"Dare Mighty Things"

     Far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy nor suffer much because they live in the gray twilight that knows neither victory nor defeat. -- Teddy Roosevelt

Last night after a journey of several hundred million miles a small hunk of metal successfully touched down rather softly on the surface of Mars. 150 million miles away (and 14 minutes later) a large group of people started jumping up and down. This is the spirit of human exploration and a desire to dare mighty things.

The scientists at the JPL and NASA may just be smiling for days if not weeks.

A happy John Grunsfeld speaking with reporters after the landing.

Deconstructed Philosophy

I came across an interesting opinion piece today and I found this quote particularly interesting (and it should be interesting to those who are wondering why nobody seems to listen to philosophers any more).

"Philosophy, it seems to me, has spoked its own wheel in its hyper-late-post-modern deconstruction that somehow deconstructed itself. It broke down in such a way that the philosopher is now so divorced from real life and sucked into a simulated one (modelled) that often he has nothing constructive to say on current events."

I think that that right there sums up what is wrong with philosophy, it has distanced itself so far from real life and current events that it is no longer applicable. I think, quite seriously, that the reason why philosophers (collectively, not individually) are no longer taken seriously is because they collectively stopped answering questions. Anyone who had to suffer through David "The billiard ball did not cause the other to move" Hume, Søren "Believe against all reason" Kierkegaard, Friedrich "There is no free-will" Nietzsche and Peter "I actually have a very good argument if you will listen to me because if you think about it long enough I'm sure that my ideas will convince you that your natural inclinations of morality and basic human needs and desires are all wrong and misguided and supremely immoral because when you consider the utility it makes sense when you weigh the interests of others against your own inclinations then it makes perfect sense it's just that the details are a little fuzzy" Singer will understand.

What it comes down to is that the field of study known as philosophy stopped offering answers or solutions to practical problems, and got caught up in arguing about trivial things (such as trying to prove that we don't exist). The reason why this happened is because there was another outlet, namely science (mostly physics) where people could turn for answers. For example, in the case of billiard balls, Hume's response was "we can't tell if one billiard ball caused the other to move". Newton's response, on the other hand, was "p_i = p_f --> p_1i = p_1f + p_2f". Well that may be slightly incomprehensible so some people, but at least it was an answer, and furthermore Newton could go on to explain about the sun and the moon and the stars and the planets and things falling and things flying through the air and light and a lot of other cool things. If you go ask a philosopher about that stuff they will probably say, "Well we can't actually see anything, and you really aren't talking to me." It's no wonder people stopped listening to philosophers.

Until this problem is fixed in philosophy you will never read a news story that quotes a philosopher (think about it, how many news stories are there that contain the phrase "Dr. So-and-So, a noted scientist/physicist/astronomer/biologist/chemist/sociologist said...", but how many have quotes from a "noted philosopher"?). This is because when news people (or people in general) want an answer to a question they go ask a scientist, never a philosopher. I can't count the number of times I met someone who found out that I study physics and they instantly say "Can I ask you about ...?", but I never have anyone say that when the find out that I also study philosophy. Mostly they just look at me funny.

Now I do realize that a lot of professional philosophers do do important work, and there are several of my former professors that I have tremendous respect for, but until philosophy in general stops arguing that there is no truth and there are no answers and is capable of providing real world applications to what they are talking about (i.e. solving real problems), then it will forever remain deconstructed and broken.

[PS: I know that there are some philosophers out there who are trying to fix this, but unfortunately there are not enough of them. There are some indications that this is changing, but it may take a while until you regularly have quotes from "noted philosophers" in news stories.]

My Favorite Computer Science Quotes.

Some of my favorite quotes relating to computer science:

Always code as if the guy who ends up maintaining your code will be a violent psychopath who knows where you live.
- Rick Osborne

 Perl – The only language that looks the same before and after RSA encryption.
- Keith Bostic

Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.
- Rich Cook

It is practically impossible to teach good programming style to students that have had prior exposure to BASIC. As potential programmers, they are mentally mutilated beyond hope of regeneration.
- E. W. Dijkstra

The trouble with programmers is that you can never tell what a programmer is doing until it’s too late. - -- Seymour Cray

Talk is cheap. Show me the code.
- Linus Torvalds

Software is a gas; it expands to fill its container.
– Nathan Myhrvold

In the future, computers may weigh no more than 1.5 tonnes.
– Popular mechanics, 1949 

Python's a drop-in replacement for BASIC in the sense that Optimus Prime is a drop-in replacement for a truck.
- Cory Dodt

Any really good ones that I am missing?

Physics Quote Of The Day. (Popper and Over-Simplification in Science.)

From Karl Popper

Science may be described as the art of systematic over-simplification.

What?  What's wrong, for example, with spherical cows? :)

Math Quote Of The Day. (Gödel's Second Incompleteness Theorem)

Wolfram stating Gödel's second incompleteness theorem informally:

Any formal system that is interesting enough to formulate its own consistency can prove its own consistency iff it is inconsistent.

The iff isn't a misspelling, it means "if and only if" for those who may not know.

I love this theorem, a source of such great philosophizing. :)

Feynman On Legitimate Scientific Theories.

In the short video above, Feynman hits the nail on the head describing how a scientist goes about formulating a new theory. (As he so often does.)

I hear people tell me, ever so often, things like: "My theory is that the universe is really a giant black hole" or "my theory is that the reason the universe is expanding is there is yet undetected matter heating up and causing expansion like when bread rises in the oven."

There isn't anything wrong with musing over such ideas but, if you want to be a real scientist you now need to go further and work out the consequences of your theory in a way that we can test it.  And your test must be one where your theory has a chance of being falsified otherwise it is not good science.

Now I'm not saying that all non-scientific ideas are foolish! Some supposed friends of science take this concept way too far.  For example, I'm not so sure you can classify the statement that a man should "not be judged by the color of [his] skin but by the content of [his] character" as a scientific statement.  But I sure believe it as much as Dr. King hoped I would.

But what I am saying is that if you want to feel you have a legitimate scientific theory you need to have one where consequences have been worked out so that we can practically verify or falsify the theory.

Math Quote Of The Day.

Having discussed the axiom of choice earlier today I wanted to post a quote by the mathematician Jerry Bona.

"The Axiom of Choice is obviously true, the well-ordering principle obviously false, and who can tell about Zorn's lemma?"

I guarantee you mathematicians will find this hilarious but for those of you left in the dark, the Wikipedia goes on to say:  "This is a joke: although the three are all mathematically equivalent, many mathematicians find the axiom of choice to be intuitive, the well-ordering principle to be counterintuitive, and Zorn's lemma to be too complex for any intuition."

Math Quote Of The Day.

From the mathematician Yuri Manin quoted here:

A proof only becomes a proof after the social act of “accepting it as a proof".

Unfortunately, there is some truth to this.

Physics Quote Of The Day

This from Introduction to Effective Field Theory by C.P. Burges,

Renormalization is a practice which used to be widely regarded as distasteful, and so was largely done in the privacy of one’s own home. That has all changed. As used in effective field theories renormalizing is not only respectable, it is often the smart thing to do...

For those who don't know what renormalization is, a good lay explanation probably is: when you calculate quantities like the mass or charge of a particle in quantum field theories they turn out to be infinite.  However, once you realize these quantities can change with energy scale, they become finite functions of energy scale.  This process of converting physical quantities to functions of energy scale is called renormalization.

 The values of these functions at different energy scales have been confirmed in particle accelerators.  Sometimes you here physicists say these "quantities" run.  This is just a fancy way of saying they change for different energy scales.  For some quantities, like those related to the graviton, this processes doesn't work, which is why you hear people say gravity isn't renormalizable.

Now, why is this funny?  Because not too long ago, this process was very difficult and seemed very fishy that it worked. (Now we know better.)  It was embarrassing, to many physicists, in the same way some other things may be embarrassing if they are not done privacy in your own home.

Physics Quote Of The Day.

The opening statement to Physical Foundations of Cosmology by Mukhanov reads:

The most important feature of our universe is its large scale homogeneity and isotropy. This feature ensures that observations made from our single vantage point are representative of the universe as a whole and can therefore be legitimately used to test cosmological models.

What an important observation.  The only reason we have any reasonable chance of understanding the universe we live in, given we can only observe it from one small spec called earth, is that the universe is so darn homogeneous and isotropic.  (See here if you don't know what that means.  Basically it means the universe looks the same everywhere inside.)

 This ensures that whatever we see here on our little "Pale Blue Dot" (See video below), we can assume applies to everywhere else.  This allows us to create physical models that account for the whole observable universe.

This means, though we live on only a tiny spec, what we see here applies everywhere.  This is vital for us to be able to say anything at all about the entire structure.

Physics Quote Of The Day.

Dr. Virginia Trimble of UC Irvine quoting Frederick Reines (A Nobel Laureate at UC Irvine) told me:

Half of of three sigma detections are wrong.

On one hand the quote is funny because three sigma is supposed to mean, roughly, that the result has a 99.7% chance of being correct.  

However, there is truth to the quote, not because you can't trust statistics, but because so often scientists are not aware of everything that can be causing a false signal.

For example, and this is what provoked the quote, we heard a 9-sigma result saying there was a preferred direction to the universe.  The statistics were done right, the team just wasn't aware that the along the eclipitic plane there is a preferred direction of photons due to our own galaxy,  Once you account for these photons, the 9 sigma detection goes away.

So perhaps the quote should be:

Half of of three sigma detections are wrong because, all too often, physicists don't understand the background signals as well as they think they do.

Physics Quote Of The Day. (Snap, Crackle, Pop?)

From Entropic Accelerating Universe:

I knew the 2nd derivative is acceleration and the 3rd derivative is jerk, but I've never heard of snap, crackle and pop!

Does anyone know if this is true, or did these authors just make this up?  If they did, they are very clever: it just may stick with the rest of the literature.

The Standard Model Particles Are Massless States?

From, the standard textbook on the subject, String Theory by Joseph Polchinski:

Masses that are not zero in string theory are of the order [the Planck mass].  This is so large compared to experimentally accessible scales that these particles appear only in the virtual states.  Thus, we will be especially concerned with the massless string spectrum, since this must include all the particles of the Standard Model.  Of course, most known particles are massive, but these masses are so small compared to [the Planck mass] that they are zero to first approximation and become non-zero due to small symmetry-breaking effects.

So, it appears that the whole standard model is embedded in the massless states of string theory and that their masses on come because of small symmetry breaking.

For those who don't know, particles getting a mass because a symmetry has been broken does happen.  The very real Z abd W bosons get a mass because symmetries are broken.

It's just fun for me to think: assuming string theory is correct: all things we observe in nature are just the massless states of string theory with a some small masses from symmetry breaking.

Ed Witten On The Definition Of A Quantum Theory.

Here is an example of why Edward Witten seems to be on a different intellectual plane from the rest of humanity.

He has some lectures on quantum field theory online.  I decided it may be fun to read some of them since: it's Ed Witten!  On lecture one he decides to define what he means by a quantum theory:

We will define a quantum theory to be a pair (A,H) where A is a *-algebra (not necessarily commutative), and H is a selfadjoint element of A, defined up to a real number.  The algebra A is called the algebra of quantum observables (operators),  The element H, as before, is called the Hamiltonian...

By a realization (or solution) of a quantum theory (A,H) we will mean an irreducible *-representation of the algebra A in some Hilbert space H, such that the spectrum of the operator H is bounded from below (representations are considered up to an isomorphism that preserves H).  We will always normalize H so that the lowest point of a spectrum is zero. 

Now, it turns out if you have taken enough math, quantum mechanics and read through the above slowly you can see that what he is saying does make sense. (Obviously, as if he would be wrong.)

But come on!  I don't think any normal human thinks about quantum principles as deeply and rigorously as this.  Edward Witten is definitely very special and part of me wishes I could understand physics at this level.

Physics Quote Of The Day.

From the opening sentence of D3-brane Potentials from Fluxes in AdS/CFT:

Since the dawn of time, humankind has wondered, “what is the potential on the Coulomb branch of the conifold gauge theory, and what are the consequences for models of D-brane inflation?” In this paper, we continue this quest.

That is one of the best opening sentences to an journal article I have ever read!  I almost died when I read that.

Quote Of The Day

Max Tegmark is a prominent cosmologist at MIT. (It turns out he is a really nice person as well.)

He has the ultimate Occam's Razor quote for defense of a multiverse.   Occam's Razor being the idea that, given two theories that seem to be equivalent up to experiment, choose the simpler theory:

A skeptic worries about all the information necessary to specify all those unseen worlds. But an entire ensemble is often much simpler than one of its members. This principle can be stated more formally using the notion of algorithmic information content. The algorithmic information content in a number is, roughly speaking, the length of the shortest computer program that will produce that number as output.

For example, consider the set of all integers. Which is simpler, the whole set or just one number? Naively, you might think that a single number is simpler, but the entire set can be generated by quite a trivial computer program, whereas a single number can be hugely long. Therefore, the whole set is actually simpler.

Similarly, the set of all solutions to Einstein's field equations is simpler than a specific solution. The former is described by a few equations, whereas the latter requires the specification of vast amounts of initial data on some hypersurface. The lesson is that complexity increases when we restrict our attention to one particular element in an ensemble, thereby losing the symmetry and simplicity that were inherent in the totality of all the elements taken together.

In this sense, the higher-level multiverses are simpler. Going from our universe to the Level I multiverse eliminates the need to specify initial conditions, upgrading to Level II eliminates the need to specify physical constants, and the Level IV multiverse eliminates the need to specify anything at all... A common feature of all four multiverse levels is that the simplest and arguably most elegant theory involves parallel universes by default.

To deny the existence of those universes, one needs to complicate the theory by adding experimentally unsupported processes and ad hoc postulates: finite space, wave function collapse and ontological asymmetry. Our judgment therefore comes down to which we find more wasteful and inelegant: many worlds or many words. Perhaps we will gradually get used to the weird ways of our cosmos and find its strangeness to be part of its charm.

Now, don't get me wrong, this is a very speculative quote.  I am not trying to sell this as mainstream at all.

However, it is one of the more interesting applications of Occam's Razor I have seen. :)

Quote Of The Day

From Dilbert:

Never argue with an idiot. They drag you down to their level then beat you with experience.

I want to apologize when I am that idiot. :)

An Inflationary Iniverse Is The "Ultimate Free Lunch"

Great quote from the Wikipedia:

Alan Guth has described the inflationary universe as the "ultimate free lunch": new universes, similar to our own, are continually produced in a vast inflating background.

This is based of of Guth's actual quote coupled with the grand view of what may be going on:

It is said that there’s no such thing as a free lunch. But the universe is the ultimate free lunch.”

Physics Quote Of The Day.

Sorry to quote David Tong two days in a row, but this guy has some good quotes.

From David Tong's Lectures on String Theory:

Our current understanding of physics... is 15 orders of magnitude away from the Planck scale. Why do we think the time is now ripe to tackle quantum gravity? Surely we are like the ancient Greeks arguing about atomism. Why on earth do we believe that we’ve developed the right tools to even address the question?

The honest answer, I think, is hubris.

Wow, it just doesn't get any more candid than that.

Physics Quote Of The Day.

From David Tong's Lectures on String Theory:

It is often said that general relativity contains the seeds of its own destruction. The theory is unable to predict physics at the Planck scale and freely admits to it. Problems such as non-renormalizability and singularities are, in a Rumsfeldian sense, known unknowns...On the other hand, some aspects of quantum gravity suggest that general relativity isn’t as honest about its own failings as is usually advertised. The theory hosts a number of unknown unknowns, things that we didn’t even know that we didn’t know.

For those who missed it, this quote alludes to Rumsfeld's poetic words:

As we know,
There are known knowns.
There are things we know we know.
We also know
There are known unknowns.
That is to say
We know there are some things
We do not know.
But there are also unknown unknowns,
The ones we don't know
We don't know.

Indeed general relativity does contain the seeds of it's own destruction, and herein lies perhaps the greatest challenge to theoretical physics.