Of course, before even being used for true cannons, gunpowder was used for rockets…
In physics, work is the energy transferred to or from an object via the application of force along a displacement. In its simplest form, for a constant force aligned with the direction of motion, the work equals the product of the force strength and the distance traveled.
I'd agree with this but after billions of years to present-day, you have to think there has emerged at least one giga-powerful, almighty planet-eating civilization.
If our physics is wrong, and I think it is, FTL is possible and other Civs would have found it eventually. But we have no evidence they are here but they should be here or have been here.
In fact, what the meteorites studies tell us is that we can even make a bolder prediction: On Mars (or elsewhere), if carbon processing life exists, then L-alanine will perform better than D-alanine in a labeled release experiment. Hopefully, repeating this experiment in its chiral modification will be considered for a future mission. No doubt, a new fascinating era of the exploration of life beyond Earth has just begun.
Quote from: dondar on 11/24/2022 11:58 amgood example of why American habit of early specialization in .... sucks.I don't understand what you mean by this, Please explain.
good example of why American habit of early specialization in .... sucks.
Quote from: arfdog on 03/07/2023 08:52 pmI'd agree with this but after billions of years to present-day, you have to think there has emerged at least one giga-powerful, almighty planet-eating civilization.That assumes that planets are particularly attractive to inter-stellar spacefarers. It may be that rocks stock in a big ball at the bottom of a gravity well - requiring you to start stripping away at the surface just to get at the juicy bits - just aren't all that useful when you can pick systems to visit with more attractive combinations of loose rubble orbiting hot stars (more energy available, less energy needed to access resources). "Aliens want to invade our planet" seems like a mere extension of the old "aliens want to steal out water" trope that ignores the teratonnes of water available floating about the rest of the solar system alone that does not require ~11km/s to drag out of a gravity well.
Thoughts: Universe 13.5 Billion years old. Sun 4.5B, Earth 4B, Life 3.8B, Humanoid 2M, Civ 15k, radio 130yrs ago, nukes 70 years ago, Spacefaring 60yrs ago, Intrasolar TBD. Interstellar TBD. Max Civ on Earth lifespan remaining, 1B years. Sun's remaining lifespan 5B. That is basically 4.5B of nothing and 1 Billion year window to GTFO. What were the previous 9B years of the Universe like? They might need stable stars that exist 5B years before Space Civs arise. Large stars die quickly. Most stable stars have planets but we don't know what percentage are in the habitable/water zone. Could be very rare. If Aliens existed and could leave their planet they would know of Earth, but either cannot get here since too far and FTL is impossible or Earth had no detectable Civs before they died out. If FTL is possible they would have been on Earth, ignored us or conquered US or had non-interference, stealth observe or colonized Earth. I think advanced civs are very rare. Maybe less than 100 per Galaxy over 10B years. FTL is the key. If our physics is basically correct FTL is not possible. No one ever goes very far, even over billions of years. If our physics is wrong, and I think it is, FTL is possible and other Civs would have found it eventually. But we have no evidence they are here but they should be here or have been here. I think most of these puzzles will be solved in the next 50 years.
And I doubt we'll ever be able to visit each other, furthermore I doubt anyone will figure out FTL travel.... seeing as no other phenomena or entity in the universe seems to have achieved this.
... all of us having just emerged from single-celled organisms recently.
*snip*Most stable stars have planets but we don't know what percentage are in the habitable/water zone. Could be very rare. *snip*
*snip*FTL is the key. If our physics is basically correct FTL is not possible. No one ever goes very far, even over billions of years. *snip*
Quote from: GalacticIntruder on 03/08/2023 07:56 am*snip*Most stable stars have planets but we don't know what percentage are in the habitable/water zone. Could be very rare. *snip*NASA's analysis of the Kepler space telescope data, shows that about half of all Sun-like stars could have a rocky planet in the habitable zone. The most conservative estimate in that study is 7% of all Sun-like stars in our galaxy should have a rocky planet in the habitable zone. This would mean there is approximately 300 million such planets in the Milky Way galaxy. https://www.nasa.gov/feature/ames/kepler-occurrence-rate
Quote from: whitelancer64 on 03/15/2023 06:33 pmQuote from: GalacticIntruder on 03/08/2023 07:56 am*snip*Most stable stars have planets but we don't know what percentage are in the habitable/water zone. Could be very rare. *snip*NASA's analysis of the Kepler space telescope data, shows that about half of all Sun-like stars could have a rocky planet in the habitable zone. The most conservative estimate in that study is 7% of all Sun-like stars in our galaxy should have a rocky planet in the habitable zone. This would mean there is approximately 300 million such planets in the Milky Way galaxy. https://www.nasa.gov/feature/ames/kepler-occurrence-rateI'd say one of the biggest unknowns about the prevalence and complexity of life in the universe is how critical and unique the Theia collision event was to life's development on Earth. If complex life could not have arisen without it, 300 million starts to sound like an awfully tiny number.
While there are alot of rocky planets out there, rocky does not equal habitable. There is alot of thought that planets close in to a m star will not have an atmosphere. To date, we've gotten info about atmospheres for a tiny number of rocky planets around m stars, and they've had no atmosphere. JWST found one didn't have an atmosphere recently. The idea that theres lots of planets, so it must've happened lots of chances misses a basic idea of statistics. That assumes that life is common, and that intelligent tool using life is rather common. Whats uncommon? People often run through the drake equation and use 1/10 chances or 1/100 for each step. What if the chance of life is 1 in a trillion? What of life developing tools is 1 in quintillion? That would mean we are the only ones in the entire super cluster. However people rarely consider numbers like that because it:1. gives results they don't life2. don't normally deal wiht numbers like that, so they are inherantly biased against considering them.Remember that aside from number of rocky planets, ALL the statistics people use are 100% made up with zero basis in fact. We simply don't have the information to make these predictions.