the electroweak interaction is considered as the most promising candidate for a metastable fundamental force. The corresponding false vacuum hypothesis is called either 'Electroweak vacuum instability' or 'Higgs vacuum instability'. The present false vacuum state is called (de Sitter space), while tentative true vacuum is called (Anti-de Sitter space). The diagrams show the uncertainty ranges of Higgs boson and top quark masses as oval-shaped lines. Underlying colors indicate if the electroweak vacuum state is likely to be stable, merely long-lived or completely unstable for given combination of masses. The "electroweak vacuum decay" hypothesis was sometimes misreported as the Higgs boson "ending" the universe. A 125.18±0.16 Higgs boson mass is likely to be on the metastable side of stable-metastable boundary (estimated in 2012 as .) However, a definitive answer requires much more precise measurements of the top quark's pole mass, although improved measurement precision of Higgs boson and top quark masses further reinforced the claim of physical electroweak vacuum being in the metastable state as of 2018. Nonetheless, new physics beyond the Standard Model of Particle Physics could drastically change the stability landscape division lines, rendering previous stability and metastability criteria incorrect. If measurements of the Higgs boson and top quark suggest that our universe lies within a false vacuum of this kind, this would imply, more than likely in many billions of years, that the bubble's effects will propagate across the universe at nearly the speed of light from its origin in space-time. Other decay modes Decay to smaller vacuum expectation value, resulting in decrease of Casimir effect and destabilization of proton. Decay to vacuum with larger neutrino mass (may have happened as late as few billion years ago). Decay to vacuum with no dark energy. Bubble nucleation When the false vacuum decays, the lower-energy true vacuum forms through a process known as bubble nucleation. In this process, instanton effects cause a bubble containing the true vacuum to appear. The walls of the bubble (or domain walls) have a positive surface tension, as energy is expended as the fields roll over the potential barrier to the true vacuum. The former tends as the cube of the bubble's radius while the latter is proportional to the square of its radius, so there is a critical size at which the total energy of the bubble is zero; smaller bubbles tend to shrink, while larger bubbles tend to grow. To be able to