Bonus panel:
People always confuse multiple things.
There is gravity, the actual effect we see every day all around us. Gravity is a real thing, it exists. Then there’s the law of gravity, this is a math formula you can use to predict the effect gravity has on things. There’s multiple variations of this one, think Newton and Einstein. For almost everything the Newton version works just fine. Then there’s the theory of gravity, this is our attempt to explain why gravity exists and why it does the things it does. This is the tricky one we don’t really have a grip on.
By mixing these things it is often portrayed that “scientists” don’t know anything, they don’t even understand something as simple as gravity.
In addition, the word “theory” has a well known definition in the world of science. It also has a layman’s definition. Those two things are completely separate.
Yes very good point!
“That’s just a theory, a game theory!” won’t fly on your PhD defense.
I made a comment the other day saying pretty much the same thing about “respect” and “tolerance”. All three have multiple definitions that certain types of people, knowingly or unknowingly, use to their advantage to push an agenda. Generally the types of people I’m talking about are either evil (doing it purposefully) or very stupid (parroting others because they have no argument on their own) and in all cases they’re being shitty and think it means they win.
Then there’s the theory of gravity, this is our attempt to explain why gravity exists and why it does the things it does.
Not just the why, but also the what. We didn’t observe gravitational waves until 2015. People have proposed the existence of dark matter and dark energy because observed gravity doesn’t behave as our models would predict at certain cosmological scales.
I like to think of it in this way: What we call dark matter isn’t the cause/source, but the discrepancies we’ve seen in our observations/data. So anybody who says dark matter doesn’t exist is plain wrong, the discrepancies are there plain as day. And it isn’t a single thing, it’s many discrepancies in a lot of data. Now the name is probably not as good, as it isn’t clear it’s actually matter and it isn’t dark but simply doesn’t interact with EM radiation. So we can’t “see” it directly, only indirectly. The name is so poor, it leads to a lot of miscommunications. But the fact is, the data doesn’t match up. So there has to be something there. And that’s data going back almost 100 years.
Just like I said about gravity. There’s dark matter, the real thing that exists and we can “see”. And then there’s the theory of dark matter, the how and why, the thing we haven’t figured out yet.
So anybody who says dark matter doesn’t exist is plain wrong, the discrepancies are there plain as day.
There’s dark matter, the real thing that exists and we can “see”.
No, we have observations that are consistent with the existence of matter that does interact gravitationally with regular matter, but does not appear to interact with light or electromagnetic forces. It’s not like any matter we know about, other than the fact that it seems to have gravity.
General relativity works really well to explain matter in the solar system. Bigger than that, you have to use something else. The general consensus is that dark matter exists, but it’s not strictly proven, as there are alternative theories.
Then, even bigger than that, dark matter alone isn’t enough, you need dark energy to explain some observations, if you assume that cosmological constants are constant. If it turns out that they’re not truly universally constant, we might need to modify some theories (including the proposed existence of dark matter and dark energy).
We still don’t know how it happens. Only why.
And Newton’s formula doesn’t work for the solar system. And later ones not for galaxies (hence Dark Matter Unicorn).
I assume the “almost everything” is relative to the things people need to calculate gravity for. Astrophysics is cool, but rather the minority compared to, say, calculating the forces a bridge has to withstand or the arc of a ballistic projectile or any other calculations concerning primarily things on our planet.
