Moreno

How can you explain the following paradox: As blackbody temperature never going to drop to the absolute zero, it will radiate some energy infinitely. If you will multiply any smallest value you have on infinity you will still get infinity. Doesn't it mean there is infinite amount of energy any body contains? Regarding energy manifesting itself or not is a tricky question, but for example: It is known that photons of lower energies are absorbed by electrons and those of higher energies by nuclei. Will the later anyhow influence interatomic bond and provoke melting, boiling and evaporation? Unless they will somehow convert to photons of lower energies and then absorbed by electrons?

Sorry, if I make mistake, but according to modern physics 0 K cannot be reached principally, and blackbody will always radiate something. Do you believe that universe is infinite? If yes, than it should contain an infinite amount of energy anyways?

Not sure it could serve as a mathematical prove. Infinity plus something still gives you infinity. Let say a blackbody radiates infinite amount of energy at ambient temperature. Then you use 1000 Joules of electric energy to heat it up to 1000 K. At 1000 K it will still radiate an infinite amount of energy, but this time we are sure it obtained a certain portion of energy which manifests itself in such visible phenomena as melting, boiling and evaporation. In one word something that affects atomic bonds and crystal structure. But still there can be a huge portion of energy which doesn't manifest itself under regular conditions. It simply doesn't affect the state of atomic bonds.

Why Plank's quantum theory was accepted in its time as the only solution to the "UV catastrophe"? Why it been accepted for granted that the blackbody radiation does NOT contain infinite amount of energy inside the spectrum? Is it absolutely true that if it would contain an infinite amount of energy it would be sufficient to destroy entire universe? Maybe this "infinite energy" just doesn't manifest itself under regular conditions and larger part of it doesn't play any role in matter heating, melting and evaporation? What is principal difference between "quant" and "photon"? Regard it as a joke assumption, it would be very nice if any radiation contain an infinite amount of energy (as classical theory suggest) and some day we would be able to find a ways to harness larger portion of it. Theoretically, some energy can be hidden and may not manifest itself under regular conditions. Why is it taken for granted that absorption and re-radiation of any kind of energy always have to lead to explosive manifestations?

I think this problem is more relevant to standardization rather than technological revolution. The turn is on phone manufacturers (both stationary and mobile) side. All they need to do is just to manufacture all the stationary phones in the hybrid version - capable support both PTSN and VoIP equally well. Such phones have to be maintenance free, so people wouldn't need to download any updates or care about antivirus - all this have to be done at the server side. Such hybrid phones need to support Skype, whatsapp and variety of other Internet programs. Once everyone will have a hybrid phone PTSN can either die slowly or people may all abandon it in X day (like it already happened to analog TV in some countries). The same is about mobile phones. Mobile manufacturers need to preinstall all the phones to support Skype, whatsapp etc, equally well as a regular communication protocols. Then people would be able to pay for Internet only and speak for free. Voice traffic takes just insignificant amount of total Internet traffic.

Let say I want to obtain a semiconductor with mixed electron-hole conductivity by doping. Typically it's not going to succeed because donor and acceptor admixtures (electrons and holes) are going to recombine with each other. How can we prevent recombination and preserve mixed conductivity? It is claimed that free electron and a hole (valence electron) cannot recombine if they have aligned spins. Can there be a material in which all the free electrons and holes have aligned spins? Can this state (and mixed conductivity) stay for indefinitely long period of time?

So, their valence band is completely full and their conduction band is half-full? It comes in sharp contrast with conductivity in semiconductors. And why II group metals are hole conductors? Their valence band is full as well?

Genetic engineering?

What type of inscription is unbreakable at modern technology?

Under which conditions a materials may have multiple conduction bands separated by band gap? For example: http://www.nature.com/articles/nmat4430 Possibly this effect can be observed in some metals as well.

How exactly?

I think it is an interesting question whether wireless will completely replace cables someday. I afraid that in order for this to happen a principally new type of technology have to be developed, based on principally different physical principles. Desirably, it suppose to be completely invulnerable to interference and make cell towers obsolete. Maybe something based on quantum mechanics? However, I afraid that such type of an "ideal" communication technology may create a huge social dangers which include at least: 1) Communications of wrongdoers which cannot be intercepted. 2) Remotely controlled bombs and suicide drones which cannot be jammed. 3) Electronic bags which cannot be jammed or detected. In one word I'm not sure if humanity is ready for that type of technology yet.

It is claimed that solar cell efficiency record achieved 32.6% under one -sun. https://en.wikipedia.org/wiki/Solar_cell Would it be possible to achieve the same efficiency someday, for living plants with help of gene engineering? If yes, how much would it change our civilization? For example, prices for food, wood and biofuel? Would it become cost efficient base all energy production on biomass burning?

How good are heavy water thermal reactors at burning Thorium or Uranium 232? What are issues behind them aside heavy water price?

If chain reaction is their regular mode, what can happen even worse than that? How runaway can happen?

It seems some countries have more Plutonium they need. For example UK. https://www.theguardian.com/environment/2012/feb/02/nuclear-reactors-consume-radioactive-waste France only experimented with them. They had sodium-cooled fast reactor but turned it down for persistent accidents. Now they continue small-scale experiments with few types of fast reactors. Japan is exactly the same story. The only full-power operational fast reactor is in Russia. This one is a sodium-cooled, but Russia plans to develop lead-cooled reactors. Gas cooled rectors don't suppose to have the same problems, because in difference from sodium helium is an inert one.

How safe are fast reactors in comparison to common water-cooled? Why nobody (except Russia and India) want to build them? There seem to be huge amount of fuel for them which is essentially free - Plutonium, Uranium 232, Thorium and thousand of tons of dangerous nuclear waste. All this could be efficiently burned in fast reactors with few nuclear waste remaining. What about gas-cooled fast reactors in particular? Why these reactors are so unpopular?

https://it.toolbox.com/blogs/voipdesk/when-does-the-pstn-end-and-voip-take-over-022615

At that frequency it is going to be a thing ray of IR radiation. At which exactly points on Earth a satellite suppose to send it?

Interesting. Can you give some link about it? Does it suppose to work like a laser then? Probably, he hopes for a "free lunch".

Not quite, until it will be accepted as a standard by everyone. I'm not sure that the final obliviation of the landline will pass completely painlessly. Fiber optic still provides much higher capacity than wireless. Govt. organizations don't hurry switch to wireless. Etc.

So, you propose to give up cables and switch to wireless completely? Not that I would be against of it but for now people don't seem ready to do that. Wireless is more susceptible to interference, what may create danger in case of emergency. It always good to have a reliable back up in the form of landline. But maybe it will ultimately come to this. What do you think about distributed wireless networks? It's when cell towers are replaced by smaller antennas located in the households and when these antennas create cooperative peer to peer network. Do you think it can reduce energy consumption and increase reliability? Also, I have question about UWB technology. Why does it have short range if it doesn't cause interference with anything? https://en.wikipedia.org/wiki/Ultra-wideband

The same strange story is with mobile phones. If you have mobile Internet you can make calls for free using Whattsap to any location in the World. But you cannot make calls using Whattsap to a landline. I guess it would be much easier if every stationary phone would support VOIP? I hope that fiber optic cables will provide more than enough capacity for everyone not to have excuses about traffic congestion anymore?

Why fiber optic cables still didn't replace copper cables completely? Is it so much expensive? I thought that once installed optic cable can serve for many decades?

I can't understand that. Don't signals go the same physical routes if you use VOIP, Skype or PTSN?