Folding Space-Time. Where Is Now? The Paradox Of The Present : 13.7: Cosmos And Culture. Hide captionThe European Southern Observatory's Very Large Telescope in Chile captured this striking view of the nebula around the star cluster NGC 1929 within the Large Magellanic Cloud, a satellite galaxy of our own Milky Way separated by a mere 179,000 light years. Manu Mejias/ESO The European Southern Observatory's Very Large Telescope in Chile captured this striking view of the nebula around the star cluster NGC 1929 within the Large Magellanic Cloud, a satellite galaxy of our own Milky Way separated by a mere 179,000 light years.
The night sky is a time machine. Look out and you look back in time. But this "time travel by eyesight" is not just the province of astronomy. It's as close as the machine on which you are reading these words. As almost everyone knows, when you stare into the depths of space you are also looking back in time. We never see the sky as it is, but only as it was. Let's take a few examples. We live, each of us, trapped in our own now. Yes, but ... Time Travel Impossible, Say Scientists. — Hong Kong physicists say they have proven a single photon cannot travel faster than the speed of light. — This demonstrates that time travel is impossible, they say. Hong Kong physicists say they have proved that a single photon obeys Einstein's theory that nothing can travel faster than the speed of light — demonstrating that outside science fiction, time travel is impossible.
The Hong Kong University of Science and Technology research team led by Du Shengwang said they had proved that a single photon, or unit of light, "obeys the traffic law of the universe. " "Einstein claimed that the speed of light was the traffic law of the universe or in simple language, nothing can travel faster than light," the university said on its website. NEWS: Warp Drive Engine Would Travel Faster Than Light "Professor Du's study demonstrates that a single photon, the fundamental quanta of light, also obeys the traffic law of the universe just like classical EM (electromagnetic) waves. " How to be in two places at the same time - physics-math - 19 July 2011. An ambitious experiment to make a glass sphere exist in two places at once could provide the most sensitive test of quantum theory yet.
The experiment will place a sphere containing millions of atoms – making it larger than many viruses – into a superposition of states in different places, say researchers in Europe. Physicists have questioned whether large objects can follow quantum laws ever since Erwin Schrödinger's thought-experiment suggested a cat could exist in a superposition of being both alive and dead. The idea is to zap a glass sphere 40 nanometres in diameter with a laser while it is inside a small cavity.
This should force the sphere to bounce from one side of the cavity to the other. But since the light is quantum in nature, so too will be the position of the sphere. This forces it into a quantum superposition. No overlap The new experiment, in contrast, would put the glass sphere in two entirely distinct places at once, with no overlap. More From New Scientist Recommended by. Primordial weirdness: Did the early universe have one dimension? Scientists outline test for theory.
That's the mind-boggling concept at the heart of a theory that University at Buffalo physicist Dejan Stojkovic and colleagues proposed in 2010. They suggested that the early universe -- which exploded from a single point and was very, very small at first -- was one-dimensional (like a straight line) before expanding to include two dimensions (like a plane) and then three (like the world in which we live today).
The theory, if valid, would address important problems in particle physics. Now, in a new paper in Physical Review Letters, Stojkovic and Loyola Marymount University physicist Jonas Mureika describe a test that could prove or disprove the "vanishing dimensions" hypothesis. Because it takes time for light and other waves to travel to Earth, telescopes peering out into space can, essentially, look back into time as they probe the universe's outer reaches. Gravitational waves can't exist in one- or two-dimensional space.
Falling Spacetime [720p] Space-Time New Discovery.