Why doesn't the star forming clouds of gas ignite and burn at once instead of collapsing due to gravity?

I have been reading literature on star formation but the gravitational collapse does not sound convincing. On earth if we ignite hydogen gas, it burns explosively. So why is that not replicated in space?Why doesn't the star forming clouds of gas ignite and burn at once instead of collapsing due to gravity?Because igniting hydrogen gas into an explosion requires oxygen. There is almost no oxygen out in space, maybe a few atoms here and a few atoms there, but certianly not in the quantities you see here on earth. In space, those hydrogen clouds are often around 70-90% hydrogen and the rest is pretty much helium. Also keep in mind that those clouds, while they may be called hydrogen are really just seas of protons. Protons are merely hydrogen atoms which have lost an electron, in other words ionized hydrogen. So these molecular clounds which form stars are often called HII (pronounced H two) regions. In astronomy HII just means ionized hydrogen. These giant molecular clounds are just protons floating around with electrons buzzing all through them. These then will not spark up into a giant explosion.Why doesn't the star forming clouds of gas ignite and burn at once instead of collapsing due to gravity?What would it burn with? Burning hydrogen gas requires a chemical reaction with oxygen. In a big cloud of hydrogen there is nothing to burn it with. It is also far too disperse to burn. When the star 'ignites' it is not burning, it is fusing hydrogen at the core. That is an entirely different process.Why doesn't the star forming clouds of gas ignite and burn at once instead of collapsing due to gravity?Starts do not "burn" in the sense of combustion by oxidation, they produce energy by atomic fusion, which requires very high temperatures and pressures to take place. That is why it does not start until gravity pulls it into a very compact mass.