Physics and Numbers
Astronomers have discovered that galaxies stop forming stars long before their central supermassive black holes reach their most powerful stage, meaning the black holes can’t be responsible for shutting down star formation.
A device that can bestow invisibility to an object by "cloaking" it from visual light is closer to reality.
For the first time, researchers have measured a long-theorized force that operates at distances so tiny they’re measured in billionths of a meter, which may have important applications in nanotechnology as scientists and engineers seek new ways to create devices far too small for the eye to see.
A team of University of Toronto physicists has demonstrated a new technique to squeeze light to the fundamental quantum limit, a finding that has potential applications for high-precision measurement, next-generation atomic clocks, novel quantum computing and our most fundamental understanding of the universe.
Hallmark has announced a recall of its jumbo snowman snow globes due to the possibility of fire.
If only the designer had read the same newspaper article as a young lady who was working on a report for the laser teaching center at SUNY Stony Brook.
Were those of us who believed an Obama administration would be more friendly to science right?
Shahn Majid
This will be my last regular post for a while because of Christmas and teaching three courses next term at my University. These past eleven posts, see here and here, have been my personal take on many of the topics covered in On Space and Time and its now time in this twelfth post to address the larger picture of the volume itself.
Einstein introduced the Cosmological Constant into his formulation of General Relativity to eliminate the uniform expansion or contraction of the universe that seemed to be inevitable without it. After Hubble's work revealed an expanding universe, Einstein called the constant his "greatest mistake."
But in recent years, the discovery of an accelerated expansion of the universe led scientists to postulate the existence of "dark energy." One candidate for that dark energy is--you guessed it--the Cosmological Constant.
(I discuss this as an open question in my book Physics: Decade by Decade.)
New research now supports that notion, though the evidence is far from conclusive.
After last week's imaginative speculation, I'd better tell you something concrete. How about the solution to quantum gravity that has been eluding us for some 90 years? Here it is ... er ... with one minor catch. We'll have to suppose that spacetime is 3 dimensional, i.e. one time and only two space directions rather than three.
It's been a long year with a presidential election campaign that never seemed to end and a stock market that exploded with volatility, mostly on the down side.
So why are the powers that be adding more than the usual one day to this leap year, and why should you care?
This deepest and most long-standing of all problems in fundamental physics still needs a revolutionary new idea or two for which we are still grasping. More revolutionary even than time-reversal. Far more revolutionary and imaginative than string theory. In this post I’ll take a personal shot at an idea — a new kind of duality principle that I think might ultimately relate gravity and information.
Science fiction writers have long envisioned sailing a spacecraft by the optical force of the sun's light. But, the forces of sunlight are too weak to fill even the oversized sails that have been tried. Now a team led by researchers at the Yale School of Engineering & Applied Science has shown that the force of light indeed can be harnessed to drive machines -- when the process is scaled to nano-proportions.
2008 was a great summer for sports' fans. World records tumbled at the Beijing Olympics. Usain Bolt shattered both the 100m and 200m world records, knocking tenths of a second off each.
In developing a model to explain the motion of atoms in a magnetic field, scientists have overcome a decades-old obstacle to understanding a key component of magnetic resonance.
