I love this story because it demonstrates the difference between science and conspiracy mongering, and between experimental science and ungrounded theory.
There is a famous quote from Shakespeare that is often hurled a scientists:
There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.
– Hamlet (1.5.167-8)
The retort from scientists should be, “that’s why we do experiments, so more things can be included in our understanding”. But the Bard was correct that Nature is always more complex than our best representations of Her, which is why “all models are wrong, but some are useful.”
In this case, some anomaly hunters were making noise that the pictures from the Moon landing just didn’t “look right.” This is not science – which requires that you take the data points that don’t appear to fit the existing theoretical framework and offer a revised theory that works better.
After talking with many engineers and NASA employees, Nvidia discovered that there were two key factors, both of which could be addressed using voxel global illumination. First, the moon’s surface is comprised of what are essentially thousands of tiny mirrors — moon dust if you will — that bounce light back at a viewer. Yet that didn’t account for the necessary level of brightness to light up Aldrin.
So Nvidia engineers began tinkering with different elements of the photograph until they discovered that it was not what was in the frame, but who was behind it. The famous shot was snapped by Neil Armstrong — who was off to the side of Aldrin in full view of the Sun — wearing a 85 percent reflective spacesuit that contained five layers of the highly reflective fabric Mylar blended with four layers of the flexible yet durable material Dacron on top of an additional two layers of heat resistant Kapton.
Using modern computer graphics, the lighting from the picture was recreated. The essential step was including not only sunlight reflecting off the lunar regolith, but also from the photographer’s spacesuit! Since we don’t live on the moon, and our intuition about lighting is based on Terran photography, we are surprised that this was important. Clearly, someone trying to fake a moon landing in 1969 would have to be unbelievably smart to think of this. Similar to the halting problem in computer science – which says that no method exists for predicting if a program will terminate early or not – sometimes the only way to know what will happen is to actually try it. This is the inherent limitation of theory uncoupled from empirical evidence. Trial and and error was also the way Aperture Science was able to discover that, in addition to reflecting 12% of incident light, moon dust is an excellent conductor of portals.
This week saw announcements of the latest round of telecommunication devices. Apple is coming out with the latest iPhones:
Amazon, for its part, has a whole new line of Kindles:
We have become almost inured to the incredible telecommunication capabilities packaged into consumer products that fit in a hand. You can pull your phone out of your pocket and watch live sports, instantly download and start enjoying virtually any book or song you can think of, call, text, email, or send a yo! to your friends. With Hulu, Netflix, and Amazon, the dream of making any movie or TV episode available on demand is coming closer and closer. And these devices don’t even cost thousands of dollars or take up a whole room. But, as spiffy as they are, these latest, incremental improvements fail to excite us as much as they used to. Now, think about a world in which no long distance communication is possible. That is, every message must physically travel from sender to recipient before it can be read. Adding instant communication to such a world would certainly be more “disruptive” than the latest app or handset.
Such was the case in the Victorian Era. As Tom Standage points out, when the telegraph was introduced, there were no airplanes, credit cards, or automobiles. But there was, suddenly and for the first time, instant communication. News from Europe arrived in the United States in minutes instead of weeks. Business orders and money could fly over wires around the world. Journalism became a mature profession. Along with the burgeoning train industry, local time was replaced with organized time zones. As a funny side-note, short distance telegrams were sometimes sent through a series of (pneumatic) tubes.
By the time of the US Civil War, telegraphy was an important part of military strategy. This was a strong centralizing force, limiting the autonomy of generals and giving it to the commander-in-chief.
Few people are reorganizing their lives in anticipation of the iPhone 6. But the world has been greatly changed as the result of a extremely low bandwidth dot-dash channel. And this:
The concept of a wavefunction is integral to quantum mechanics, the most successful model of reality Humans have yet devised. And still, no one agrees on what a wavefunction is, even though it correctly predicts the outcome of any experiment we throw at it.
The basic idea is that if you square the wavefunction, you will get a “probability density” that tells you how likely the particle will be in a certain place. The wavefunction itself evolves according to Schrodinger’s Equation. All of chemistry is essentially keeping track of complicated wavefunctions of atoms and molecules:
One of the crazy properties of the wave function is that measurement can collapse it, or at least, appear to do so. Some belive this is due to the fact that any measurement must disturb and change the system. Others argue for the interpretation that the wavefunction is just a representation of OUR knowledge of the Universe, so making measurements that increase our information will affect the wavefunction.
In a paper on arxiv, the arguments for each side of the “ontic” (wavefunctions have a reality independent of observers) vs. “epistemic” (wavefunctions represent someone knowledge of the Universe) debate are presented. Since no one agrees even on the basic interpretation of quantum mechanics, or the way to look at thought experiments like Schrodinger’s Cat (and its extensions, such as Wigner’s Friend), the one certainty is that that controversy is far from over. And of course, more predicted quantum weirdness becomes reality all the time. Like creating images using entangled photons that never interacted with the object they are imaging.