I have two degrees, from Southampton (UK) University - the first in Physics and the second in Maths. [I now work as a Java and Oracle programmer specialising in Web Development. Ho hum]
I am on occasion wrong, as are we all, but I don't think so this time. Neither, it seems, do the various moderators.
Continuous green light would result in continuous red light out in pulses plus... blue light! Well, it depends on what frequency is allowed through by the retreating boundary, but light shifted up. You can Doppler shift the other way by just sending the shockwave the other way. I think that's both your first two points covered.
As to you last, I think you're exactly right. The authors only suggest that it is near 100% efficiency while the shockwave is going the way you want...
Justin.
Re:For how long?
on
Mastering Light
·
· Score: 2, Interesting
Firstly, a photon will bounce off the material boundaries within the crystal forever unless it has the frequency we want.
Assuming the pressure wave is reversed (ie the crystal doesn't explode), then yes the light will be doppler shifted the other way if it hits the rebounding boundary.
This could be taken care of by careful timing, although it might limit the range of practical shifts.
But who cares about practice! I was always a theoretician - didn't like getting my hands dirty with real photons;-)
Oh, and the shift will occur whatever the speed is, it'll just be a smaller shift for a slower boundary.
Justin.
Re:Invisibility possible now?
on
Mastering Light
·
· Score: 2, Interesting
What an excellent thought!
The difficulty would be to get the shock waves going in the direction of light for all directions or light!
That doesn't mean it can't/won't be managed though.
Justin.
Re:For how long?
on
Mastering Light
·
· Score: 5, Interesting
IANAP, but I am a Physics grad, so...
Reading the article it seems that the light frequency is altered for only a short time, the time during which the shock wave passes through the crystal.
So you put through another shock wave and another and another and another...
You will get the same number of peaks and troughs out, but those that have bounced back and forth a bit (and thus got Doppler shifted) will come out later, having travelled further, and shifted. This technique stretches the light pulse.
So, (asciiart time!) you could put in pulses of green and get out continuous red:
S S S S
gggg gggg gggg gggg
rrrrrrrrrrrrrrrrrrrrrrrr
[View it in a fixed-width font, it'll make sense I promise]
Each green pulse g has been stretched by the shockwave sent at each S and turned to red light r, filling the time for pulse + gap.
'Standard users'? Does that include black hats? If you can't see that this is going to result in security holes then
If you write your own compiler, as you say, then you need the source code. The fact that reflection gives you private member access at/runtime/ is clearly a problem.
The Epson's only 800L, actually, but it works perfectly well so long as there is no direct sunlight on the screen. Thus I have placed the screen at the opposite end of the room to the window.
For best effect, I must admit, I have a variable lamp in the living room, so I can have enough light to see the room, but leave the screen nice and bright.
20 dollars? About 13 quid? Excellent, I can see a visit to Maplin (UK equiv of Radio Shsck) tomorrow!
Let's start with the observation that it isn't fixed. All they've done is turn off the password change routines at the back end...!
Personally I suggest everyone reading this makes sure to tell everyone they know, in order to stop people blindly trusting any incompetents. The fact that it's MS just makes the schadenfreude better.
Your spouse will hate wires if you have one. Work out where your cable runs should be and make sure they are invisible. Or go wireless.
Projectors are now at a sensible price, starting at about 900gbp for an Epson EMP-30. I use one of these and it's fine. My girlfriend and I love the way the TV and everything disappear when not in use, meaning the house centres naturally around the fireplace as if it were 1940 again!
Projectors also work really well with a KVM switch. Put the monitor output into the 'Computer' input and the sound into a hi-fi, add a wireless keyboard and you are laughing, whether you have ten PCs or two.
If you are expecting lots of different audio channels: PC, TV(etc), CD, not to mention the old favourites like radio, then get a separate pre-amp with/lots/ of channels and a good amp. I didn't do this and I now find myself swapping cables, which is irritating. I will be buying a good pre-amp soon!
The solution is bin the CRT. I put in an Epson EMP-30 in a ceiling box plus an old roll-up screen three months ago for 900gbp (about 1400usd?) and it's lovely.
With the TiVo this means that we only bring the screen down when we actually want to watch telly, not just when we can't think of anything better.
It's the way forward, it looks amazing and it's cheaper than you think;-)
That observation is a fine argument for keeping the old stuff, and I wasn't suggesting changes to the stuff that's already there, but this article is about buying new stuff, in which case going MS for data entry is still dumb.
That said, Access?! That's not a database, it's a kiddy's toy.
Something else to keep in mind - we're not exactly paying the big bucks on salary either, especially for NYC. The kind of people who use these computers are very frequently people on a welfare assistance program that requires you to work to get your welfare check. Most of the time, these are some pretty great people, but they didn't exactly grow up with a computer in the house... ease of use is a big issue, and I think that it's still safe to say that crown belongs to Microsoft.
If ease of use is an issue for your data entry clerks because they don't have much computer experience, then MS is the worst thing to give them.
Dumb terminals would be cheapest, connected to a single *nix/bsd box per ten or fifteen users.
Windows, licence fee and all is total overkill for data entry.
Polyphonic ringtones reproduce using several frequencies at once, so instead of rendering (for example) the 5th as dee-dee-dee-diiiii, you get something that doesn't sound electronic. They may still be irritating in the library/theatre/cinema, but they don't jar the ear.
Windows Update is committed to protecting your privacy. To provide you with the appropriate list of updates, Windows Update must collect a certain amount of configuration information from your computer. None of this configuration information can be used to identify you. This information includes:
If a lawyer writes "this information includes...", then that's exactly what they mean. They don't mean that it is a complete list; there may be other stuff that they're not explicitly telling you about.
Let me give an example. The reviewer condescends the book for assuming a "Strategist" role is necessary in a successful project, since the customer undoubtedly knows his or her own business.
I think a lot of businesses could use a techy to analyse their suggested processes. In my current contract, the first thing I had to do was go and see the business client to explain to them that the report they had asked for wouldn't support the business requirements they had.
They are referring to the principle that there should be:
a presentation layer, eg jsp over a presentation package, eg tags
and
a business logic layer, eg java classes over a data abstraction layer, eg bc4j
If you do this, you get re-usable, maintainable code. If not, and you're building anything bigger than a pretty noddy app, you're not going to be able to do anything with it six months after the initial build.
Hell, I've even built noddy apps badly and had a hard time maintaining them six months later.
Incidentally, wtf is extreme programming? Somebody?
I recently had a contract where the marketing department lobbied management to cut our development deadline by six weeks (with eight to go) "so that we make an extra six weeks profit"
I suggested in that case they should have built it last year and they said "uh-huh"!
Slashdot Mirror
J.
According to this doo-hickey here, you've got money in your shoe too...
Thank you for your enlightening comments.
I have two degrees, from Southampton (UK) University - the first in Physics and the second in Maths. [I now work as a Java and Oracle programmer specialising in Web Development. Ho hum]
I am on occasion wrong, as are we all, but I don't think so this time. Neither, it seems, do the various moderators.
Justin.
As to you last, I think you're exactly right. The authors only suggest that it is near 100% efficiency while the shockwave is going the way you want...
Justin.
Assuming the pressure wave is reversed (ie the crystal doesn't explode), then yes the light will be doppler shifted the other way if it hits the rebounding boundary.
This could be taken care of by careful timing, although it might limit the range of practical shifts.
But who cares about practice! I was always a theoretician - didn't like getting my hands dirty with real photons ;-)
Oh, and the shift will occur whatever the speed is, it'll just be a smaller shift for a slower boundary.
Justin.
The difficulty would be to get the shock waves going in the direction of light for all directions or light!
That doesn't mean it can't/won't be managed though.
Justin.
Reading the article it seems that the light frequency is altered for only a short time, the time during which the shock wave passes through the crystal.
So you put through another shock wave and another and another and another...
You will get the same number of peaks and troughs out, but those that have bounced back and forth a bit (and thus got Doppler shifted) will come out later, having travelled further, and shifted. This technique stretches the light pulse.
So, (asciiart time!) you could put in pulses of green and get out continuous red:
S S S S
gggg gggg gggg gggg
rrrrrrrrrrrrrrrrrrrrrrrr
[View it in a fixed-width font, it'll make sense I promise]
Each green pulse g has been stretched by the shockwave sent at each S and turned to red light r, filling the time for pulse + gap.
Justin.
I'm a web developer and I really don't fancy telling my customers that one!
J.
'Standard users'? Does that include black hats? If you can't see that this is going to result in security holes then
/runtime/ is clearly a problem.
If you write your own compiler, as you say, then you need the source code. The fact that reflection gives you private member access at
Justin.
The OpenLoo project's stalled...
The Epson's only 800L, actually, but it works perfectly well so long as there is no direct sunlight on the screen. Thus I have placed the screen at the opposite end of the room to the window.
For best effect, I must admit, I have a variable lamp in the living room, so I can have enough light to see the room, but leave the screen nice and bright.
20 dollars? About 13 quid? Excellent, I can see a visit to Maplin (UK equiv of Radio Shsck) tomorrow!
J.
Personally I suggest everyone reading this makes sure to tell everyone they know, in order to stop people blindly trusting any incompetents. The fact that it's MS just makes the schadenfreude better.
Justin.
Your spouse will hate wires if you have one. Work out where your cable runs should be and make sure they are invisible. Or go wireless.
/lots/ of channels and a good amp. I didn't do this and I now find myself swapping cables, which is irritating. I will be buying a good pre-amp soon!
Projectors are now at a sensible price, starting at about 900gbp for an Epson EMP-30. I use one of these and it's fine. My girlfriend and I love the way the TV and everything disappear when not in use, meaning the house centres naturally around the fireplace as if it were 1940 again!
Projectors also work really well with a KVM switch. Put the monitor output into the 'Computer' input and the sound into a hi-fi, add a wireless keyboard and you are laughing, whether you have ten PCs or two.
If you are expecting lots of different audio channels: PC, TV(etc), CD, not to mention the old favourites like radio, then get a separate pre-amp with
Justin.
The solution is bin the CRT. I put in an Epson EMP-30 in a ceiling box plus an old roll-up screen three months ago for 900gbp (about 1400usd?) and it's lovely.
;-)
With the TiVo this means that we only bring the screen down when we actually want to watch telly, not just when we can't think of anything better.
It's the way forward, it looks amazing and it's cheaper than you think
Justin.
That said, Access?! That's not a database, it's a kiddy's toy.
J.
If ease of use is an issue for your data entry clerks because they don't have much computer experience, then MS is the worst thing to give them.
Dumb terminals would be cheapest, connected to a single *nix/bsd box per ten or fifteen users.
Windows, licence fee and all is total overkill for data entry.
Justin.
Lamer answer: Depends what you want to do.
...but only Java and C++ rock.
I've studied about ten[1] and learnt something from each of them.
Justin.
[1] Thinks... several Basics, C, C++, Pascal, Fortran (shudder), Lisp, Java, JavaScript, Oracle PL/SQL, Rexx. There's prolly more...
If I know that I will spend a million years in prison if I am caught, but I don't think I will be, then I will still do the crime.
The keys to cutting crime are all before the event.
Polyphonic ringtones reproduce using several frequencies at once, so instead of rendering (for example) the 5th as dee-dee-dee-diiiii, you get something that doesn't sound electronic. They may still be irritating in the library/theatre/cinema, but they don't jar the ear.
Justin.
Windows Update is committed to protecting your privacy. To provide you with the appropriate list of updates, Windows Update must collect a certain amount of configuration information from your computer. None of this configuration information can be used to identify you. This information includes:
If a lawyer writes "this information includes...", then that's exactly what they mean. They don't mean that it is a complete list; there may be other stuff that they're not explicitly telling you about.
Justin.
Pah! Easy! You should try the Advanced Queuing package ;-)
If Google ever examines my usage, it'll discover that I am useless at remembering Java APIs, and too lazy to walk to the bookshelf ;-)
Justin.
I think a lot of businesses could use a techy to analyse their suggested processes. In my current contract, the first thing I had to do was go and see the business client to explain to them that the report they had asked for wouldn't support the business requirements they had.
I shouldn't have had to do that... but...
a presentation layer, eg jsp over a presentation package, eg tags
and
a business logic layer, eg java classes over a data abstraction layer, eg bc4j
If you do this, you get re-usable, maintainable code. If not, and you're building anything bigger than a pretty noddy app, you're not going to be able to do anything with it six months after the initial build.
Hell, I've even built noddy apps badly and had a hard time maintaining them six months later.
Incidentally, wtf is extreme programming? Somebody?
I suggested in that case they should have built it last year and they said "uh-huh"!