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Physics, Astronomy & Cosmology / Re: Does the ability to collect microwaves for electric current cut off at some temp

« on: 12/11/2017 14:55:24 »

Ok, so the limitations  of resonant frequency, diode perfotmance requiring large voltage and grneral low intensity of such cold Black Body radiation, but could some power br collected in principle?

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Physics, Astronomy & Cosmology / Re: Does the ability to collect microwaves for electric current cut off at some temp

« on: 10/11/2017 13:38:42 »

I am not even talking about CMB, but any cold environment - a crater on some distant asteroid, a lab, whatever. I mean, the wavelength of black body radiation is dependent on temperature and if the temperature is low enough, it is microwaves.

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Physics, Astronomy & Cosmology / Does the ability to collect microwaves for electric current cut off at some temp

« on: 09/11/2017 21:46:28 »

So, collecting microwaves/ radiowaves for electric current is relatively easy using a length of wire and a diode aka an antenna, right? The current is small, unless high power microwave source is nearby or the antenna is very big, but thats irrelevant for my question. 
What I am wondering - is there some (very low) temperature where this process ceases to?
Why am I wondering this, you might ask? Well: what if we put such an antenna in a very cold environment - 12 kelvin, where the black body radiation is microwaves?

Edit: changed "background thermal radiation" to "black body radiation"

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Physics, Astronomy & Cosmology / Is it possible to generate electricity from infra red radiation?

« on: 05/11/2017 17:41:22 »

Sorry about the vague title - the system doesnt allow it to be very long.
The expanded question: It is possible to collect radiowaves and microwaves with a simple antenna and a diode to produce electric current, right? What if we lived in an such a cold environment where the background thermal radiation was microwaves, instead of infrared - I see no reason (other than than it being a perpetual motion of the second kind) why the background microwaves couldnt be harvested for electricity. Please explain.
In extension - what, fundamentally, disallows for a similar collection of infrared? Other than there being no diodes that work fast enough for the higher frequency of infrared, but that seems more like technical limit, not a fundamental.

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Physics, Astronomy & Cosmology / Re: Does very light matter make gravity appear weak?

« on: 13/09/2017 19:13:30 »

Damit, some admin changed my topics title.. again.

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Physics, Astronomy & Cosmology / Re: Does very light matter make gravity appear weak?

« on: 13/09/2017 12:58:53 »

E.g. the mass in each case would be very different.

Sure, the mass would be different, but, then again, gravity is directly tied to the mass - of course it would be different.

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Physics, Astronomy & Cosmology / Re: Does very light matter make gravity appear weak?

« on: 13/09/2017 12:54:57 »

My understanding of “light matter” is that it would be a small amount of matter in a gravitational field.  Is this what you mean?

Anything, even a planet, is light matter compared to black holes. Sorry, I just didnt know how to describe it better.

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Physics, Astronomy & Cosmology / Does very light matter make gravity appear weak?

« on: 13/09/2017 11:14:03 »

I mean, regular matter, atoms and molecules, is far, far lighter than, say, a neutron star or a black hole. How weak is gravity if we compare a proton sized black holes gravity to the electromagnetic strength of a proton?

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Physics, Astronomy & Cosmology / Is it possible to climb out of a gravity well with less than escape velocity?

« on: 30/08/2017 13:40:43 »

I am pretty sure the answer is "yes" - thats the whole idea with space elevators, isnt it? As long as you can keep applying a force away from the well, by pulling on a cable or just having super thrusters,  you should, eventually crawl out of the gravity well.

Now, to the real question - what about black holes? Their whole thing is that the escape velocity becomes >c  below the event horizon and, since nothing can travel >c, thats that... but what about slow crawling way I mentioned above?
To avoid spaghettification lets use a supermassive BH.

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Physics, Astronomy & Cosmology / Re: Is there a Hawking equilibrium?

« on: 30/08/2017 13:12:47 »

It is quite a big misconception that a black hole looses mass because and antiparticle falls in and annihilates. That notion is wrong and makes no sense. Even if an antiparticle falls in and even if it annihilates with "black hole stuff" then the released photons would still be trapped in the BH and it would, in fact, increase in mass.

The real explanation is quite a bit more complex and I dont fully understand it, but, as far as I understand, it has to do with the gravitational potential energies being different for both virtual particles - the one closer to the Event Horizon will have less gravitational potential energy than the other and, since the one closest is pulled in, the furthest virtual particle will become real with unbalanced potential energy.

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Physics, Astronomy & Cosmology / Re: Can a heat pump system generate electricity from temperatures over 0 Kelvin?

« on: 26/08/2017 09:37:40 »

Congrats OP. There's a patent (US20080127657A1) describing exactly what you were trying to explain.

Woah, cool. But, apparently, nothing has come from it in the 10 years since its was filled. Either it really, fundamentally, doesnt work or its hard to get efficient enough thermo-electric generators or no one has tried, or both. I am sorry that I cannot explain my thoughts better, I am not smart.

Hmm, but if there is a patent and I, or someone else, actually build it and it does work as suggested - does that mean I would be braking some laws or something?

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Physics, Astronomy & Cosmology / Is the strength of the Casimir effect the same everywhere?

« on: 25/08/2017 15:57:41 »

Have there been measurements of the Casimir effect at different altitudes on Earth, in orbit, in interplanetary space? Is there even reason to think it might vary from place to place?

What got me thinking of this is "Einstein's Missing Inch" - the fact that massive objects warp space and so the circumference is smaller than pi*2R. That kinda means there is .. umm.. more space density, for a lack of a better term, in certain regions and with that might come different strengths of the Casimir effect.
if not that, maybe something else, just curious.

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Physics, Astronomy & Cosmology / Re: Can we use light to look into the past?

« on: 25/08/2017 15:25:07 »

If you traveled at the speed of light 1 light year away and instantly set up a huge mirror, people back on earth could see no further (and no less) back in time than the instant you left - 1 year ago. It would always be 1 year ago. If you set up a mirror 2ly away, then we could see 2 years back (but 2 years will go by before anyone can put the mirror in place). Not sure of practicality of such a system, other than, perhaps, if the mirror is truly humongous and our telescopes are up to the task, 100, 1000 or 10000 year mirror as a gift for future archaeologists.

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Physics, Astronomy & Cosmology / Re: Can a heat pump system generate electricity from temperatures over 0 Kelvin?

« on: 21/04/2017 08:08:58 »

I understand, but what happens if I put a 35% efficient thermal-electric engine on a 3kwh heat source (the output of the heat pump) ? It generated 1.05 kilo watts of electricity, doesnt it?

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Physics, Astronomy & Cosmology / Re: Can a heat pump system generate electricity from temperatures over 0 Kelvin?

« on: 21/04/2017 07:41:13 »

Question 2 : Are there thermal generators (steam, peltier, w/e) that work at 35% + efficiency?

An electric heater is essentially 100% efficient. 

Not thermal generator as a device generating heat, but a device generating electricity from temperature difference (peltier generators, Stirling engines and the like)

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Physics, Astronomy & Cosmology / Re: Can a heat pump system generate electricity from temperatures over 0 Kelvin?

« on: 24/02/2017 17:18:38 »

Question 1 : Are there heat pumps that work with effective efficiency of 300% + (that is - 1 kwh of input electricity produces 2kwh loss of heat on one side and 3 kwh influx of heat on the other) ?
Question 2 : Are there thermal generators (steam, peltier, w/e) that work at 35% + efficiency?

I really dont want to sound like a crack-pot, but, ... ughhh. What do I need to do to build this myself? A working heat pump + the thermal generator = rather expensive. I am really not in a position to play around with money like that. Then I could see exactly what happens.

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Physics, Astronomy & Cosmology / Re: Can a heat pump system generate electricity from temperatures over 0 Kelvin?

« on: 23/05/2016 13:07:40 »

For a heat pump system to extract energy from the environment you need both a source of heat and a source of cold that is why power stations spend a lot of money building cooling towers. 

Did you mean that for thermoelectric effect (or steam engine or something the likes) to work you need a temperature difference? Sure, of course.

But a heat pump actually work the best when both source temp and target temp are the same (and it works to make one cooler and one hotter), doesnt it?

*Input = 1 unit
*Hot side = 3 units ->> generate anything >1 unit using thermoelectric/ piston/ whatever generator.
*Cold side = -2 units ->> is replenished to 0 from environment.

Sorry, I just cant let this thing go
 

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Technology / Re: Could small, compressible balls be used to negate the effects of ice expansion?

« on: 23/11/2015 17:10:54 »

Im thinking, perhaps something as simple as simple as  "unpopable" bubble wrap? How could that behave at freezing temperatures and those pressures?

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Technology / Re: Negate the expansion of freezing water using small, compressible balls

« on: 16/11/2015 20:30:03 »

I saw a device for use in pipes; you put a long plastic pipe inside the copper pipe, and then when the water freezes it squeezes down on the plastic and the copper pipe doesn't burst.

I cant seem to find such a thing. How is it called? In fact, I cant really find any solution that would be similar to this and even when I ask some people on the internet who live full time in motorhomes/ campervans, all I get is "Nop, just empty the pipes and tanks" or something on the lines.

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Technology / Re: Negate the expansion of freezing water using small, compressible balls

« on: 15/11/2015 16:43:33 »

Hmmm... so it might work. Ok, next question - how much does it actually expand? And, when it freezes from top- down, it tries to compress the still liquid water with each mm of ice more and more, so the buffer has to even larger, doesnt it?

Basically, I am planning to live in a motorhome in winter time. I can empty all the pipes so they dont burst, buy it would be a waste to dump all the water from the tanks. In case I leave the van un-heaed for a while and water starts to freeze. When I am back in the van and start up the heating system, the water would melt again and be usable.

Kinda ambitious.