> At 16:12 12/09/97 +0000, you wrote:
How can I put this? Not STRICTLY true. In the same way that Einstein's theory
of relativity showed that under certain conditions Newton's laws do not hold,
so the laws of quantum mechanics show that under certain conditions the laws
of relativity do not hold. In essence, the laws of quantum mechanics make a
lot of things 'fuzzy'. I have never seen it used to specifically prove that a
'real universe' particle can exceed C, but I wouldn't put it beyond it, given
quantum mechanics allows some things to be at two places at one time.
> Transmission as tachyons? I don't know anything about tachyons
Indeed. The theoretical physics says they should be there. Finding them is a
bit more tricky. Same thing people thought about black holes 30 years ago.
> Back in the real world, there were a couple of researchers who claimed
Don't know about that but I have a feeling I would disagree. I seem to
remember an experiment that attempted to measure gravity waves failed pretty
much. Something about measureing a very long pole's position with a laser.
Whether that means gravity waves don't exist or the experiment didn't work, I
don't know. I have a feeling that if gravity did propogate at C, the expanding
universe theories I hear so much about would have big problems. Part of the
big bang theory is based on the fact that all bits attract all other bits
propotionate to mass, regardless of distance.
> Phil, expecting to be corrected by someone who knows more about this
I wouldn't know about that. But I do know what I know. And then there's Terry
Pratchett's famous kingions.
> Andy Skinner wrote:
Quoting somebody (himself? that's what my mailer indicates):
> Does converting yourself to energy or a signal and transmitting
Now, I'm not a physicist, but my (limited, and not very mathematical)
understanding is that _everything_ (that we are certain exists -- see
below) is limited to the speed of light under general relativity, or at least
that's what I read. That includes matter (infinite mass at C), energy (photons
have no mass, but move at C by definition) and information (which has to get
from A to B somehow)
> Transmission as tachyons? I don't know anything about tachyons except
Quite possibly all three. Tachyons, particles which _have_ to move FTL,
are a
theoretical possiblity -- that is, their existence is not directly
forbidden by GR, which basically says that infinite energy is needed to
accelerate a mass to C, so you can't get past that speed. The trouble is, if
you do the maths, you end up
with tachyons having an "imaginary" mass, and no-one knows quite what
that might mean.
There have been some good SF stories written about spacecraft that use
"tachyonic transfer" to go FTL, notably Brian Stapleton's Hooded Swan series.
The idea, never explicitly detailed, seems to be that you accelerate to high
sub-C speed, then somehow switch from normal matter to tachyon matter
with the same energy state, then bleed energy off so that you go faster (for
tachyons, the _less_ energy you have, the faster you move), and vice
versa to slow down.
Back in the real world, there were a couple of researchers who claimed that
they had detected tachyons a few years ago, but since there's been no further
info on this, I guess they were mistaken (either that, or the gummint moved in
on them <g>). So, the existence of tachyons remains to be proven, AFAIK.
> Aren't the effects of gravity supposed to be effective immediately
Nope. Last I heard, gravity waves move at C, just like EM radiation.
Phil, expecting to be corrected by someone who knows more about this than I
do...
> be instantaneous? <
Don't know about that but I have a feeling I would disagree. I seem to
remember an experiment that attempted to measure gravity waves failed pretty
much. Something about measureing a very long pole's position with a laser.
Whether that means gravity waves don't exist or the experiment didn't work, I
don't know. I have a feeling that if gravity did propogate at C, the expanding
universe theories I hear so much about would have big problems. Part of the
big bang theory is based on the fact that all bits attract all other bits
propotionate to mass, regardless of distance.
Ok, gravitational waves move at the speed of light. Gravitational
waves are ripples in space-time caused by masses moving around.
Stationary masses do not (NOT!) cause gravitational waves. What, you say?
Well, remember, stationary charges do NOT cause electromagnetic waves. If
charge up a pith ball, it will not start emitting light. I have to have it
accelerate to cause radiation. The same is true for gravitational waves. If I
were to take the sun and start wiggling it back and forth it would cause
gravitational waves just like the wiggling electrons in a radio antenna
radiate radio waves.
With regards to the big bang. One of the really cool things about general
relativity is that it is a local theory. (E and M is the same
way.) A local theory means that a particle here -->* only cares about
what is locally around it. The electron that are screaming towards my computer
screen to light up phosphurs only care about the E and M fields in their
immediate vicinity, they don't care about the E and M field at the plates on
the sides of the Cathode Ray Tube. This means that you form a nice chain. For
the big bang, this means everything effectively acts on everything else in the
universe because you can say, something a gazillion light years away
gravitationally acted on
something a gazillion -1 light years away, which then acted on
something gazillion -2 light years away, etc etc etc.
Anyway, enough physics (I am an astronomer afterall). I suggest that everyone
with questions about this read the sci.astro FAQ. A lot of the things we are
talking about are answered there. The http address is:
http://astrosun.tn.cornell.edu/students/lazio/sci.astro.html
and I suggest the astrophysics section for stuff on tachyons and gravitational
waves.
cheers brad
(snipage!)
> Anyway, enough physics (I am an astronomer afterall). I suggest that
The SCI.ASTRO FAQ page is COOL!! 8-D What these astronomy/physics texts
don't explain to me...If light has no mass (so it can travel at the speed of
light), how can anyone feel it? (Go from a dark room, to the bright sunny
outdoors...You will feel a faint differance...That is the pressure of the
light!) If you can't feel it, how can it possibly bounce off of things so we
can see them?
It is my humble opinion that somethings have been missed. Whether it is simply
that we humans just don't know...who knows?
My favorite pet explanation of light, is it is a very tiny (quantum scale)
object. Light bounces at perfect angles like billard balls. Automobile
headlights don't explode when you are driving down the road (from the light
piling up inside the bulb...the car's speed plus that of light, puts it over
the speed limit). When you look at light one way, it looks like a partical (I
think it is...) and when you look at it another, it looks like a wave (an
ocean wave is made up of water molocules). You can feel the sun shining on
you.
Just MY opinions...
> Mike Wikan wrote:
gonna tell us where...or make us look:)
The game was called "Gravitar" and it is a lot of fun and available as
freeware for the PC on the web....
> At 11:37 12/09/97 -0500, you wrote:
You're probably more well informed than I am so fair does about this (as I
said, I dropped out of a physics degree so my knowledge is patchy in places).
But if what I have quoted is true, how does that cope with relative motion?
for example to us travelling round it the sun is in a fairly fixed position
and would therefore not emit gravity waves. But to someone sitting at galactic
centre (presuming someone could) the sun would definitely be moving, and
therefore would emit gravity waves. And regardless of where you are the rest
of the universe is moving (away, very quickly) and therefore we should be
flooded with gravity
waves/gravitons.
Ain't physics a bummer?
TTFN
Jon
> At 17:19 14/09/97 -0700, you wrote:
That would be impact of photons. See, light acts a particle (which by
definition has mass) and an energy wave (which doesn't) depending upon how you
look at it. Or alternatively, it would be a feeling of pressure due to your
skin expanding as it heats up:). Actually, there was a theory (getting back to
spaceflight) that you could push a very light ship along with a sail and very
big laser. Wouldn't be very good for combat boats, but
would make a heck of a scenario - sail ship moves 2" per turn and
anything that passes through it's rear arc takes the equivalent of an A
battery hit. Can you knock it out before it crosses the table.. What I never
figured about that was they always had the laser back on the home planet,
never fitted to the back of the ship. Then there was a video game ( I think
called Gravity, surprisingly) where the ships moved by opening a small gravity
well in front of the hull, which the ship then fell in to. Then you move the
well on a bit more, and the ship falls down again. Acceleration for free,
provided you could maintain the gravity well.
> It is my humble opinion that somethings have been missed. Whether it
The problem is you see, we don't now what we don't know so we can out and find
out about it, if you see what I mean:).
> My favorite pet explanation of light, is it is a very tiny (quantum
Something which we haven't mentioned of course is that, moving very close (or
beyond) C, it's VERY difficult to navigate. By the time your sensors have
detected something, you're already crashing into it, which with ~c momentum
would be very messy. As I believe Holly once said 'brown trousers time...'. So
in other words to maintain a real universe FTL fleet not only requires FTL
drives and FTL navigation, but also FTL sensors. Or very, very
accurate star maps. Which is why I actually prefer the wormhole / jump
point / hyperspace ideas. I just don't think near-c travel is feasible
even if some propulsion method is found.
TTFN
Jon
> Donald Hosford writes:
@:) My favorite pet explanation of light, is it is a very tiny @:) (quantum
scale) object.
Well others have answered this. This is actually pretty well understood
already. Light acts like a particle sometimes and like a wave other times.
Actually all particles act like waves sometimes but the more massive they get
the less likely they are to act like waves.
Human beings act like waves but not very much because, quantum-wise,
we are extremely heavy.
@:) You can feel the sun shining on you.
Well, you can definitely feel the heat of the Sun, but you can't actually feel
the light pressure. Also you may have seen a radiometer, a little glass bulb
with four vanes inside that rotate when you shine a light on them? From what I
hear that motive principle in that case is actually heat. The black sides of
the vanes get hot when light shines on them and heat the air next to them,
which expands and pushes on the vane. The white sides stay cooler so the vanes
turn only in one direction.
Light pressure is there, though, and has been used experimentally on a few
space probes. It's never been used to actually propel a spacecraft yet,
though. What you need is a big sheet of light reflective material like
aluminated (is that a word?) mylar. Point that at the Sun and the sun will
push it away, pulling your spaceship behind it. You can also use a laser to
push on the sail.
Somebody asked why laser-propelled spaceship systems are always
depicted as having the laser on the ground - the answer is that you
can build a MUCH bigger laser on the ground. By removing the engines and fuel
from your spacecraft you make is much, much lighter and it can go much faster.
Plus you can use a much larger engine because you have an entire planet to
store it on.
> Alan E. Aebrain Carmel J. Brain writes:
@:) Of course, so does Newtonian physics, within its realm. Case in @:) point:
FTL transmission of information has been achieved over @:) macroscopic
distances, about 2 cm if memory serves.
Quantumly speaking, I think the difference between 2cm and 2ly is not great.
@:) A piece of music was played, and transmitted via tunnelling, @:) arriving
at a speed not less than a large multiple of c, and @:) recognisable as the
tune being played (very distorted, a lot of @:) signal loss). Still, even such
a small crack in the FTL door @:) rather puts the Kibosh on the absolute
"Thous shalt not transmit @:) any information faster than light" prohibition.
Wow.
@:) Now this does not an FTL drive make. But it _IS_ interesting. I'll
@:) see if I can dig up the references to the experiment.
Please do. Note that this system, cleaned up and expanded to large distances,
provides about a third of the technology required for teleportation. Scanning
an object at the quantum level and storing all information about it is, of
course, no mean feat, and I haven't heard of any way to construct an object
particle by particle but... well, it's imaginable at least.
> Deeply in Love with Dot writes:
@:) Then there was a video game ( I think called Gravity, @:) surprisingly)
where the ships moved by opening a small gravity @:) well in front of the
hull, which the ship then fell in to. Then @:) you move the well on a bit more
, and the ship falls down @:) again. Acceleration for free, provided you could
maintain the @:) gravity well.
If you actually move the gravity well, you would presumably have to
put a lot of energy into it - and presumably lose all the momentum you
got from it. I guess if you destroyed it and created a new one that might be
better. Of course we're talking fiction so whatever makes for better movie
special effects is what you'd use.
> Whilst writing about light and stuff, Jon wrote:
> That would be impact of photons. See, light acts a particle (which
Not strictly true. Light never has any mass, but it does have momentum. The
momentum is obviously not given by the Newtonian formula of mass times
velocity, but rather by Planck's Constant (h) divided by wavelength.
Hence when light reflects of a mirror there is a transfer of momentum
to that mirror of 2 x h / wavelength for each photon. This is the
principle behind solar sails. The problem is that you need a lot of photons
and a very, very light sail in order to get any appreciable acceleration. I
once worked it out using very thin copper foil and the sail had to be bigger
than a continent in area! And that was for
a sail-ship operating near the Earth's orbit, further out you'd need
an even bigger sail.
And strictly speaking light is always a wave and a particle at the same time,
as indeed is everything else in the universe. How you look at it is simply a
matter of picking which one is easiest to work with in approaching any
specific scientific enquiry,
Cheers,
> joachim writes:
I am not necessarily saying Einstein is wrong (or not wrong really) I just
understand that the possibility exist. I try to follow the thinking that "If
you can think it, it can be done"
(a truly positive way of thinking)...
> How can I put this? Not STRICTLY true. In the same way that Einstein's
These are the things that allow me to remember that: though we may have great
ideas and be very gifted in thinking, we are not always right... even if it
almost always works and even if every body believes it.
The Greeks believed in Greek gods, were they right? it was believed and almost
always worked...
They just didn't know...
I believe: "WE JUST DON'T KNOW"
Call me a rebel
CMC
> That Joachim Heck chap wrote:
> A piece of music was played, and transmitted via tunnelling,
I've heard of this experiment before. The music was meant to be transmitted at
about 4.5c. I can't remember why but people are getting very suspicious of it.
It might turn out to be another Cold Fusion cock up.
> Now this does not an FTL drive make. But it _IS_ interesting.
Nanotech. Instead of scanning the person you disassemble them. As you do so
you record all the data you need. You then throw the disassembled matter into
the storage bins. Transmit the data to a receiving booth. Here more nanobots
use the data to assemble a new copy of you from the matter stored in the bins
at this end. There is no need to scan at the quantum level, whatever that is,
as memory is stored by chemical means, so an atomic level will surfice. There
will be an obvious gap in consciousness but no worse than when you go to sleep
and wake up again. Unless you believe in the existence of a soul in which case
any sort of transporter should be impossible.
Cheers,
> Tony Christney writes:
@:) > Quantumly speaking, I think the difference between 2cm and 2ly @:) >is
not great.
@:)
@:) Pardon? I think that at any scale the difference between 2cm and @:) 2ly
is very significant! Tunneling through a 2ly barrier is much @:) more
difficult than tunneling through a 2cm barrier. Probability @:) of
transmission goes like an inverse exponential.
I'm not sure about exactly what probabalistic law the uncertainty principle
follows. My point was that 2cm is an enormous distance in quantum terms. If
they had transmitted over 2 picometers, fine, big
deal, who cares - but 2cm is real distance. After you've moved your
quantum effects into the macroscopic world, 2ly or 200ly is not such a big
jump.
@:) If 2cm produces much signal loss, imagine the distortion even over @:)
10cm. I wonder if the signal would even be readable with extreme @:)
filtering. Probably not.
That sounds like a technical quibble. If information can be transmitted faster
than light, it's one of the most significant technical advances of the
century. Certainly the biggest one since the lightspeed barrier was imposed by
Einstein (1919?). Filtering, signal to noise, those are problems that have
already been solved.
@:) I don't think that this technique actually stores or scans any @:) info.
From what Alan has written it seems like they used a @:) regular electronic
signal, but tried to pass it through an @:) "impenetrable" barrier.
Right. You'd get the signal from your scanning apparatus (which is also
practically impossible to build).
@:) The three major technical problems with teleportation I would say are:
@:)
@:) 1. The uncertainty principle. Makes it impossible to actually make @:) an
exact copy of any object. Star Trek makes a point in including @:) a
"Heisenberg compensator" into their teleporters. How it works is @:) anyone's
guess.
Ha. Yes this would be a problem. Someone has already mentioned that you might
not have to copy people at the quantum level. Even if this is so, however,
copying people at a protein level is still almost unimaginably difficult.
@:) 2. Storage space. How many particles (ie. neutrons, electrons & @:)
protons) make up a human body? Storing this info would require an @:)
enourmous amount of memory.
Yes indeed. I guess it's time to start storing multiple bits per electron in
our quantum computers, huh?
@:) 3. Bandwidth. You think that a 28.8 modem is slow, imagine trying @:) to
transmit billions of terabytes with no signal loss (oops, @:) sorry, your arm
timed out on the transmit, come back tomorrow...)!
Yes, getting a GPF while transporting would kinda blow chunks. I think,
though, that the storage and transmission problems are
solvable. They're just scaled-up versions of problems we have already
solved so hopefully they'll work out.
> Alan E. Aebrain Carmel J. Brain writes:
Pardon? I think that at any scale the difference between 2cm and 2ly is very
significant! Tunneling through a 2ly barrier is much more difficult than
tunneling through a 2cm barrier. Probability of transmission goes like an
inverse exponential.
> @:) A piece of music was played, and transmitted via tunnelling,
If 2cm produces much signal loss, imagine the distortion even over 10cm. I
wonder if the signal would even be readable with extreme filtering. Probably
not. However, I would like to find out more about this experiment. It is
interesting how you can trick nature in this way.
> @:) Now this does not an FTL drive make. But it _IS_ interesting. I'll
I don't think that this technique actually stores or scans any info.
> From what Alan has written it seems like they used a regular electronic
Similar to a tunneling electron microscope, which presumably also would
transmit info FTL, at least for part of the system.
The three major technical problems with teleportation I would say are:
1. The uncertainty principle. Makes it impossible to actually make an exact
copy of any object. Star Trek makes a point in including a "Heisenberg
compensator" into their teleporters. How it works is anyone's guess.
2. Storage space. How many particles (ie. neutrons, electrons & protons) make
up a human body? Storing this info would require an enourmous amount of
memory.
3. Bandwidth. You think that a 28.8 modem is slow, imagine trying to transmit
billions of terabytes with no signal loss (oops, sorry, your arm timed out on
the transmit, come back tomorrow...)!
The trillion dollar question is: any solutions?
> -joachim
> Phillip Atcliffe wrote:
> Now, I'm not a physicist, but my (limited, and not very mathematical)
Yup. The Theory is a pretty good approximation of reality too, it works rather
well.
Of course, so does Newtonian physics, within its realm. Case in point: FTL
transmission of information has been achieved over macroscopic distances,
about 2 cm if memory serves. A piece of music was played, and transmitted via
tunnelling, arriving at a speed not less than a large multiple of c, and
recognisable as the tune being played (very distorted, a lot of signal loss).
Still, even such a small crack in the FTL door rather puts the Kibosh on the
absolute "Thous shalt not transmit any information faster than light"
prohibition.
Now this does not an FTL drive make. But it _IS_ interesting. I'll see
if I can dig up the references to the experiment. In the meantime,
> Alan E. Aebrain Carmel J. Brain writes:
@:) Frankly, anything which pokes a hole in such a well-tested
@:) principle as no-FTL is suspicious! ... But it appears, on the
@:) best evidence to hand, to be real rather than mismeasurement.
@:) As for Cold Fusion - see some of the latest papers on the
@:) subject.... In engineering terms, it _appears_ that we're NOT
@:) very far away from getting a new power source.
Can you provide any web links for any of this information? I'd be quite
interested to see it if it were available.
In message <l03102800b0433165b5fa@[142.104.2.101]>
> Tony Christney <acc@uvic.ca> wrote:
> >@:) A piece of music was played, and transmitted via tunnelling,
IIRC, one of the arguments against this experiment proving anything, was that
they already knew what to expect at the destination, and so no real
information was transmitted.
(it sounds like a wacky argument, but quantum physics is like that
sometimes...)
> Steve Pugh wrote:
> I've heard of this experiment before. The music was meant to be
Frankly, anything which pokes a hole in such a well-tested principle as
no-FTL is suspicious! The results showed that the speed had to be
greater than 4.5c, and if memory serves, had to be greater than 16000 c.
Measurement of such small times is still an interesting engineering exercise
though, one fraught with chances of error. We're still a long, long way from
making this a useful phenomenon, if ever. But it appears, on the best evidence
to hand, to be real rather than mismeasurement.
As for Cold Fusion - see some of the latest papers on the subject. A lot
of work has been done quitely on this, if only to disprove it. Tritium
production and other otherwise-inexplicable nuclear effects are now
being observed regularly, even repeatably, but still not enough
neutrons. The effect is definitely there, but possibly/probably is not
fusion as such. It may be Casimir effect within the crystal lattice though, ie
Vacuum Energy. It's a net energy producer though, figures as high as 1000 kj
per j input have been measured, for several days. In
engineering terms, it _appears_ that we're NOT very far away from
getting a new power source. This one is quite exciting. I believe a firm in
the US is currently renting experimental kits for about $2500 so even
the smallest college can do some hands-on experimentation.
> Joachim Heck - SunSoft wrote:
> @:) As for Cold Fusion - see some of the latest papers on the
I'm working on it! The best I can do for now is refer you to the Proceedings
of the International Conferences on Cold Fusion (ICCFs).
Also: Some reasons why some early experiments weren't repeatable, but ones
using later equipment are, are given in some detail in: "Calometric Principles
and Problems in mesaurements of Excess Power
during Pd-D2O Electrolysis" by M.H.Miles,B.F.Bush,D.Stillwell in Journal
of Physical Chemistry 1994 pp948-952
Clean Energy Technologies Inc are the marketers of the Patterson Power Cell
research kit (cost now USD 3,750 p.a., my info was old or my memory
defective), which makes use of principles described in US patents
After Jon T. mentioned the multiple FTL drives of the Hooded Swan series (for
those interested, the Swan itself used "mass relaxation", which I took to
involve
> tachyonic conversion and energy dumping), Niall wrote:
> Check out Vernor Vinge's "A Fire on the Deep". In this there are 3
In the slowness for instance you can't travel faster thal light. In the
transcend just about anything is possible. Dependent on which area your
civilisation is in, you can be more or less technologically advanced. The only
problem is that high tech stuff doesn't work in the lower areas of space.
Therefore no transcend techs in the slowness, etc. This creates some
interesting possibilities.
<<
This sounds all too like the city of Cynosure from the comics Warp and
GrimJack (especially the latter). "Sweet, cynical Cynosure" is located at
something like the centre of time and space, and all sorts of dimensions phase
in and out of the place (don't get me started on the "snowballs" <g>). Plus,
the city itself is made up of a variety of "realities". Magic works here,
science there. Makes life interesting, especially if you're a cop; there has
been at least one
wonderful scene in which a high-tech assassin didn't watch where he was
going
(actually, he couldn't read), and flew straight into a no-tech zone. So
much for him after his jetpack stopped working at a thousand feet..!
More to the point, Cynosure Starbase is a fun place to visit. Set up in an
"everything works" part of town, the flight line can contain all sorts of
things from
"conventional" starships to dragon/pteranodon airliners (think "The
Flintstones")
to DC-10s to sail barges to dirigibles -- if it flies, you're likely to
find it there at some time.
As someone who has been known to teach people air games by flying fighters
against a dragon or UFO, I _love_ Cynosure -- and aren't there 10^nth
possibilities for games, particuarly if you're prepared to be a bit
silly..!
Phil