I start reading about free and unlimited energy source. I keep reading that fairy tale. Then, out of the blue, an alien appears from the sky! He shouts loudly, "Ethereum 3.0 will save us!". OP, you shouldn't believe whatever you read on the internet. The internet is the ocean of fake news.
With the right resources, anyone can easily utilize this unlimited energy to launch a 51% attack on the Bitcoin network. The cost of launching such attack would be incredibly low.
How? How would it be incredibly low, can you explain that to me? The rock knows how to do SHA256 hashes too or you'll need some millions of ASICS miners?
As soon as the news breaks out, Bitcoin price will plummet. PoS and Ethereum 2.0 is the future.
