Back to the Future, cold DeLorean  - Page 1
Forum section: electronics / general

author: abebarker
author_rank: Contributor
timestamp: October 08, 2015, 04:51:13 am
content: I was just reading the wiki for the DeLorean in Back to the Future because, well, we're coming up the time. I came across some thing that I had forgotten because I haven't seen that movie in a very long time. The wiki mentions that the DeLorean gets 'extremely cold'.That is about where I get off the subject of the movie and get back into thermodynamics. I am the first to say that an engine can not possibly be more than 100% efficient. It just can't happen. The working fluid would have to stop it's motion within the engine and, hence, the engine would stop.Although it is true that an engine, by itself, can not be more than 100% efficient, it can be combined with another device that is more than 100% efficient to achieve complete input heat conversion. As long as the efficiency of the engine is greater than the inverse efficiency of the 'other' device the combined efficiency would be more than 100%. Theoretically, the combination could be run on ambient heat until there was not enough energy in the environment to sustain the machine.The 'other' device is common and the theory seems to be solid enough.Nikola Tesla talked about devising such a machines in his article "The problem of increasing human energy". The main problem, and one that he did not mention in the article, is not technological. The problem is humans. The problem is that people refuse to control themselves. If you feed the hungry they will go have more children and come back hungry and with additional hungry children.This has been a pervasive problem with the species. In the past it has always been solved in ways that do not address the problem, like war or famine. Now it is a significant problem with the technology that we use today. Every body is aware of the effects of the problem like over fishing or the extinction of species or climate change.Technology is not going to solve the problem but it can make it an even bigger bloody problem.

author: SteveLy
author_rank: Regular Contributor
timestamp: October 08, 2015, 06:51:54 am
content: Efficiency <= 100%, come what may.

author: nctnico
author_rank: Super Contributor
timestamp: October 08, 2015, 11:58:50 am
content: Quote from: abebarker on October 08, 2015, 04:51:13 amActually this is not true at all. In rich countries people have less children and therefore the population shrinks. Its the poor countries where the population grows.

author: HighVoltage
author_rank: Super Contributor
timestamp: October 08, 2015, 12:19:27 pm
content: 200 countries in 200 years.Well presented by BBC / Hans RoslingOf course, he is not mentioning exponential growth of the human population on earth.

author: briselec
author_rank: Regular Contributor
timestamp: October 08, 2015, 09:35:01 pm
content: Quote from: nctnico on October 08, 2015, 11:58:50 amIsn't that basically what he is saying?

author: bitslice
author_rank: Frequent Contributor
timestamp: October 08, 2015, 09:48:50 pm
content: Quote from: abebarker on October 08, 2015, 04:51:13 amIf it could provide cheap energy that then solves a lot of Western and 3rd world issues.But socially in the west we are committed to creating conflict over the worlds remaining resources, and while 3rd world countries remain forever retarded by religion and tribal thinking, we are going to prevail.Pragmatically, war is an efficient solution to many problems, the lack of war creates difficult issues to solve.

author: John Coloccia
author_rank: Super Contributor
timestamp: October 09, 2015, 02:02:14 am
content: Quote from: abebarker on October 08, 2015, 04:51:13 amIs this like some sort of secret code language or something? Anyhow, if you had something that was more than 100% efficient, why would you combine it with anything else? Why not just use it? Probably because without the engine it won't do actually do anything, and if it doesn't do anything there won't be any data to wrongly acquire, poorly analyze, misinterpret and/or otherwise screw with until it shows some mysterious effect.

author: free_electron
author_rank: Super Contributor
timestamp: October 09, 2015, 03:13:39 am
content: since the machine is time travelling and thus possibly going faster than light it needs to leave its energy behind when rematerializing. so it ends up extremely cold.makes perfect sense to me.

author: abebarker
author_rank: Contributor
timestamp: October 09, 2015, 04:52:05 am
content: Quote from: briselec on October 08, 2015, 09:35:01 pmThank you briselec, that is exactly the reaction I had.Moving on.Quote from: John Coloccia on October 09, 2015, 02:02:14 amSo I'm sure that everyone here knows what an engine does. It applies heat to some material, usually a gas, which changes pressure and works upon some mechanism.The 'other' device takes some material, usually a gas, changes its volume and condenses heat into a more compact space thereby raising its temperature. No mystery, no magic. It follows the Pressure Volume Temperature equation. The energy you put in is what you get out.Now for the magic.When a material changes phase, from a gas to a liquid, it takes an unusual amount of heat to do so. That unusual amount of heat is called latent heat. The word latent; from Latin latent- ‘being hidden,’. This latent heat does not get counted in the Pressure Volume Temperature equation. So our 'other' device takes a certain amount of energy to squeeze heat into a smaller space raising its temperature. Now instead of the energy you expect to see there will be more that has stowed away for the ride. You didn't have to pay for the extra latent heat to get it there at that elevated temperature. The coefficient of performance is greater than 1.Our 'other' device is a common heat pump.Can you think of any instance where you have seen a heat pump taking the rejected heat from an engine, compressing it and feeding it back into the intake? Would it be beneficial even if the efficiency of the engine were less than the inverse efficiency of the heat pump?

author: SteveLy
author_rank: Regular Contributor
timestamp: October 09, 2015, 05:29:17 am
content: This is total pseudo-science bullshit. One can't apply the ideal gas law (or any gas law for that matter) to a liquid-gas phase transition and expect sensible predictions. Of course you're going to get nonsense like greater than 100% efficiency & violation of fundamental conservation laws (from which gas laws are derived in the first place).Garbage in, garbage out.

author: abebarker
author_rank: Contributor
timestamp: October 09, 2015, 06:28:46 am
content: Quote from: SteveLy on October 09, 2015, 05:29:17 amOne can't apply the ideal gas law to a liquid-gas phase transition. That goes with out saying.Here are some more things that go with out saying;One can't apply the ideal gas law to incompressible fluids.One can't apply the ideal gas law solid state physics.One can't apply the ideal gas law orbital mechanics.One can't apply the ideal gas law find out how many licks it takes to get to the center of a tootsie pop.Garbage in, garbage out.

author: Psi
author_rank: Super Contributor
timestamp: October 09, 2015, 06:44:16 am
content: The DeLorean is sitting at Sylvia park mall in Auckland, NZ at the moment. In case others in NZ weren't aware