Gravity Without Mass Could Explain Dark Matter

Honestly it's got to the stage where if somebody wrote a paper saying "it's not dark matter, it's magic moonbeams", then, quite frankly, I'd consider that just as valid as any other explanation so far.

"...suppose you have a laser-eyed unicorn, but let's leave this aside for now. I'll come back to this later." Promises were made!!

Wow, what a clever solution. Instead of the effects of dark matter being caused by undetectable positive-mass particles, they're caused by undetectable NEGATIVE-mass particles. Truly... stunning thought process there.

"It's like when people complain about me on Twitter. It averages out to zero." Literally LOLed at that one. Well done!

01:22 That explains why I suddenly can't find my laser-eyed unicorn anywhere.

If the equivalence principle continues to hold for negative mass (i.e. if gravitational and inertial mass are the same), then a negative mass, while being repelled by a positive one, would still accelerate towards the positive mass, because the direction of force and acceleration would be opposite. You could immediately construct a self-accelerating structure by fixing two opposite masses to the ends of a stick. The positive mass would always try to accelerate away from the negative one (because it is repelled and the force on it and its acceleration have the same direction), the negative mass would always try to accelerate towards the positive one (the force on it points away from the positive mass but it accelerates in the direction opposite to the force), so our stick would accelerate in the direction pointing from the negative to the positive mass... Of course, this would immediately lead to problems with momentum and energy conservation (if the stick itself was not massless).

Time to apply Occams razor and look for flaws in the theories that predict dark stuff.

Thanks so much for creating and sharing this informative video. Great job. Keep it up.

If the mass is effectively zero, how does it somehow still curve spacetime?

Gravity without mass sounds like Science without evidence.

Fascinating! Thanks, Sabine! 😊 Stay safe there with your family! 🖖😊

Great video Sabine and very nice simulation.. best wishes.

As an engineer, I have had contact with classical mechanics, electromagnetism, electronics etc but nothing to do with theoritical physics or cosmology after university. However, listening to Sabine's podcasts and similar I get the impression that physics is that those fields are a much more fragile edifice than we were made to think.

Sabine's speaking tone and pace in this video is much improved over others I've watched. It is easier for me to follow the subject.😊

I have few questions: i) Why it is llamative to have gravity without mass? So far I know it is exactly what happens in stable Lagrange points like L4 and L5 ii) Could be considered what happens in unstable Lagrange points L1, L2, L3 as a negative mass point?

This is basically like "we can't find dark matter, MOND does not work... let's try invisible pink unicorn pulling stars with giant harness".

I have been curious for a long time about the potential of space-time curvature from powerful enough photons. That would not explain dark matter or anything, but I am curious about this from a mass-energy equivalence and some descriptions of gravity that I have read.

You don't have a laser-eyed unicorn?! I thought everyone had one of those.

This is the kind of news I want to hear on the radio while driving to and from work, thank you for this channel ^_^

❤❤❤ Love your work!