pavelcherepan

Senior Members
  • Content count

    816
  • Joined

  • Last visited

Community Reputation

137 Excellent

About pavelcherepan

  • Rank
    Protist
  • Birthday 08/09/1984

Profile Information

  • Gender
    Male
  • Favorite Area of Science
    Geology, Physics

Recent Profile Visitors

10346 profile views
  1. Storing Renewable Energy

    I agree with what you wrote, except this ^. Every time a spark plug discharges somewhere between 12-45 kV, it takes the energy directly from the battery which is then recharged by alternator. Therefore, battery gets a lot of use, it has to supply energy to every spark plug many times per second and keep recharging as well. It gets pretty busy.
  2. As far as I understand it, the increase in size of a benign tumor simply increases chances of further random mutations which will eventually allow one to become malignant. Benign tumor cells usually have developed a mutation which allows them to multiply uncontrollably, but can still be contained by the actions of immune system. At the same time this uncontrolled replication increases the chances of further mutations coming along which will alter some of the genes relating to immune response, such as being able to evade natural killer cells. https://en.wikipedia.org/wiki/Natural_killer_cell#NK_cell_evasion_by_tumor_cells From that point on, you get a malignant tumor.
  3. What happened to the riverwall?

    Ground/surface waters washing away the foundation?
  4. It is not as simple as just saying "we share 96% of our genes". It matters really not just how many changes there are in total, but what changes do in fact alter the phenotype. The % difference in on itself doesn't really tell us much at all when comparing different species. It is mostly useful for genetic testing of parenting, since here we are comparing DNA of two individuals of the same species: https://en.wikipedia.org/wiki/Human_evolutionary_genetics
  5. Gravity and Human Evolution

    Correlation ≠ causation. You'll need some proof that the causation exists. You can't base a theory on correlation.
  6. Table Tennis, Lawn Tennis, Badminton Smashes.

    The way Prashant has been describing the situation, a strong shot from the back line would also be considered a "smash". Let's not forget about the weight of the projectile here. In table tennis the ball is very light and even though subjected to severe drag, in a short distance to opponent's side it travels essentially in a straight line. It is, therefore, necessary in order to perform the strongest possible shot to hit when the ball is above the level of the net. In tennis the ball is significantly heavier and, when hit from the back line will travel on a ballistic trajectory even when hit with the maximum force. Hence, it's possible to perform the strongest shot even when the ball is below the level of the net provided that there is sufficient distance to target. It is easier in table tennis, I don't argue this point, but returning smash is very much possible in lawn tennis, especially when the play is done on "slow" surface, especially grass, which allows players more time to get to the ball after opponent's shot.
  7. Table Tennis, Lawn Tennis, Badminton Smashes.

    This (highlighted) makes no sense. If for smash you need to hit such that the ball or the shuttlecock can't be returned back, then you can't have returned smashes in any of those games. If, on the other hand, you are referring to simply a very strong shot, then can return "smashes" in each and every game you mentioned. Just watch some high-level badminton or tennis play, especially if you look at some masters of back line play like Andre Agassi.
  8. Gravity and Human Evolution

    Or it can be linked to dozens other factors that change when moving from the equator towards the poles. What is your proof that it's related to gravity? If, for example we took a person who was born and lived all life at equatorial region and sent them to live in Canada, would that result in an increase of dopamine levels? Has this been tested? First time I've heard that touching my chin means asking "why". I'd love to see the reference for this study. Proof or it didn't happen.
  9. Table Tennis, Lawn Tennis, Badminton Smashes.

    Define "smash" please. If you're using the term as it is used in lawn tennis, i.e. a shot that is hit above hitter's head, then this: Is not really the case. And this: is just wrong. There's no reason it can't be done. This one is correct for a simple reason - in badminton the shuttlecock is not allowed to hit the play court, so it can't bounce up.
  10. Electrons, how do they work?

    Are you certain that electrons interact with Higgs field? I thought it was mostly for gauge bosons.
  11. Which salt? There are many nitrate salts.
  12. Ammonium nitrate is a nitrate salt though - (NH4)(NO3) Actually, come to think of it, depending on your area of residence, buying it might require a license as it can be used to make explosives.
  13. Ammonium nitrate is a rather common fertilizer. Most gardening shops will have some form of it.
  14. Time and space

    Are we heading towards solipsism then?
  15. Heating of a house

    Australian winter, not a proper cold one, but then on the other hand, houses in Australia have absolutely garbage insulation.