3 ms·

> However, saying 'there is x amount of unobservable stuff there' in order to make our calculations correct seems like lazy science. That's not how this works.

> However, saying 'there is x amount of unobservable stuff there' in order to make our calculations correct seems like lazy science. That's not how this works. Dark matter and energy are placeholders for anything that can explain the discrepancy. The most likely explanation for dark matter is just undiscovered particles, but changing the physics of it to make the calculations come out right is also something that people do. There's not really a difference between the two either. Post-QFT the concept of a particle is much blurrier than before, and "changing the physics" might just involve introducing a new background field that behaves differently in different places based on its concentration. In essence, you have introduced a new particle. Please note that while it feels like lazy science, coming up with alternate theories that have the same success and rigor as QFT is very hard. Its not that they are hanging up their pencils and declaring premature victory. It is that literally the best description of physics out there to date doesn't explain this, and within that description yet-to-be-observed particles is its best bet. They are working on better explanations, but Rome wasn't built in a day.

teamonkey 10y ago
Here's an interesting theory. https://astronomynow.com/2016/06/16/did-gravitational-wave-detector-find-dark-matter/ https://astronomynow.com/2016/06/16/did-gravitational-wave-d... The gravitational waves we're detecting come from black holes, but the readings we have from LIGO suggest that they most likely come from 'primordial' black holes formed at the birth of the universe. If many of these black holes were formed they would be distributed much as MACHO theory predicts. 'Normal' black holes have very specific mass profiles so were generally ruled out as MACHOs, although obviously 'dark matter = black holes' has had a lot of consideration.
iaw 10y ago
"The most likely explanation for dark matter is just undiscovered particles" <--- all valid points but I'd argue that dark matter may actually be strictly the result of yet-to-be-understood underlying fields. e.g. dark matter may not have any particles itself but could be the gravitational of spacetime in a sense Just a nit.
- johncolanduoni 10y ago
  Unless the field is not quantized, this is not a distinction. Electrons, protons, etc. are a fields as well.
  - iaw 10y ago
    The fields that results in the Casimir effect are non-quantized, correct?
    - johncolanduoni 10y ago
      On the contrary, Casimir forces only arise because the field is quantized.
- Manishearth 10y ago
  I said exactly this in my comment. There is little distinction between particle and field in this context.

teamonkey 10y ago

Here's an interesting theory. https://astronomynow.com/2016/06/16/did-gravitational-wave-detector-find-dark-matter/ https://astronomynow.com/2016/06/16/did-gravitational-wave-d... The gravitational waves we're detecting come from black holes, but the readings we have from LIGO suggest that they most likely come from 'primordial' black holes formed at the birth of the universe. If many of these black holes were formed they would be distributed much as MACHO theory predicts. 'Normal' black holes have very specific mass profiles so were generally ruled out as MACHOs, although obviously 'dark matter = black holes' has had a lot of consideration.

iaw 10y ago

"The most likely explanation for dark matter is just undiscovered particles" <--- all valid points but I'd argue that dark matter may actually be strictly the result of yet-to-be-understood underlying fields. e.g. dark matter may not have any particles itself but could be the gravitational of spacetime in a sense Just a nit.

johncolanduoni 10y ago
Unless the field is not quantized, this is not a distinction. Electrons, protons, etc. are a fields as well.
- iaw 10y ago
  The fields that results in the Casimir effect are non-quantized, correct?
  - johncolanduoni 10y ago
    On the contrary, Casimir forces only arise because the field is quantized.
Manishearth 10y ago
I said exactly this in my comment. There is little distinction between particle and field in this context.