Sans clarification/qualification, it is not unreasonable to treat hydrogen as hydrogen-1 and helium as helium-4.

Sound can't be heard in space because there is no medium through which sound can travel. So you don't need to be in the vacuum, the vacuum just needs to exist between you and the source of the sound; there is no way for the sound to traverse that vacuum even if the source and destination aren't in vacuums themselves.

So no sound from the boosters can travel through space outside the shuttle then reach them in side.

That said, the boosters are still connected to the shuttle itself and sound can travel through the shuttle and inside and they will still be able to hear that.

Two hydrogen atoms have less mass than one helium atom because helium atoms have neutrons in addition to protons while hydrogen atoms just have protons.

Because it evolved to do so. All life has evolved on this planet under these conditions so as organisms got larger and more complex, that came with it the necessary internal and external structures to survive in the conditions of its environment.

Don't forget that life came from the sea where the pressure is even greater.

And also don't forget that we aren't sealed tight. We establish an equilibrium with our environment.

The fact that you don't have control over the price of potatoes in general. You can sell what you own for whatever you want, but you have no power or authority over an entire commodity.

Because it's never been a rule that abbreviations have to inherit the pronunciation of their parent word. The Hard C probably comes from it sounding better.

Units are arbitrary. Consider, you wouldn't balk at me having a line that is 6 units long and then dividing it into three segments each 2 units long apiece.

But all I have to do is then say that the whole line is 1 unit. That automatically makes the segments 1/3 long each. Exactly. You can't say they were all exactly 2 units long but then refuse to accept them being 1/3 units long now. They didn't change their actual length simply by me using different units to represent that length.

So either no number can be exactly represented or they all can.

The answer is not never, but it's just unlikely.

To help understand this, it might be helpful to consider a 2D rectangle first. Imagine a circle enscribed about the rectangle, like this:

https://imgur.com/a/fbfArUy

Where the diagonals meet (at the center of the rectangle) is the center of gravity (assuming uniform density). However the rectangle lands on the table, if you draw a line from the center of gravity to the table, that line will pass through one of the sides of the rectangle. Whichever side it passes through will be the side it ultimately lands on.

As we can see with the diagram, the angles that will ultimately result in it landing on a long side are so much bigger than the angles that will ultimately result in it landing on a short side.

So whenever the rectangle makes contact with the table, the angle is going to be extremely likely to be one that results in it landing on a long edge rather than a short one.

Just about any job search engine anywhere allows you to specify whether the job is part time or permanent. And temp agencies typically do all sorts: temporary jobs, temp to per, and perm. The only way to know is to call and ask them.

Because boiling isn't evaporating. Water boils at 100 C but can evaporate at any temperature above 0 C.

The temperature of some amount of water is basically the average kinetic energy of its molecules. Some molecules will have more energy and some less.

Some of the molecules with more energy will be at the surface.

And some of those high-energy surface molecules will have enough energy to overcome the surface tension of the water and pressure of the air above it and shoot off into the air.

This is evaporation.

So, over time, any body of non-frozen water will slowly evaporate.

Basically they include A) hidden and/or B) bad information that your average reader/write will A) not see (and therefore not duplicate) and/or B) "fix" when writing it.

When the console attempts to play the game it will A) notice that the hidden information isn't there and/or B) see that the "bad" information has been "fixed" and then not run the game.

You'd have to have a custom/proprietary reader to correctly read those parts in order to write them correctly.

It's just a spooky internet story that random people add on to and expand. That's pretty much it. Someone thought of the idea, wrote a bit about it, and others have contributed their own ideas.

Basically it involves exploiting natural processes to "renew" the energy for us.

For example, you could have a large, elevated weight as an energy source. When it falls, it produces energy. Problem is, if you want to use it again, you have to get that weight up high. If you do it yourself, you are just going to expend more energy than you get out of the system in the first place.

But let's say a giant bird flies by and picks the weight up for you. In the end, more energy was still put into the system than you get out of it, but the bird paid for that cost, not you, so you don't care.

This is basically how renewable energy works, but for natural processes driven by the world or sun.

The Earth spins and the sun unevenly heats it, creating wind. We can use wind to spin turbines. The Earth and Sun are paying the cost to spin those turbines, but we are reaping the rewards.

Same for hydroelectric. Water falls and turns a turbine. The sun heats the water, evaporates it where it turns into clouds, the rains back down again, refilling the reservoir we use to turn the turbine.

So any time there is some natural process that operates on short time spans, and we can use that process to get energy out of it, that's renewable energy.