• Drifting •

[jantheman]

I've been to heaps - I love them! Are you wearing the kilt traditional style?

[php_daemon]

First one I'll be going to is my sister's one this June, and I'll be wearing a kilt

And the second one will be yours, and you'll be wearing a wedding dress? (ok that's lame but I felt the urge)

[jantheman]

Maybe he could make it a double wedding in June, as he will be wearing a dress anyway

[php_daemon]

[akritic]

Nice.

Let me put you at ease: No Dress, No going 'Traditional' style with kilt. Sorry to dissapoint you Jan & Saul

[php_daemon]

OK, now I will laugh all day

[jantheman]

Aww, pity. I was looking forward to the wedding pics in the photography forum.

[Datura]

[Shaun(OfTheDead)]

I've only ever been to one wedding.

It was really small... only about twelve people there (if so much). We hummed "Here comes the bride" haha

It was great.



I've been to quite a few receptions though...

[Datura]

I love weddings and the mood that they have: the joy, the hope, the promise, the beauty. All too often have I witnessed weddings though where I knew it could not last, but also the other way around.

Weddings are often just too elaborate IMO, there is so much pomp and pretense connected with them, it is just pretty sick.

[php_daemon]

Yes, everyone seems to forget that wedding is the end of man's life. That should be noted and cried over properly, I think.

[akritic]

^

[vgarcia]

don't read this sober you'll never understand it

Why FTL implies time travel (tachyon pistols)

The entire "FTL implies time travel" meme has to do with what's sometimes called "failure of simultaneity at a distance". In addition to the effects that pop treatments of relativity mention (that is, time dilation and length contraction), relativity proposes that the definition of "right now" is also different, depending on which observer's coordinate system you use. This is an effect much like the revolution of deciding that the direction "up" wasn't the same everywhere, but varied from place to place on earth. With relativity, the revolutionary notion is that the direction "futureward" (or "now-ward") isn't the same everywhere, and varies with velocity.

We can describe this effect by idealizing FTL to be "instantaneous", and describing how the more familar time dilation implies this effect. But remember, the same points apply to any FTL speed, you just have more messy arithmetic to grind through.

Consider a duel with tachyon pistols. Two duelists, A and B, are to stand back to back, then start out at 0.866 lightspeed for 8 seconds, turn, and fire. Tachyon pistol rounds move so fast, they are instantaneous for all practical purposes.

So, the duelists both set out --- at 0.866 lightspeed each relative to the other, so that the time dilation factor is 2 between them. Duelist A counts off 8 lightseconds, turns, and fires. Now, according to A (since in relativity all inertial frames are equally valid) B's the one who's moving, so B's clock is ticking at half-speed. Thus, the tachyon round hits B in the back as B's clock ticks 4 seconds.

Now B (according to relativity) has every right to consider A as moving, and thus, A is the one with the slowed clock. So, as B is hit in the back at tick 4, in outrage at A's firing before 8 seconds are up, B manages to turn and fire before being overcome by his fatal wound. And since in B's frame of reference it's A's clock that ticks slow, B's round hits A, striking A dead instantly, at A's second tick; a full six seconds before A fired the original round. A classic grandfather paradox.

Note, this is NOT a matter of when light gets to an observer, it is NOT an optical illusion. It is due to the fact that, in SR, the question of what occurs at the "same time as" something else is observer dependent.

As A fired that first show at tick 8, the bullet effectively teleported from A's gun to B's back instantly --- instantly according to A. But for B, who was moving at 0.866 lightspeed WRT A, B was hit in the back by the bullet 4 seconds BEFORE the bullet was fired. And again note, this is NOT due to the optical illusion of lightspeed delay in viewing A's turn-and-shoot; the light form that event wouldn't reach B until MUCH later, not tick 4.

Here's a spacetime diagram of a referee (O3) and two duelists (O1 and O2). Space is up/down, time is left/right, in the diagram.



The paths O1 and O2 take through spacetime are the colorcoded arrowed lines. The events in spacetime that each considers "simultaneous" and "8 seconds after the start" are along the thinner, non-arrowed colorcoded lines. So we see that, each of the three observers thinks the other two have slow clocks, and that if we are allowed to move faster than a lightcone, we'll end up going "pastward" in somebody's reckoning.

We can trace out the shots on this diagram, also. Step through it one more time: if green shoots at 8 seconds out, the shot will go along the green "line of simultaneity", and hit blue at 4 seconds elapsed. If blue returns fire from there, it will return along a line paralel to the blue "line of simultaneity", and catch green napping at 2 seconds elapsed.

You can see more about spacetime diagrams, and more about the notion of "lines of simultaneity" at

sr-ticks-n-bricks.html
sr-twin-01.html
Finally, FTL still can can bite you in non-instantaneous cases; where we're only going a "little bit" faster than light.

If you warp out, go to Tau Ceti, then with normal reaction engines accelerate away from earth, warp out again to go back to earth, you will indeed get back before you left. (Presuming that the real-space delta-v before the warp/hyperdrive/tachyon-watziz trips was "large enough"... there are formulas for such things in the textbooks).

[Datura]

Man, I think I need to drink something (Datura tea?) to understand that one

[Shaun(OfTheDead)]

Yes, everyone seems to forget that wedding is the end of man's life. That should be noted and cried over properly, I think.

hahahahaha

[jantheman]

Yes, everyone seems to forget that wedding is the end of man's life. That should be noted and cried over properly, I think.

Obviously you have never been married? It's a fact that married men live longer and are more content (I think...).

I've only had half a beer so I'm going to save vgargia's post until later....

[Shaun(OfTheDead)]

married men /.../ and are more content (I think...).

See if nothing else gave it away... this prooves you're not a guy, jantheman.


Okay okay, so I haven't been married yet either, but I've had ex-girlfriends who made me wish I was dead so I imagine having someone like that around you in the same house 24/7 can't be too good for your sanity and well-being.

[jantheman]

See if nothing else gave it away... this prooves you're not a guy, jantheman.

Not necessarily - I might be just a really smart, sensible, content guy.....do they exist??

Okay okay, so I haven't been married yet either, but I've had ex-girlfriends who made me wish I was dead so I imagine having someone like that around you in the same house 24/7 can't be too good for your sanity and well-being.

Sounds like it is a good idea they are EX

[jantheman]

I love weddings and the mood that they have: the joy, the hope, the promise, the beauty. All too often have I witnessed weddings though where I knew it could not last, but also the other way around.

Weddings are often just too elaborate IMO, there is so much pomp and pretense connected with them, it is just pretty sick.

I once went to two weddings on one day (one morning, one evening) and they both went down the tubes.

Fortunately both found new true love and are living happily ever after

[php_daemon]

Obviously you have never been married? It's a fact that married men live longer and are more content (I think...).

No, I haven't been married, otherwise you wouldn't see me here probably. That fact is so untrue, and you're talking of single men. Marriage is such an unnatural and unpractical thing. You won't see anywhere in nature other animals doing anything like it (need to confirm). Just humans. There's no possible explanation of this phenomena.

Not necessarily - I might be just a really smart, sensible, content guy.....do they exist??

Yes, guys like that are called single.

[vgarcia]

No, I haven't been married, otherwise you wouldn't see me here probably. That fact is so untrue, and you're talking of single men. Marriage is such an unnatural and unpractical thing. You won't see anywhere in nature other animals doing anything like it (need to confirm). Just humans. There's no possible explanation of this phenomena.

many penguins are lifelong partners just for one quick example

ps being at the top of the intelligence/food chain means we don't have to do things like other animals

[php_daemon]

that's not quite the same thing, i meant marriage as such. I don't think penguins go through hell and pay alimony for the rest of their lives if something goes wrong.

It's true that we don't have to do many things animals do, but we still have the instincts and we constantly look for substitutes to satisfy them. But that's irrelevant.

Anyways, i probably should already tell that my above statements are suposed to be purely humourous and that is not my real point of view. I do believe in long time relationship and happy marriage. Sadly often those ideas come true.

[angilina]

here in pakistan, its winter and sun totally vanish at about 5:15.

sun comes up at about 6:30 in the morning.

for last couple of days, I havnt seen the sun, its raining + today, at the moment , I see snow coming down

[Shaun(OfTheDead)]

here in pakistan, its winter and sun totally vanish at about 5:15.

sun comes up at about 6:30 in the morning.

for last couple of days, I havnt seen the sun, its raining + today, at the moment , I see snow coming down

God, now that's a segway. haha

I didn't know it snowed in Pakistan.

[akritic]

http://www.segway.com/