361

Technology / Re: Can you power a jet engine by combining hydrogen and oxygen?

« on: 19/06/2017 18:35:00 »

Yes, you most certainly can. Concepts for jet aircraft powered by liquid hydrogen have been done before (one example being the Lockheed CL-400 Suntan, although it was never built). Hydrogen has the benefit of burning cleanly, but it has the disadvantage of needing to be refrigerated to keep it liquid. It also has a lower energy density per unit volume than traditional hydrocarbon-based jet fuels. An aircraft that carries 1,000 gallons of liquid hydrogen will have a shorter range than that same aircraft if it carried 1,000 gallons of hydrocarbon fuel instead.

362

New Theories / Re: Perpetual motion and perpetual energy using gravity and magnetic forces to power

« on: 05/06/2017 01:56:52 »

If the force exerted by the magnets on the arm is greater than the force exerted by gravity on the arm, then the arm will not be able to pass the repulsive zone because the amount of momentum given to the arm by gravity will not be sufficient to overcome the repulsive force. Alternatively, if the force exerted by the magnets on the arm is less than the force exerted by gravity on the arm, then the magnets will not be strong enough to push the arm all the way back up to the top.

Remember, the amount of energy input required to lift an object against gravity to a given height is equal to the amount of energy released by that object when it falls that same height (assuming no air resistance). Therefore, the magnets would have to create a force against gravity equal to the force that gravity initially pulls on the rod with in order to raise it all the way back to the top and complete the cycle. If it was perfectly balanced in a vacuum with frictionless bearings, it might actually be a perpetual motion machine of the third kind. However, any attempt to extract energy from the system would interrupt that balance and cause it to stop moving.

363

Physiology & Medicine / Re: Do genes and DNA respond to musical vibrations?

« on: 30/05/2017 23:19:51 »

If it helps relieve stress, then I could see habitual exposure to music acting to change hormone levels and therefore possibly epigenetic expression as well. We know that fear can be inherited epigenetically in mice, so I wouldn't be surprised if something like this could have some heritable effect as well. I don't think it can actually affect the DNA sequence directly, however.

364

Physics, Astronomy & Cosmology / Re: If the universe as we know it is expanding ? what exactly is it expanding into?

« on: 22/05/2017 01:12:26 »

As far as we can tell, it's not expanding into anything, it's simply expanding. It is technically possible that the Universe is expanding into a higher-dimensional "hyperspace", but it's not a necessary requirement. Just think of it as the amount of space in the Universe increasing over time.

365

Physics, Astronomy & Cosmology / Re: What is the effect on the moon's orbit of harvesting tidal energy?

« on: 21/05/2017 04:14:35 »

According to my calculations, the Moon gains about 3.826 x 10^18 joules from the Earth due to tidal action every year. It gains 7.564 x 10^18 joules of gravitational potential energy due to the increase in distance from the Earth (3.82 centimeters per year) and loses 3.738 x 10^18 joules of kinetic energy due to the slowing of its orbital speed. That assumes I didn't make any kind of calculation error. The Moon has been doing this for billions of years and will continue to do it for hundreds of millions of years yet. Of course, the rate has varied in the past (it would have taken energy from the Earth at a much faster rate in the distant past when it was much closer to the Earth). In the future, that rate will slow down. The rotational kinetic energy of the Earth is 2.138 x 10^29 joules.

It's pretty safe to conclude that nothing humans could do in the immediate future would come remotely close to exhausting such a resource.

366

New Theories / Re: What is the smallest particle of matter? neutrons and protons or quarks?

« on: 14/05/2017 17:35:23 »

Quarks are more fundamental than protons or neutrons, but "size" isn't well-defined for subatomic particles. They have associated wavelengths, but you can't think of them as tiny, solid spheres with a hard radius.

367

Just Chat! / Re: what are some occult technologies?

« on: 13/05/2017 20:41:56 »

Like I said, you have zero evidences whatsoever that occult technologies do not exist presently.

This is exactly what he was talking about when he said "It's quite impossible to prove a negative". You can't prove the non-existence of something.

None.

I wouldn't go that far. Government black budgets no doubt experiment with technologies that are kept hidden from the public for at least some time. Nuclear weapons and stealth technology are two historical examples. There are probably some other things they are working on that they don't want others to know about, but I wouldn't call it anything supernatural. It's just cutting edge science.

368

Chemistry / Re: What is the difference between a Carbohydrate and a Hydrocarbon?

« on: 02/05/2017 22:12:58 »

Hydrocarbons only contain hydrogen and carbon, whereas carbohydrates contain carbon, hydrogen and oxygen (usually in the ratio CxH2xOx).

369

That CAN'T be true! / Re: Could satellite surveillance be used to follow an individual?

« on: 27/04/2017 02:50:48 »

If this is a satellite we are talking about, seems more like it would have to look through ceilings than walls. If the ceiling isn't made of metal, X-rays could be used to see through it. However, firing an X-ray beam from space and then detecting the reflection given off by it would be a tall order: lots of power and precise instrumentation would be needed. Then there's the possibility of such a powerful X-ray beam causing harm to the occupants within or damaging electronics.

Alternatively, a laser beam that can pick up vibrations might be used to listen to what's being said inside of the house. Over such large distances, that would have its own problems and filtering out noise would be important. It might be easier to just wait until the person leaves their house and track them visually.

370

Physics, Astronomy & Cosmology / Re: Laws of thermodynamics

« on: 21/04/2017 17:14:48 »

Higher temperature doesn't mean higher entropy. An increase in entropy over time can also be seen as a loss of the capacity of a system to do work over time (the total energy remains the same, but it is converted from potential energy into kinetic energy). At absolute zero, the entropy is only zero for perfect crystals.

371

New Theories / Re: Is heterogenics is the sole purpose of sex?

« on: 21/04/2017 00:26:33 »

Last I heard, sexual reproduction evolved because it allowed genetic variation to improve the adaptability of species in changing environments.

372

Physics, Astronomy & Cosmology / Re: Interesting finding about PI and scientific constants

« on: 20/04/2017 21:17:15 »

For an infinite string of digits that never repeats itself, you should eventually find any numerical sequence imaginable in it.

373

Physics, Astronomy & Cosmology / Re: How could atoms stick together to form a primordial planet?

« on: 13/04/2017 05:23:41 »

A collision between two atoms is quite different from a collision between two macroscopic objects like rubber balls. Atoms have fuzzy electron clouds with mobile electric charges inside. For example, two hydrogen atoms that approach each other at low speed will form a bonding orbital (and anti-bonding orbital, but this is usually unoccupied) due to overlap of their 1s orbitals. Since this bonding orbital is lower in energy than the individual 1s orbitals, the bond is stable and holds the atoms together. If the atoms are moving too quickly (i.e. the gas is too hot), the bond will not be strong enough to hold the atoms together.

Gas clouds in space cool off over time by radiating heat and expanding, so any cloud would eventually become cool enough to contract under the force of gravity and (if it contains the appropriate elements), condense into solid bodies. Tiny solid particles like dust were found in an experiment in micro-gravity to attract one-another due to electrostatic charges. This helps the process of forming larger solid bodies which eventually grow until they have the needed gravity to accelerate their growth into fully-sized planets.

374

Physics, Astronomy & Cosmology / Re: How hot would a man inside a sealed, heat-proof bottle become?

« on: 05/04/2017 04:27:45 »

I'll give this a shot, since this is exactly the kind of eccentric physics question that I would find myself thinking about.

2,000 kilocalories a day is 8,368,000 joules a day, 348,667 joules per hour, 5,811 joules per minute or 97 joules per second. 97 joules per second is, of course, the same as 97 watts. Since I've read (a long time ago) that mammals require about 10 times as much energy as reptiles of similar size thanks to the waste heat produced by their metabolism, I'll assume that 90% of that energy is turned into waste heat. This results in our human releasing about 87 watts of heat energy (given that I've seen other estimates between 80 and 100 watts for human waste heat, this seems to be a reasonable estimate).

So now you can easily calculate how many joules this "man-in-a-bottle" would accumulate over different time spans. After a day, it is 7,531,200 joules, after a year, it is 2,750,770,800 joules, and after a million years, it is 2,750,770,800,000,000 joules.

Converting that into a temperature measure is trickier, since human beings have a complex composition. However, I'll simplify it by assuming that our human has a heat capacity equal to their own mass in water (humans are mostly water anyway). Although heat capacity changes with temperature, I think we can still get some meaningful results here. Thankfully, I saved a calculation that I did a while ago where I found that the average heat capacity of water over its entire liquid range is 4.19555 joules per gram times Kelvins.

Our "man-in-a-bottle" has a starting body temperature of 310.15 Kelvins and a mass of 100,000 grams. It therefore takes about 419,555 joules to heat him up by 1 Kelvin. On day one, 7,531,200 joules of heat energy are added, resulting in an increase in temperature of 17.95 Kelvins (a total temperature of 328.1 Kelvins, 54.95 degrees Celsius or 130.91 degrees Fahrenheit). If this was a normal person, they would be quite dead on day 1. However, our super-man can keep going, so now on to a full year...

Before we can add a year's worth of energy, we have a new problem to face: we need to find out how much energy it will take to get our man to the boiling point. Why? Because the heat capacity of water vapor is different than that of liquid water. Also, energy will be consumed in the very act of boiling water (heat of vaporization). Without taking these into consideration, we can't expect our estimate to be accurate. Take note that this assumes that our man has enough room inside the bottle to vaporize into steam. If not, the water he is composed of will remain liquid for longer (due to the pressure increase) and probably throw off the calculations.

The boiling point of water is 373.15 Kelvins, so that's 63 Kelvins that would have to be added to our human from an unheated start. This results in a requirement of 26,431,965 joules, which will be subtracted from the total energy input over a year's time (2,750,770,800 joules - 26,431,965 joules) to give 2,724,338,835 joules left over after reaching the boiling point. The heat of vaporization of water is 2,256 joules per gram, so now we need 225,600,000 joules to take the water from liquid to gas. The remainder, 2,498,738,835 joules, will go into heating up the resulting water vapor.

The heat capacity of water vapor varies quite a bit depending upon the temperature. Right at water's boiling point, it's about 1,890 joules per gram times Kelvins, or 189,000,000 joules to heat up our steam man by one Kelvin. This would increase his temperature by 13.22 Kelvins for a final temperature at the end of one year of 386.37 Kelvins, 113.22 degrees Celsius or 235.8 degrees Fahrenheit. Since this is not significantly above water's boiling point, the given heat capacity of water vapor is probably accurate enough for the sake of this calculation.

A million years is going to be a doozy and I probably cannot calculate it accurately. I can, however, place somewhat of an upper limit on it (since heat capacity tends to increase for water vapor as its temperature goes up). If we assume (wrongly) that the water vapor's heat capacity remains at 1,890 joules per gram times Kelvins, we can calculate the resulting temperature after adding 2,750,770,547,968,035 joules (the energy remaining after boiling the water at its boiling point). The result is about 14.55 million Kelvins after a million years. This is almost certainly wrong. The thermal behavior of such a high temperature plasma would no doubt be very, very different from that of water vapor. I suspect our immortal man would be nowhere near that hot in actuality. I would need some kind of heat capacity for plasma at high temperatures to get a good ballpark estimate.

375

Cells, Microbes & Viruses / Re: When did bacterial and viral diseases first emerge on Earth?

« on: 04/04/2017 21:53:30 »

I like to think that all life began with viruses and everything else are just vehicles for viruses to multiply and spread.

Scientists have speculated that, in fact, giant viruses ("giruses") are evidence of this - for example: https://www.thenakedscientists.com/articles/science-news/giant-virus-comes-cold

The argument goes that these agents contain such a wide diversity of genes not see elsewhere in the biosphere that they (the viruses) must be the ancestral forms of life.

However, people are becoming less convinced of this argument these days...

Or they could have those genes because they are descended from unicellular ancestors which also had them. Maybe they are "degenerated" prokaryotes. Basically, viruses are parasites and simplification is one of the evolutionary routes that parasites often take.