The Sorry State of Dark Matter Alternatives

Scientists can’t directly observe dark matter, and they still don’t know what it is… so why are they so confident it exists?

Hosted by: Reid Reimers

----------
----------
Dooblydoo thanks go to the following Patreon supporters:
Lazarus G, Sam Lutfi, D.A. Noe, سلطان الخليفي, Piya Shedden, KatieMarie Magnone, Scott Satovsky Jr, Charles Southerland, Patrick D. Ashmore, Tim Curwick, charles george, Kevin Bealer, Chris Peters
----------
----------
Looking for SciShow elsewhere on the internet?
----------
Sources:

Images:

[OctoNocturne]

Alright, so we know there's stuff out there that we can't see. But what are telescopes made with? Mirrors. What can't you see in mirrors? Vampires.

*Space is full of vampires*

[SweatyShivers]

""Along with 'dark matter' and 'anti-matter' we've recently discovered the existence of 'doesn't matter', which appears to have no effect on the universe whatsoever"---Richtennant.

[TommoCarroll]

“Dark matter. Each pound of it weighs 1000 pounds”




Is my math right?

[gravijta]

I guess dark matter is just another state of regular matter. The Sorry State.

[derklempner]

In Hawking's book, "The Universe in a Nutshell", he posits that dark matter may be nothing more than the gravitational effect of a nearby brane or multiple branes containing their own universes. The matter in those universes could gravitationally affect our universe, causing the effects we see and describe as "dark matter".

[Ryukachoo]

Mond totally glosses over gravitational lensing too, which definitely a thing

[z-beeblebrox]

4:33 I can't believe you passed up an opportunity to say Sextillion

[busdriver]

Thanks Reid, quite interesting! All of the hosts on this channel are great but you are my favourite! I look forward to your next video.

[garypalmer]

I really like this episode. You should do more shows focusing on the disagreements with in the science(s)

[jrpipik]

SciShow 1887 is still putting all their money on luminiferous aether to explain the motion of light through the cosmos.

[MidnighterClub]

I like this video about ideas that *almost* work. It feels like actually being on the cutting edge of science to think about alternate theories and what might be wrong (or right) with them.

Also helps explain *why* scientists believe what they do. "MOND doesn't work well at scales larger than galaxies" is a pretty good reason to prefer dark matter.

[mattbarr]

I'd like to see a video update of the Parker Solar Probe, exploring it's wild top speed, and first data that come from the project! Thanks SciShow!

[lordgarion]

Another big problem with MOND is those 2 galaxies(forget the name) that passed through each other and had almost all of their gases ripped out and the gas from both galaxies is now sitting together in the space between the galaxies.

Both of the galaxies have less mass escht than the gas cloud, but the smaller galaxies show affects of dark matter while the more massive gas cloud shows absolutely no affects from dark matter.

That pretty much destroys MOND.

[RobertGarveyATL]

NDT once suggested we refer to it as "dark gravity" because calling it "dark matter" presumes we know more about what it is than we do. I like that. And ... does MOND explain lensing effects attributed to dark matter?

[Jynxedlove]

I spent the entire video wanting to fix his collar and didn't hear what he said, so I had to rewatch it without the video.

[NewMessage]

Meat alternatives... sugar alternatives.. we've gone too far with Dark Matter alternatives..

[liammargetts]

I wonder if there's anti dark matter?

(Edit: This brought a much larger debate than expected)

[Youcanscienceit]

It was really reading the papers about the bullet cluster that convinced me. Most of the ways that Dark Matter is popularly discussed feels like some kind of MOND could work. However, ultimately the case of the bullet cluster simply doesn't work without some kind of space-time distorting gravitational effect that isn't associated with the visible matter - e.g dark matter. What dark matter actually is, is still hard to say but it's not compatible with modifying gravity on large scales.

[Strype]

reality: "where am I? what's the matter?"
science: "dark"

[TBomb]

you know, it's fun learning the research of the grand overarching melody of the stars and galaxies, but it's sad we can never affect them. That's why I'm a chemist, I work with stuff that I can directly affect, and have a positive effect on the world in the near-term (relatively speaking)