Is There a Cosmological Constant?

Dark energy, we thought maybe was constant, like per chunk of ace. That's what the cosmological constant is. We can also look at the very, very early universe and try to measure how much dark energy was there back ten. Measure that musing like the cosmic microaid background radiation. And those two numbers don't agree, right? Unso there's some sort of mismatch there,. Like there doesn't seem to be enough dark energy in or the universe, to get us going as fast as we seem to be going today.