve this any more. It's awful."
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Patrick Elliott wrote:
> Think we may be talking about different things here... The idea I am
> talking about is that you programmaticaly do the equivalent of:
Well, if you're talking about logical reversability, sure. But that's not
all that much more interesting than memoization.
> 1 + 2 + 4 * 5 = result
> roll back to 1 + 2
> 3 * 10 + 5 = result
Pulling out the result is irreversible.
> The point of the idea being that if you do not have to "turn on" a
> switch, only shut some off, the cost is lower.
That's not how it works. You have to drive the circuit backwards. You don't
just turn off parts of it, as that's irreversible too. Unless you're talking
about "logical reversibility", which isn't what I'm talking about.
> it didn't require a quantum computer to do so.
It doesn't necessarily need to be quantum entanglement. But the only
mechanism people have used (at least that I've heard about) that worked is
to do the computing with a chain of atoms that calculate what you're trying
to calculate, with the calculation being driven along by a voltage gradient.
--
Darren New, San Diego CA, USA (PST)
Serving Suggestion:
"Don't serve this any more. It's awful."
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>>> And yet, the uninformed masses have no problem saying that "it is
>>> obviously too complex to come about by chance and therefore must have
>>> been created".
>>
>> It is clearly too complicated to have been created.
>
> That is an insight that makes sense to us.
>
> Unfortunately once you believe in an omnipresent, all knowing, all
> powerful, arbitrary and apparently uncaring but malicious deity then
> anything is possible.
Let us not forget, Intelligent Design isn't about proving a novel
scientific theory; it's about pretending that Genesis is science. The
so-called scientific evidence and logical arguments are just window
dressing.
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On 07/01/2011 08:59 PM, Darren New wrote:
> Googling "string theory test" brings up a bunch, but I haven't looked at
> many of them. Indeed, I myself thought it was a fundamental attribute of
> string theory that it could describe every possible set of physical
> laws, or some such.
String theory is one possible candidate for the Theory of Everything
(ToE). Currently we have a theory of big things (general relativity) and
a separate, incompatible theory of small things (QED). A ToE is not
*literally* a theory that explains "everything", it just means a single,
consistent theory that works over all scales.
So yes, the /idea/ is that eventually string theory should be able to
explain and make predictions about the real world. And the day that
happens, it will be science. But until that day, it is only
proto-science, no matter how sciencey it looks.
The fundamental difference between ST and ID, of course, is that ST has
a realistic possibility of becoming testable some day soon. ID does not.
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On 07/01/2011 10:00 PM, Warp wrote:
> While I know virtually nothing about string theory (well, string theories,
> as there are many; the unified theory would be the so-called M-theory),
> I find it a bit "unlikeable" for one reason.
> However, which observation or measurement is string theory based on?
> As I said, I know next to nothing about it, but it just sounds to me
> like string theory is based on *nothing* at all. It just throws a big
> bunch of extra dimensions from nowhere, based on no measurement,
> observation or other rational justification, and builds up a huge
> bunch of random hypotheses based on these unfounded assumptions.
It's in idea, a theory, and they're trying to see whether it plays out
or not. Currently the math doesn't even work properly, but there's quite
a lot of people working on fixing that. There have been plenty of
scientific ideas in the past that people have come up with on a whim
which turned out to be correct, or almost correct. And besides, I rather
suspect that the basic assumptions of string theory aren't as arbitrary
as they seem, it's just that string theory is so highly abstracted from
the everyday world that most presentations of it for the general
population get watered down to the point where it /seems/ arbitrary.
Then again, I know little about string theory (or should that be
"theories"?) I'm content to just sit and wait to see if they eventually
sort it out or not.
The fundamental idea of string theory is that each subatomic particle is
actually a vibrating string (or possibly sheet), and each type of
vibration corresponds to a different particle. Note that this is not the
first time such an idea has been voiced; way back when the periodic
table was discovered, Lord Kelvin suggested that perhaps each elemental
atom was a different type of knot tied in the ether. The study of knot
theory began because people thought that be enumerating all possible
knots, they would discover the structure of the chemical elements. (But,
apparently, it turns out atoms are different due to the combinations of
subatomic particles they contain...)
And then, of course, there's Stephen Wolfram, who suggests that not just
matter but time itself is quantum, and that the universe is actually a
giant cellular automaton, and that the observed quanta are actually the
cells of the cellular grid. (They guy probably needs to put down the CA
simulator and go outside for a little while.)
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On 07/01/2011 10:25 PM, Warp wrote:
> I think you are confused. The modern banana (that yellow one) is
> only something like 200 years old. It's the product of a mutation of
> a single wild banana plant which suddenly started growing that yellow
> sweet version. The wild banana is much smaller, green, full of seeds
> and almost inedible in raw form.
>
> The mutation in question is actually so severe that the modern banana
> plant is sterile: It cannot reproduce by itself, requiring human
> intervention for cultivation (this happens mainly by transplanting
> underground stems or tissue cultures).
>
> (Ironically, the modern banana is so mutated that it can be considered
> by all practical means "unnatural", as without human intervention it would
> have died right from that very first mutated plant 200 years ago, which
> makes it a perfect example of gene manipulation by humans, yet people who
> strongly oppose gene manipulation have usually no problems in eating
> bananas.)
Well, there are plenty of other plants that are so mutated that they are
now incapable of reproducing for themselves but for some special animal
that farms them. (I might mention, for example, the fungi that
leafcutter ants culture, for example.) The natural world is full of
complex partnerships such as this. I don't think you could call the
banana "unatural".
As for people who oppose genetic engineering, they will argue that
bananas are OK, because the gene alteration happened "naturally". If the
gene alteration had happened because of a man in a white coat, that
would obviously be "unatural", which is bad. Obviously.
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>> So mathematics is not science?
>
> No, math is not science.
I concur with Darren.
Science is the systematic investigation of the real world. Math is the
systematic investigation of abstract systems of axioms of an arbitrary
nature. Some of these systems may or may not be related to something
that happens in the real world, and as such may be "useful". But there
is no requirement for that in pure math. (Applied math is another
matter, of course...)
Some have asserted that "mathematics is the language of science" (which
is not the same as "mathematics *is* science").
On the other hand, more recently some have suggested mathematics
becoming an experimental discipline. (After, e.g., the fiasco with the
4-colour map conjecture and its proof.)
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On 07/01/2011 04:51 PM, scott wrote:
> For someone with no chemistry or biology education past basic
> school-level, that was really interesting, thanks. It answered some of
> the questions I had, and made me hungry to find out more...
The mark of a well-written piece. ;-)
Yes, I too have little chemistry knowledge, beyond what I could get from
The Osborne Introduction to Chemistry. In particular, the idea of
catalysis seems bizarre and inexplicable.
If you read a typical encyclopaedia entry, at best you'll discover that
DNA makes proteins, and proteins do chemical reactions, and that's how
cells work. It might even mention that there's an RNA step in between,
tell you which organelles do all this work, and perhaps even show you
the table of amino acids and which codons code for them.
The reality of the situation, as I wrote, is far, far more complex (and
interesting).
If a human being had designed the cellular machinery, they would
redoubtably have designed it as a set of independent little compartments
that all do their own thing in an orthogonal way, signalling to each
other as appropriate. But when you read about how /actual/ living cells
work, you find a tangled mess of haphazard interactions and fortuitous
reuses of molecules and structures for multiple simultaneous purposes -
/exactly/ as evolution would predict. It's really a very striking
demonstration, to me.
If you read a brick-thick tome like The Molecular Biology of the Gene,
it talks about Daltons and thermodynamic equilibria and van der Waals
forces and so forth as if you have any idea what the hell it's talking
about. Only Behe describes proteins as "the motors, gears, pulleys and
scaffolding of the cell". This explains what it's all about far more
vividly than any discussion of activation energy levels.
Still, not being an expert chemist, I find myself lacking an intuition
for how individual molecules of a substance behave. You can sort of
imagine an amino acid chains as being like a string of beads on a
necklace. The books tell us that some of these beads are watery, some
are oily, some electrically changed negative or positive, some are
acidic or basic, the beads are all different sizes... but it's difficult
to really visualise exactly how that makes them move. Or, for that
matter, how some RNA molecules can fold up and edit themselves, chopping
out introns automatically.
Basically, I lack an intuition for how these molecules float around in
their environment.
Then again, protein folding is one of the great problems of this decade.
(Remember folding@home, anyone?) So maybe the chemists don't yet
understand it either...
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> Amazing to see how molecular biology uncovers how the operating
> mechanisms of living cells are not so much chemical as they are
> nano-mechanical.
>
> The "nanobots" are out there already.
The wheel? Nature did it first.
Explosives? Nature did it first.
Powered flight? Nature did it first.
Sonar? Nature did it first.
Electricity? Nature did it first.
Turing-complete computers? Nature did it first.
...and you're surprised that nature has already done nanobots? ;-)
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>> The more I read about molecular biology, the more interesting it becomes.
>
> Really incredible stuff goes on. I'm never sure whether I'm more amazed
> that it works like this, or that we can figure out that it works like this.
Indeed. It's not surprising that people win Nobel prises for this kind
of work.
Take a look at the paper I linked to. Just look at how much statistics
went into merely checking whether human opioid receptors have changed at
all, and if so whether it's by chance or due to selection pressure.
(The idea of the human brain containing receptors for opium has always
bothered me. Opium is a foreign substance that doesn't belong there; why
the hell would every single walking human have receptors for responding
to it? The answer, of course, is that they aren't *opium* receptors at
all! They're endorphin receptors. They respond to the endorphins that
the human brain itself naturally produces. And yet, even the word
"endorphin" means "endogenous morphine". How backwards can you get?)
>> Mutations that are fatal are vigorously eliminated by natural
>> selection. And indeed, you can find genes that have barely changed for
>> billions of years. These are the so-called "highly conserved sequences".
>
> I remember reading somewhere that there's a gene that controls how many
> fingers you have *and* something about the reproductive system, so any
> mutation in that gene tends to keep you from reproducing for entirely
> unrelated reasons. Hence the reason why everything from fish to bats to
> birds to people have five finger bones.
Actually I think you'll find it's that all tetrapods are descendants of
a single fish ancestor, which just happened to have 5 digits. By now it
would be far too difficult to change it.
Incidentally, you may have heard about the theory that embryos retrace
their ancestry as they develop. For example, a human embryo initially
looks not unlike some kind of bizarre fish. Similarly, baleen whales
initially grow teeth before later reabsorbing them (since their
ancestors had teeth, but they do not).
Actually this theory is wrong. Embryos do not /literally/ retrace their
evolutionary history. What /is/ true is that alterations to the early
parts of embryology tend to bugger up more things than do alterations to
the later parts of embryology. Not as an absolute rule, just a general
tendency. The net result is that typically animals change their final
body plan by changing the later stages of their embryology rather than
the early ones.
In short, I suspect that tetrapods all have 5 digits because there are
now highly complex, well-developed and extensively inter-dependent
systems of gene regulation for building 5 digits. You'd have to change a
hell of a lot of stuff to make it, say, 6. If you just changed one
chemical gradient, for example, you'd break so much stuff... it just
wouldn't work.
If you look at things that aren't tetrapods, you find that 5 isn't so
special.
>> Speaking of which, here's a thing: Every single living cell in the
>> human body (with a few exceptions) has the exact same genome.
>
> Every single *human* cell. About half (or more) of the cells in your
> body aren't human, tho.
Humans are eukaryotes. Eukaryote cells are apparently *way* bigger than
bacterial cells. So it's not difficult for bacterial cells to outnumber
human cells; they're smaller. And while we're on the subject, everybody
thinks of bacteria as "those things that make you ill". But the vast
majority of bacterial species have no effect on human health at all. And
a large number of them are /beneficial/.
(For example, E. coli is well-known for making people ill. But it's a
normal resident of the human body, and it even "communicates" with the
human digestive system, telling it for example how much nutrients it
needs. The human digestive system then absorbs all but that amount,
leaving enough behind for E. coli (and friends) to stay fed. They are
symbionts.)
Then of course, there's the theory (presented by Richard Dawkins as if
it's an accepted scientific /fact/) that most of the organelles of the
eukaryote cell are actually symbiotic bacteria which have become reduced
almost to nothing, retaining only their key chemical processes that
benefit the cell. If it were true, it would mean that basically the
entire chemistry of visible life is possible due to bacteria.
> I'm not sure why you have a job in IT instead of a job in teaching.
I'm not sure why I have an honours degree in computer science, and yet
my sister actually gets paid to write computer programs. o_O
Then again, she works in London, so...
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