CuriousOnes

I read this YouTube comment this morning from user Aural Escape on Anton Petrov's 'Was there something before the big bang' video he released Aug 16th. Got me thinking of ways to see beyond the edge of the visible universe and I thought I might have a way you could in theory cheat and know what galaxies there may be beyond the edge of the visible universe. Imagine a far future where we can travel at or near the speed of light. We travel to the edge of our galaxy or even into Andromeda. There we meet and share information with an ET civilization that has been doing astronomy for X billion years and keeping records all that time. Those ancient records would effectively show us galaxies that are currently red shifted beyond what is possible to detect today right? Its cheating, sure, but assuming accurate records were kept...

We know that elementary particle anti-particle pairs appear and annihilate even in a vacuum. This phenomena is (I believe) happening everywhere in the Universe, vacuum or not. What struct me as an interesting question and brought me here is whether the (volume?/quantity?/energy density?) of this phenomena is influenced by the expansion of the universe. For Example, say the rate of particle anti-particle pair creation is 100MUU (Made Up Units) per M^3, would that value decrease over time as the Universe expands. Or more interestingly, have been twice as prevalent when the universe was half its present size? Nearly infinitely more powerful right after the big bang? If I'm even close to being grounded with this question, the follow up question is whether this is a remotely testable theory.

Curiosity question. We keep a small fridge and the temp is kept quite cold. When I take a bottle of sparkling water out, it is clearly in liquid form. When I open it, within 5-20 seconds the better part of the bottle has turned into a frozen slush. I'm aware that pressure can affect freezing temperature, but opening the bottle should lower the pressure which should actually raise the freezing temperature. What is happening here? I'm stumped.

Thank you! I consider myself somewhat scientifically literate, but this question had been bugging me for sometime. Skimmed over Moseley's law too. Was completely ignorant of it.

Okay, this is a simple question, but the context is a bit unconventional. There is a claim from a man named Bob Lazar that he was hired by the government in the 80's to help reverse engineer a UFO. He claims that the fuel used by the UFO(s) was a stable isotope of Element 115, AKA Moscovium. Obviously there is a lot of unpack there about the veracity of the claim and we could easily get off track. What I want to know is how you would know what it was you had in your hand. For the sake of argument, let's assume that a materials scientist had a stable isotope of element 115 about the size of a ping pong ball. I could be wrong, but I don't think spectroscopy would be of use here since there has never been anything to base the results off of. You could do a spectroscopic analysis, but the results wouldn't match any known element. It would assumedly be very dense and heavy, but that really does no good in identification. Could a chemist predict how it would react with other chemicals and break it down into other periodic elements?