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It seems with enough vertical layers underwater in the ocean, you could get more power for the same surface footprint (W/m^2 ocean surface area) than with solar which can only use 1 layer on the surface. Also since it would be running off thermal radiation from the water rather than sunlight it...

I sat down with a thermodynamics professor at Chico State University a week or two ago to discuss the idea, and he insisted it wouldn't work because it would violate the 2nd Law of Thermodynamics. If it works one could achieve the same outcome as Maxwell's Demon by putting the 3.5 micron...

For example if it works as I described then I could charge a battery with an 80F (300K) heat source like the ocean for a long time day or night (depending on the area of the panel) and then use the stored energy from the battery to boil some water in an espresso machine. Boiling water 373K...

If you talk to a thermodynamics professor they'll likely say the concept is the problem because extracting usable energy from a single temperature reservoir is considered a violation of the 2nd Law of Thermodynamics and it's also considered a perpetual motion machine of the 2nd kind...

It is actually photovoltaic since it's a photodiode operating with zero bias voltage... Photodiode article from wikipedia:

Well if you lowered 1 square meter (m^2) panel into the 80F (300k) ocean at night (horizontally), and it generates a certain amount of power (W), voltage (V) and current (I) from the water's 3.5 micron infrared black body radiation to charge a battery connected across the terminals of the 80F...

Lowering the temperature of the Earth's oceans by 1 degree C yields around 1.5*10^9 terawatt hours if I did my calculations correctly.

Well the power is proportional to the surface area, but in a stack the surface area is proportional to the volume, but the energy is proportional to the enthalpy of the Earth which is far larger in total than the world's oil reserves. More interesting to me is if it works even slightly it...

Right but since it would be running off of invisible infrared light from a room temperature thermal source like the ocean, not light directly from the sun, you could put the panels in stacks, so the power would be based on volume not surface area. There's also the possibility of tuning the band...

I know this will turn into a heated discussion about the 2nd Law of Thermodynamics, so I will just state the facts as I understand them. The question is: can a battery be charged by any amount via the following method? Facts: 1) This research paper about photovoltaic infrared detectors...

I ran a simulation of a BLDC vehicle that I tried to make similar to a Leaf (same drag coefficient, frontal area, loaded mass) and find with 80kW output the vehicle could reach ~126mph if geared appropriately, but the actual top speed with the gearing of a Leaf is around 90mph, which suggests...

Found some videos of variable field motors online... seems to achieve the same desirable properties as continuously variable transmissions with reduced complexity. With the stator inserted, one gets max torque per amp, and with the stator retracted, one gets max rpm per volt...

True but similar travel time on the flat route takes 25x the initial kinetic energy. For longer routes the practical depth limit, say 2450m, precludes fully optimizing the travel time. Even so, 2450m depth gives ~490mph of acceleration almost for free, then most of the rest of the tunnel could...

...I’ve been having some interesting conversations over at physics forums adding friction into the equation. Suppose you want a “traversable” pathway optimized for travel time between 2 points horizontally separated by 5000m in 9.8m/s^2 gravity in a vacuum, and your magnetically levitated...

“designed to eventually hit speeds of around 1,200 km/h (745 mph), which would make it possible to travel from LA to San Francisco in just 30 minutes” Virgin Hyperloop completes its first ever passenger test

https://aapt.scitation.org/doi/abs/10.1119/1.11441?journalCode=ajp https://aapt.scitation.org/doi/full/10.1119/1.5126818

Suppose we have a flat 100km track w/ negligible friction environment and we are using $27.76 worth of $2.14/gal gasoline at 25% efficiency to accelerate a 30000kg shipping container from 0 to 658.69mph, and factoring a 1g acceleration time, the total trip time is 5.91 minutes, and we will emit...

Below around 350m, an amount of water that costs the same as a gallon of gasoline has roughly the same usable energy content in the form of kinetic energy than can be transferred to the vehicle using the oberth effect.

It would be yet more efficient to obtain the “initial kinetic energy” via the oberth effect at the bottom of the tunnel, rather than pushing against the ground at the surface. Instead of using electricity to push against the ground at the top, the vehicle starts with 0 velocity, descends the...

With 0 initial velocity, you’d need a perfect vacuum to make it all the way to the end of the tunnel. But with an initial velocity, as long as the friction in the tunnel doesn’t remove all of the initial kinetic energy, the vehicle can make it all the way through and back out again. The...

There is a physics problem called the "Brachistochrone problem" which seeks to identify the "path of quickest descent" for a frictionless body on a ramp with the only force acting being gravity. For bodies with 0 initial velocity, the problem was solved centuries ago by Isaac Newton. The...

Revised Land Based Oberth Maneuver Vehicle: Original Land Based Oberth Maneuver Vehicle: -------------------- I've completed a basic comparative analysis of the 2 options and found that in essence they are equivalent in terms of efficiency, but the revised version is more practical since the...

it isnt quite as efficient as the passenger vehicle traveling at depth, but.... in the following diagram, the vehicle (in vacuum) accelerates from gravity pulling down the water tank until the tank reaches the flat section at the bottom of the tunnel, at which point the vehicle applies a...

I had been responding to your comparison with using linear accelerators... suppose the 40,000kg load i mentioned being shipping containers... think of how much energy big rigs use... wouldn’t it make sense to use the gravitational potential energy of the container itself as the fuel rather than...

In many places the heat of the rocks at 4.4km depth is more than sufficient to boil water & generate steam: Source: Electrical Power Generation from Geothermal Sources Perhaps a man-made geyser could quickly & efficiently get the water back out of the hole: Source: Geyser - Wikipedia

this youtube video has a good visualization: & my own land based oberth maneuver:

Suppose we use the same amount of water (750kg + 150kg tank) to move a 40000kg passenger/freight section instead of 1350kg passenger section in the previous example. In this case with more freight, from conservation of momentum, the mechanical impulse that stops the same mass water tank is only...

here is the illustration: and the formula for the mechanical energy of the push from the vehicle that stops the water tank:

My understanding so far is that limiting the slope of the ramp limits the negative g’s experienced by the passengers during the coast to the bottom while still giving the same kinetic energy at the bottom as long as the depth is the same. Then using a longer tether limits the g-forces during...

I had envisioned the water being emptied into and evaporating from a separate chamber at atmospheric pressure. Since evaporation is proportional to surface area and temperature, I had imagined it being emptied into shallow but wide pools, at a depth where the rock temperature is significant...

(re-posted because I thought I couldn’t create a new thread as a new member, but I just had to strip out the images) I've been researching a land vehicle concept that takes advantage of a maneuver more commonly used in spacecraft propulsion-- the oberth maneuver, and an underground tunnel is...

I am trying to estimate how much electromagnetic drag a coasting, magnetically levitated vehicle in a vacuum will experience. I was looking at a paper describing the use of null flux coils for electrodynamic suspension. I was confused by one of the charts in the paper... it appeared to show...

(re-posted without images since I'm a new member and the first attempt didn't appear) I've been researching a land vehicle concept that takes advantage of a maneuver more commonly used in spacecraft propulsion-- the oberth maneuver, and an underground tunnel is the perfect environment for it...

I've been researching a land vehicle concept that takes advantage of a maneuver more commonly used in spacecraft propulsion-- the oberth maneuver, and an underground tunnel is the perfect environment for it. I hope it can be built one day because it uses only sustainable fuel- namely a...

In my analysis of the Tesla where I stated "The ratio of kinetic energy to total kWH consumed with the Tesla is about 6.78%..." I put the decimal in the wrong place, it is actually 0.68%... so where I said "The ratio of kinetic energy to total kWH consumed with the wormhole is about 100% (~93.2%...

I've been researching a land vehicle concept that takes advantage of a maneuver more commonly used in spacecraft propulsion-- the oberth maneuver. A more complete discussion of the physics can be found here: Land Based Oberth Manuever? I hope it can be built one day because it uses only...