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Russell: What is space - empty space? I'm not just thinking of outer space. I mean any sort of space - the space here – the space where you're sitting. Well the answer seems obvious you know. Empty space? It's just another name for Nothing. But that's not how the modern physicist views it. Take for example a space station. It's orbiting the earth. Why? Why doesn't it just go drifting off into outer space in a straight line? Gravity - the earth's gravitational force acting on it. Well fair enough. But what if an astronaut steps outside the space craft? He too is orbiting the earth and in more or less the same orbit. Why? Earth's gravity again. But the astronaut is much lighter than the space station, so in order to get him to go in the same orbit the gravity force on him has to be less than on the craft.So how does gravity know how much less it has to pull on him than on the space craft? And in any case, why would gravity want them to go in the same orbit? The puzzle is solved once one sets aside the idea of the earth exerting a gravitational force and instead thinks of gravity curving the space around it. Okay, this is something I’ve rigged up. This surface represents normal, empty space and if we have an object going through that space, perhaps a space craft, then the natural path to follow is a straight line, like that. But look what happens once I put a heavy object into that space, the earth. Now you see what it’s done to the surface, it’s curved the surface so now the natural path for an object passing through it like a space craft is no longer a straight line, it’s a curved path a bit like this. Okay well forget about the spiralling in that’s just due to the friction we’ve got here but for the space craft above the atmosphere there’s no friction to speak of so we get a steady, repeated orbit.
Let me just show you how it comes about that the astronaut and the spacecraft go in exactly the same orbit at the same sort of speed. As you can see I happen to have got a curved surface here and now we’ll make the heavy ball represent the spacecraft and the lighter ball is the astronaut who’s just stepped outside the spacecraft to go for a space walk. And this is what happens. So the reason why the astronaut and the spacecraft follow the same orbit is that that is the natural path to follow. The natural path is no longer a straight line, a straight line which has then got to be curved because of the action of a force. This way of viewing gravity we owe to Einstein. It's part of his Theory of Relativity.
So, space is not nothing. Space is a something - a mysterious something that can be curved. And that's not all. The universe is expanding - distant galaxy clusters are receding into the distance. This is all in the aftermath of the Big Bang. But that's not to say the galaxies are moving through space, into an outer space where previously there had been nothing. No. They are moving because it’s, it’s space itself that is expanding. The space between us and the distant galaxy is carrying the galaxy along on a tide of expanding space. Okay here I've got some galaxies.
The galaxies have moved apart, not because they have slid over the rubber, but because the rubber in between the galaxies has expanded and carried them along with it. Okay that's what's happening out there. Space - so-called 'empty space' - is pushing the galaxy clusters apart. This is a diagram of the various stages of the expansion of the universe. The Big Bang occurred here. A brief period of exceedingly rapid expansion called inflation. And that's followed by the more gentle, normal kind of expansion - like what I showed you with the balloon. The rate of expansion at this stage further slows down somewhat because of the mutual gravity between the galaxies. But look what's happening here. The rate of expansion is now increasing.
This is due to what is called dark energy. Space - empty space - has energy. And whereas matter attracts through its gravity, empty space, through its dark energy, repels.
Now I reckon that's weird. Space, so-called empty space is not only something that can be curved by gravity, but it can also push around heavy things such as galaxies. things as heavy as galaxies around. No, let's face it, the simplest thing we can think of - so-called empty space, is not simple at all. It's a deeply mysterious something - but what?
After piece
Russell: Tony. Can we do the balloon sequence again, I’ve just had a brilliant idea. Okay, I get this far blowing it up but then if I blow some more and and it burst okay we’ve got all the bits flying around, that could like the accelerated expansion due to dark energy yeah? Shall I try it yeah?
Tony: No, no, Russell, Russell, no, no.
Russell: Well, well why not?
Tony: Sorry Russell, blowing up universes is not allowed, it’s against health and safety, sorry.
Is the word ‘space’ – so-called empty space – simply another name for ‘nothing’? No. It appears to be something that can be curved by nearby heavy objects, such as the sun or earth. It is this curvature that gives rise to gravitational effects. The observed expansion of the universe is not due to the galaxy clusters moving through space but, instead, space itself is expanding and carrying the galaxies apart, much like a tide carrying floating objects out to sea.
It has recently been discovered that space has energy – known as dark energy. Dark energy exerts a force; unlike gravity, which attracts, dark energy repels. The distant galaxy clusters, far from slowing down under the influence of their mutual gravity, are now known to be accelerating away from each other by this property of space, meaning that space is not nothing but instead, a deeply mysterious something.
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Empty space
Sorry
but this seams to be more like a good Idea that closely fits the observation.
We say that gravity bends space time, and we see that photons/light is/are deviated by this, could it not be that gravity is the only force that acts on a photon? more -over that a photon acts on gravity, but due to its low mass deviates.
Bends in space cause the deflection, mmm, what we see is that the path of a photon deviates, is it that space pushes the photon around the gravitational force? Not so sure
What is the possibility of, as it now appears that most building blocks have an opposite, the photon having an opposite, that of a darkon, not dark matter but that of mass but no energy.
I know, E=MC2, all be it in vacuum, what if the speed of light is super constrained?
Yours very confused and serching.
dave S
-SPACETIME – Speed of
-SPACETIME – Speed of light.
I’m trying to answer the following:
Was time created (once upon a time) or constanly beeing created…
If the latter:
How fast is new time created?
I write down in ’free thinking’ what comes to me and hope to get a better ’picture’ of
’The barrier of the knowable’ (appering when basic facts on the subject runs short or missing.)
Time is continiously ’created’ as cosmos itself is ’swelling’ at lightspeed in all directions.
New space-time flows constantly into cosmos and causes volume expansion throughout the universe. Time is an appearens/creation of expanding univers/spacetime.
The older the universe grows, the ’new spacetime’ added - increases every year, like
equally thick layers of skins on a ’growing onion’.
Time is appearing as a ’carrier’ in any corner or point of cosmos, an unstoppable ’sprinkler’ throughout the universe.. Time is created at the speed of light = expansion of cosmos.
At the speed of light - time halts, i.e. new time slows to zero. High speed counteracts the universal timeflow and ’time creation’ from adding new time at the same pace.
If the swelling of cosmos slows, time creation also will slow – speed of light in vacuum
slows accordingly.
Imagine moving near light speed in a spacecraft for approx. 10 years and returning to the earth. Let’s say time drift on the earth = 10.000 years.
When the spacecraft lands on earth – how mutch has the visible universe expanded in size
– is it according to 10 or 10.000 lightyears.?
Vu = Speed of universal expansion t = time passed on earth
C = Speed of ligt T = Your time (close to lightspeed)
t _ = 1 _ .
T √ 1-V²/ C²
Vu = C t/T (Vu = C 10000/10)
Vu = C _ .
√ 1-V²/ C²
To travel faster than time itself is created, (gauged by the speed of light in vacuum),
is contradicting.
Travel backvards in time violates the law of entropy. To really go back in ’your own’ time also must include a shrinking of the visible universe (the size back then), dead flowers and people to reappear made of the same atoms etc.
Thus rulig out ,with the same arguments, that a visit from the ’future’ is possible.
Time is a ’component’ in speed and gravity. No speed can be measured without time, neither
the force of gravity. In cosmos light speed is equal to ’speed of gravity’ (300.000 km/s).
Gravity speed - in the world of particles (micrococmos) has ’slowed’ to zero.
In microcosmos electrones ’jumps’ from one shell to another - instantly, disappear and
reappear in the very same moment. Is it the same electrone or two more electrones
- in a ’complemtary’ action? (ref. wave/particle paradox)
A rainbow has complemetary colours , i.e. turnes to grey, white, or black when mixed.
Do electrones also possess the ’same’ duality in a ’complementary dimension/environment’? Altering beeing a particle or energywave as a response to variable conditions.
In the ’stamcell matter’ still outside the expanding border of cosmos, the time has not begun. Not ’iniciated’ by the ’border’ to create ’spacetime’ in our own universe.
Time in a 3D world can be experiensed as a growing size of volume or movement of matter.
How is time and space appearing when seen through 4D glasses.? Can matter exixst without time?
Until the beginning of our time/cosmos (big bang), everything was ’outside the universe’.
The ’inflation’ at the very beginning of the big bang made the first spacetime for all matter
in the universe to evolve.
The ’border’ far outside the observable univers - moving at lightspeed - pours ’new time’ and additional spacetime into our universe - black holes do the opposite.
Is there a possibility for the ’border’ to hit a new ’singularity’ and thus generate another ’big bang’ inside our own universe?
Yours wondering
Tronn