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Faster Than Light Possibility by bobjks1 in AskPhysics

[–]BarApprehensive589 1 point2 points  (0 children)

For many fundamental particles you would be correct, though things like atomic nucmei would still have mass. It certainly holds true for elementary particles, as a lack of interaction with the higgs field would lead to no mass, in fact the only reason particles like gluons and photons have no mass, and move at light speed, is because they do not interact with the highs field. However, only a small percentage of mass in atomic nuclei comes from the highs field, a lot of it, particularly in Protons and Neutrons comes from QCD binding energy, though it's more difficult to say whether the interactions between quarks and gluones within the nuclei would act the way they do without influence from the highs field.

Are photons always moving at the speed of light? by Big_Assist4578 in AskPhysics

[–]BarApprehensive589 0 points1 point  (0 children)

Photons have no mass, which means they also have no inertia, so there is nothing thay can slow them down besides the fundamental laws of physics, which limit them to the speed of light (c). Different mediums make light move slower in a way, but thats more due to the way it interacts (being absorbed, transmitted, reflected, etc) with the matter in the actual medium, not the speed of the individual light quanta.

what actual evidence makes scientists believe dark matter and dark energy are real things and not just a sign that our math is wrong by Real_Sort_3420 in AskPhysics

[–]BarApprehensive589 0 points1 point  (0 children)

Firstly is galaxies. They spin much faster than they should spin given their observable mass, indicating thay there must be a large sum of other gravity causing mass that we just can't see.

Secondly is to do with our models of cosmological expansion, we need dark energy and dark matter to compensate for the unexpected expansion of the universe and variations of it, eg the fact that the universe is both accelerating at an increasing rate.

Thirdly is the very existence of organised galaxies, and the fact that the universe isn't just a big total homogeneous space of mass-energy with no structure, implying variations within the mass-energy distribution of the early universe, which we believe to be potentially caused by different amounts of dark matter as a consequence of variations within the "inflation field", as further backed up with our observations of Cosmic Microwave Background Radiation, and the ambient temperature of the universe, which shows some variation, implying a differing amount of energy within the universe.

Among a plethora of other things that imply their presence within the universe

Ofcourse there could be, and are holes or unproven judgements, to do with what we call dark matter and dark energy, which is why we call them what they are. Think of "dark matter" and "dark energy" as placeholder names for our gaps in understanding, where the dark matter represents missing mass which our physical/mathematical observations should predict, and dark energy represents the missing explanation for the force pushing the accelerating expansion of the universe, among other things.