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Gian

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Posts posted by Gian

  1. Apparently the Orion Project for nuclear powered spaceflight asserted that by this method with an acceleration of 1G an Orion spaceship could attain a speed of 10% of the speed of light (c.)

    Mathematically, how do I work out

    1. the length of time it would take to get from 0 to a speed of c/10 (ship's time,) and

    2. what would be the distance travelled in that time?

    Cheerz

    GIAN🙂

  2. 28 minutes ago, joigus said:

    Yes, the fact that there are lots of methane and ethane could be very useful to obtain energy/store it for different purposes. I don't know about how efficient electrolysis of water in Titan would be. Maybe someone can help about that. My personal favourite in terms of generating oxygen is analogues of cyanobacteria that could work in Titan's conditions. You would need a microorganism that liberates oxygen... It seems that the most abundant source of oxygen in Titan is water. Not much CO2 from volcanos.

    Bacteria and archaea of some kind on Earth manage to exploit virtually any redox-reaction that the chemists have been able to draw on the whiteboard. So, possibilities there are.

    https://en.wikipedia.org/wiki/Titan_(moon)

    Magnetosphere. Stars and gas giants have very powerful magnetic fields around them that, in the case of Saturn, whip their moons with very strong and potentially very damaging ionizing radiation. This radiation is mutagenic, and most mutations would result in cancer. The Earth, e.g., is protected against the Sun's magnetosphere by its own magnetic field. The problem with these moons is that generally they are geologically inactive, so the don't have own magnetospheres to act as shields.

    https://en.wikipedia.org/wiki/Magnetosphere_of_Saturn

    Here they seem to suggest the opposite of what I was saying, that Saturn's magnetosphere shields the moon from solar wind. [?] Maybe it's a question of prevailing winds...

    As to soil minerals, the problem with life is that you must move all the chemicals in cycles: nitrogen, carbon, water, iron... That would take a massive engineering grand scheme of recycling.

    Because Titan is being the subject of intense study now, I wouldn't take anything we know now as set in stone.

    I'm no expert on this. I only want to entice nice and informed conversation here, because the topic is interesting. +1

    Thanks 🙂

  3. I picture explorers creating giant igloos to use as greenhouses, with methane-powered heating to room temperature and melting water ice for crops and pasture, and also extracting oxygen from water (electrolysis?) to make breathable air. But yes I suspect there wouldn't be enough 'goodies' on the Titanian surface to grow stuff, so the astronauts would have to bring their own compost.

    Can you define magnetosphere and explain why it would be a problem for animals please? (I'm a novice at science) Thanks

    GIAN 🙂

  4. When explorers eventually reach Titan, I suppose they could take some farm animals with them which if they had enough to eat would create manure, although I'm not sure how pigs and cattle would get on in the low gravity (flying pigs?)

    But would there be enough minerals lying about on the surface to use as soil to grow crops? Would there be enough nutrients in it? Titanian wheat and potatoes?🙂

  5. On 7/16/2020 at 8:11 PM, Danijel Gorupec said:

    I think, if our civilization continues without a reset, we will very soon start to intentionally change ourselves at a rate much faster than natural evolution could do. We will engineer our genetic codes (we will also install non-living implants into our bodies to obtain above-natural capabilities and we will even create self-reproducing machines not based on DNA that will continue to evolve themselves at an 'explosive' rate).... So, ironically, the 'intelligent design' might soon be thought as a mainstream :)

    On the other hand, could biology one day become machines? Eg, scientists could design biological organisms to do what machines do for us now? A biological motorcar which can drive passengers around on wheels at upto 100mph but also eats grass for fuel?

  6. 21 hours ago, dimreepr said:

    Evolution doesn't have an agenda, it's a discription of a process; you may as well ask "If I got £20 using my bank card from an ATM today, will I get £100 tomorrow?".

    The natural human lifespan has extended from the lifespan of the first life forms. Is the extension of lifespan a natural consequence of evolution and will it continue?

    21 hours ago, delboy said:

    3. Something extinct cannot evolve again - extinction is final. Something similar - seems unlikely but who knows. 

    What I mean is, is it at least possible with natural selection that vast organisms something like dinosaurs could evolve again? 

  7. Three questions

    1) If the first life forms c 4y.billion ago lived about 24 hours (?) and we now live about 80years, in another 4y.billion will life expectancy continue to increase in a straight line and our descendants will have lifespans of 2.5y.millon?? If so it will certainly make intergalactic travel more practical!

    2) Is our species H.Sapiens continuing to evolve? Will our descendants become a new species or species?

    3) Will the natural course of evolution without human agency cause the dinosaurs or something like them to evolve again in the far future?

    Cheerz GIAN 🙂

  8. If we can create nuclear bombs 1000x hiroshima, wouldn't it be fairly simple to use it to power space ships which could accelerate to the point where a trip to the outer planets would take days rather than years?

    Is it true that this is already quite possible, but governments won't let us do it because of the potential dangers of nuclear accident?

    Cheerz GIAN xx

  9. inow and swansont

    Well yes,  hopefully sunlight could be turned into energy in another form eg motion and/or light. Yes there would be waste heat but presumably not as much as if the sunlight energy had not absorbed at all. And yes a percentage of the 'harvested' sunlight would also be reflected away from the Earth.

    Presumably if if it was done on a big enough scale there would be a net cooling of the Earth, plus an additional reduction of CO2-producing forms of energy production?

    cheerz

    Gian

  10. At the BIS Christmas lecture in December John Zarnecki spoke about how he and his team designed and built the Huygens probe for Titan from scratch. No wonder it took so long and was so expensive.

    Why can't someone design a generic spaceprobe which can be used anywhere and built on a production line like Boeing airliners? Has anyone tried this?

    Cheerz Gian☺

     

  11. On 5/10/2018 at 10:00 PM, Airbrush said:

    1.  Good question.  Anyone know how big the waves can be on Titan?

    2.  Certainly boats can float on liquid methane, but a propeller wouldn't get much traction.  You need another propulsion method.  How about wind sails?:)

    3.  With high atmospheric density and low gravity, I would think gliding would be easier on Titan than on Earth.

    4.  To burn methane you need oxygen.  Maybe better to split water ice into oxygen and hydrogen and use them as fuels.

    5.  That sounds right

    6.  Yes

    So far only tiny waves detected:

    http://www.bbc.com/news/science-environment-26622586

    "We think we've found the first waves outside the Earth," he told the meeting.  What we're seeing seems to be consistent with waves at just a few locations in Punga Mare [with a slope] of six degrees."

    But assuming these were indeed waves, Dr Barnes calculates that a wind speed of around 0.75 m/s is required to produce ripples with the requisite slope of six degrees.

    That points to the waves being just 2cm high. "Don't make your surfing vacation reservations for Titan just yet," Dr Barnes quipped...."

    Spoke to Prof John Zarnecki after a lecture he gave about Titan last month and he said that yes astronauts on Titan could use the nitrogen and there would be enough water ice to extract oxygen to make breathable air. He also said that there will be big waves and it will be possible to go surfing on Titan!☺

  12. Science says (I think) we can make artificial gravity in space using a centrifugal force on the inside of a rotating circular structure.

    If so, anyone know what maths and physics I need to calculate speed of rotation for a given radius of a circular spaceship?

     

    Cheerz GIAN:D

    Space station.jpg

  13. 2 hours ago, swansont said:

    Yes. It's another word for that particular isotope. If you just say hydrogen, you are not specifying an isotope, and the implication is you are talking about whatever natural mix that you have.

    cheerz :)

  14. On 26/06/2018 at 8:09 PM, taeto said:

    You do not need any formulas. How about you think about what you are asked: how many times do you have to multiply .5 = 1/2 to itself to get 1/32? How would that work? Like 1/2 x 1/2 = 1/4 does not quite get there, neither does 1/2 x 1/2 x 1/2 = 1/8.  You need to multiply a 2 together with itself enough times to get 32 as the answer.

    THANKS!!!!! Got it (I think)

    1/2x1/2=1/4 (viz to the power2)

    x1/2= 1/8            (to the power3)

    x1/2= 1/16          (to the power4)

    x1/2= 1/32          (to the power5)      So ans=5

    Is there a particular formula I should use though? Or is working through it methodically number by number the right way to do it? :)

  15. Excuse my complete ignorance, but I'm new to this.

    I have a question from a GCSE physics book as follows;

    "Cobalt-60 is a radioisotope made by placing cobalt in a nuclear reactor. It has a half-life of 5 years. The activity of a piece of Cobalt-60 is 32.0 kBq. How long would it take to fall to (a)16.0kBq (b)1.0 kBq?"

    I guess question (a) would be five years, or one half-life; but what maths/ formulae should I use to calculate (b)?

    Of course I guess I can get it by just counting down multiplying by 0.5 each time, but I wondered if there's an algebraic formula I should use for this?

    (kBq is kilo-bequerels)

    cheerz

    GIAN:)

  16. On 10/05/2018 at 10:00 PM, Airbrush said:

    1.  Good question.  Anyone know how big the waves can be on Titan?

    2.  Certainly boats can float on liquid methane, but a propeller wouldn't get much traction.  You need another propulsion method.  How about wind sails?:)

    3.  With high atmospheric density and low gravity, I would think gliding would be easier on Titan than on Earth.

    4.  To burn methane you need oxygen.  Maybe better to split water ice into oxygen and hydrogen and use them as fuels.

    5.  That sounds right

    6.  Yes

    So far only tiny waves detected:

    http://www.bbc.com/news/science-environment-26622586

    "We think we've found the first waves outside the Earth," he told the meeting.  What we're seeing seems to be consistent with waves at just a few locations in Punga Mare [with a slope] of six degrees."

    But assuming these were indeed waves, Dr Barnes calculates that a wind speed of around 0.75 m/s is required to produce ripples with the requisite slope of six degrees.

    That points to the waves being just 2cm high. "Don't make your surfing vacation reservations for Titan just yet," Dr Barnes quipped...."

    THANKS! :):):)

  17. a  few further queries I mentioned earlier

    (1) I guess there's wind and tidal forces on Titan so maybe we can walk along the beach of one of the methane seas with methane washing up and down?

    (2) If liquid methane has less than half the density of water, would it still be possible to have powered craft which could float on the surface of Titan's lakes?

    (3) Could explorers go hang-gliding? Or maybe even a nanolight powered by methane?

    (4) Presumably with all the methane about, power won't be a problem. When explorers get to Titan I guess temperature suits would have to be powered (unless NASA has an insulation fabric which could withstand −179 °C?)

    (5) As the atmosphere is mostly nitrogen, presumably explorers would only have to take oxygen with them and have a mechanism for mixing it to make breathable air?

    (6) And given that there's water on Titan, would it be possible to mechanically extract enough oxygen to add to the nitrogen to make breathable air? altho I guess it would take a helluva lot of water....

    cheers

    GIAN

    :):)

  18. On 08/05/2018 at 10:59 PM, druS said:

    I've been wondering about similar topics, so hope this is not considered off-topic.

    How would wind and waves on Titan compare to Earth. Instead of swimming how would sailing be effected?

    PS: Gian - if this is too far astray from your query let me know I'll start something else.

    Not at all, although I've no idea of the answer!

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