Joined: 4/30/2006
Posts: 480
Location: the secret cow level
No, the speed of light is the absolute constant in the universe. Even black holes don't affect the speed of photons, they can only affect their trajectory.
It's theoretical, and it's doubtful we'll have technology to ever prove it. Theories aren't worth much without empirical evidence to support them.
Also, I wish the title of this thread was "Ask an intelligent question, get an intelligent answer", so we wouldn't get questions about "tweaking" a beam of light.
Actually, "tweaking" is more or less what is done in the caesium gas experiment, which sends the front of a light wave faster than light. The wave of light lengthens as it travels, sending it faster than light. Or at least, that's my understanding.
Wikipedia has some info.
The game engines do have some parts in common right?
I don't think so. My guess is that they're vastly different and finding a major similarity (except for the code that interfaces with the hardware) would be like finding a composite prime.
I'm having some trouble with the zstyle matcher.
I'm trying to make it auto complete things that match my home directory when my pwd isn't ~.
I'm also having some problems getting it to autocomplete module names when I'm a standard user, it works when I'm root though (we use the same zshrc.)
Finally, it won't expand globs when dealing with certain types of matches (notably package names). Generally when I type in *blah* it'll just put everything that matches on my command line, but when I'm dealing with packages it simply displays the list.
My .zshrc:
# Lines configured by zsh-newuser-install
fg_cyan=$'%{\e[0;36m%}'
fg_light_gray=$'%{\e[0;37m%}'
fg_red=$'%{\e[1;31m%}'
fg_purple=$'%{\e[1;35m%}'
PROMPT="${fg_red}%(?..(%?%))${fg_purple}%n${fg_red}@${fg_purple}%m${fg_red}%#${fg_light_gray} "
RPROMPT="${fg_cyan}%~${fg_light_gray}"
alias ls='ls --color=tty'
XTITLE="%n@%m:%~"
HISTFILE=~/.histfile
HISTSIZE=1000
SAVEHIST=1000
setopt beep extendedglob nomatch notify
unsetopt appendhistory
bindkey -v
autoload -Uz compinit
compinit
# End of lines configured by zsh-newuser-install
# The following lines were added by compinstall
zstyle ':completion:*' matcher-list 'm:{a-zA-Z}={A-Za-z}'
zstyle :compinstall filename '/home/omnipotententity/.zshrc'
zstyle ':completion:*' completer \
_complete _prefix _approximate:-one _ignored \
_complete:-extended _approximate:-four
zstyle ':completion::prefix-1:*' completer _complete
zstyle ':completion:incremental:*' completer _complete _correct
zstyle ':completion:predict:*' completer _complete
zstyle ':completion:*:approximate-one:*' max-errors 1
zstyle ':completion:*:approximate-four:*' max-errors 4
zstyle ':completion::complete:*' use-cache 1
zstyle ':completion::complete:*' cache-path ~/.zsh/cache/$HOST
zstyle ':completion:*' expand 'yes'
zstyle ':completion:*' squeeze-slashes 'yes'
# }}}
# {{{ Don't complete uninteresting users
zstyle ':completion:*:*:*:users' ignored-patterns \
adm apache bin daemon games gdm halt ident junkbust lp mail mailnull \
named news nfsnobody nobody nscd ntp operator pcap postgres radvd \
rpc rpcuser rpm shutdown squid sshd sync uucp vcsa xfs
# ... unless we really want to.
zstyle '*' single-ignored show
# Separate matches into groups
zstyle ':completion:*:matches' group 'yes'
# Describe each match group.
zstyle ':completion:*:descriptions' format "%B---- %d%b"
# Messages/warnings format
zstyle ':completion:*:messages' format '%B%U---- %d%u%b'
zstyle ':completion:*:warnings' format '%B%U---- no match for: %d%u%b'
# Describe options in full
zstyle ':completion:*:options' description 'yes'
zstyle ':completion:*:options' auto-description '%d'
# End of lines added by compinstall
path+=(~/bin)
Build a man a fire, warm him for a day,
Set a man on fire, warm him for the rest of his life.
Something I've wondered about ever since I learned about it in science class. This is sort of along the same lines as the information on paper question.
Okay, so pheromones are sort of what make us attracted to the opposite sex right? One would assume that it's something you could only experience from direct humans, but why is it that it works via paper/TV? I mean, does the paper have pheromones in it? It's something that's been bugging me for quite some time.
Joined: 11/18/2006
Posts: 2426
Location: Back where I belong
Pheromones are part of attraction, but are by no means the only factor. Pheromones can be implanted in paper, but as for tv other factors take over. I think that pheromones are thought to be a major component of mating in lower mammals, but once you get up to the higher mammals, including primates, it's not the only thing to worry about.
Joined: 11/11/2006
Posts: 1235
Location: United Kingdom
Titus Kwok wrote:
No, the speed of light is the absolute constant in the universe. Even black holes don't affect the speed of photons, they can only affect their trajectory.
I'd just like to clarify that the speed of light in a vacuum is an absolute constant. Light has been slowed successfully in the past. This BBC article has suitable coverage of the phenomena.
<adelikat> I am annoyed at my irc statements ending up in forums & sigs
If I'm not completely mistaken, a particle with no rest mass at all (such as a photon) cannot travel at any other speed than c. There's some physical reason for this, AFAIK. Any particle traveling at a speed lower than c has rest mass (and thus cannot travel at c).
The average speed of light through a medium is slower than c, but that's only its average speed. At no point does the light actually travel at a speed lower than c. What happens in a medium is that the light gets absorbed and then emitted again with a delay. This delay is what causes the average speed to be smaller than c. Between emissions and absorptions it travels at c.
Joined: 11/11/2006
Posts: 1235
Location: United Kingdom
Warp wrote:
If I'm not completely mistaken, a particle with no rest mass at all (such as a photon) cannot travel at any other speed than c. There's some physical reason for this, AFAIK. Any particle traveling at a speed lower than c has rest mass (and thus cannot travel at c).
I remember there was something like this written in A Brief History of Time but unfortunately I no longer have the book, nor remember the specifics. So heres a question for this topic:
What is the theory above called and who came up with it?
<adelikat> I am annoyed at my irc statements ending up in forums & sigs
What happens in a medium is that the light gets absorbed and then emitted again with a delay.
It seems that this explanation is, after all, incorrect. Light never travels slower than c even inside a medium, but the reason for the average speed being smaller than c seems to be something else.
Joined: 4/20/2005
Posts: 2161
Location: Norrköping, Sweden
I think (I'm not 100% sure) that the reason why light takes a longer time to move through certain medium is becuase of refraction - instead of moving straight through the meduim, it "bounces" through the medium, thus moving a greater distance and thus taking a longer time to get through, without the speed of light changing. Can someone confirm if this is correct?
there are mediums in which light travels faster than in vacuum. galaxies also travel faster than light.
Randil wrote:
it "bounces" through the medium, thus moving a greater distance and thus taking a longer time to get through, without the speed of light changing.
my speed doesn't change when i go through water, it just appears to change. like the speed of light appears to change when it goes through a medium...
but everything is appearance... so why not just say that it changes...
Perhaps light-speed is not the fastest possible speed, it's just very slightly lower, by an almost undetectable margin. So photons have an amazingly small mass, which even moving at c is not very noticeable.
Or maybe photons don't exist.
This is not actually true. The galaxy isn't moving that fast, it's just that there's more space between us and it. Imagine a balloon with marker dots on it, and ou blow up the balloon... the dots get further away fom each other even though they're not moving. Galaxies are moving sure, but that's not why they're receeding relative to our light cone.
someone is out there who will like you. take off your mask so they can find you faster.
I support the new Nekketsu Kouha Kunio-kun.
Joined: 4/30/2006
Posts: 480
Location: the secret cow level
Stephen Hawking, A Brief History of Time wrote:
The fundamental postulate of the theory of relativity, as it was called, was that the laws of science should be the same for all freely moving observers, no matter what their speed. This was true for Newton's laws of motion, but now the idea was extended to include Maxwell's theory and the speed of light: all observers should measure the same speed of light, no matter how fast they are moving. This simple idea has some remarkable consequences. Perhaps the best known are the equivalence of mass and energy, summed up in Einstein's famous equation E=mc2 (where E is energy, M is mass and C is the speed of light), and the law that nothing may travel faster than the speed of light. Because of the equivalence of energy and mass, the energy which an object has due to its motion will add to its mass. In other words, it will make it harder to increase its speed. This effect is only really significant for objects moving at speeds close to the speed of light. For example, at 10% of the speed of light an objects mass is only 0.5% more than normal, while at 90% of the speed of light it would be more than twice its normal mass. As an object approaches the speed of light, its mass rises ever more quickly, so it takes more and more energy to speed it up further. It can in fact never reach the speed of light, because by then its mass would have become infinite, and by the equivalance of mass and energy, it would have taken an infinite amount of energy to get it there. For this reason any normal object is forever confined by relativity to move at speeds slower than the speed of light. Only light, or other waves that have no intrinsic mass, can move at the speed of light.
An equally remarkable consequence of relativity is the way it has revolutionized our ideas of space and time. The Newtons theory, if a pulse of light is sent from one place to another, different observers would agree on the time that the journey took (since time is absolute), but will not always agree on how far the light traveled (since space is not absolute). Since the speed of the light is just the distance it has traveled divided by the time it has taken, different observers would measure different speeds for the light. In relativity, on the other hand, all observers must agree on how fast light travels. They still, however, do not agree on the distance the light has traveled, so they must therefore now also disagree over the time it has taken. (The time taken is the distance the light has traveled- which the observers do not agree on- divided by the light's speed- which they do agree on.) In other words, the theory of relativity put an end to the idea of absolute time! It appeared that each observer must have his own measure of time, as recorded by the clock carried with him, and that identical clocks carried by different observers would not necessarily agree.
Joined: 11/18/2006
Posts: 2426
Location: Back where I belong
The surface area of the balloon is increasing, so therefore the dots have to be moving further apart from each other. They are not moving, however their distances in relation to each other can change due to the amount of stretch in the balloon (due to there being more "dead space" ie strained chemical bonds between the atoms of the rubber)
The surface area of the balloon is increasing,etcetcetc
roflmao. ok, first of all... most of einsteins theories and big bang are illogical nonsense without any real evidence that tries to sound smart and shouldn't be taken seriously. and second: the dots are moving because the particles that the balloon and dots are made of are moving.
and third: the universe is infinite, it can't be compared to a @£¤#&¤% balloon.
Raiscan wrote:
Basically so long as you have mass, no matter what energy you have, you'll never get as fast as light. :(
maybe according to relativity, but not according to reality. there's no evidence that mass increases as you come closer to lightspeed.
roflmao. ok, first of all... most of einsteins theories and big bang are illogical nonsense without any real evidence that tries to sound smart and shouldn't be taken seriously.
Relativity has been proven repeatedly in experiments. As have all of Einstein's other theories that remain accepted.
If this were not the case, those theories would not be accepted, because that is not. how. science. works.
How fleeting are all human passions compared with the massive continuity of ducks.
