Horizon: How Big Is the Universe? (T) Mon 21:00

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Feb 15, 2011
3,860
2
Elsewhere
Maybe we struggle with the idea of something from nothing because all around us things come from something then go back into something else. We are born, we grow, we die. Go back far enough and the earth will not have formed, go forward far enough and it will be no more. Same applies to the sun. But in each case we can trace the path of energy that temporarily is arranged to form an earth and a sun and then is re-arranged in another form.

Indeed but the universe does that too, it continually creates stars, planets, gallaxies from existing matter then recycles them which adds to the conundrum of the universe starting from nothing,..........If in the begining there was nothing,then where does all the matter in the universe, including ourselves, originate.?
 

cave_dweller

Nomad
Apr 9, 2010
296
1
Vale of Glamorgan
Who says they come from nothing? Nothing cant exist, If it did it would be defined as such, and would then be something :)

Just had a read ( im no academic nor scientist nor follower of science) and what it says is that those particles are a temporary change in the amount of energy. Not new energy creation. So if they are a change then they are created by the original source of energy, whatever that may be.

As far as I know energy can't be created or destroyed, it can only change form, so it's not really meaningful to talk of 'new energy creation', regardless of how many parents there are. The 'event' here is that particle/anti-particle pairs can be created "from nothing" (or at least in a vacuum) and then collide again to annihilate each other - returning to nothingness. There's no energy creation there - though when this happens on the event horizon of a black hole, one of the pair can disappear in, while the other gets ejected, which *appears* to create energy. That's kind of oversimplifying it, but I don't understand it any deeper than that.
 

cave_dweller

Nomad
Apr 9, 2010
296
1
Vale of Glamorgan
I was always taught you can't create energy [or destroy it], only alter it from one type into another i.e. potential to kenetic.

So there is no more or less energy than there ever has been, it's just in a different state now than what it was. So if you need mass to make electricity [energy] there is no more or less mass than there ever has been, only now it's occupying a bigger space, or spread out over a bigger area?

E=mc[SUP]2 [/SUP]. Energy and mass equivalence. Energy can be converted to mass, and vice versa. Combined with the 'T' symmetry, thermodynamics and observations of how entropy changes, we can use it to define which direction time moves in. Simples. Apparently ;)
 

ex-member Raikey

Bushcrafter (boy, I've got a lot to say!)
Sep 4, 2010
2,971
3
We werent talking about a vacuum though. We were talking about hot and cold :)

but temperature and pressure are directly proportionate,...

low temperature = low pressure

pressure low enough = vacuum

hence the "vacuum of space" could equally be described as the "cold of space"

the lack of (or miniscule amount) of heat energy available to heat up such a large space results in a low pressure or vacuumous enviroment.
 

ex-member Raikey

Bushcrafter (boy, I've got a lot to say!)
Sep 4, 2010
2,971
3
the theories here are great,..

i think some of the best ones have come from the simplistic look, from a relaxed point of view,

overthinking this stuff doesnt seem to help me,...


i do think that the perception approch is good,

especially where times concerned,..

a fly lives a day or two?...it doesnt think (if they indeed do think) " oh no,..i only live a day" ,...

it percieves a full lifetime,...

so, what if the bigbang and all we can see and all we know , our Universe , everything , was just a flying ember in someones fire,.

from out perception its our universe and it flew out of the fire billions of years ago , its all we know,..

but from the viewpoint of the guy whos fire it is, ,...

its a brief flicker, burning out in half a second,

but whos to say he didnt set up camp and light his fire on someone elses flying ember,..

a bushy analogy, ha,....

but still a perception angle,...
 

treadlightly

Full Member
Jan 29, 2007
2,692
3
65
Powys
the theories here are great,..

i think some of the best ones have come from the simplistic look, from a relaxed point of view,

overthinking this stuff doesnt seem to help me,...


i do think that the perception approch is good,

especially where times concerned,..

a fly lives a day or two?...it doesnt think (if they indeed do think) " oh no,..i only live a day" ,...

it percieves a full lifetime,...

so, what if the bigbang and all we can see and all we know , our Universe , everything , was just a flying ember in someones fire,.

from out perception its our universe and it flew out of the fire billions of years ago , its all we know,..

but from the viewpoint of the guy whos fire it is, ,...

its a brief flicker, burning out in half a second,

but whos to say he didnt set up camp and light his fire on someone elses flying ember,..

a bushy analogy, ha,....

but still a perception angle,...


The Universe in an ember....a very good image and one to ponder the next time you're out in the woods watching the Bushcraft TV.
 

HillBill

Bushcrafter through and through
Oct 1, 2008
8,141
88
W. Yorkshire
Ok then. :)

but temperature and pressure are directly proportionate,...

low temperature = low pressure

pressure low enough = vacuum

hence the "vacuum of space" could equally be described as the "cold of space"

the lack of (or miniscule amount) of heat energy available to heat up such a large space results in a low pressure or vacuumous enviroment.
 

santaman2000

M.A.B (Mad About Bushcraft)
Jan 15, 2011
16,909
1,114
67
Florida
Space is never just space. Theres always some mass in it and so it has a temperature, be it a ridiculously small amount.

True enough. But not neccessarily a measureable amount and for the context of my post "none" is accurate enough.
 

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