nik

Then shouldn't v=-c? <_<

Another good question. Velocity is a "vector." It has direction. So negative velocity means it's just going the other way. Example: A car with v>0 is going away from me, and one with v<0 is coming towards me.

This is tough stuff. In grad school, we pretty much proved that spacelike continua are

non-causal in our continuum, forgot about it,and then went on to develop transformations for electromagnetic fields in free space, from charges, etc. My teacher, being rather sadistic, decided to make us derive the path of a relativistic electron near a magnetic monopole. (So it was OK to break Maxwell's equations, but we barely spent any time in the spacelike continuum.)

Jeanway, here's a way of representing these continua. Get a piece of paper. Pretend for now that the universe has two dimensions, length (x) and time (t). Draw a coordinate system on the paper. X horisontal, time vertical. Any path drawn on that

system is called the "world line" - where it is at time t. (Negative time is the past, positive the future.) What if you have a photon, which v=c? At time 0, say it's at x=0. At t=1s, it's at x=c*1, 2 seconds: x=2*c, etc. So we have coordinates (x,t) = (0,0),

(c,1), (2c,2), (nc,n), and we can also have a photon going the other way, so that

the x coordinates are negative as well. Draw these points and lines on the paper. This is called the light cone. Now, do this. (And I will not say anything else.) Draw points on the paper where you think an object with v<c is, and an object with v>c would be. Let me know what you get. This is how physicists think of space an time a lot.

Here, I found a web site with good pictures:

Light cone physics

Fine question, Jeanway.

The spacetime continuum essentially extends into four dimensions (for simplicity, say four). The fourth dimension, in current paradigms can be represented with imaginary numbers ("imaginary" is just a very bad way of extending our number system. It's

really not imaginary as we think of it).

Well, in space and time, there are singularities when v=c.

(Meaning that equations become undefined. Things approach infinity or negative infinity.) However, when v<c - the universe we live in, things are fine. We call this regime a "timelike continuum". And, when v>c, the equations are also defined well, but

there is a factor of i (the square root of negative one), and when this is squared, we

get negative values in the equations involving momenta. This is called a "spacelike" continuum. In this continuum v>c always. If you apply a force (impulse) to a particle, it's momentum will decrease along the direction or force - opposite what happens here.

Now, here's the answer to your question. We can define a coordinate system in either reference frame and we can do transormations between coordinate systems in a continuum. Think of the question you asked about why coordinates are different in space and on the earth. We can fairly easily convert from one to the other becuase information can be transfered between these frames. (We use what are called Lorentz transformations to do this - essentially parametrized space coordinates on

hyperbolic axes, i.e. x in one frame is a linear combination of hyperpolic functions of x and t in another). We say that they are causally connected. We cannot convert from a coordinate system in the spacelike continuum to one in the timelike continuum and vice versa. They are not causally connected.

In a sentence: Light (information) does not go from a spacelike continuum to the next.

He'd order Baghdad torpedoed and phasered out of existence, had a brew with Bush and Blair, found Monica and pulled a Willy, then go to the 2004 CMT Flameworthy Music Awards and accept the award for best Cameo in a video since his alterego, William Shatner, couldn't be there.

 

 

William Shatner, Little Jimmy Dickens, Jim Belushi, and Jason Alexander won for best Cameo!

Agreed. And he would have to somehow find Saddam, so he can hit him with a flying kick, then a two-fisted shot. Somehow, he'd have to get his shirt ripped off in the process.

Anyone see any last night? I had the privilege of watching a few. I left the office at about 4am, and watched some when I got home. Not too bad. Fairly high in the night sky, with a few long streaks. Not the most frequent, but impressive.

I'm an accountant and I have a knack for numbers...but words...no way...

so I have a hard time getting across what I want to say and sometimes it

comes out wrong and causes problems, I guess that's why I like it hear...

In a room full of people I don't talk, this is easier <_<

Yeah, I know the feeling. I'm a scientist, and I have a knack for numbers, but when it comes to socializing - I'm a bit slow - has nothing to do with being nerdy, just heavily pre-occupied all the time.

I really like them all, but the one that really sticks to me was Prime Directive. Captain Kirk didn't just save the Universe, he saved himself!

Improvised Explosive Device. need I say more?

whoa! <_<

Can't say much about that except, "Thanks for laying it on the line for freedom, man!"

David Byrne wrote "And She Was" about a friend of his who took LSD and contemplated a YOHOO factory.  Therefore, physics doesn't enter into it.

 

The point of the Talking Heads song is that reality is elastic, "she" is both earthbound and airborn.  If you've ever indulged (or in my case), studiously observed, on many occasions- the nature of psychedelia you know that all opposites are dissolved.

 

I hope this post answers more questions than it answers, asks, intimates, confuses, or confirms your question

Now I'm really confused!!!!!

However, going with the flow......

Did you see CNN's "Worst all time songs" list? Most of those were great songs.......

I don't get it?

Yes, that is a fine explanation. The UPENN group does good work in that field. Fine work indeed. Thanks!

No, not at all. This is real. Try googling the following:

Cerenkov (or Cherenkov, depending on the conversion from Cyrillic.) or Cerenkov radiation.

Whipple collaboration - I used to work for this group doing image analysis, cluster algorithms, and spline fits to data back in my undergrad days.

nik, thats great thanx.....

Of course! ::bows low::

Actually nik, in water or any other substance for that matter the light doesn't actually slow down.  What happens is that the light (photons) are aborbed and consequently reemitted by the electrons in the atoms of the substance, giving the illusion of the light slowing down.  So light travels the same speed everywhere:

 

c = 299 792 458 m / s

c = 186 282.397 miles per second

True enough. So the answer is that if we have a particle that enters a medium at

a speed apparently faster than that of light in that medium, information transfer across that medium is limited to c/n. We see a phenomenon called Cerenkov radiation

(after a Russian). As the particle slows, light is emitted from the particle in a cone

called (what else?) a Cerenkov cone. I'm guessing that Ensign Jim Phaserman

has observed this effect, and maybe he'll tell you about it. However, it also occurs

in our atmospher. As cosmic rays enter the atmosphere, they will produce

what we call Cerenkov showers - huge cigar-shaped sources of light 100s of meters to

several km long in the atmospher. Typically very faint, but fascinating to observe with

extroardinarily large telescopes.

UH OH, I'm In Trouble Deep Now <_<  You've got formulas for all this, correct? PM them to me, I'll give it a try, no guarantees nik, it's been a while. 

Formulas? They're pretty involved, but doable none-the-less. They typically don't

teach the fundamentals of this stuff until grad school. (Derived formulas in college.)

However, it's always good to try. I can recommend introductory texts:

"Electicity and Magnetism" By Griffiths

for something a bit more involved, try: "Classical Electrodynamics" By J.D. Jackson.

(It's actually more than just classical.)

Carborata?  I think someone made that up. :P No such thing back in those days, nik <_< We, We, We?? Do?

I think "carborata" is like a loan word or something. In the process of learning Latin, I

found a phrase book, and that one stuck in my head, but I think the original does not mean what it means today. That's the problem with dead languages. I don't know enough about Latin to know the origin. Might be a good research.

Volunteered to fly with a Chinook to drop off supplies to Marines in Um Qasr. let's just say that that's where I got my Purple Heart.

Wow! Would you mind sharing more?

Erm, I still don't know who that Depalma character is. <_<

 

I think it has to do with how recognizable they are. If the show's been over for a while, and people still know exactly who the character is when they see them, then you've got a great character. I agree with the lists already given; just adding a few more.

 

Let's see...

 

Cliff & Clair Huxtable

Tim & Jill Taylor, Wilson Wilson

Kramer

Roseanne

Kirk, Data

Fran Fine

Any of the Golden Girls

Bob Newhart

Any of the big tv superheroes

Granny Clampett

Any of the big cartoon characters (Bugs, Homer, Flintstones, etc)

Mary Richards (Mary Tyler Moore)

The Fonz

 

 

These are just a few I thought of. There are a bunch more...

Nice list indeed! Who could foget the Fonz?!

Can't say I've ever done that. I have named them after great scientists, such as my

pet lizards named Kepler and Copernicus.

I think it would be funny, however, to give pets Borg designations: 3rd of 5,

1st of 7, etc......

Well, there's still about 150 games left to set things straight. It's one of the things I love about baseball. A team that did crappy one year, can turn it around the next year.

Well said, Chronic.  Life is a big song, and the best thing to do if we can't

anticipate it is just dance with it.

 

Or..... as my ancestors said:

 

Minutus cantorum, minutus balorum, minutus carborata descendum pantorum.

 

 

 

 

 

Did you say what I think? <_< Pm please :P

Actually, my ancestors probably didn't say that. But they did indeed speak Latin....

so maybe they said that, but I doubt it.

Last Place-Detroit Tigers-One season removed from becoming the 2nd worst ream in baseball histroy and losing a shameful 119 games Detroit has nowhere to go but up.It will be a few years before they can contend but adding world series MVP Ivan Rodirgues and shortstop Carlos Gullien will help.

Ouch! Painful for any Tigers fan. However, things are looking up this year. In fact, they are doing fairly rescpectably.

That Nolan Ryan quote is classic. Although he didn't say too much about baseball,

Yogi Berra come up with some classic quotes as well.

The Leafs are going to give Detroit a run for their money. Detroit in 7. Three games will go into OT.

Yeah, he'll get it. That's only a few more season's worth.

I just really am not too keen on steroids in baseball. If Barry Bonds breaks the record, and it's found out that he used the 'roids, I would discredit his record immediately. I just lose a lot of respect for any athlete when they use drugs as a quick fix.