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Posts posted by Gian

  1. On 9/16/2023 at 4:25 PM, Janus said:

    Nuclear fission converts ~ 0.1% of the mass into energy.  If all of that energy was convert into KE for the remaining mass (acting as the reaction mass), then you might get a exhaust velocity of ~.045c...

    Thanks! So would nuclear be a practical possibility for a tiny space probe? Eg a camera and the computing ability of my cellphone? 

    I would imagine a single cellphone could gather quite alot of data and then send it home? Or if you got it upto say 50%c turn around and bring it home?

    Would it be possible to use the Hiroshima bomb or bombs to send a projectile upto speed say 50%c from earth or from the moon without it having to power itself?

    Yes I know I'm ignorant but it's so important


  2. Since at least WW2, scientists and science fans have been speculating about how to accelerate a spaceship fast enough to reach other star systems. The most sought-after method seems to be nuclear fusion (I think,) currently out of reach.

    But what’s wrong with nuclear fission? If the power of the Hiroshima bomb could be channelled, I would imagine that would get us to alpha centauri pretty damn swiftly.

    I did hear once that governments will not allow the use of nuclear for space exploration. Anyone know if this is true?


    PS As you've probably guessed I'm not a scientist but I hope to be one day

  3. 4 hours ago, swansont said:

    A PhD is not a guarantee of lots of money, or any specific job. The narrative of getting a degree and becoming a professor is not based on the reality of the job market, as CharonY notes.

    To paraphrase a former boss of mine, a PhD in physics affords the opportunity to work on interesting problems.


    I'm not interested in earning Shed loads. If I'm a scientist I want to be discovering stuff! Like John Zarnecki or Carolyn Porco, and I'm trying to find the best pathway to getting there.

    Cheerz for the info.


  4. 11 hours ago, sethoflagos said:

    How comfortable are you with poverty....

    Mr Sethoflagus, thanks! That's exactly the sort of guidance I need.

    Careers advisers just give the smiley official blurb ("Just go to university for 3y, and of course you will get a fulltime job straight away as an astronaut.")

    I guess I'd like to have a career like planetary scientist Dr Carolyn Porco...

    Thanks again, lots to think about!


  5. 8 minutes ago, CharonY said:

    Generally speaking, researcher positions are fairly limited, especially purely research ones (i.e. without teaching, for example). Also typically that requires a PhD in most disciplines. In experimental sciences, a Master's would be required for a research technician position. A BSc basically just indicates that you might be qualified to get more specialized (graduate) training. 


    So do you think it's worth it?

    I'd be gutted if I spent 7y getting to PhD, then finding I couldn't get a job at nasa, and have to settle for merely being prime minister

  6. On 9/6/2023 at 2:19 AM, TheVat said:

    Hannah Arendt nailed it with her phrase the banality of evil.


    Im reading Hannah Arendt right now. The picture that's emerged so far is that for Adolf Eichmann and for Jews and many others in Germany at that time, it's, well... complicated.This is a surprise for me 🙄🙄🙂

  7. I hear the proportion of science graduates to jobs is not good. What do people think my prospects would be if I study BA physics or astrophysics wanting to be a research scientist? I wouldn't want a job designing aeroplanes for Boeing, I'd wanna be discovering planets! Besides a degree what sort of work experience would potential research institutions want? Would I need MA/PhD? 🙄


    GIAN🙂 xx

  8. I was about 8 when my mum and dad told me about the Shoah. My first critical thought was something like Even if everything the National Socialists said about those of the Jewish Faith was true, it would not in any way justify the Holocaust.

    How does that strike people here as an approach?

    We're Catholic btw

  9. On 8/30/2023 at 1:49 PM, iNow said:

    Not everything you read on the internet is true

    What similarities do you see between fear of snakes and fear of who those snakes happen to love and find sexually appealing?

    Phobias are irrational. There are no dangerous species of arachnid in the UK so arachnophobia is irrational.

    Two gay men doing what they want with each other in their own home cannot possibly harm anyone else, thus homophobia is irrational.

  10. 22 hours ago, Genady said:

    How did they (the observers) know that they observed a fear of heights and not something else? Especially, it is strange because cats do not fear heights.

    What they did was something like this. They put the kittens on a walkway (catwalk!) which had 2 thick black lines painted along its length.

    Then there was a gap several feet deep with the lines running down it, so the kittens could clearly see the lines appearing to go downwards.

    But the gap was covered in transparent Perspex, so the kittens could have walked across it. But they all shied away from the gap, so evidently they had an inborn sense that heights are dangerous because they could fall


  11. 22 hours ago, Sensei said:

    I would not like to advertise/recommend a device that I have not checked myself. Here in a relatively large city there is a lot of dust, light pollution etc. We are lucky to see 1% of what a person in the countryside a few dozen kilometers away sees.

    Ten+ years ago I bought a digital camera, and after the fact I noticed that it lacked a timelapse function (the device with the built-in function was twice as expensive as my device). This is an extremely useful thing for events that take a lot of time, such as astronomy. So I wrote a special app that sent 'take picture' commands to the device via a USB cable from my computer. I took nice timelapse transitions of the sun and moon in the sky during a trip across the sky over several hours. For real astronomy, you should have a device that tracks the rotation of the Earth during time-lapse sessions.

    Photons from a distant object are needed to get a good quality image, but the Earth is rotating, so if the camera/telescope is not rotating properly, the image will be blurred. There are special applications to 'de-blur' images taken by home astronomers.

    Thanks! that is useful info🙂

  12. 1 hour ago, Genady said:

    Keep the expectations low. Stars will be just dots, anyway. You will see more of them, and they will be brighter. You will see some details of the Solar system objects, such as rings of Saturn and other planets' satellites. These will be exhausted soon. Nothing like crisp and spectacular images one finds online.

    I would still like to be able to gaze at Saturn's Rings, and Jupiter directly

    2 hours ago, Sensei said:

    I would be looking for something that would allow me to plug in a USB cable and be able to record image..


    Such as?🙂

  13. 1 hour ago, Genady said:

    I think that such a distinction is undefined. Can you clarify what you mean by "inborn or not"?

    Then why it's in the Ethics forum?

    Well because homophobia seems to be an ethical issue, although perhaps I should have put it in one of the Science sections.

    I read of an experiment once where newborn kittens were found to have a fear of heights, implying It's something they're born with.  I just wondered if it's true of homophobia


  14. On 3/2/2023 at 5:09 PM, iNow said:

    There is ambiguity in source of our own sexual preferences, but homophobia regarding the preferences and practices of others is decidedly not genetic. 

    Because their local religious leader(s) said that God said it's bad. Because it makes Jesus cry or something. End program. 

    I don't recall Jesus saying anything whatsoever about homosexuality. 

    But to get back to why I started this topic, are phobias (arachnophobia, homophobia, claustrophobia etc) nature or nurture?

    On 1/24/2023 at 9:37 AM, Markus Hanke said:

    Well put +1

    I think it is a crucially important life skill to - in some situations - be able to respect things that we don’t personally like. This isn’t always easy, since we generally tend to equate our own preferences, views, beliefs and opinions with some notion of “truth” about the world. It takes a certain amount of introspective awareness to recognise this dynamic and suspend it, if and when necessary; sadly, not everyone is able to do this.

    Well yes, but my question is not about whether it is morally right or wrong to be homophobic, but whether phobias (arachnophobia, homophobia etc) are inborn or not. 

    I always used to think phobias were socially constructed, but now I'm reading stuff which says they may be inbuilt

  15. On 1/24/2023 at 6:07 PM, swansont said:

    Homophobia is a fear. Not just a lack of attraction towards those of the same sex, but fear of those who are gay, and/or (especially) that you might be gay. That sounds like learned behavior.


    Well I used to read that phobias (eg arachnophobia claustrophobia etc) were socially constructed. But now I'm reading stuff that phobias may be inborn

    On 1/24/2023 at 9:47 AM, exchemist said:

    Exactly. But my problem with the term "homophobia" is that it may be closer to my own personal discomfort at the prospect of a sexual advance from another man than it is to any inability by some to respect the sexual preferences of others. So what we stigmatise in society as homophobia is actually not that, whereas a feeling of personal discomfort or distaste, which could perhaps be described as a mild kind of "phobia" (though overstating it), is a natural thing and not reprehensible at all!     

    So is homophobia (along with arachnophobia etc) inborn or isn't it?

  16. On 1/24/2023 at 3:31 PM, iNow said:

    No. Infants don't pop out of the womb hating others for who they love

    I suppose the sort of homophobia I mean is repulsion rather than hatred. I heard of an experiment once with newborn kittens who were found to have an immediate fear of heights. This is not irrational of course, but would seem to be inborn. 

    With phobias, which are defined as irrational, eg arachnophobia (I think I'm right there are no dangerous spiders in Western Europe) these are thought to be socially constructed. 

    I have my own irrational repulsions, and children of course love saying "Eeeugh!"

  17. 20 hours ago, iNow said:

    No. Infants don't pop out of the womb hating others for who they love. 


    Science used to say that phobias were socially constructed, but I seem to remember experiments with newborn kittens showing that they had an immediate fear of heights and could "read" 3D space, before they'd had time to be taught anything.

    However I suppose a fear of heights is a genuine defence mechanism, wheras a phobia is supposed to be an irrational fear. The idea of 2 gay men "doing it" can't possibly hurt you, but it can still elicit the yuk response. But perhaps there's some evolutionary advantage to not being gay lke

    "my genes will reproduce better if I do it with the oppo sex rather than same sex"

  18. 15 hours ago, CharonY said:

    What benefit would that have over having people living  normally? 


    11 hours ago, Phi for All said:

    Fiction always skips the boring details of living, and sci-fi often skips travel with warp drives and folded space. If we were to send actual humans on a long space flight, it would be criminal to put them to sleep when they could be running experiments and measuring everything they can and basically taking every advantage of a human payload. It seems to me that drugging a live crew until they show up at their destination means that crew has nothing to do until then, which means they probably aren't scientists. And if they aren't scientists, why not take robots?

    Well, I mean suppose families are emigrating to start a new life on an Earthlike planet in another star system. Or tourists want to visit the moons of Saturn, but don't want to be sitting in the spaceship for months until they get there?

  19. I don't mean "suspended animation" but would it be possible to put someone in an induced coma for several months or years while travelling to other parts of the solar system?

    If so would the following mechanisms be necessary?

    I guess a machine would have to keep moving the person's limbs into different positions to prevent clotting and emboli.

    And electrodes to keep stimulating the person's muscles to prevent wastage.

    I guess the waking crew would have to keep waking the sleepers regular to make sure everything's ok

    Sound any good?

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