Jump to content

Danijel Gorupec

Senior Members
  • Posts

    713
  • Joined

  • Last visited

  • Days Won

    2

Everything posted by Danijel Gorupec

  1. EdEarl, in your OP you provided an advertising article. So I took a look at Wikipedia, and also found an 'undercover' advertising article there... Anyway I have a hard time finding anything non-advertising about this. The technology is patented (I have mixed feelings about patenting)... Any more realistic information source?
  2. I am no expert either, but reptile eggs should have leather-like shell. Well, maybe it is not too late to put them back and wait to see what will come out.
  3. I liked the first paragraph - I would suggest to equip cars with proximity sensors that record our behavior (how close we drive). Then after, this record is to be used as an input to insurance companies to charge us the car insurance. I think this would help solve the problem. The second paragraph seems less charming - Space-based solar arrays do not seem very green to me. It takes too much chemical fuel to place it into orbit... Also, some people could notice that harvesting energy in space and transferring it to earth would add to global warming.
  4. Apes. Still, I think, the octopus intelligence is more charming and more important, and should be studied more. Because this is a completely separate branch of intelligence (from the evolutionary point of view). It gives hope that the intelligence did not happen just by a chance. I am not sure about pig intelligence. I never saw much intelligence in my pigs... Maybe I just eat them too early - should I wait somewhat longer for their brightness to emerge?
  5. Well... I would leave the current transmission (and production) systems as is, at first - I would only convert to DC at the last step (last substation) or even inside a home (if the customer wants both, AC and DC). But eventually, the DC network should spread to the entire block(s) of houses. This is to address problems with the changeover. The local small PV power stations should be connected to such DC networks - I hope to avoid 50/60Hz inverters (DC/DC converters could still be needed to increase voltage, so I am not sure if the solution will be much cheaper). I hope that electric cars in future will have rapid charging batteries/capacitors. Our local charging stations will have large batteries/capacitors to store the energy that will be poured quickly into our cars. These large batteries/capacitors will be filled from the DC network during the night (at lower price). During the early evening (highest power load), any residual energy from these large batteries/capacitors can be returned back to the DC network. ... hmm... electrocution problem... I never thought about this one... It will be more of problem here in Europe where we don't like to electrocute people
  6. I think, the same RMS voltage as it is now (230VDC in Europe). This will in fact allow somewhat thinner cable insulation because voltage never goes as high as with AC (Vpp). It might also allow somewhat smaller copper area because there is no reactive current component and no skin effect. The converting from high voltage level to low voltage level (24VDC, 12VDC, 5VDC...needed for most electronics) is done using switching-mode supplies anyway. Therefore, today we do not benefit from AC in our home.
  7. One quick question... What drawbacks do you see if our homes are supplied by DC voltage, instead of AC? That is, imagine that about 100 years ago we opted for DC, not AC and that everything is engineered accordingly. Would now our homes appliances cost less or more, overall?... Please, don't consider power distribution problems at first. I am only interested about possible drawbacks once the current is delivered to a home. The problem I see is about replacing AC motors with DC motors - DC motors being either more expensive or less reliable (washing machine, compressors for refrigeration, water pumps, fans...). On the other hand, powering various electronics (TV, computer...) seems a bit cheaper as today these are usually powered by switching-mode power supply.
  8. FYI, you can try (free trial) DesignScience MathType software - this is a more powerful version of the MS Equation Editor. You can also try sw of mine: Math-o-mir (better for rapid typing, but requires longer learning time - and, of course, renders equations more corase than the LaTeX)
  9. But... there are two issues regarding math notation when math is used on computer... The first one, perfectly solved by the LaTeX, is concerned about rendering math. The second one is concerned about entering math into computer (either using keyboard or hand-writing recognition). The second one is the problematic one, IMO. This is why I am a bit afraid of the LaTeX software - it is providing so much various symbols and those symbols are very appealing to mathematicians. But if mathematicians start using all those fancy symbols wildly, it will become problematic to find methods to type them effectively into computer... I am a developer of one rapid-math-typing software and when I look at those LaTeX symbols lists, I am having trouble sleeping But now, we are probably getting too far from the original post.
  10. The math notation seems notoriously difficult to type on computer. If in the near future more mathematicians choose to type its math on computer (instaead of pencil-writing it on paper) some re-standardization will probably happen. If this will be the case, there is a chance that some diversity will be reduced among various math fields. As I always say, math wants to be written - if you change the writing tool, the notation will adapt.
  11. How come? I see no reason for dust, maybe the ventilation is needed for toxic fumes?... BTW do you know anything about chemistry behind the process? Of course, I will also check your link.
  12. I just wanted to hear typical comments on 'user experience'... Some examples how the 3D printer expanded his possibilities, what are typical real-life limitations of 3D printing, what is the speed of 3D printing.... For example, my desktop CNC mill is not as useful to me as I originaly hoped because it is very slow, and some extensive preparation is needed to even start working (while I am a lazy person). Compared to a mill, I think, the 3D printer has following advantages: - silent work - no dust - no need to prepare and fasten the workpiece - no need to change toolbits However, there might be some disadvantages I don't see. I also suppose that the printing speed is very low. Surface quality is also questionable.
  13. BTW, is there anyone here that already worked with a 3D printer? I would like to hear some first-hand opinions. There are DIY 3D printers, as I understood by reading some formus. (I made myself a desktop mill to make aluminum/plastic parts, but a 3D printer would also be nice). Is there already some standard software (CAM?) that can be used with 3D printers?
  14. Nice thread. I am very interested in 3D printing and I think this technology has a bright future. There are certanly some production niches where 3D printing will rule. In far far future, atomic level printers might become possible, but thisis not the same technology that is now used by 3D printing pioneer hobbyists. Therefore, I think we should not mix these when we talk about 3D printing technology... The 4D printing is also a foggy term, I think... Anyway, I hope that we will mostly discuss a more realistic 3D printing technology here. I hope for a small (desktop) 3D printer that is able to produce several different materials (hard, soft, el. conductive or resistive...) so that I can make more complex parts - this is something I would like to have. I suppose that 3D printers will become cheap, and many of us will have one to make "toys". However, for any more serious stuff (a car part, for example), we will go into a local shop nearby, and ask Bob (or Ed) to make what we need on his professional printer.
  15. When you say 'solar' you mean PV? Solar energy can also be used to generate steam. Still, I think PV would be much better choice for a Moon colony, except maybe if >1GW is needed.
  16. Oh, the most common Croatian beer called "Ozujsko Pivo", or "Zuja" for short (both 'z' letters actually have a small inverse hat above them - common in Croatian language.) Sure, few hundred/thousands years longer to develop technology means a bit more probability for a large comet/meteor strike or similar event that will reset any progress. Therefore, some lucky 'shortcuts' do slightly improve probability that the high tech level will be achieved.
  17. Without oil-and-coal, our development would be delayed for 300-400 years, but that is nothing compared to intelligence evolution time. You might be afraid that without oil-and-coal we would never manage to get over some threshold level, but I am confident we would… I think it is not oil-and-coal that made us the high-tech civilization, but introduction of the experiment into the scientific method. This was The Moment. The oil-and-coal was only a lucky shortcut we found on our way. So, if tech-capable intelligence gets created by evolution, all it needs is some time in peace. Few hundred years more or less to grow into communication-capable civilization is not a big deal. The favorable conditions that I think are needed for tech civilization to emerge are mostly concerned about stability and sustainability. Now, this is my one-hundred post and I opened a beer bottle .
  18. I understand this all... I made some bad examples. However note that I agree that some favorable conditions are necessity to develop a tech-civilization. I am only thinking that your example (coal and oil) is misleading because readers here might assume that probability of coal-and-oil forming has anything to do with probability of tech-civilization forming. Those two are not related, because, I believe, there are zillions of other options for a tech-wannabe-civilization. But I am not sure what we are now talking about? Tech-civilization can exist without coal and oil (I would call old Egypt a tech-civilization, wouldn’t you?). Tech-civilization can exist with only mild energy sources. Do we talk about inter-stellar-communication capable civilizations – is this why we are talking about cheap energy now?
  19. First, the 'rude' is probably bad word choice. Sorry... I was thinking that it is somehow 'impolite' to pretend that we even know what a favorable condition could be. Their world could have, say, a hundred times faster wood production than our world - so they could use it for burning. Or they could have an animal that is ten times as strong as horse and very easy to work with... But this are all pale examples because we cannot even imagine what would be favorable for them. (What would be a favorable condition for orcas, I wonder?) For the intelligence probability... Intelligence happens often on earth. All species capable of learning, I would say, posses intelligence... For the tech-capable intelligence, I mostly agree with you. It is a bad sign that it first happened so late in evolution (after 4b years) as it means low probability. I beleive that the difference between human and animal intelligence is only quantitative (not a major step for evolution), and therefore I must conclude that there is not much evolutionary pressure toward tech-capable intelligence.... Still, romantically, I beleive there are so many evolutions out there that many tech-capable intelligences exist anyway. [he he... maybe some tech-capable intelligence existed on earth long time ago, but had not enough oil and coal to make a mark.]
  20. I believe the probability that other intelligent beings are gazing at galaxies is 1. I believe the probability that out there exist at least one civilization that is aware of any other civilization is also close to 1 – but among all civilizations, I believe, only an extremely small fraction ever detected others. I believe that the probability that there is at least one civilization that detected our civilization is 0. Our civilization is only detectable in about 100ly radius (our radio waves had no time to spread any further) – unlikely any other civilization is located that close. ... You also asked for wider PERSONAL OPINIONS on life and intelligence… I believe in life, in a sense that life is resilient. Once the life forms, it will find ways to sustain and will spread to every possible niche it can reach – including intelligence. (It is my opinion that there are many intelligent species on Earth. Few of them even evolved to become technology capable.) Therefore, to me the most important question is – what is the probability for the life to form from non-live mater. There is no clear evidence that life formed on Earth more than once. Therefore, it is possible that life-creation event is a very rare affair. Still, I choose not to believe so. But once the life forms, it is on a safe track. If there ever was a life on Mars, then I believe it is still there – maybe in a form of very resilient spores (I wonder if they ever tried to create favorable conditions on Mars soil samples, just to check what will come out.) The probability of a technology-capably intelligence is obviously low (as far as we know, it only happened few times here on Earth, and only from one evolution line). The probability of technological civilization is even less likely because some further favorable conditions are needed. (Swansont ‘rudely’ mentioned coal and oil – I said ‘rudely’ because I think that there are so many other possible favorable conditions that even mentioning one as an example is rude, in a sense) I am sad because our civilization is placed in the middle of the nowhere. I would like to live close to the galaxy center – there a 100ly year radius would provide some hope. I believe, our civilization will never make the Contact. Most likely we are going to die alone.
  21. Just observation... maybe it was not a chemical, but fungi gave the bad taste to your bananas. I guess that fungi can attack even non-ripened bananas... Why no ripening occured after such a long time, I have no idea - not sure if fungi can generate such effect.
  22. I wonder... In first scenario, some dense matter that does not exist as wood. In the second scenario, plasma maybe. I am only guessing, sure. (If the plate is much larger area, say 1km x 1km, then I beleive wood might have the chance to go through in the first scenario - without significant compression)
  23. When I was a kid, a was fascinated with the fact that ice broke through Titanic hul. I imagined that Titanic should easily cut through the iceberg. I suppose that by metal you mean steel (steel would be, unlike sodium, a respectful metal). I also suppose that the wood chunk is ball shaped, or half-ball shaped. I also suppose that the metal plate edges are strongly supported. With your thick-but-small-area metal plate I GUESS two scenarios: - a wooden (half)ball is slowly pushed into metal plate by very large force - I suppose the wood whould break into pieces, but if it is somehow supported from all sides it would compress into something that is not wood and will finally pierce the plate - a wooden ball hits the plate at high-enough velocity - yes it will go through, but when it exists at the other side, it will not be wood any more.
  24. There are other ways to generate electricity from heat source. Diesel generators are used to about 1MW. Gas turbines can be used to tens of MW. However, the steam cycle is still the best choice to generate electricity from large (>1GW) concentrated heat source. It is a cheap, clean, silent and efficient method. Cheap... low temperatures - low material stress (compared to gas turbines). Less complex than diesel motors. Clean... What would happen if you use nuclear powered gas turbines – you would have to discharge the gas directly into environment. In steam cycle, if needed, you can use double-circuits so that water (steam) released is newer in touch with the fuel. Silent... you know how a diesel generator or a gas turbine sounds. Efficient... There is a nice trick with steam. You can condense it into water (low volume) and then pump it back into the high-pressure boiler. This makes closed steam-water circuits efficient. But look... diesel generators, gas turbines, steam cycle... all these are using the same physics (see Carnot cycle). No fundamental differences here. It is actually water that makes steam cycle so appealing. Water is cheap and clean and has high thermal capacity. We know no fundamentally different method to generate large quantities of electricity from heat sources (you can try with thermo-couples for minute quantities). As you can see, the world doesn't change that much fundamentally. We are just reusing many old fundamental technologies. Science is only rarely able to give us new insights. Most of the time the world is pushed forward by plain old engineering (reusing known fundamental stuff in a smarter way).
  25. Off-topic, but IMHO important: please note that the square of the light speed is not equal to the double of the light speed. It seems to me that you might mix these.
×
×
  • 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.