Recent content by IllyaKuryakin

Is a magnetic field real? I mean, we can't see it or touch it. The fact is, as stated above, it is as real as anything else. We have a very good mathematical model of it and we can measure the accuracy of the way that math describes the magnetic field to any arbitrary degree of accuracy. So for...

If you call the ground level = 0 energy level, and you dig a hole in it, you can call the whole -1 energy level and the dirt next to the hole +1 energy level. When you put the dirt back in the hole, it all goes back to 0, but you didn't really destroy the dirt. Just another way to look at it.

Yes! You are quite correct. Pumped hydroelectric storage cycle efficiency is 75% or better. Thanks for the correction. As you noted, suitable sites with the water and elevation are the constraining factors.

Yes, but batteries aren't the only way to store power. Power can be stored by electrolysis and regenerated with a fuel cell for instance, or it can be stored by pumping water up a hill and regenerated with hydroelectric generators as it runs back downhill. In either case, theoretical efficiency...

With respect to replacing ALL of our power production with PV, someone said, "I am sure it would be more expensive. The question is whether it's practically possible (and I might add, without drastic measures such as diverting entire world's lithium production into batteries production for...

Yes, I agree, there are many ways to store energy, but none can cost effectively store the amount of energy needed to get us through the night. Sorry, that's just a fact. Do a bit of research into the matter as I have and I'm sure you will reach the same conclusion. Now, if you create a cost...

Quite simply, no, we can't produce all our power with PV. The reason is that the sun doesn't shine at night and there is no practical way to store enough power to get us though the night. The efficient combined cycle power plants or nuclear plants take days to start up, so they can't even be...

In physics we can never say anything is "absolutely right". There could always be an experiment that we haven't thought of that could prove that the theory is wrong, or at least incomplete. Of course Einstein understood that Special Relativity was incomplete, but does that make it wrong? Very...

I asked this question in an engineering class many decades ago. For the most part, the answer is as noted above, thermal stress. If the bulb is being vibrated, it could also be mechanical stress. More rare is a surge in power causing the weakest part of the filament to fry. It's also possible...

Sorry, I can't understand your question. I gave the reasoning for my numbers in my post. Five billion species have evolved on earth, but only one could build a radio. By that reasoning, species of life capable of building a radio seem to be very rare, and others are very unlikely to have...

Oh, I agree completely. It seems very unlikely, given the vastness of the Universe, that we would be the only intelligent life. Most estimates predict very many occurrences of simpler forms of life, but very few occurrences of intelligent life, i.e. life capable of building a radio. That's...

I agree. The possibility of other advanced civilizations is discussed at length in the book, Rare Earth, by Peter D. Ward (Author), Donald Brownlee (Author). It's a great book on the subject. The conclusion is we are very rare and special. I also hope we someday act like it.

It's speculative, but Seth Shostak is a recognized expert in this field. He's also a great person that will answer questions from students: http://www.popsci.com/science/article/2010-08/search-aliens-should-include-search-intelligent-machines-says-seti-astronomer Best of luck.

Loren, I was responding to the original question that was a thought experiment based on intelligent life like ours. We could branch out from there in any number of directions with different forms of life that existed in the past or in the possible future, or speculative methods of communications...

The short answer, it's unlikely there are any ETI's with our level of development or greater within 100 light years of Earth. That's about the distance we could detect a powerful military radar with the square kilometer array. Edit: I now see that russ_watters answered this question above. Note...