nev

@nev

active 3 months, 3 weeks ago
  • nev posted a new activity comment 3 months, 3 weeks ago

    This is a good, motivating post. But how can happines bring you money if you do nothing?

    The problem of rock starts and actors is in the fact that they can’t control themselves with a bit amount of money.. that’s another question

    • Doing nothing is not an option, you have to do something. At that something should be what you are passionate about. You can’t be happy in a card board box and expect the world to just give you stuff because you exist, some people will give to you and you might find a few that are extremely generous…but at the end of the day doing nothing…[Read more]

  • nev posted a new activity comment 3 months, 4 weeks ago

    There are lots of cases where people have tried to commit suicide with a shotgun or even just a simple hand gun and failed.. leaving them horribly disfigured. Not nice at all 🙁

  • nev posted a new activity comment 4 months ago

    Personally speaking when reversing in the kind of situation that you describe I’ve always viewed it as my responsibility to give way in order to complete the manoeuvre safely.

    I would generally achieve this by pulling over to the left to allow the vehicle behind to pass before I hit reverse.

  • nev posted an update 5 months, 2 weeks ago

    SpaceX rocket was a hoax
    The image of the Tesla with a round earth behind it was, a good marketing hoax to sell cars, according to The Flat Earth Society.

    Are they serious in their beliefs, or just joshing and don’t know how to stop now?

    “Perhaps unsurprisingly, we’ve received many questions about the recent SpaceX launch, and the resultant “li…[Read more]

  • nev posted a new activity comment 5 months, 2 weeks ago

    There are all sorts of reasons why growing crops in fields is bad. These include:

    -Huge losses due to pests and diseases (and costs/ damage due to chemical treatment)

    -Water use efficiency. Not a problem in most parts of the UK, but globally a huge issue

    -Radiation use efficiency. Not necessarily a problem, but photosynthetic pigments only…[Read more]

  • nev posted a new activity comment 5 months, 2 weeks ago

    Maybe these containers could be put on rooftops as independent farmers/veg shops.

    It’s an interesting idea for colonisation in space. Would such a project work on the ISS?

  • nev posted an update 5 months, 2 weeks ago

    Why is it so hard to escape Earth’s gravity?
    This may be a stupid question to a rocket scientist, but i’d appreciate it if somebody could dumb down the science to help explain it to me.

    • Getting up there is relatively easy. But staying in orbit needs enormous sideways velocity; you need to be going so fast that rather than falling into the earth you miss it. There is an excellent way to think about this involving a really tall tower, and throwing a ball from it faster and faster – the ball lands further and further away, and…[Read more]

    • You need a certain force (the rocket) to lift whatever you want against gravity. But that also needs to lift itself so it needs to be bigger.

      Then add in the air resistance once it’s moving and you need a bit more rocket to overcome that resistance, and even more rocket as it moves faster as drag increases at the square of the increase in…[Read more]

    • Seems an odd question. You might as well ask why is it so hard to breathe underwater or why is Andromeda so far away.

      It’s not hard, or easy, it’s exactly as you would expect.

    • It isn’t as hard as people think – rockets are a very poor way of doing it. It comes down to the fact that you need rocket fuel and reaction mass to push the rocket, and you need more rocket fuel and reaction mass to push that rocket fuel etc etc.

      If there was a solid road to push against you wouldn’t need reaction mass, or reaction mass to…[Read more]

    • I think if you integrated the equation for potential energy to increase height above surface with respect to distance, g decreases, you would be surprised by the magnitude of energy required works surprise you, add to that the energy to burn to a velocity to keep orbit stable.

      Fuel is heavy.

      • Most of the energy is in forwards velocity, not height, for a stable orbit. Although the OP didn’t specifically refer to orbits.

        It’s not actually that much energy required. A quick estimate suggests the minimum energy required to put mass into geostationary orbit is about 60 MJ/kg or 16 kWH/kg, or about £2.50 worth of electricity at reta…[Read more]

    • It’s not gravity itself but the energy required to accelerate the payload and the initial but decreasing propellant mass up to the required velocity to achieve a more or less stable orbit, the point where instantaneous velocity and acceleration due to gravity reach a balance. remember the formula for kinetic energy includes V squared, so the…[Read more]

      • The energy required for a change in velocity also helps to understand why the Voyager missions were fly-by affairs rather than orbital insertion and long term study. At the speeds required to escape earth and, with the gravitational assistance of some of the planets, and at the eventual approach velocity there was never any question of something…[Read more]