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Thu - May 26, 2005Supertasking with the genie of the lampA little demon now appears and decides that he
will keep pressing the button so as to leave the lamp on for ½ minute, then
off for ¼ minute, on for 1/8 minute, off for 1/16 minute and so on. Simple
mathematics shows us he will have pressed the button an infinite number of times
after 1 minute.
Posted at 08:25 PM Read More How to do an infinite number of things before breakfastItamar Pitowsky of the Hebrew University of
Jerusalem in Israel has shown that if the travelling twin can accelerate his
spaceship sufficiently strongly he can record a finite amount of the universe's
time on his own proper time clock while his twin brother, who is not
accelerating, records an infinite amount of proper time elapsing on his
clock.
Posted at 08:25 PM Read More Rogue star shown the galactic door"It's the first clear-cut case of a star that's
no longer gravitationally bound to the Milky Way," says Warren Brown, an
astrophysicist with the Harvard-Smithsonian Center for Astrophysics, who led the
study, soon to be published in The Astrophysical Journal.
Posted at 08:09 PM Read More The first evidence for string theory?One of the strangest features of string theory is
that it requires many more dimensions than we can see: the only way the
vibration modes of the superstrings can be sufficiently diverse to create all
particles is if the superstrings vibrate in a space-time of 10
dimensions.
Posted at 08:03 PM Read More Shadow over gravityBut, says Duif, that doesn't explain why
scientists observed gravimeter anomalies during an eclipse in March 1997 in a
very remote area of north-east China, while an experiment in Belgium found
nothing on 11 August 1999, when millions of Europeans left their homes to
observe the total solar eclipse.
Posted at 08:02 PM Read More Sunspot effectBut they found a link between numbers of sunspots
and prices of US durum wheat (www.arxiv.org/abs/astro-ph/0411165) most of which
grows in one part of North Dakota, where localised weather conditions could have
a dramatic impact on total production.
Posted at 08:00 PM Read More The light stuffThe proposed satellite test of the equivalence
principle (STEP) will involve four metal cylinders (each made of a different
metal and having a different mass) free-falling for around 16 minutes in
orbit.
Posted at 07:50 PM Read More Postcards from the edgeTo calculate it, astronomers need to know both
the distances between us and nearby galaxies, and their speeds as they hurtle
away from us. They discover their speed by looking at the colour of light coming
from the galaxies - the faster a galaxy is moving away from us, the redder it
appears, and the further characteristic lines in its spectrum of light are
shifted towards the red end.
Posted at 07:49 PM Read More Black holes haunt ghost particle theoryThe theory's attraction for cosmologists is that
it promises to explain at a stroke three of their most pressing conundrums: the
nature of the dark energy that is pushing the universe apart, the nature of the
dark matter that holds spinning galaxies together, and what it was that caused
the universe to undergo a rapid inflation just after the big bang (New
Scientist, 7 February, p 32).
Posted at 07:43 PM Read More Einstein's warp effect measuredCiufolini, from the University of Lecce, Italy,
and Erricos Pavlis from the Joint Center for Earth Systems Technology in
Baltimore, US, analysed millions of laser range-finding signals that are
reflected by the satellites Lageos and Lageos
2.
 Posted at 07:41 PM Read More Monsters of the universeEach laser fires pulses of ultraviolet light
lasting about 3 billionths of a second and containing 1.8 million joules of
energy - that's 500 times more power than the output of all the power stations
in the US. When the pulses smash into the target chamber, they will produce
blasts of X-rays that will converge on a plastic capsule filled with heavy
hydrogen fuel at the heart of the chamber.
Posted at 07:34 PM Read More The mysteries of lifeGiven the vastness of the universe, the diversity
of its environments, and the fact that life has certainly evolved once, you can
argue that the chances are pretty small that Earth is the only place life
exists.
Posted at 07:32 PM Read More Twisted magnetic fields fire jets from black holesNow, the most realistic computer simulations yet
suggest that as black holes spin they coil up the magnetic fields around them so
tightly that when these fields uncoil they spew particles hundreds of thousands
of light years into space.
Posted at 07:14 PM Read More Unique moon may partner SednaTHE mystery surrounding Sedna - the most distant
object ever seen in the solar system - deepened as astronomers calculated that
the planetoid's "missing" moon must belong to an entirely new class of celestial
object, and is possibly the darkest body in the solar system.
Posted at 07:13 PM Read More |
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Total entries in this category: Published On: Oct 30, 2005 10:14 PM |
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