High speed data communications in previously unused (and unregulated) spectrum. Anyway, how do you regulate light.
Actually, 120 GHz is a fully regulated part of the radio spectrum. The Powers That Be regulate it (and assign users) up
to 300 GHz. There is increasing interest
in this part of the spectrum, partly because the
lower frequencies are getting crowded in
some parts of the world, and because atmosphereic
attenuation (which is high at these frequencies)
makes frequency reuse a lot easier. The military
are interested too, since that same attenuation makes
it hard for unfriendlies to listen in on tacitcal
communications. Unless they're right in the
middle of the battle, in which case they have other
things to worry about...
Anything beyond 300 GHz is terra incognita - electronic techniques become
impractical, and optical techniques
don't work well
until you go lots higher in frequency.
You can buy infrared data links that will shoot
data across town, and they are not regulated
(as radios) in any way. They require laser
certification only.
Look at a map. There's not a major city within 100 miles of Fort Stockton, Texas.
Cape Canaveral is much closer to major metro areas than Fort Stockton ever will be.
For range safety purposes 100 miles is
nothing. The permissible launch azimuths from
Cape Canaveral are set by Newfoundland to the
north, and Brazil to the south. Fort
Stockton, on the other hand, launches right
over the biggest cities in Texas.
Vandenberg has a limited range of
launch azimuths, but since they can launch
due south without any danger of hitting
anything (look at a map), they are
the preferred site for U.S. launches
to polar orbit.
Film vs. digital? I do both, because they
complement each other nicely.
I like to use my digital camera for
quick and dirty shots. No processing, instant
pictures. I use Polaroid if I know I'll
need pictures before I can get back
to a computer.
I also shoot medium
and large format. They require
more care and thought in setup and use, and
cannot produce a picture as quickly. But
even if digital could produce the quality
and general impact of a good large format
print (debatable; some digital is crap,
and some is awfully good), I couldn't
afford to do it.
At least, not in this epoch:
my total investment in photo gear
wouldn't buy a professional digital camera,
let alone the printer I would need to go with it. So I
continue to play with wet things
in the dark.
I will cheer, long and loud, when people
actually do return to the Moon. I wouldn't
mind going there myself.
Sadly, frankly, Transorbital looks like a
scam. Where is the technical information? If they're
launching next year, where are the prototype
probes? Where are the test results?
Where are the pictures of shiny hardware?
Have they built anything, other than
a webpage with lots of broken links?
As far as I know, not one of these over-hyped
projects has put a gram even in to low Earth
orbit.
On paper, the economics work. People
are expensive. There
are lots of straightforward nuts-and-bolts
questions that computers can handle,
simply, efficiently, and cost-effectively.
Unfortunately, most companies
let computers do all the stuff, whether they
are suited to it or not, and lay off all the people. Or (sometimes worse!) farm the support out to a call
centre who don't have a clue.
If my call was that important
you would have answered it by now!
...laura
Re:Can I Renounce My Citizenship?
on
Want Freedom?
·
· Score: 1
...can i renounce it and get Canadian Citizenship or something?
Sure.
Canada is far from perfect. But we're
such nice people.:-)
Perhaps it would be more constructive to try to
fix your own country. You fucked it up.
You fix it.
Those are indeed hefty numbers, but
in modern commercial service, the numbers
that really matter are mass to geostationary
transfer orbit, because that's how you launch
communications satellites, and that's where
the money is.
Rockets don't lift satellites directly to a
40,000 km orbit. Instead, they launch to
an elliptical orbit whose apogee (the highest point in
the orbit) is about the right height. At apogee they
fire the rockets again to increase the perigee
(lowest point of the orbit), achieving
a circular orbit.
The minimum orbital inclination is
always achieved by launching due east,
and is then equal to the launch site latitude.
Inclination changes require lots of fuel,
which is why folks like Arianespace
(who have updated their web page to lock
out all but Internet Explorer and
Netscape, so I will not post
the URL)
set up shop so close to the equator.
The best the U.S. could do was Florida,
a long
way north.
The move from IPv4 to IPv6 is an instructive example.
I continue to be amused at the fact that every
square micron of the Earth's surface could
have (approximately) 660 billion IPv6 addresses
of its very own.
Goddess knows what the bacteriafolk would do with them...
you don't want the probes to survive longer than planned. You want them to be like F1 race cars: ideally, the engine should explode
_just_ over the finish line. Only then have you maximized tolerances. However, due to uncertainty, you engineer in a margin of safety.
One relatively scarce resource for Earth-orbiting satellites
is radio frequencies to talk to them on.
By running a satellite on batteries, you guarantee that
it will die, and have a fairly good idea
how long it will take to do so. This
can make it a lot easier to license it
with The Authorities.
The colours on money are chosen to try
to scramble colour
scanners and photocopiers. The
intent is that if you get one colour on the
bill right, you'll mess up another. This
is why you see certain colours over and
over, like the funny purple and turquoise
that appear on so many notes. The new
Canadian $5 note, for example, is
a distinctive blue, but also has
"funny purple" highlights.
Brightly coloured notes sometimes
have unexpected effects, like noting in
an Australian TV show
that a small-time
armed robber had netted $50 (two reddish-orange,
one blue).
Why? A subjective quality of the claim doesn't change the scientific method.
Theoretically, no. In practice, yes.
The problem is that such claims are at odds
with too many aspects of physics that are too well
established. Einstein wasn't actually at
odds with the experimental results that
motivated relativity; he explained
results that nobody could otherwise explain.
His ideas were different, but they've withstood
a great deal of scrutiny and experimental
testing, and have proven to be right.
People seem to think that just because
somebody is viewed as a crank, that they
must be on to something. 'taint so!. Sometimes
a crank is just a crank...
It's in progress now here in Vancouver. There
are some clouds around, but not enough to spoil
the experience.
My low-tech equipment is a pinhole camera
made from a cardboard box. It has a piece of
white paper taped inside as a viewing screen,
with the "lens" a pinhole poked in a piece
of 120 film backing paper.
It works fine, and I
observed 1st contact at 0003 UTC, 1703 PDT.
Echo cancellation is a classic application
of adaptive filters. Every
reference ever published on the subject
discusses it. I like
Haykin's book myself.
I just did a search on
Google
and came up with 4000 references.
The underlying theory is pretty hairy, but
the implementation of an algorithm like LMS is
straightforward.
It's been a long time since I read deeply on the matter, but I believe this is incorrect. The accepted theory in Galileo's time - spheres within spheres with Earth at the centre - predicted positions of the planets visible to the naked eye quite well...
Not really. The retrograde motion of
the outer planets around opposition had been known
for a long time, and Ptolemy & Co. had
a very hard time explaining it.
Jupiter and Saturn have shown this very
clearly over the last few months.
Explaining these motions was
dead easy for
Copernicus. Kepler provided further
refinements
(elliptical orbits instead of circular),
based on Tycho Brahe's observations.
Newton fleshed out the physics.
The real fly in the ointment
was the Moon. It actually does
revolve around the Earth.
Anything which can be decrypted is going to be breakable.
Actually, no. A one-time pad really is unbreakable if properly applied.
One way of looking at it is that since
the one-time pad is random and was not generated
by algorithmic means, no algorithm can
break it. Crypto folks use different
terminology, but the result is the same:
unless you compromise the pad itself, no decryption
can do better than random chance.
These results are well established,
and any decent text on information theory
will fill in the details.
An interesting side-effect of this came up with
some U.S. decrypts of Soviet espionage
activity in the 1950s, which were decrypted
when agents misused their one-time pads.
The authorities didn't take any action, partly
because they were concerned about proving
in court that the decrypts were accurate...
One of my funniest examples of
mixing languages up was speaking
English (my mother tongue) with a
German accent after working for 2 weeks at a trade show
in Duesseldorf...
Speaking French with
a Quebecois accent after a week with
a customer in Montreal makes perfect sense.
I guess.
Yes, I sometimes dream in languages other than English.
Occasionally, just to screw around, I'll
phrase things in English as literal translations from
other languages - e.g. "I must get myself in gear the ass" and "By me there is a not-ness of coffee!" for "I must get my
ass in gear" and "I have no coffee!" I leave
the source languages as an exercise for the
reader...
Languages are a goodness. They beat the hell out of card games.
Now that the dust has settled from my
employers' restructuring last May, things are looking pretty
good. I'm having fun. I'm doing new things. They're taking pretty good care of me, and paying me lots. That's
what happens when too many people they were counting on
walk.:-)
The net result is that what's left isn't much of a show. But it's my show,
and I now find myself in the most senior position I've ever had. True, it's largely
by attrition. But no matter how I got here,
I'll take it.
Do I like it? Yes, for the most part.
I qualify the answer because while I have no plans to
leave any time soon, I do
know, in some detail, what circumstances would cause me to do so.
A colleague of mine is of Slovak descent, and
tells me one of the wildest dodges in the Bad Old Days was
CPUs with weird numbers of bits, like 28 bit
words. It seems that it was illegal to
export 32 bit CPUs to the Eastern Bloc. But anything smaller
was OK.
In Wireless World in the late 1980s there
was a very good series of articles on Eastern Bloc computing, including all the PDP-11 and S/360 clones that have been mentioned. Sorry, I don't have the
exact citation. Check your library.
It's not. The parent post is inaccurate. The horsehead nebula is actually just off Orion's belt.
Yep. The Great Orion nebula, aka M42,
is a naked-eye object under any
reasonably un-light-polluted sky. I see it
well in 7x50 binoculars, and it's amazing in
my 115 mm telescope. I see 4 stars
in the Trapezium easily, and under good conditions
the nebula is faintly green.
It
photographs as pink, but that's another
story about the different spectral response
of the humn eye and colour film.
The Horsehead nebula, on the other hand, is
tough. I have photographs that show M42 clearly,
with a limiting magnitude about 7.5,
but not a hint of I434 and friends,
which is 3 degrees north of M42.
...laura, looking forward to seeing
NGC3372 aka the Eta Carinae nebula in
a few weeks
Slashdot Mirror
If I wore a suit and tie to work people would look at me even funnier than they already do.
I've known women who could pull such things off, but I'm not one of them.
...laura
Actually, 120 GHz is a fully regulated part of the radio spectrum. The Powers That Be regulate it (and assign users) up to 300 GHz. There is increasing interest in this part of the spectrum, partly because the lower frequencies are getting crowded in some parts of the world, and because atmosphereic attenuation (which is high at these frequencies) makes frequency reuse a lot easier. The military are interested too, since that same attenuation makes it hard for unfriendlies to listen in on tacitcal communications. Unless they're right in the middle of the battle, in which case they have other things to worry about...
Anything beyond 300 GHz is terra incognita - electronic techniques become impractical, and optical techniques don't work well until you go lots higher in frequency. You can buy infrared data links that will shoot data across town, and they are not regulated (as radios) in any way. They require laser certification only.
...laura
For range safety purposes 100 miles is nothing. The permissible launch azimuths from Cape Canaveral are set by Newfoundland to the north, and Brazil to the south. Fort Stockton, on the other hand, launches right over the biggest cities in Texas.
Vandenberg has a limited range of launch azimuths, but since they can launch due south without any danger of hitting anything (look at a map), they are the preferred site for U.S. launches to polar orbit.
...laura
Film vs. digital? I do both, because they complement each other nicely.
I like to use my digital camera for quick and dirty shots. No processing, instant pictures. I use Polaroid if I know I'll need pictures before I can get back to a computer.
I also shoot medium and large format. They require more care and thought in setup and use, and cannot produce a picture as quickly. But even if digital could produce the quality and general impact of a good large format print (debatable; some digital is crap, and some is awfully good), I couldn't afford to do it.
At least, not in this epoch: my total investment in photo gear wouldn't buy a professional digital camera, let alone the printer I would need to go with it. So I continue to play with wet things in the dark.
...laura
She said "Daddy" once. But just one word doesn't count, I know. Even if Elizabeth Taylor said it.
...laura who feels The Simpsons are well past their Best Before date
Do I believe them? No.
I will cheer, long and loud, when people actually do return to the Moon. I wouldn't mind going there myself.
Sadly, frankly, Transorbital looks like a scam. Where is the technical information? If they're launching next year, where are the prototype probes? Where are the test results? Where are the pictures of shiny hardware?
Have they built anything, other than a webpage with lots of broken links?
As far as I know, not one of these over-hyped projects has put a gram even in to low Earth orbit.
...laura
We can only wish.
On paper, the economics work. People are expensive. There are lots of straightforward nuts-and-bolts questions that computers can handle, simply, efficiently, and cost-effectively.
Unfortunately, most companies let computers do all the stuff, whether they are suited to it or not, and lay off all the people. Or (sometimes worse!) farm the support out to a call centre who don't have a clue.
If my call was that important you would have answered it by now!
...laura
Sure. Canada is far from perfect. But we're such nice people. :-)
Perhaps it would be more constructive to try to fix your own country. You fucked it up. You fix it.
...laura
Those are indeed hefty numbers, but in modern commercial service, the numbers that really matter are mass to geostationary transfer orbit, because that's how you launch communications satellites, and that's where the money is.
Rockets don't lift satellites directly to a 40,000 km orbit. Instead, they launch to an elliptical orbit whose apogee (the highest point in the orbit) is about the right height. At apogee they fire the rockets again to increase the perigee (lowest point of the orbit), achieving a circular orbit.
The minimum orbital inclination is always achieved by launching due east, and is then equal to the launch site latitude. Inclination changes require lots of fuel, which is why folks like Arianespace (who have updated their web page to lock out all but Internet Explorer and Netscape, so I will not post the URL) set up shop so close to the equator. The best the U.S. could do was Florida, a long way north.
...laura
Yes, you do. Well, sort of.
This is (was?) the doctrine of Fair Use - that certain minor forms of copyright infringement were OK, and even A Good Thing.
It's fair use if I pull some tunes off CDs (for which I have already paid) and make a custom CD to listen to in my car.
It's not fair use to sell such a CD, unless I make the approriate arrangements.
...laura
I continue to be amused at the fact that every square micron of the Earth's surface could have (approximately) 660 billion IPv6 addresses of its very own.
Goddess knows what the bacteriafolk would do with them...
...laura
One relatively scarce resource for Earth-orbiting satellites is radio frequencies to talk to them on. By running a satellite on batteries, you guarantee that it will die, and have a fairly good idea how long it will take to do so. This can make it a lot easier to license it with The Authorities.
The colours on money are chosen to try to scramble colour scanners and photocopiers. The intent is that if you get one colour on the bill right, you'll mess up another. This is why you see certain colours over and over, like the funny purple and turquoise that appear on so many notes. The new Canadian $5 note, for example, is a distinctive blue, but also has "funny purple" highlights.
Brightly coloured notes sometimes have unexpected effects, like noting in an Australian TV show that a small-time armed robber had netted $50 (two reddish-orange, one blue).
...laura
Theoretically, no. In practice, yes.
The problem is that such claims are at odds with too many aspects of physics that are too well established. Einstein wasn't actually at odds with the experimental results that motivated relativity; he explained results that nobody could otherwise explain. His ideas were different, but they've withstood a great deal of scrutiny and experimental testing, and have proven to be right.
People seem to think that just because somebody is viewed as a crank, that they must be on to something. 'taint so!. Sometimes a crank is just a crank...
...laura
It's in progress now here in Vancouver. There are some clouds around, but not enough to spoil the experience.
My low-tech equipment is a pinhole camera made from a cardboard box. It has a piece of white paper taped inside as a viewing screen, with the "lens" a pinhole poked in a piece of 120 film backing paper.
It works fine, and I observed 1st contact at 0003 UTC, 1703 PDT.
...laura
Echo cancellation is a classic application of adaptive filters. Every reference ever published on the subject discusses it. I like Haykin's book myself.
I just did a search on Google and came up with 4000 references.
The underlying theory is pretty hairy, but the implementation of an algorithm like LMS is straightforward.
...laura
Not really. The retrograde motion of the outer planets around opposition had been known for a long time, and Ptolemy & Co. had a very hard time explaining it. Jupiter and Saturn have shown this very clearly over the last few months.
Explaining these motions was dead easy for Copernicus. Kepler provided further refinements (elliptical orbits instead of circular), based on Tycho Brahe's observations. Newton fleshed out the physics.
The real fly in the ointment was the Moon. It actually does revolve around the Earth.
...laura
Actually, no. A one-time pad really is unbreakable if properly applied. One way of looking at it is that since the one-time pad is random and was not generated by algorithmic means, no algorithm can break it. Crypto folks use different terminology, but the result is the same: unless you compromise the pad itself, no decryption can do better than random chance.
These results are well established, and any decent text on information theory will fill in the details.
An interesting side-effect of this came up with some U.S. decrypts of Soviet espionage activity in the 1950s, which were decrypted when agents misused their one-time pads. The authorities didn't take any action, partly because they were concerned about proving in court that the decrypts were accurate...
...laura
We've just upgraded our network and are now fully RFC 2549-compliant nation-wide. Works just fine.
...laura
Actually, French and Russian, respectively.
Consider the literal translations of the sentences Je dois me laver les mains ("I must wash my hands") and u myenya nyet dyeneg ("I have no money").
...laura
One of my funniest examples of mixing languages up was speaking English (my mother tongue) with a German accent after working for 2 weeks at a trade show in Duesseldorf...
Speaking French with a Quebecois accent after a week with a customer in Montreal makes perfect sense. I guess.
Yes, I sometimes dream in languages other than English.
Occasionally, just to screw around, I'll phrase things in English as literal translations from other languages - e.g. "I must get myself in gear the ass" and "By me there is a not-ness of coffee!" for "I must get my ass in gear" and "I have no coffee!" I leave the source languages as an exercise for the reader...
Languages are a goodness. They beat the hell out of card games.
...laura
Now that the dust has settled from my employers' restructuring last May, things are looking pretty good. I'm having fun. I'm doing new things. They're taking pretty good care of me, and paying me lots. That's what happens when too many people they were counting on walk. :-)
The net result is that what's left isn't much of a show. But it's my show, and I now find myself in the most senior position I've ever had. True, it's largely by attrition. But no matter how I got here, I'll take it.
Do I like it? Yes, for the most part. I qualify the answer because while I have no plans to leave any time soon, I do know, in some detail, what circumstances would cause me to do so.
...laura
A colleague of mine is of Slovak descent, and tells me one of the wildest dodges in the Bad Old Days was CPUs with weird numbers of bits, like 28 bit words. It seems that it was illegal to export 32 bit CPUs to the Eastern Bloc. But anything smaller was OK.
In Wireless World in the late 1980s there was a very good series of articles on Eastern Bloc computing, including all the PDP-11 and S/360 clones that have been mentioned. Sorry, I don't have the exact citation. Check your library.
...laura
You mean hours of ads, with the occasional snippet of football, don't you?
...laura, not absolutely certain of the very significance of the Super Bowl
Yep. The Great Orion nebula, aka M42, is a naked-eye object under any reasonably un-light-polluted sky. I see it well in 7x50 binoculars, and it's amazing in my 115 mm telescope. I see 4 stars in the Trapezium easily, and under good conditions the nebula is faintly green. It photographs as pink, but that's another story about the different spectral response of the humn eye and colour film.
The Horsehead nebula, on the other hand, is tough. I have photographs that show M42 clearly, with a limiting magnitude about 7.5, but not a hint of I434 and friends, which is 3 degrees north of M42.
...laura, looking forward to seeing NGC3372 aka the Eta Carinae nebula in a few weeks