The farther we peer into space, the more we realize that the nature of the universe cannot be understood fully by inspecting spiral galaxies or watching distant supernovas. It lies deeper. It involves our very selves.
This insight snapped into focus one day while one of us (Lanza) was walking through the woods. Looking up, he saw a huge golden orb web spider tethered to the overhead boughs. There the creature sat on a single thread, reaching out across its web to detect the vibrations of a trapped insect struggling to escape. The spider surveyed its universe, but everything beyond that gossamer pinwheel was incomprehensible. The human observer seemed as far-off to the spider as telescopic objects seem to us. Yet there was something kindred: We humans, too, lie at the heart of a great web of space and time whose threads are connected according to laws that dwell in our minds.
Is the web possible without the spider? Are space and time physical objects that would continue to exist even if living creatures were removed from the scene?
The idea that all particles are mini black holes has major implications for both particle physics and astrophysics, say scientists.
Could it really be possible that all particles are mini-black holes? That’s the tantalising suggestion from Donald Coyne from UC Santa Cruz (now deceased) and D C Cheng from the Almaden Research Center near San Jose.
Black holes are regions of space in which grsavity is so strong that nothing, not evenlight, can escape.
Trouble with gravity is that on anything other than an astrophysical scale, it is so weak that it can safely be ignored. However, many physicists have assumed that on the tiniest scale, the Planck scale, gravity regains its strength.
In recent years some evidence to support this contention has emerged from string theory where gravity plays a stronger role in higher dimensional space. It’s only in our four dimensional space that gravity appears so weak.
Since these dimensions become important only on the Planck scale, it’s at that level that gravity re-asserts itself. And if that’s the case, then mini-black holes become a possibility.
When a jet is flying faster than the speed of sound, one small mistake can tear it apart. It was so feared that the physics blended with the supernatural in the mid 1940s. Luckily, Chuck Yeager didn’t believe in demons.
There was a demon that lived in the air. They said whoever challenged him would die. His controls would freeze up, his plane would buffet wildly, and he would disintegrate. The demon lived at Mach 1 on the meter, seven hundred and fifty miles an hour, where the air could no longer move out of the way. He lived behind a barrier through which they said no man would ever pass. They called it the sound barrier.( Ridley in the 1983 movie ‘The Right Stuff.’)
But at truly high speeds flight still has plenty of risk and when the jet is so experimental that it must fly unmanned, only a computer control system can pilot it so the magic involves a control system that can react to variables like a human. Ohio State University engineers say they have designed control system software that can do just that — by adapting to changing conditions during a flight.
Government agencies have been developing faster-than-sound vehicles for decades. The latest supersonic combustion ramjets — called scramjets — burn air for fuel, and could one day carry people to space or around the world in a matter of hours.
The recent success of NASA’s X-43 hypersonic jet has spurred research into the control systems for these vehicles, said Lisa Fiorentini, doctoral student in electrical and computer engineering at Ohio State University. She and associate professor Andrea Serrani are developing a new control system in collaboration with the U.S. Air Force Research Laboratory (ARFL) at Wright-Patterson Air Force Base in Ohio.
There has been a dramatic recent shift in sentiment in relation to the most appropriate model for developing software systems. The shift has marked a change from the tradition of preparing a detailed requirements specification as the first phase in the development cycle, to a less rigid adaptive evolutionary approach.
The ongoing goal of software engineering is to ensure that a system meets its primary aims in terms of the quality criteria of functionality, performance, reliability and efficiency. Achieving rigorous standards of reliability and efficiency has never been the major problem for developers; rather it has been the potential for basing the system’s requirements specification on obsolete or inadeqaute premises, which on completion delivers sub-optimal outcomes.
This is similar to the mathematical problem of using excellent deductive logic to draw conclusions from a set of axioms, but reaching a wrong conclusion because the axioms themselves are incorrect or incomplete.
Time and again this Archilles heel of software development emerges- particularly when a project is large, complex and operates within a dynamic environment. Systemic failure is more often the norm and the litany of collapsed projects keeps growing; particularly in the government and multinational business domains of procurement, supply, logistics, human resources, health, education, customer services etc.
The research in my laboratory focuses on the molecular mechanisms that bacteria use for intercellular communication. Our goal is to understand how bacteria detect multiple environmental cues, and how the integration and processing of this information results in the precise regulation of gene expression.
The bacterial communication phenomenon that we study is called quorum sensing, which is a process that allows bacteria to communicate using secreted chemical signaling molecules called autoinducers. This process enables a population of bacteria to collectively regulate gene expression and, therefore, behavior. In quorum sensing, bacteria assess their population density by detecting the concentration of a particular autoinducer, which is correlated with cell density. This “census-taking” enables the group to express specific genes only at particular population densities. Quorum sensing is widespread; it occurs in numerous Gram-negative and Gram-positive bacteria. In general, processes controlled by quorum sensing are ones that are unproductive when undertaken by an individual bacterium but become effective when undertaken by the group. For example, quorum sensing controls bioluminescence, secretion of virulence factors, sporulation, and conjugation. Thus, quorum sensing is a mechanism that allows bacteria to function as multi-cellular organisms.
