Off Topic

[Digit]

Yep! So you now agree with me that light must have mass, s-o-o-o, back to question one. Where does the energy come from to accelerate a photon to the speed of light if to do so requires infinite energy?

[marduk]

but it doesnt reach the speed of light
thats a bit of a misnomer as light speed is the upper limit
most photons are a little slower than that
if they reach it or exceed it they become tachyons

[Digit]

Precisely my point. Either the 'speed of light' ain't the speed of light or Einstein was wrong. Which leads to the next question, what happens to a tachyon when it slows down?

[marduk]

it is no longer a tachyon
it becomes a photon

like what happens to a speeding driver when he slows down
he gets booked

[Digit]

On the basis that photons must have mass, however small, the amount of energy needed to accelerate the number of photons in the universe must come up short of available energy. E=MC2 requires that we need to know the mass to make the calculations, if you derive that from E=MC2 you need to know C, if photons don't travel at at C what is C?
If the amount of energy per photon is significant, a tachyon must give forth a significant amount of energy when changing its state to a photon.
I would also point out that black holes do give up energy, if only in the X ray end of the spectrum, in addition the Law of Conservation of Momentum requires that a black hole must be a very oblate spheroid, thereby having less gravity at its poles, which is supported by the fact that the poles appear to be the point where X Rays escape from.

[marduk]

its lucky for physicists then, that both Tachyons and black holes are entirely theoretical

[stan]

black holes theoretical?
I thought numbers of them have been found.

[marduk]

behind the fridge or under the sofa ?

[Digit]

I'm with Stan.

[marduk]

To date, the existence of tachyons has been neither proven nor disproven.

http://en.wikipedia.org/wiki/Tachyon

Black hole expert Marek Abramowicz at Gothenburg University in Sweden agrees that the idea of dark energy stars is worth pursuing. "We really don't have proof that black holes exist," he says. "This is a very interesting alternative."

http://www.newscientist.com/article.ns? ... news_rss20

George Chapline, an applied physicist at Lawrence Livermore National Laboratory, gave a talk based on ideas he's been incubating for several years. His goal: to amend astrophysics by applying theories of dark energy and condensed matter physics.

His work reinvents black holes as so-called "dark energy stars," which are what is left over when matter transitions to dark energy as it passes a point of no return similar to a black hole's event horizon. That redefinition, if correct, would invalidate much of the intellectual framework of traditional black holes.

http://www.seedmagazine.com/news/2006/0 ... t_exis.php
ner

[Digit]

A rose by any name will smell as sweet.

[marduk]

The fault, dear Brutus, is not in our stars,
But in ourselves, that we are underlings

[Beagle]

http://www.telegraph.co.uk/connected/ma ... eman08.xml

The human family tree will have to be redrawn in the wake of a discovery that an apeman skeleton is not as old as originally thought, suggesting it may not be a direct ancestor of humankind

From: The Daily Grail

[marduk]

errr
well in fact this fits in perfectly with the homo family tree where this species is already known to be living alongside homo erectus and also the ancestor of the same species

[bandit]

http://www.spaceref.com/news/viewpr.html?pid=21419

quite an appetite for something that doesn't exist.