Elad

If you have a wise account you can order the virtual or physical card which moonpay accepts. I have used it many times on trust wallet.

Then you will know that the Big Bang theory is not about how the universe started, its about how the universe evolved from a time when all the matter and energy was already present about 13.8 billion years ago. There is no scientific theory on how the universe was created and any physicist will say "we don't know".

I like this scientific side to ya Sunmaster, keep it up ???? A rotating solid disc like that is quite complicated, there's a lot of forces going on including accelerations and its not easy to explain. However, it seems a little backwards to me because time slows down with increasing radius so I would put CC at infinity where time comes to a stop on your diagram. At the center time should be flowing faster ????

To determine how the universe evolves in terms of the expansion/contraction, we need to know the energy density values for radiation, matter and dark energy. All current models show that the universe is dominated by dark energy and that the universe will continue in its accelerated expansion forever. See below Radiation (blue) was dominant in the very early universe, to then cross over to a matter (red) dominated universe, this actually slowed the expansion until around 4 billion years ago when dark energy (green) takes over. Notice how the dark energy density remains constant throughout, while matter and radiation dilute as the universe gets bigger. Also note that the matter density (red) includes dark matter + normal matter.

I was being generous using light cause it gets even worse for sound ???? Since we're on the subject of seeing events I just want you to know that in physics there's a difference between 'seeing' and 'observing'. Seeing an event (like we just discussed) is when the light from that event reaches your eyes or scientific instrument, whereas observing an event is the exact time and place the event happened. So for example if I see the explosion of a distant star tonight that was 10 lightyears away, then I would report the time of the explosion as ten years ago. In special relativity we are only interested in observing events NOT seeing events, so when we assign coordinates to events its when and where those events actually occurred in a particular reference frame. Just wanted to make that clear since its very important in understanding how time works in relativity. There's a common misconception in SR which is 'moving clocks tick slowly' and although its true that you will observe a moving clock to run more slowly than your own, there's actually more to it than that and the relativity of simultaneity shows us that its time itself that changes from one frame to another where observers take different paths through spacetime. I'll try to explain using two reference frames. Imagine yourself (Tippaporn) on Earth and me (Elad) travelling at some speed V relative to you. Since speed is relative then I could say that I'm at rest, and you, on Earth, is travelling at speed V, it makes no difference in relativity. Due to this symmetry not only will you observe my clock running slow, but I will also observe your clock to be running slow, sounds like a paradox but its not when you take the relativity of simultaneity into account. If you observe and assign coordinates to two events that occur simultaneous but at different locations in your frame, and remember this is observing so those events really do happen at the same time in your reference frame. Then in my frame, I will observe the same two events at different times lets say two seconds between each event. How can this be because if time was just slowing down then the two Events would still be simultaneous in any frame. Time changes on different paths through spacetime. In SR when we do the transformations of coordinates from one reference frame to another, the math shows us that the time coordinate depends on the space coordinates, and space depends on time, there's a mixing of space and time into one spacetime and this is how the universe seems to work. The condition of two events being simultaneous is a relative one not an absolute one. I'm finding it very hard getting this across, and I'm not the best science communicator ????but I hope it helps you to understand that time is not absolute, it make no sense to say "I wonder what aliens are doing right now in the Andromeda galaxy" because our now is not the same as theirs, if they exist. I would've liked to add some 2D spacetime diagrams to illustrate better how it works but I'm not sure you'd appreciate them. Instead of searching the thread would it be possible to send me a link on Seth's definition of time, I'd like to have a look at it.

I might respond to one or two of them but don't expect much from it because you already know I'm a bit of a materialist ???? I need to clear a few things up with @Tippaporn first with regard to time. Bear with me please because I'm not always at my laptop and I hate using the mobile.

Its just a common joke among scientists. Of course physics works, you only have to look at all the technology around you to know that.

Some cosmologists think that we live on the surface of a 3-sphere. A 2-sphere is like the Earth which is spherical, has a 2D surface, and has no beginning and no end. A 3-sphere, is a sphere with a 3 dimensional surface that has no beginning and no end, so if you traveled in a straight line for many billions of light years then you'd end up in the same place you started. Sounds plausible but I have problems visualizing it. And it solves the problem of where does the universe end, like the surface of the Earth it never ends.

No one is claiming to be a scientist here but even if they were, so what, scientists aren't special people they get things wrong all the time, especially the physicists. Have you ever heard that saying: If it smells, its chemistry If it wriggles, its biology If it doesn't work, its physics ????

I don't really like to speculate but it wouldn't surprise me if there were extra dimensions. Have you ever heard of a 3-sphere?

I'm no Einstein trust me ???? but I have been studying physics part time for the last 9 years or so, I'm no expert but I dare say I know more than the average person when it comes to physics. In Minkowski spacetime, the time axis becomes a length so its has the same units as the x,y,z, and when you measure the spacetime separation between events from any inertial reference frame its an invariant quantity. Events with a positive >0 separation are time-like Events with a zero (or null) separation are light-like Events with a negative <0 separation are space-like. I can't really go into it anymore without using some math ????

It's how we visualize it in Minkowski spacetime, if you look at the lightcone above, all events within the lightcone are time-like and can be causally connected, events that occur on the edge of the lightcone are light-like which could be connected by light signal. Events that occur outside the lightcone are space-like and these events cannot be causally connected. This is all part of special relativity.

It's hard to visualize any higher dimensions, but some people think the universe is expanding into another dimension. Whats your definition?

Yes, that is a 3D lightcone 1 time and two space. For a 4D lightcone those cones would become spheres. When I look at my friend, Im looking slightly into the past lightcone. What other options does it have?

We are actually always looking into our past lightcone. If you are talking to a friend who is stood 1 m away from you, then it takes light about 2 nano seconds to reach your eyes and then your brain has to process that information, so in that sense, everything you do in your life what you think is the now, is actually slightly in the past.