Jump to content

Danijel Gorupec

Senior Members
  • Content Count

  • Joined

  • Last visited

Community Reputation

72 Excellent

About Danijel Gorupec

  • Rank

Contact Methods

  • Website URL

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. I remember we had a similar discussion on SFN already, no? I recall that I commented positively about the idea. While in periods of increased volcanic activity Mars might be able to acquire an atmosphere thick and greenhouse enough to develop significant surfaces of open water, I agree that most of the time it had to be ice covered.
  2. Hmm "...for the first time in decades, NASA is about to open some of the pristine samples..." Is it possible that 'in decades' there was no single technological advancements worth it? I would be expecting that each time a technological progress is made, some amount of samples get unsealed and examined. I think I would be more generous toward scientists regarding sample quantities. First, samples can get destroyed or contaminated (accidentally or by an intentional attack). Second, I would expect new missions to bring new samples (I don't think NASA planned not to have a mission for 50 years). Anyway, it seems to me that waiting so long was sub-optimal. What do you think?
  3. I read today that some samples retrieved from Moon by Apollo missions were sealed and never examined. Is this true? What is the rationale for such decision?
  4. We expect that the field has a mass (that is, mass-energy). I however understand that this was not yet observationally confirmed, at least not by a direct observation, due to technical difficulties. This is not my view. Even the fact that the field is a voluminous object (spreads away from the thing that is 'generating' it) requires it to exist independently.
  5. Thanks - I think these answers pointed me in the right direction. I think I understand now where I was wrong... Following equations bothered me (field transformation from Wikipedia): My error was because I failed to understand that E' and B' refer to the field at coordinates that are also 'contracted'. That is, if the E and B are, say, one meter in front of particle, then E' and B' are not one meter in front of particle but 1/gamma meters in front of particle. This also resolves my previous question (unanswered) about possible mismatch regarding Lorentz transformation of fields.
  6. By this remark I only wanted to point out that when computing fields using Maxwell equations, the observer will be dealing with the moving particle (as he sees it). I suppose that Maxwell equations will provide different results if you compute fields of a moving particle than if you compute field of a stationary particle. In the original post, this approach (computing field of a moving particle directly by Maxwell equations) is contrasted to the approach quoted in the first paragraph (taking a field of a stationary particle and then using transformation equations to obtain the field as seen by a moving observer). I am not sure if I made it clear enough. [ In my question there is only one particle and one observer that are in relative motion. ]
  7. I don't know how to best ask this boring question... A moving observer observes a charged particle. We could use field-transformation equations to compute the field that the moving observer will see [various sources say that the electric field will look somewhat oblate and there will be a magnetic field around the particle]. But what if the moving observer simply uses Maxwell equations to compute the field of the particle (the particle is moving in his frame of reference) - will he again obtain equally oblate electric field and the magnetic field?
  8. Do they travel aimlessly and accidentally stumbled on Earth (and decide to conquer) or did they come with the goal? If a robotic probe visited Earth long time ago and recorded a primitive civilization, then it can be possible that sleeper ships arrive centuries later expecting a low-tech civilization. It is possible that someone makes such a judgement error... It is however unlikely that they won't send more subsequent robotic probes just to observe how the situation is going. Another possible scenario with sleeper ships is that settlers arrive only to discover that the planet is already taken. Then, because they are in some sort of emergency situation and have no way back, they decide to fight. But there is always this problem with the inter-stellar travel. It seems to me that a civilization capable of doing it (even in sleeper ships) must be far more advanced than us today. Currently we are completely unable to make even a sleeper ship. We don't know how to sleep and we don't know how to make a ship that maintains itself for hundreds of years... Maybe they can have some biological advantage that makes their ships simpler (an inborn ability to cool down and sleep infinitely long, plus a resistance to radiation) Just read the synopsis on the Wikipedia... Interesting idea of inherited knowledge... I only do not understand why did the previous civilization perish if it was capable of interstellar travel (or if it was not capable of interstellar travel, then how did those elephants develop the needed technology - it is not a small step)?
  9. I don't know the work of Lemaitre (Georges?) and Abraham (Max). So, from my perspective "Hubble-Lemaitre" and "Abraham-Minkowski" don't have the weight comparable to "Maxwell-Faraday"... Should I reconsider? Einstein-Bose... Well, anything including Einstein might be in the same weight level as the "Maxwell-Faraday", but for the trivial reason. Lorentz-Heavyside - This one I find the most interesting. I very much respect the work of Heavyside (including his likely write-down of the Maxwell-Faraday equation, lol)... that term certainly has its weight. BTW, I just remembered the Fermi-Dirac statistics - how does it compare? I think the Maxwell-Faraday still outweighs it a bit.
  10. Okay ... I would give to it the same number of points as to the Maxwell-Faraday equations... mostly thanks to Einstein's weight. I guess you consider Rosen a heavyweight contender?
  11. This is just for my amusement... There is this "Maxwell-Faraday equation". I was thinking is there any scientific formula or law or a thing that might include two stronger names? For example, is there something like Einsten-Newton stuff in physics, or something like Euler-Gauss stuff in mathematics?
  12. I did not read... Which elements of the invasion did you find unique and realistic? (I am not afraid of spoilers, but other members could.) Do you only consider a hostile military invasion? Or you also consider a trading invasion or a scholarly invasion? I must say that I never found a novel that, in my opinion, would depict a realistic hostile invasion to our home planet. Probably such novel cannot even exist because I think that a realistic attack would end in matter of minutes - nothing much to write about. Interestingly, I found Predator (1987 movie) relatively realistic. It is not an invasion, but I can imagine how a macho asshole (possibly an outlaw) from a more advanced society comes here doing his macho stuff. Some people do this too.
  13. As I see it, you are not required to tolerate infinitely. On the contrary, you are expected to find a solution to whatever bothers you. Instead, the advice to tolerate should be understood as: tolerate until you find a solution that won't lead to escalation of violence. Solutions can vary. Walking away is a respected one.
  14. But we are talking 50 years in the future. A very distant future, if you ask me - so I expect that until that time even the lowest-income countries will have better networks than highest-income countries have today.... Hmm., if I think about it again, 50 years in the future is so distant that not much can be claimed. I think 20 years in future is much more manageable to make a forecast. It does not surprise me... Latency will also be an issue (today's internet seems to suffer from 'jerking' data rate - video stream solve this by buffering, not sure how will they solve this with games - do they mention this?)... Anyway, when I said that I don't expect much increase in data rate, I meant it 'in comparison to what can be achieved in 50 years if we make this our main goal'. Of course the data rate increase will be significant still.
  15. Lol... and I am still searching for the "unwanted porn"... It seems that google only provides misses.
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.