Science & Futurism With Isaac Arthur
  • Threads
  • Categories
  • Users
  • forum
  • group
  • search

delt0r

  • Members
  • Member since March 20, 2019
  • message Posts
  • forum Threads
  • favorite Followers
  • favorite_border Follows
  • person_outline Details
message Posts forum Threads favorite Followers favorite_border Follows person_outline Details

delt0r has posted 7 messages.

  • See post chevron_right
    delt0r
    Members
    How to become a scientist? General April 1, 2019, 9:48 p.m.

    I went into and out of science more than once. And am now looking at going back. My student debt is huge :D. So Basically the only real way to be a full "scientist" is do a degree then masters and eventually a PhD.

    However if you have some good programming skills you could work for a group as a programmer for example and learn the feild as you go. However it would be hard to be a "full scientist".

  • See post chevron_right
    delt0r
    Members
    Astrobiology, Extraterrestrial Civilizations & the Fermi Paradox Thread General March 22, 2019, 4:46 a.m.
    @Stellarator has written:

    You have a good idea of the subject delt0r, but I respectfully disagree with the following points:

    @delt0r has written:
    1. If there is life on other planets and star systems then it is either panspermia or so utterly different from life as we know it. It will not be compatible with us in anyway. Basically you can't eat alien fruit. That is it won't have DNA.. it will probably have possible DNA analogue, but probably not specifically DNA. IT wont' be 20-22 amino acids. etc. It will almost definitively be carbon based however. Other base atoms just don't work. At ALL.

    While I totally agree with you that the biochemistries of exoplanets and Earth will be 90% of the time incompatible, I don't think that each planet with life will on it will have radically different, exotic biology. Certainly, on average, each planet may have life inhabiting different biomes, utilize different forms of bioenergetics, have differing trophic levels and so forth, but parallels will appear as examples of convergent evolution. Wings, hair, scales, eyes, exoskeletons, endoskelatons and other basic traits all have evolutionary uses independent of chemical composition. So what if an alien's eye is made out of tiny indium needle-like hairs that sense pressure and heat instead of visual light in a cold, high-pressure atmosphere - the point is that the biological imperative for sensing one's environment is there. The real differences occur when natural selection interferes and gradually alters the appearance or even use of that trait, sometimes removing it or adding something new to it.

    I'm not talking macroscopic things. I'm talking chemistry. Litterly DNA. You can store information in a LOT of different carbon based molecules. I mean litterly just about an infinite variety. We don't think DNA is the only thing. In fact if we found DNA in any extraterrestrial life even with different bases (ie extras over AGCT or not AGTC at all) it would be a very very strong case for panspermia.

    Even with billions of earths, There are Trillions apon trillions of possibilities here. Finding something the same chemically in the entire Observable universe is very improbable.

    @Stellarator has written:
    @delt0r has written:
    1. Gray goo IS life. Really really. a single e-coli cell left to replicate unchecked would be the mass of earth in just a few days. We are a grey goo disaster!

    This is incorrect. Grey-goo and other forms of nanotechnology do not strictly meet the scientific definition of life, biological or otherwise. They can be likened to viruses, which are also not 'alive' in the academic sense. This is somewhat controversial, since defining 'life' is tricky, but nevertheless grey-goo technology cannot be consider alive in most cases. See en.wikipedia.org/wiki/Life#Definitions .

    Not really sure of what point your trying to make here. Gray goo disasters are a sci fi trope. The math basically means they don't and can't happen. There have been some papers put out about it. Self Replication no matter how (technically life or not) is all you need for "grey goo". AKA life is a observable case of grey goo.

    @Stellarator has written:
    @delt0r has written:
    1. Even with panspermia sorting out earth contamination vers native life in something like mars is trivial so trivial it is kinda weird how nasa is with the contamination protocols. It is up there with moon astronauts decontamination.

    I'm not entirely sure what you are saying here. If you are pointing out that it is an unnecessary for NASA to decontaminate their rovers because Earth-life was originally from MArs anyway, then this is fallacious thinking because enough time has elapsed in dividing the biology of the two planets to make an addition of different organisms inimical to the native life. Plus, outgoing Earth-probes are sterilized to prevent cross-contamination. If NASA one-day finds life on Mars, it would be seriously disappointing if was just a colony of UV-resistant bacterium that hitched a ride on a early rover landing and proliferated in the following years.

    Mars is so hilariously more harsh than just UV. Oh and there isn't any such thing as UV resistance. You can't have DNA for that! We use UV to sterilise labs and equipement as a standard procedure. It kills everything.

    But working out that is earth bacteria is again so cheap and easy. Its a simple DNA sequencing test.

  • See post chevron_right
    delt0r
    Members
    Rogue planet enters our solar system Science Questions March 22, 2019, 4:25 a.m.
    @Marvin has written:
    @delt0r has written:

    First of all it will not be in the plane of the solar system. It will come high or low and be on a hyperbolic trajectory.

    It will be most likely in the plane of the solar system. The plane of the solar system lines up pretty well with the plane of the Milky Way. I'd expect that most rouge objects are somewhat in that plane. So the probability for objects in or near the solar plane will be higher than those perpendicular to the plane.

    As what would happen, there are some simulators out there like Universe Sandbox. If anyone has one of these they could run some simulations for us.

    We don't line up with the galactic plane. Just look at the milky way and where planets are ie the ecliptic. Its about 60 deg IIRC. And rouges will have to be from stars around us. Just the way the math works with the frequency we would expect, you still get a inverse square law with distance and "rouge planet flux". That is from a area not large compared to the thickness of the milky way this far from the galactic core. This is a super ultra unlikely thing to happen. And even if it did, it would tend to be far from the sun, many AU away. Again just because that is where all the space is.

  • See post chevron_right
    delt0r
    Members
    Hitchhiker's Guide Discussion Book of the Month March 20, 2019, 9:02 p.m.

    The first few books are great and i loved em. But things get a bit too strange and random by about book 3. Marvin has a special leg which kinda makes him fairly important later on as is the heart of gold.

    My first experience was with the BBC TV show. love it. I do like the latest movie version. Zaphod is my favourite character by far.

    Best quote of the series concerning all versions. "Are you wearing my underwear? Because I'm wearing yours and it an't doing the trick" Zaphod.

    Oh and the best idea ever! Get all the telephone cleaners etc on that generation ship stat!

  • See post chevron_right
    delt0r
    Members
    Book of the Month: House of Suns ***Spoilers*** Book of the Month March 20, 2019, 8:52 p.m.

    Mostly loved this book. And i don't always with AR. I love the idea of churn. This seems very plausible.

    Cheap sake trope wormhole FTL and a galaxy being censored was lame. I read it not that the machine people censored it, but that was the effect of FTL. The censoring hypothesis. But it was a while ago that i read it.

    My fav thing is Stasis pods or whatever it was called. A bubble of very slow too frozen time. You don't need to violate causality to have that. But the boundary conditions are interesting. Yea i tried to work it out. light coming into such a field would get blue shifted. At almost frozen time everything would be gamma rays.

    Of course Peter Hamilton has the same idea with Zero Tau pods in his reality dysfunction trilogy.

    Didn't' think revenger was his best. But better than the blue remembered earth series and pushing ice.

    But have you seem the short animation Zima blue! It is super good. Almost exactly as i imagined the story! On netflix, one of the Love Death & Robots episodes.

  • See post chevron_right
    delt0r
    Members
    Rogue planet enters our solar system Science Questions March 20, 2019, 8:35 p.m.

    Well a rouge planet will most likely be very far away and pass though with little effect. However i expect you mean something like coming inside the orbit of earth. Next is what mass do you expect it to have? Lets say about earth size (it seems that "planets" tend to be larger for whatever definition of planet we want to use).

    First of all it will not be in the plane of the solar system. It will come high or low and be on a hyperbolic trajectory. It will be booking it. Going fast. So it will give everything a little gravitation nudge, but over a fairly small amount of time. Unless it is very close to earth it probably won't have a huge effect. Things in less stable orbits (trojans etc) will probably all get shifted a bit. A lot of our asteroid catalogues will now be wrong, as it will tend to increase there inclinations. That sort of thing.

    it would probably be a mother of all comets as well. Rouge planets will be cold and have their atmospheres frozen. As it gets close to the sun, it may not be able to hold onto all the atmosphere.

    But mostly meh. So that is boring. Lets have it come close to earth or/and be as big or bigger than Jupiter.

    Well how long is a piece of string. You can make it as bad as you want. Huge tides and tsunamis wiping entire coastal areas. To even crustal stability issues with the mother of all earthquakes everywhere at once. perturbing orbits as to make earth orbit long term unstable... To getting swallowed whole buy a rouge Jupiter.

    Well a rouge Jupiter would be pretty bad either way. Our orbit even if never closer than 0.5 AU (hell even 1AU) away would get totally screwed up. We would cook/freeze then freeze/cook if we weren't straight out ejected.

  • See post chevron_right
    delt0r
    Members
    Astrobiology, Extraterrestrial Civilizations & the Fermi Paradox Thread General March 20, 2019, 8:10 p.m.

    Love Astrobiology. I worked in population genetics and know a few astrobiology people. (I was in physics before that). It is super cool.

    There are really 4 main points I want to make, where sci fi gets it really wrong. And SFIA gets it a lot more correct.

    1. If there is life on other planets and star systems then it is either panspermia or so utterly different from life as we know it. It will not be compatible with us in anyway. Basically you can't eat alien fruit. That is it won't have DNA.. it will probably have possible DNA analogue, but probably not specifically DNA. IT wont' be 20-22 amino acids. etc. It will almost definitively be carbon based however. Other base atoms just don't work. At ALL.

    2. Simple bacteria is NOT simple. It has more organisation and complexity that an entire vertical manufacturing facility and then some. Simple life could be really common, but by simple something much much simpler than a bacteria. Self replication is what life really is. And you don't need to be as complicated as bacteria if your not competing against bacteria.

    3. If there is life there then it would be trivial to detect. The whole "but would you recognise life" is a bad star trek trope up there with "beings of pure energy" and silicon based life. Once something can self replicate, even very slowly. It totally dominates the local chemistry of everything. Evolution will happen and then in just millions/billions of years then it is everywhere as well. Gray goo IS life. Really really. a single e-coli cell left to replicate unchecked would be the mass of earth in just a few days. We are a grey goo disaster!

    4. Even with panspermia sorting out earth contamination vers native life in something like mars is trivial so trivial it is kinda weird how nasa is with the contamination protocols. It is up there with moon astronauts decontamination.

    So my belief on the resolution of the Fermi Paradox is at least one great filter and a lot of major filters such that a civilisation in galaxy is very rare. What those filters are is best for perhaps another thread. like specifically on filters. Or just on the relevant SFIA episode since it is covered well.

    Also no FLT. Just the universe we live in.