Classroom Aid - Galactic Dark Matter (4K)

This covers galaxy rotation curves for Andromeda, the Milky Way and NGC 6503. It highlights the difference between these curves and what we get in a Keplerian System.

[garyliu]

This means we have more mass at the disc, but not necessarily dark matter.

[mikeypx]

I love your videos. Thank you for making them.

[kieranrichmond]

Place a millimetre rule horizontally behind a cylindrical glass of water and you'll see an astonishing expansion of the markings towards the outer edges - as if a 2-D 'slice' through the 3-D gravitational lens. I'm not claiming the water glass trick precisely mimics galactic gravitational lensing but could it be that the 'size' at which we PERCEIVE galaxies has been wrong all along? Could it be that exaggerated outer galactic radii are the real reason for 'excessive' orbital velocities? At a time when even erudite journals are questioning the existence of dark matter, is it not high time to consider a simpler and eminently logical alternative that is staring us in the face? QED.

[ryanblais]

Do dark matter and dark energy have anything to do with the quantum ground state energy of empty space or the flux of virtual particles in that "empty space"?

[OmniGuy]

Could you please do a video explaining how we know entanglement works at distances clear across the universe?

[rkreike]

Q: If in the future also in other galaxies objects will be discovered as:
Exoplanets, rogueplanets, stars that don’t emit visible light,
then part of the darkmatter-mystery will be solved?
Or not?

[rubenanthonymartinez]

*No need for dark matter.* Think like an engineer engineer, a galactic differential system.
Solution; what drives the rotation of the Galaxy it's not the center of the spiral Galaxy but there are two separate systems. Central galactic system and the outer system.
In other words, there are two systems at play here, the inner galactic center and a separate outer ring system. Two systems are tenuously held together but nevertheless there are separate systems. The outer circumference is governed mostly by plasma rotation and the inner is governed mostly by gravitational forces.
The central galactic zone behaves classically but the periphery breaks away from this Newtonian behavior, the objects in the outer zone are sped up due to plasma rotation.