Cliches about tech and travel

You mean Einstein's GR? Sure it can.

Spoiler: Physics

Quantum physics and GR only conflict with each other in the circumstance of the singularity, other than that, there are little to no conflicts. I could explain it in greater detail if you'd like, but the main issue comes from the fact that GR requires smooth spacetime and QM has a minimum unit of both space and time.

You are confused by pop science about terminology, when scientists speak of things, they choose their words very carefully, journalists, not so much. GR has valid solutions that would equate to a white hole, but it requires some exotic matter that has a negative energy density. We've never seen such a things and don't expect such a thing to be stable. Being mathematically valid, and actually predicting existence are not the same thing.

An Alchierre drive is mathematically valid in GR, but again requires negative energy density to achieve, ergo impossible.

We know dark matter exists because we can see it. It's invisible to us only in terms of light, it's gravity we can see very clearly. It's like being in the water and using a telescope to look out. The water would be invisible to us, but we'd see things in the distance distorted by the density differences between us and it. The same thing happens in space because space curves in the presence of gravity. We've used math to map the dark matter, it's definitely there, there have been lots of proposals, all of which have determined to be invalid so far.

There are a lot of mathematical reasons why folding spacetime is not possible, for one, it would break the concept of smooth space.

 

Thanks for the explanation. I'm still in high school, we're still doing star light spectrums and pressure so this is all beyond me.

I follow tech and science quite a bit but, as you said, in newspapers rather than in theses or actual accounts of experiments.

From what I've read we've seen some light distortions that COULD help to find out what dark matter is.

Right now it seems to be mainly a process of elimination. If DM was light particles we'd see it, if it was protons or such we'd be able to observe it, if it was caused by black holes we'd observe it.
Those three are crossed off the list, on to the next [infinity] possibilities for what causes it.

 

I was curious about folding space so I dug though the literature. Homer Ellis come up with some valid mathematical solutions than involved a ship moving through what could be described as folding space. Like the Alchierre drive, it requires exotic matter with negative energy densities, but the math sort of works. His solution works in an ideal situation (I didn't check, but it's peer reviewed,) so I decided to take the field equations and see what happened when things go wrong. It goes very wrong, if it collapses anything but perfectly, you create a cosmic string, which is essentially a crack in spacetime.

No problem, feel free to reach out to me with questions of higher level physics. Dark matter is a fascinating subject and I suggest reading the literature about it, a lot comes out because it's so mysterious. Process of elimination is what science is, the scientific method never claims to be able to determine what's right, only what's not right. There were actually a LOT more theories than just protons and black holes: planets, antimatter, quantum foam, modifying the laws of gravity. There are only a handful of theories left, the most exciting is SUSY. It predicts 16 more fundamental particles that are very heavy and do not interact with light. The reason it's getting so much attention is that the LHC is able to create energy densities right at the lower end of what's expected, so we may see it soon.

 

I worked as an intern in a lab for a week. The process of elimination part is true, but what the physicists were woking on in that case was pretty specific and they had a general idea of what they were looking for so didn't run too many variations of the same experiment (a few hundred, which is apparently quite low from other research experiments I've seen)

What I love about science can be summed up with this: Stephen Hawking spent half his life proving black holes exist, and spent the other half trying to disprove them.

 

And yeah, those were three examples I could find. I'm sure there are thousands of other now disproven theories!

 

This all sounds like the making of a great book title: "All the Worlds We Shall Never See".

I'm so ashamed, I never know if the period should be inside the quotes or out.

 

You think that's bad, I don't know how to use a ";".

 

I have to say, I'm pretty discouraged reading this thread. I write FTL because that's what I like reading about (although I'd admit my writing trends more on the fantasy side). I had no idea it was so frowned upon...I'd much rather read it then some of the other sci fi tropes out there.

 

That's why you stick with laws of physics that haven't been discovered yet, not manipulating laws that are already understood in pop-science ways.

I remember there was an episode in Star Trek TOS where they got stuck in a living organism surrounded in a space of negative energy density. Anything they did made things worse, they needed to counter the negative energy density with more negative energy. Someone came up with antimatter. I started yelling at the tv. "No Kirk, antimatter just has the opposite charge, it's still positive energy density." Seems the writers of TOS didn't know that. Things like that bother me, their warp engine does not. If you want to use things that scientists understand (even if the public doesn't) like antimatter or negative energy density in your story, you'd better have a decent understanding of them.

 

It wasn't antimatter they were using, it was doesn'tmatter.

So now we need a guide to what has not been disproven to write a sci-fi, you take all the fun out of this stuff newjerseyrunner. You cannot know what you don't know.