Huge difference: when Higgs was predicted there was a clear path to how to find it. We do not currently have a theory that describes a way to find LCDM that is not begging the question of its existence (not circular reasoning), although we do have several shots-in-the-dark that are ongoing (and a handful that have concluded with no observation).
Also IIRC, Rubin's seminal observations on dark matter were in the 60s too, and dark matter was postulated in 1930.
> Huge difference: when Higgs was predicted there was a clear path to how to find it.
is that really a huge difference? plenty of eventually-proven math conjectures were initially posed with no knowledge of how a proof will be found.
perhaps with the higgs it was easier because it was conceivable that we could produce the necessary collision energies here on earth, while other problems remain at unattainable scales for a clear path to exist today.
As a theoretical math major and a practicing scientist, I'm just going to have to say that these are not comparable, neither in process, nor ontologically.
> conceivable
that's a very weak way of saying the scaling factor of collision energies was known, and the technology to build the required machine right around the corner (we could have found the higgs with technology proposed for the hole in texas, only 20-or-so years after the prediction of the higgs; at the time higgs was postulated superconductors were already known for 10 years and the first superconducting NMR was 10 years away).
Anyways, my point is that there is a categorical difference. At the time of its postulation, building an experiment that could say yay or nay about the existence of the higgs was largely an engineering problem.
True. But f.e. search for Higgs on Tevatron pretty much started after top quark discovery, ca 1995. And Tevatron was covering one energy range after another in search for Higgs, and would have found it if not being closed, around today date. We knew what to look for.
With DMwe're shooting in the dark, so to speak, in hope something will turn up
I'm not sure why this is being downvoted, it's technically correct (tho I'm not sure if it was in good faith) the observations don't explicitly require Dark Matter, it's just currently the most likely answer given the theoretical frameworks and observational evidence we have.
There are essentially 3 (or 2.5) explanations, that we have (a lot of) missing mass, that we don't understand gravity or that we don't understand spacetime.
Most theories revolve around the missing mass part this includes all possible theoretical candidates for Dark Matter from both within and beyond the standard model, overall a single candidate or a combination of a few likely ones seems to fit our observations the most.
Modified Gravity; these theories actually have gotten plenty of attention in the 80's and 90's but the problem is that most of them don't fit observations especially modern ones like the bullet cluster and gravitational waves, most of them aren't relativistic (or don't have a relativistic formulation) and they overall suck at predicting everything else including the formation of galaxies and stars in the first place.
"Modified Spacetime"; mostly relegated to the dark corners of the web and to pseudo scientific forums technically possible but I haven't seen anything that comes close to being an actual theory as in having an actual mathematical basis.
They basically revolve around various possible ways of affecting spacetime curvature, basically if you could curve spacetime without out mass to the same extent as say the earth's mass does you'll technically will end up with the same gravity well. The more "serious" of these tend to revolve around various attempts at gauge gravity.
I usually consider the "Modified Spacetime" as being an offshoot of Modified Gravity theories.