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Morganne (2004-01-29)  
Isn't it true that Art is created and Science discovered?

This is mostly so, but not entirely. Even for a Platonist like myself, it's difficult to argue that scientificfacts are just sitting there waiting to be discovered by some cleversleight of hand. First, a language must be created for those factsto become expressible.  This language is purely a human creation. Second, a physical law need not be absolutely true to be considered scientific.

For example, Newtonian mechanics considers only objects whose masses are independentof their speeds, spins andtemperatures. It's now clear (from the many experimental results confirming the quantitative predictions ofSpecial Relativity) that such things simply do not exist. Yet, Newtonian mechanics was and remains a superb scientific theory. It's clearly not theultimate law of nature, but it would be silly to demandthat Science and scientists suspend all publications until all flaws are resolved.

Scientists must routinely invent and create new concepts like mass, velocityor entropy. The meanings of such constructs may evolve and none of themare strictly necessary to describe physical reality. They are just clever human creations whose beauty is ultimately revealedby their ability to organize human thoughts and computations about the World.

An artist may have a lot more creative freedom than a scientist does,but Science still entails considerable leeway. At the deepest level,scientific theories are beautiful carvings which describea specific abstract approach to reality, just like most sculpturescapture one aspect of reality for the sole sake of beauty. In both cases, random chiseling is not permissible;a lot of skill and channeled creativity is required.

A heap of scattered scientific facts is toa consistent scientific theory what an uncarved block of marbleis to a polished statue.

Without dreams,  there is no art, 
no mathematics,  no life. 
Sir Michael Atiyah  (1929-2019)

(2005-06-20)  
Skepticism and Empiricism.

Locke, Bekeley, Hume, Newton.
Recovering the power of the senses.
Induction,deduction.
The arrogance of the senses.

(2005-06-20)  
Mind and Matter.  Free will and the clockwork universe.

Anne Finch Viscountess Conway: Body, mind and spirit.

(2005-06-20)  
Intuition:  Certainty all at once.

Certainty all at once.

(2011-10-29)  
The question of the existence of God is not a scientific one.

Napoléon:  Où est Dieu dans tout cela?
Laplace:  Sire, je n'avais nulle besoin de cette hypothese.
Pierre-Simon Laplace (1749-1827)

(2004-03-26)  
In the SETI project, we've spent only a few minutes "talking". What's wrong with that?

We've spent only a tiny amount of time "talking to" possibleextraterrestrial civilisations. If those have the same attitude, there is no point listening. The painful conclusion is that we have to spend some unselfish timetalking if listening has any sense at all. This is true in spite of the fact that we'll never get any feedback.

I argue that morality  (in the senseImmanuel Kant defined it) is either unselfish or nonexistent. If we value at all the extraordinary gift it would be to receivea message from other civilizations, we must extend the same courtesyby sending them something to listen to.

If we bother listening, we have a moral obligation to talk.

(2004-03-26)  
The Universe we see must have properties that allow human life.

(2004-03-26)  
What makes a society worth defending... [Bob Wilson about FermiLab]

(2006-08-30)  
What's "mathematics", anyway?

No one shall expel us from the paradise which Cantor has created for us.
David Hilbert  (1862-1943)
 
A self-destructive democratic principle was advanced
in mathematics(especially by Hilbert),according to which
all axiom systems have equal right to be analyzed,
and the value of a mathematical achievement is determined,
not by its significance and usefulness as in other sciences,
but by its difficulty alone, as in mountaineering.
Vladimir Arnold  (1937-2010)

Most philosophers have not practiced enough mathematics to graspthe significance of any nontrivial mathematical endeavor,let alone put them all in perspective. Most mathematicians have not practiced enough philosophy to feel anyneed to reflect on their own discipline, let alone "define" it. So, who's to say what mathematics really  is?

Well, ... / ...

Mathematics is all about the acquisition of certainty. Following traditional rules to obtain results does not validate such results;the rules themselves must be scrutinized "mathematically"to remove all doubts and allow absolute confidence in whatever resultsare ultimately stated.

For example,Distribution theory  validatesour intuition about Dirac's delta "function". If intuitive  manipulations of the delta function weren't valid,ditribution theory shows that other trusted algorithm wouldn't be either. Results based on the concept of distribution are astrustworthy as those which involve only elementary arithmetic.

(Tom H,2007-05-15)  What istime ?
(Blue22op,2007-05-15)  Are scientists working on atime machine ?

Here's one of my favorite quotes (a translation byJohn A. Wheelerof a provocative statement ofJ. Henri Poincaré):

"Time is defined so that motion looks simple."

In other words, "time" is defined as the independent variablewhich makes the equations of mechanics take on a simple form. This operational definition was designed in a simpler era of "classical" physics. It still holds for nonrelativistic quantum theory,where time remains an old-fashioned independent variable.

However, at a deeper level of understanding, time cannot be simply such an"independent" parameter against which events are recorded. Instead, it's a component of spacetime (to a degree, time and space can be traded for each other). This has profound implications for our modern descriptions of the physical world. Especially in the quantum realm.

Time Travel and Perpetual Motion

Time travel is like perpetual motion; it's both unavoidable and impossible. Let me explain this paradox:

At the microscopic level, time-travel is unavoidable. Elementary particles routinely go backward in time;there's no difference between a particle moving forward in timeand its antiparticle moving backward in time. So, a "particle-antiparticle" pair creation may also be described as a particlechanging the direction of its "time flow".

Now, can this fundamental mechanism be harnessed to make coherent systemsconsisting of many particles (and carrying definite information with them) go back in time?

The answer is as much of a "no" as what applies to the related question ofwhether it's possible to transform brownian motion into coherent motion(that would be what's called perpetual motion "of the second kind"). If you don't believe in one, you don't believe in the other...

Of course, science is not supposed to be about beliefs, but it is (to a degree). It's a much more productive belief (from a scientific standpoint)to assume that perpetual motion can't exist than the opposite... In one case, you'll refine the basic laws of thermodynamics. In the other case, you may waste your life on doomed tinkering. Similarly, the impossibility of time-travel imposes useful constraintson the very laws of fundamental physics we are aiming to formulate. It's almost certainly the more useful of two possible beliefs, to put it in provocative terms.

This does not mean you can't have fun thinking about the paradoxes of time-travel. However, those very paradoxes should be an indication thatattempts at building an actual time-machine are as doomed asattempts to build a perpetual motion machine. Or vice-versa.