File this under “everything you know is wrong.” I read a few years ago that the speed of light wasn’t constant, and the main thing I’ve found about it on the web is this story about a group of astronomers who think the speed of light has slown down since the beginnings of time.
But I remember reading an article around summer or fall of 2000 about some scientists that had managed to slow down light in a laboratory setting.
The US government is calling together scientists to draft a plan to combat asteroids. I think this is a great step in the right direction for foresight.
National Geographic: U.S. Summons Experts to Draft Asteroid Defense Plan
(via New World Disorder).
If you’ve never been to cyberpunk maestro Rudy Rucker’s website, you’re missing out on his free fractal and alife software, artwork, and writing. It’s quite the nifty site.
Matrioshka Brains are hypothetical supercomputers that “consume the entire power output of stars (~1026 W), consume all of the useful construction material of a solar system (~1026 kg), have thought capacities limited by the physics of the universe and are are essentially immortal.”
The full paper is here and you can also find more info on Wikipedia.
(via Boing Boing)
According to the Telegraph, scientists have discovered that although the sun will expand in 7.7 billion years earth will survive. As the sun expands its mass will decrease which will lower its gravitational pull, allowing the earth to orbit further and further away from it:
According to the team from Sussex University, however, these calculations missed out a crucial effect: the loss of mass by the ageing Sun as it expands and its gravity weakens.
Taking this effect into account, the team found that the Earth would manage to dodge a fiery fate, its orbit expanding away from the swelling Sun.
According to Dr Robert Smith, one of the team that made the discovery, the dying Sun will make two attempts to destroy the Earth. In the first, about 7.7 billion years from now, it will expand to about 120 times its current size, engulfing the two innermost planets, Mercury and Venus.
Telegraph: Good news: Doomsday has been postponed
(via Fark).
MyPhysicsLab is a place where you can play god with gravity and stuff.
Stephen Hawking is rewritting A Brief History of Time as a kids book (update: this has been published as The Universe in a Nutshell). It will also be targetted towards adults who want to better understand the original book. Meanwhile, Hawking warns the world that space migration is the only way to escape certain doom.
Dig this year’s Ig Nobel prizes, honoring achievements that could not or should not be duplicated. My favorites are the “discovery that black holes fulfill all the technical requirements to be the location of Hell” and the patenting of the wheel in the year 2001.
It seems someone has come up with a theoretically workable time machine concept:
RONALD MALLETT thinks he has found a practical way to make a time machine. Mallett isn’t mad. None of the known laws of physics forbids time travel, and in theory, shunting matter back and forth through time shouldn’t be that difficult. […]
To twist time into a loop, Mallett worked out that he would have to add a second light beam, circulating in the opposite direction. Then if you increase the intensity of the light enough, space and time swap roles: inside the circulating light beam, time runs round and round, while what to an outsider looks like time becomes like an ordinary dimension of space. A person walking along in the right direction could actually be walking backwards in time–as measured outside the circle. So after walking for a while, you could leave the circle and meet yourself before you have entered it (see Diagram, opposite).
The energy needed to twist time into a loop is enormous, however. Perhaps this wouldn’t be a practical time machine after all? But when Mallett took another look at his solutions, he saw that the effect of circulating light depends on its velocity: the slower the light, the stronger the distortion in space-time. Though it seems counter-intuitive, light gains inertia as it is slowed down. “Increasing its inertia increases its energy, and this increases the effect,” Mallett says.
As luck would have it, slowing light down has just become a practical possibility. Lene Hau of Harvard University has slowed light from the usual 300,000 kilometres per second to just a few metres per second–and even to a standstill (New Scientist, 27 January, p 4). “Prior to this, I wouldn’t have thought time travel this way was a practical possibility,” Mallett says. “But the slow light opens up a domain we just haven’t had before.”
Update: Mallett has written a book called Time Traveler: A Scientist’s Personal Mission to Make Time Travel a Reality. His work has been heavily criticized. See the Ronald Mallett entry on Wikipedia.
Lene Hau‘s work is also worth looking into.
© 2024 Technoccult
Theme by Anders Norén — Up ↑