EdEarl

Both amorphous (e.g., glass sheet) and crystalline (e.g., aluminum foil) solids are held together rigidly by electrostatic forces between atoms or molecules (see Van der Walls force), whenever the heat energy that vibrates atoms/molecules provides little force to break the electrostatic bonds. Adding energy in the form of heat (e.g., a torch flame) or impact (a hammer impact) can break the bonds and cause the solid to melt (from a flame) or deform and/or break (from an impact). Also, either an amorphous or crystalline sold can be altered by a strong gravity field, for example that of a black hole, neutron star, or massive planet.

I don't know the answer to this question, but hope someone who does know will answer. My reply will keep the thread active a while longer.

During WWII the inhabitants of the Warsaw ghetto had very little to eat, and children who survived it and lived to old age were thin for their entire lives.

Optics: Grind some lenses with some small pieces of glass and make a refracting telescope, similar to the one Galileo made. Many amateur telescope makers grind mirrors for reflecting telescopes, but those need to be mirrored, which is usually done professionally. Lenses in a refracting telescope do not need to be mirrored. You might be able to get a large cardboard tube (e.g., 10 cm) from a company that sells carpet (I think carpet is rolled on cardboard tubes). If not, you could make a cardboard tube using paper and a plastic pipe as a form.

Does this innovation spell the end of a big segment of the construction industry? Another robot can lay bricks. There will still be a need for electricians, plumbers, glaziers, etc. to do some work, but I'd expect even those jobs will be done by robots soon. How long until a house is made like a printed circuit board, traces of metal and plastic for electronics, plumbing, and air conditioning all done by machine. Fixtures for the electrical, plumbing and air conditioning just plug into the wall with color codes and plug shapes making it impossible to make a mistake; finishing tasks anyone can do. Vehicles that drive themselves will put taxi drivers out of work, and people that drive trash trucks, snow blowers, road equipment, etc. Farm equipment can now pick strawberries and other delicate fruit. Automated tellers eliminate lines and workers; stocking machines will soon be possible. Robots are being made to clean up the Fukushima nuclear disaster, which is an extremely complex job. These advancements will make robots capable of doing many jobs now reserved for people. How long can capitalism survive with no common laborers making money to buy things. "The times they are a-changing," Bob Dylan seems to have been a profit as well as a song writer. Not only does the human race face 4C climate change this century, also economic upheaval. Will political systems survive? My children, and some of us will live in interesting times.

You should consult a lawyer.

Welcome diya saini; enjoy.

I'm sorry you feel that way. I'm sure you can change it, and make your life meaningful. You only need to choose a meaningful thing to do, even if it is as simple as making someone smile each day. Start by smiling, even if it is a forced smile it will make you feel better.

See also flow battery. I suspect that microbial fuel cells may be used for microscopic applications and flow batteries for macroscopic applications, provided both are perfected, because a flow battery promises to let one to fill a tank with "liquid electricity" and run an electric motor without the anode and cathode of the battery being consumed. Although a microbial fuel cell has similar specifications, it seems unlikely the power density will be as high as flow batteries.

Algae makes biodiesel most efficiently. But the remainder of it, which includes protein and carbohydrates might be made into ethanol.

Petroleum and coal come out of the ground, and when burned add CO2 to the atmosphere. Algae and other biofuels remove CO2 from the atmosphere when they grow. When burned, they add the same CO2 into the atmosphere. The amount removed equals the amount added, so they do not add CO2 to the atmosphere. They are carbon neutral. Growing algae has a couple of nice benefits that other crops do not have. First, it grows faster than any other crop; algae can double its mass in 24 hours. Second, there are millions of acres of desert with underground salt water where algae can be grown, and that algae will sequester CO2 that is currently in the atmosphere. By the time the algae oil and other algae parts are used and the CO2 released into the atmosphere again, there will be several days delay, which means that more CO2 will be sequestered than will grow in one day.

To get debris to fall from orbit, it is necessary to slow the velocity of that debris. A laser fired from the ISS or another satellite can push a bit on debris and slow its orbit; after which, it will fall to Earth. Expanding foam would merely add mass to the debris already orbiting and make it more dangerous.

The simple machines all include solids as working parts. There should be analogs using fluids, or are machines that use solids and liquids a different set of simple machines. A nozzle increases flow rate and decreases volume; is there a solid simple machine analogue, for example a lever, or is it the nozzle another machine?

I agree

Although some government officials are found to be corrupt, sometimes, I think the greater problem is one called groupthink. Sometimes lawmakers act as two groups: Democrats and Republicans, and sometimes they act as a single group. When they act as a single group, they are often influenced by big political contributors, and occasionally by public interest. In both cases, the decisions are usually suboptimal and occasionally quite bad. Consequently, the government appears to be corrupt; although, few politicians can be prosecuted for corruption. Civil servants fall into a different category; only a few can make decisions. Their role is to follow laws and rules established by the three branches of government. Since the laws and rules they follow are suboptimal or bad, diligent civil servants can appear corrupt. That an occasional government employee is convicted for corruption reinforces the image of the government as being corrupt.

One should choose according to the greater good. You have not given enough information to answer specifically, because it is possible one of the ones to die on Saturday or Sunday does greater good than the doctor who saves lives during the week. It is also possible that one of the ones saved would do greater harm than the doctor does on the weekend. And, one must weigh the accuracy of ones information about potential future events, in other words an estimate of the future may be incorrect and cause you to make a mistake about whom to save; thus, leading you to do greater harm.

I wonder if it will be psychologically addictive and induce people to continually take it to have perfect pitch?

There are several different stages of sleep, and people sleep lightly in some and soundly in others. I once slept through a storm during which a tornado came within a mile of our house. My wife is a much lighter sleeper than I am. We live in an area with relatively low risk of a tornado, compared to tornado alley. There have only been 4 deaths from a tornado within a 30 mile radius since 1950.