What goes wrong with baryon- only cosmologies?
	• Text examines isothermal and adiabatic perturbations.  There are problems. – We know baryons are not dominant. – Big issue is that temperature fluctuations observed are not big enough: – Should be > 0.001 for this analysis, required to be even in general, but are much smaller. – It’s a bit more complex than this, but the general arguments hold.