[DF9sLGSU]

Hi Dr Karl..
I tried to ask this question on the radio a couple weeks ago, but was not able to tune in to see if you had replied. Sorry.

Hmm. Not sure how to explain this, but this is my best shot.
The theory of relativity basically states that nothing can exceed the speed of light. Or if it does it will be incredibly dense/heavy.
I heard your description of what occurred during the Big Bang recently and it kindof cleared things up. But also made be even more curious.
I assume that when the Big Bang occured light and "stuff" was released in all directions (along with what ever created matter).
And from memory, I think you said things are accelerating away from the original source.?
So... the light (and stuff) going in one direction is travelling at double the speed of the light (and stuff)travelling in the opposite direction.. relativally speaking..
And if it is accelerating..
So some of this light (and other stuff) by now is travelling very very fast..
Is this what the black holes are?
And stars being "sucked into" the Black Holes are really stars that are travelling away at "1/2 the speed of light plus a little bit" from The "Big Bang" in the opposite direction to us and so exceeding the speed of light in relation to us?

[TOPERink]

Dr Karl doesn't come here.

I’m not an expert but:

So some of this light (and other stuff) by now is travelling very very fast..
Is this what the black holes are? No. Black holes are collapsed stars.

And stars being "sucked into" the Black Holes are really stars that are travelling away at "1/2 the speed of light plus a little bit" from The "Big Bang" in the opposite direction to us and so exceeding the speed of light in relation to us? No.

Imagine that a large object (such as a planet) somehow crashed into our Sun. We would probably see all sorts of interesting effects, including perhaps the planet being pulled apart by the Sun’s gravity before smashing into it. The sun would also be a bit larger because it has gained mass.

This is what happens when a star is “sucked” into a Black Hole. It gets pulled apart and smacks into the collapsed star that is the black hole. We just wouldn’t see as much of the process because the gravity of the Black Hole prevents light escaping. (More about that soon).

[Breevereurl]

There seems to be a very common misconception about Black Holes.

I’m sure someone will correct me if I’m wrong.

My understanding is that there is nothing “magical” about a Black Hole that makes it “suck” more than normal stars.

If you replaced our Sun with a Black Hole of the same mass, then it wouldn’t eat up Earth, or Venus or even Mercury. Our Solar system would still exist much as it does now, except a lot darker and colder (and probably some other issues relating to Solar Wind etc). That Black Hole wouldn’t “eat” anything that our Sun wouldn’t.

However, many Black Holes seem to be in locations where there are lots of other things around that will collide with them. As these things do collide with the Black Hole, they add mass and thus the Black Hole gets stronger gravity, which then means that it is able to “eat” things that it couldn’t reach before.

[tiereenny]

First the BB was a creation of space and time as we know them today.....
Nothing with mass travels FTL.
Space has no mass so there is nothing wrong in it expanding FTL.

A BH is one of three remnants of the death of stars......they are White Dwarfs, Neutron Stars, and BH's.
Which one that results depends on the mass of the star.
Our Sun for example is relatively small, and will leave a WD when it has exhausted its available nuclear fuel...
Neutron Stars are left when stars of higher mass exhaust their fuel....
And finally we can have BH's form when really big stars use up their available fuel.

A star is stable as long as the Radiative pressure from fusion reactions, is supported by gravity.
Very massive stars undergo many fusion reactions...H to He to Mg O and eventually if they are big enough they fuse Iron/Nickel....Then no more fusion is possible so they have a drop in radiative pressure and gravity simply takes over.
All the outer mass is slammed and rebounded off the Iron/nickel core, which results in a supernova and a core so dense that the escape velocity of light is reached...We then have a BH.
This is a rough account of what happens. That basically is all a BH is.

Important things to know...
[1] the BB was not an explosion of matter and energy...It was a creation and expansion of space and time as we know them.

[2] Matter came later during what we call phase transitions and the decoupling of the super force...similar to the changing of water to Ice or vise versa...

[3]Since the BB was an expansion of space/time from an infinitesimal point, the BB has no center of origin and can be seen to have happened everywhere at the same time due to the expansion of that space/time



[4] Light [photons were unable to travel through the UNIVERSE/SPACE/TIME until at least 400,000 years after the BB.
This was when temperatures and pressures from the original BB was able to drop far enough [through space/time expansion] to enable electrons to couple with hydrogen nucleii to form the first element and thus enable space to become transparent and light [photons] to flow.

[5] Gravity caused these massive clouds of hydrogen and some Helium to conglomerate into a disk like fashion which over a few hundred million years collapsed to reach extreme temperatures again and undergo nuclear ignition and the first stars.



[] Nothing of mass can travel at "c" the speed of light or faster.

[constanyiskancho]

Just to clear up a couple of points that may cause some confusion.

The four forces we know of today. the EMF, Gravity Weak nuclear and Strong Nuclear were all combined just after the BB into what we call the "Superforce"
We got our phase transitions when this superforce started to decouple as space expanded.


Even when the escape velocity of light is reached at the core after a star goes supernova, that isn't the end of things.
That BH since it has reached what we call its "Schwarzchild Limit" keeps collapsing until a point is reached at the center we call a singularity.
From here, just as at the BB itself, our laws of physics and GR break down.

[padlabtard]

Or if it does it will be incredibly dense/heavy. not so. the actual rest mass of the object doesn't change, that is the objects mass when at rest, but it's energy content increases in line with E=MC^2. a bit like dropping a bullet onto a sheet of paper as opposed to firing from a gun at the paper. the mass of the bullet hasn't changed but it's energy has. (this will probably be corrected by someone who actually knows)

o... the light (and stuff) going in one direction is travelling at double the speed of the light (and stuff)travelling in the opposite direction.. relativally speaking.. not so either. velocities aren't added like you normally do with everyday objects when those velocities are nearing, or at, lightspeed.

So some of this light (and other stuff) by now is travelling very very fast.. light always travels at lightspeed in a vacuum for all observers. so if you were travelling at 98% the speed of light and you measured the speed of light you would find that it was 299,792,458 metres per second. if you were travelling at 80% the speed of light you would measure it at this speed too.

[ReginaPerss]

And from memory, I think you said things are accelerating away from the original source.?
So... the light (and stuff) going in one direction is travelling at double the speed of the light (and stuff)travelling in the opposite direction.. relativally speaking..
And if it is accelerating..
So some of this light (and other stuff) by now is travelling very very fast.. Yes, in the universe as a whole we call it the "horizon". The material in the universe beyond the horizon is travelling away from us so fast that we can't see it. General relativity allows this, but we can't see beyond the horizon because there's no way that light can travel faster than the speed of light.

Is this what the black holes are? Very similar. A black hole also has a "horizon" beyond which we cannot see.

[Wr8dIAUk]

WOW...
Thanks everyone for your explanations.
Far more info than I had expected and it will keep me pondering for a while.

Now I have to think about not doubling the speed of things going in opposite directions :/
But I like this..
[3]Since the BB was an expansion of space/time from an infinitesimal point, the BB has no center of origin and can be seen to have happened everywhere at the same time due to the expansion of that space/time


I can go to bed tonight with plenty to think about.
Fantastic ..

Just sad Dr Karl doesn't visit.

[brraverishhh]

Now I have to think about not doubling the speed of things going in opposite directions :/
But I like this..
[3]Since the BB was an expansion of space/time from an infinitesimal point, the BB has no center of origin and can be seen to have happened everywhere at the same time due to the expansion of that space/time
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>


Hi RosieB.....This line of thinking may help....All of space/time that exists now in our observable Universe was all compressed within the volume of an atomic nucleus. Therefor the BB must have happened everywhere at once.

[crestorinfo]

Hi RosieB.....This line of thinking may help....All of space/time that exists now in our observable Universe was all compressed within the volume of an atomic nucleus. Therefor the BB must have happened everywhere at once.

That helps a lot. So long as I don't think too hard.

Still having trouble with not adding the speeds of things travelling in opposite directions when viewed from the point of view of the objects in the "here and now" .

[FelikTen]

Still having trouble with not adding the speeds of things travelling in opposite directions when viewed from the point of view of the objects in the "here and now" http://hyperphysics.phy-astr.gsu.edu...iv/einvel.html

might help.

"c" is the velocity of light and is usually represented by 1.

the other velocities "u" and "v" are represented by a percentage of 1.

ie 80% the speed of light would be 0.8

look at the other links on that page as well.

[desmond001]

That helps a lot. So long as I don't think too hard.

Still having trouble with not adding the speeds of things travelling in opposite directions when viewed from the point of view of the objects in the "here and now"
:::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::::::::::::



What also should be realise Rosie, is that at "c" or near "c", things do happen that can reconcile one to the fact that we need not add speeds and that does help explain that apparent quirk of nature.
At and near 'c" [relativistic speeds] from the view of someone in an outside FoR we have length contraction and time dilation that takes place.