.......... is what I just put in the other thread about "free will".I suppose that depends on one's interpretation of "free will".
There seems some implication in us humans that it means limitless possibilities and modes of action... I tend to think that nothing is limitless; including the universe we live in.
I think "free will" has to be in some type of contextualised, ethical mind space.
Example: One may have free will to commit murder but is that a good thing? If the society catches you will you suffer because you have brought suffering on others? Doesn't sound like a fun way of having free will to me.........
In the case of Sag A* they measured the velocity of the orbiting 'S-Stars' to calculate the gravity and thus work out the mass.I see: We use the mass of our own Sun, as a base line to work out the mass of other objects in space. We learn new things every day. Thanks.
So how did they work out the mass of something like a black hole? I mean, technically we can't see them, only imagine how big they are etc.. Yes I know that they used multiple telescopes to get that image about a month ago, but that was 'generated'.
Err... Maybe we should start this up in the Astronomy threads.
A somewhat heretic follow-up question would be how they can be so sure as all current physics don't seem to work anymore when it comes to calculating the outer regions of spiral galaxies (the're moving faster than they should in relation to the inner regions), which in the end led to such exotic auxiliary constructions like dark matter and dark energy.In the case of Sag A* they measured the velocity of the orbiting 'S-Stars' to calculate the gravity and thus work out the mass.
The orbits are shown in this video;
Hm, i might have something that would react similarly. Give me half an hour i'll make a video of it quickly.A somewhat heretic follow-up question would be how they can be so sure as all current physics don't seem to work anymore when it comes to calculating the outer regions of spiral galaxies (the're moving faster than they should in relation to the inner regions), which in the end led to such exotic auxiliary constructions like dark matter and dark energy.
It's the word "dark" that have people confused.Dark Matter would be the extra mass required to explain the orbital velocities of the outer stars.
Dark Energy is the acceleration of galaxies (outside our supergroup) away from us.
The two items aren't connected in any manner I'm aware of.
Best explanation EVER! SeriouslyIt's the word "dark" that have people confused.
They should be named differently.
Dark matter should be named something like "Non-reactive matter", because it doesn't interact with normal matter in any other way but gravity itself.
Dark energy should be called "Negative pressure" or "Energy density of empty space".
But that would suggest scientists have an idea what's going on, so... "dark" it is.
This article, after reading it more thoroughly now, showed that in one point I was wrong:
But I was still right (according to this article), that it's believed that these irregularities could be explained by dark matter:The entire galaxy rotates, with objects closer to the center rotating faster, and those further from the center rotating more slowly. The curve of this differential rotation shows irregularities that cannot be explained by visible mass alone.
Here, it is likely that invisible dark matter plays a role. And the astronomers face yet another problem: despite the rotation, the spiral arms do not unwind, but have maintained their shape for billions of years. One explanation for this is shockwaves that propagate throughout the whole system and compact the matter in the spiral arms like a traffic jam on the motorway. Researchers are still puzzling over what causes these density waves.