Prof Brian Cox explains space-like events

[Flextaa]

Dam my brain hanged itself on a noose trying to process this.

[aFemale1]

what is he talking about ?

[Glamberter]

@aFemale1 Order, Basically. Like he said, If the camera man fell off the wall and then Brian threw the ball, It just wouldnt work, Brian would needed to have thrown the ball to trigger the fall. But about the sun. One person could see the sun explode then Brian talk about it when another person could see Brian talk about it then the sun explodes, It just about order&light basically

[kinskifreak2011]

I wished I would have had a physics teacher like that back in school - when he explains things, I understand everythjng... my phsyics teacher on the other hand was incapable of teaching us anything....

[idotrustpwr]

HUHmmm well now let´s watch some porn :D

[aFemale1]

@idotrustpwr ha ha ha 

[Dannoneusk91]

My brain just literally told me he'd had enough, he couldn't take and more and walked out the room...

[aFemale1]

This man, professor Brian Cox is so beautiful, inside out!! Amaising person, i am honnored even to see him speak.

[theart1rm]

@AngeloNiklis What does rabbits shutting their eyes have to do with the Sun blowing up?

[x1plus1x]

important caveats are important :)

[AmyK007]

Um....what? :)

[pancakeguru1990]

he never explained what a light-like event is :(

[jacksawild]

@pancakeguru1990 Light is time-like. You are unable to effect the order of light events as its speed is constant regardless of any space-like events. Einstein famously said if you are on a train traveling at the speed of light and you shone a torch ahead of you, you would see a normal beam. A stationary observer would not see the light leave the torch until you slowed down. At these speeds, the thing which is changing is time and space. My head hurts.

[Ishamoridin]

Important caveats are important. Cox is a troll!

[ThePinkishGizmo]

Wow, somehow, he explained that, and I understood... So much more effective than lectures, sheesh!

[xCometo]

Good o_O

[DanLFC8]

so really that person who runs past the universe is really travelling back in time to see you talk about the sun (i know its not a person)

[edga69]

@DanLFC8 who's time? there is no universal clock. look up special relativity.

[Ishamoridin]

@edga69 Nobody is time. Time is not a person.

[Ishamoridin]

@edga69 I may not have been entirely genuine in asking that question.

[Ishamoridin]

@DanLFC8 They're not travelling backwards in time, they're perceiving time going in the same direction just with some events in a different order as a result of their velocity relative to them.

[oystersdontbleed]

Surely everything is a space-like event, and things only appear otherwise because of the scale at which we perceive things?

[KillahMate]

@oystersdontbleed It's not just a matter of perception, there is actually a very particular point of separation. Just like prof. Cox said, it's all about the speed of light:

1. If one thing happens, and then another thing happens *soon enough and far enough that not even light could get from the first to the second event if it tried* they're space-like. Point being they cannot 'cause' each other (no influence can travel faster than light) so causality is preserved.

2. All others are time-like.

[Ishamoridin]

@oystersdontbleed No, there's a sphere of influence around any event the radius of which is the speed of light multiplied by the time since the event happened and any events that happen in that sphere are timelike to the initial event and any that happen outside it are spacelike.

[ArtisanTony]

If the sun explodes and you live on Earth it doesn't matter a hill of beans what someone in space thinks :)

[zionravescene]

"Important caveats are important." - Prof. Brian Cox

[MrArekusa]

i love this guy

[meatpie29]

I don't understand anything:(

How can you reverse the order of the claps? He said the past is protected.

The first clap is in the past?

[SIRA063]

Its admirable that brian cox can explain let alone understand such theories of the universe. I wonder what kind of man it takes to actually formulate them, even if it did take 10 years... Einsteins question of riding the speed of light apparently came from a dream he had when 2 horses were pulling a sleigh. How a molecular brain logically assembles a thought, let alone a man coming up with a never before heard of idea. to completely have a unique picture of things is truely impressive.

[raverdeath100]

Simples!

[ransomdave]

I don't get it... what's the difference between the time it takes for the ball to leave a hand and knock someone off a wall (perhaps 3 seconds) and the time it takes for someone on earth to notice that the sun has exploded (8 minutes)? Both seem to be the same basic cause and effect situation, only obviously on two different scales.

[scooterdooter]

@ransomdave Here's how I interpret it:

Let's say the sun explodes at noon. Alice is on top of the sun and notices immediately, at noon. But at that exact moment (noon), for Bill on earth, the sun has NOT exploded.

At noon+8 seconds, Bill sees the explosion take place. From Bill's perspective, Alice's observations of the explosion happened BEFORE the actual explosion. The order of events seems reversed (an explosion being observed 8 seconds before it has 'happened').

[GTAMultiPlayerAlpha]

@scooterdooter Friendly correction: 8 minutes (not seconds).

Also, I hope Alice has a high SPF on.

[scooterdooter]

@GTAMultiPlayerAlpha You're right, 8 minutes. Alice is gonna need some serious-strength sunglasses as well.

[uv4jjj]

@scooterdooter it's 8 mins but cheers thats the ticket mate

[ATReade]

@scooterdooter 8mins, not seconds

[BarriosGroupie]

Suppose you have two events separated in space and time. A moving frame can be found where the events can be located at *either* the same time or space, but not both. So space like events are always separated by space, time like separated by time in every possible frame.

[JimmyTheKiller]

omg being stoned and listening to him explain shit is so crazy

[BillyBobsEel]

So if you threw a ball at him from really far away. Does it become a space like event?

[Meejoe27]

If the speed of light was infinite, space like events and time like events would be impossible to distinguish from each other.

[featheredmusic]

@Meejoe27 yes!!

[jt101010]

Lol horrible explanation...but confusing stuff so its understandable

[1modernmessage]

yeah yeah - a time like event ....Brains lips move ,then my head explodes :D

[SIRA063]

@1modernmessage  LOOOOOOOOOOOOOOOOOOOOOOOL

[gimp2]

You just blew my frakking mind...