Sensible Erection | The size of your own personal lightcone

Wednesday, 3 December 2008

quote [ From the moment of my birth, light [that I could have influenced] has been expanding around the Earth and light [which could influence me, from an increasing distance of origin] reaching it -- this ever-growing sphere of potential causality is my light cone. ]

my personal light cone:

47. HR4523
HR4523 is 30.1 light years from Earth. It was enveloped by your light cone 4 months ago.

http://en.wikipedia.org/wiki/Light_cone

[sci&tech] [by mhy@4:45pmGMT] [+10 Interesting]

Comments

Joe_Luma said @ 5:06pm GMT on 3rd Dec
interesting, but not substantial. beef your post up some, please! :)

mhy said @ 5:13pm GMT on 3rd Dec
oh its just a little something to entertain your thoughts.

the idea of an expanding field of causality is an old notion of mine, but i never knew that there were a real theory about it.

k0k0peli said @ 5:19pm GMT on 3rd Dec
The idea isn't original (were are all the products of the sum-over-time of all events that preceded us, and we participate in determining all events that follow us) but the implementation is.

monday said @ 5:30pm GMT on 3rd Dec [Score:2 Funny]
Bend over and I'll show you the products of the sum-over-time of all events that preceded you.

k0k0peli said @ 2:14am GMT on 4th Dec
Just the Feynmann diagrams will be sufficient, thanx.

f00m@nB@r said @ 2:44am GMT on 4th Dec
i feel a great perturbation in the force.

arctan said @ 6:32pm GMT on 3rd Dec
The interesting thing about the light cone is that it's *finite* -- it means that there are some events in the universe, outside your light cone, that you can never, ever know about and that can never, ever influence you in any way.

warmseat said @ 7:17pm GMT on 3rd Dec
That's what she said.

wyckedfae said @ 5:25pm GMT on 3rd Dec [Score:2 Funny]
I enveloped Ursae Majoris a month ago. Mutha fucka never saw it comin'.

ComposerNate said @ 5:47pm GMT on 3rd Dec

-_- said @ 6:20pm GMT on 3rd Dec
Why cones?
I always thought of it as a sphere.

-_- said @ 6:23pm GMT on 3rd Dec
I'll be absorbing 44 Bootis in 2 months ... maybe I should bake a cake to mark the occasion ;)

umm...weird said @ 6:26pm GMT on 3rd Dec [Score:1 Funny]
Xi Bootis in 3 months for me.....ya old bastard.

swiggy said @ 6:58pm GMT on 3rd Dec
booti booti booti booti, rockin' everywhere.

robotroadkill said @ 1:24am GMT on 4th Dec
I remember when I first got my influential mits on Xi Bootis. Boy did I wreak havoc. Xi Ursae Majoris better look out in 2 months. Of course I set all this up as a newborn.

cache22 said @ 6:29pm GMT on 3rd Dec
It is a sphere in physical space. The cone model maps a cross-section of that sphere over time.

foobar said @ 7:24pm GMT on 3rd Dec [Score:1 Funny]
Actually, it's a hypercone in four dimensional space-time. Your causality sphere at any one point in time is a 3 dimensional cross section of that hypercone.

It's drawn as a three dimensional cone with 2 dimensional circular cross sections because drawing hypercones on paper tends to summon tentacled monsters and isn't comprehensible to mere mortals anyway.

Saint_Marck said @ 8:18pm GMT on 3rd Dec [Score:1 Funny]
And if you spend too much time trying to visualize one you will literally break your mind so don't do that.

damnit said @ 8:49pm GMT on 3rd Dec
It's easy... just blink your right and left eye in succession. It's more effective with people around... they'll think you're having a seizure.

OR

3D-glasses... 3D viewing + 3D glasses = 4D.

Misanthrope said @ 6:13am GMT on 4th Dec
I think my attempts to actually imagine a model of the universe from an exterior perspective actually did break my mind a little.

KropperPrime said @ 10:56pm GMT on 3rd Dec [Score:1 WTF]
I tried and I summoned this :

Did I fail?

Baxter_UK said @ 11:08pm GMT on 3rd Dec
THERE ARE NO WORDS. JUST RIPPLES OF MANFAT.

cold_water said @ 3:20am GMT on 4th Dec
You sure that's a man...?

foobar said @ 11:22pm GMT on 3rd Dec
Shoggoth?

IronMahatma said @ 8:17pm GMT on 3rd Dec [Score:2]
The "choice" of cones, or rather a double cone, has to do with Einstein-Minkowski spacetime, and the way in which *any* observer can determine the length between two events. There is a double cone centered at each and every event in spacetime.

In Euclidean space (which we are all used to), we might imagine an ever expanding sphere emanating from some point source. The sphere grows with time. This is not a convenient model for spacetime (but perhaps it is for the separate distinction between "space" and "time").

So, how can we interpret "space" and "time" dimensions from spacetime? We can only use a metric that is absolute. Time itself is not absolute, as time runs differently for observers with different inertial frames of reference. However, the speed of light is the SAME for all inertial observers, regardless of the motion of the source.

Then, to measure the "space" or "time" between different events in spacetime, we can emit a flash of light toward some event and measure the time needed for the light to reflect or echo back to us. This would give us a measurement of the spatial distance and time between some distant event and an event on our worldline (the line that passes down the axis of the double cone for an observer at rest).

In this sense, then, the double-cone represents a boundary of the events that could be probed with a light experiment. The top half of the double cone represents the boundary between all the events that could or could not be probed by a light flash emitted at the vertex/apex/pointy tip of the cone. Similarly, the bottom half of the double cone represents all the directions or events from which a light flash could have been emitted and received at the vertex/apex/pointy tip of the cone.

Long story short, the cones model is better.

Rumpspringa said @ 7:27pm GMT on 3rd Dec [Score:5 Funny]
I don't understand anything of this, but i'm modding this post up to not seem stupid.

kishi said @ 9:14pm GMT on 3rd Dec
Cool. But too bad it doesn't go back just a few years further.

EPT said @ 9:19pm GMT on 3rd Dec
Ha! My light cone just absorbed Beta Virginis

Hrm... how did it know what I was going to do today?

Vibrating @ the Speed of Light said @ 10:24pm GMT on 3rd Dec [Score:1 Funny]
Is this the same as my carbon footprint? Am I gonna have to shell out money to Al fucking Gore to buy cone credits or something?

robotroadkill said @ 1:27am GMT on 4th Dec
I am currently selling these "cone credits" that I just heard of. I accept all forms of currency.

f00m@nB@r said @ 10:48pm GMT on 3rd Dec
look at the date on the bottom: MW 2003-12-14

ancient. i've had this in my feed reader for a few years, now. i think it might even have been posted/commented about here at one point.

601 said @ 12:19am GMT on 4th Dec
Overtaking ~~Alpha~~ Centauri makes me sad.

raiderusmc said @ 12:20am GMT on 4th Dec
So far, my cone of light has reached, or at least in 5 weeks will reach, 18 Scorpii which is 45.7 light years away!!