Atom Smasher

Can you build an atom smasher out of household materials? -Cosmic Cat

Short answer: No.

Long answer:

In a way, you already probably have one in your house. The cathode ray tubes found in televisions and computers use electromagnets to smash electrons into phosphors.[1] But this is another
case where the easiest solution is boring. And we wanted to build an atom smasher out of household materials, not find one in the house.

There are two types of atom smashers (linear and circular; the names are pretty self-explanatory), and both contain a laundry list of parts. They are: electromagnets, which keep the flying particles on the right path; targets, which the flying particles collide with; detectors (self-explanatory); vacuum systems, which keep the atom smasher clean of air; cooling systems (self-explanatory); computers to analyze data, a monitoring system for safety (safety, schmafety), electrical power for the atom smasher; copper tubes for the particles to fly down; klystrons, which are powerful microwave generators; and storage rings to store particles when they're not being used. Oh and, protective shielding so that you won't be killed by deadly radiation. If you forget that, you could have a minor problem on your hands.[2]

The first part of this would be to see if we can buy or build the parts at a reasonable price. Let's start with the particle generator part. The SLAC particle accelerator fires an electron beam at tungsten. I was surprised to learn that you can actually generate an electron beam with a cathode ray tube.[3]
You may not have tungsten in the house, but you can buy it in the form of tungsten shot or welding electrodes (look for ones with green tips), according to Theorore Gray's book The Elements. This will generate positron-electron pairs. Copper tube can be found at hardware stores and it isn't illegal to possess.^{[citation needed]} The problem is that you'll need several miles of it, but with enough money you could probably get that. Next up is a klystron, a microwave generator a million times as powerful
as a microwave oven.[4] I thought this would be impossible to get, but it turns out you can buy them on ebay for a few hundred to a few thousand dollars.[5] You can get a lot of stuff on ebay. Next step: magnets. They are fairly common^{[citation needed]}, so it's probably possible to buy sufficiently powerful ones. Targets can vary, but the simplest ones are probably thin sheets of metal foil. Go look in the kitchen and you'll probably find some. Still stuck? Or, if you insist, you can try gold foil. Detectors are where we get stuck. One typical detector is described as a "barrel-shaped, solid-state detector that stands more than six stories tall and weighs more than 4,000 tons". I don't typically gamble, but I'd gladly bet any amount of money that one of these won't be found in the typical home. Or hardware store. Or ebay.

Sorry.

Faster Than Light

Why can't anything move past the speed of light? --ConorT99

Let's start at slow speeds and work our way up.

One 100-millionth of the speed of light is about 6.7 miles per hour. This is between typical walking speed and typical running speed. Nothing weird happens here. One 10-millionth of the speed of light is 67 miles per hour, roughly the speed of a car on the typical interstate highway. One one-millionth of the speed of light is 670 miles per hour, slightly faster than an average passenger airplane. These speeds are quite common, but if you're in a car, you'll probably fly into the air at that speed.[1] One 100-thousandth of the speed of light is 6706 miles per hour. This is faster than most things made by man, including cars.^{[citation needed]} This is just shy of Mach 9, the speed of NASA's X-43. Even at Mach 3, aerodynamic heating causes temperatures of 500 Fahrenheit[2] , so Mach 9 would likely cause very high temperatures. If you're on earth at least. If you're not on earth...

One 10-thousandth of the speed of light is 67,061 miles per hour. This is close to the speed of the spacecraft Juno as it slingshotted around Earth.[3] Juno is one of the fastest manmade objects[4], so it's clear that we won't be getting anywhere near the speed of light using anything manmade. But who said anything about manmade objects?

I'll skip ahead to relatavistic speeds. Going at 90 percent of the speed of light, strange things start to happen.(Don't ask me why. Ask Albert Einstein instead.) Time dialation would be noticable. Spend 10 minutes at that speed and 20 minutes would have passed for the rest of the world. The Dopper effect would also distort the colors of objects towards the blue end of the spectrum.[5] The mass of an object approaching the speed of light would also increase significantly. A 1-gram object moving at 0.9c would have a mass of 5.26 grams.[6] This would be a problem for any object with substantial mass, since it would take an even larger amount of energy to get an object close to the speed of light than it otherwise would. Luckily, the universe is made full of very small and light things.^{[dubious-discuss]}

A hydrogen atom is pretty light, so it seems like a good particle to start off with. To be specific, a hydrogen atom's mass is one amu. An amu is 1.66*10^-27 kilograms and a hydrogen atom at 0.9999c would  have a mass of 5000 amu or 8.3*10^-24 kilograms. How much power would this take? The formula for watts is kg*m^2/s^3. An object sustaining this speed for one second would trvel 299,762.4788 kilometers. So, plugging in results in a power consumption of 2.48 femptowatts. We can do better. I'll throw in a few more nines. The people reading hypothetical science blogs really like lots of nines, don't they? A hydrogen atom moving at 0.999999999c would have a mass of 500,000,000 amu or 8.3*10^-19 kilograms. The power used would be a quarter of a nanowatt.
Let's try 0.9999999999999999999999999999999999999999999999999999999999999999999999c (I pressed 9 a lot of times just for the hell of it). This is so huge that my TI-84 Plus calculator gets a divide-by-zero error when I try to figure out the mass increase. So that means that there's an effectively infinite mass, which would take infinite energy to move at all. And we're still not even at the speed of light.

Lighter particles (such as neutrinos, the lightest known particles[7]) can get you closer, but they won't get you to the speed of light. To offset the fact that the mass of an object is infinite at the speed of light, a particle would have to have a mass of zero. Photons have no mass, but they still won't get past the speed of light, only to it.

To get past the speed of light, some laws of physics would need to be broken. (DISCLAIMER: If you break the laws of physics in your jurisdiction, I am not responsible)

With that out of the way, let's consider the idea of negative mass. In that case, a 1-gram object traveling at 1.01c would have a mass of -49.75 grams. The problem: negative mass does not exist.[8] But if it is ever created, then it could be used to build an Alcubierre Drive, which can travel faster than light.Come to think of it, if you're willing to break the laws of physics, building a working Alcubierre Drive would be a decent science fair project. Might even win first place.

But if you aren't prepared to take the risk of breaking the laws of physics, is there still a way to do this? Turns out there is! As you may know, light goes at different speeds through different materials. And if you cool sodium atoms down to near absolute zero, they become a Bose-Einstein condensate, and light would travel at a speed of 38 miles per hour.[9] So if you can get something to move as fast as a car through a vat of Bose-Einstein condensate...it'd be going faster than light.

Living On Food Pills

Is it possible to live off of vitamin, mineral, carbohydrate, and protein pills? --Cosmic Cat


I could just Google food pills and see what comes up, but who wants to do that? That would be boring.


Let's deal with vitamins and minerals first. There are already pills that provide these. A random example includes Vitamin A, some B Vitamins, Vitamin C, Vitamin D, Vitamin E, Omega 3s, iron, calcium, zinc, magnesium, and iodine. Some more Google searching shows that various other dietary minerals can be purchased as supplements. Apparently even arsenic supplements exist. You probably don't want to overdose on those. As one might imagine from the existence  of multivitamins, such a pill would be small enough to consume. Summing up the weights of all the suggested daily values for the various vitamins and minerals (using the tables here and here) comes out to about 11 grams, so it's safe to say that you could make a pill-sized pill that could satisfy your vitamin and mineral needs.


Macronutrients such as carbohydrates and protein are difficult though. The USDA suggests consuming 130 grams of carbohydrates per day, about 30 grams of fiber, again about 30 grams of fat, and an average of perhaps 45 to 50 grams of protein. When we add all these together, we can see that a macronutrient "pill" would not exactly be a pill. More like a blob of stuff weighing about half a pound.

But let's just go with the half-pound blob. There's a simple problem with this: the average American consumes 1996 pounds per year (according to an NPR blog), which comes out to just under 5.5 pounds per day--more than 10 times the weight of our glob of nutrients. That will cause some problems with satiety, or the state of feeling full. If one has early satiety (the state of feeling full after eating a small meal), then this could still work. Early satiety is caused by a lot of nasty diseases, so inducing it isn't something you should try at home. If you do decide to contract a deadly disease, then all I can say is wow, you must be really determined to live on food pills. At least it would work better than breatharianism though.

Antimatter Car

What would be the fuel economy of a car powered by antimatter? --Myself

Note: I originally put this post on pastebin. 

Antilithium is probably the best type of antimatter for fueling a car. It's not a gas like antihydrogen or antihelium, but it's easier to make than heavier anti-elements. So first, I took the density of lithium. Theodore Gray's book The Elements tells me that lithium has a density of 0.535 grams per cubic centimeter. Obviously, antilithium will have the same density. A gallon contains 4000 cubic centimeters (~4 liters * 1000 cubic centimeters in a liter). So a gallon of antilithium would have a mass of 2140 grams. Wikipedia's article on antimatter weapons states that one gram of antimatter could be converted to 180 terajoules of energy. Thus, 2140 grams of antimatter could be converted to 385.2 petajoules of energy. Next, I needed to find the energy in a gallon of regular gas. A PDF from the University of Washington tells me that this number is 130,000,000 joules. 385,200,000,000,000,000/130,000,000 is 2,963,076,923, so antilithium fuel is about approximately 2.963 billion times as efficient as gasoline fuel. But how efficient is gasoline? Obviously, the fuel economy of cars varies hugely, but some blog says that the average fuel economy for new cars in 2013 was 24.9 miles per gallon, so we'll go with that. Multiply 24.9 by 2.963 billion and we get 73,780,615,382.7 miles per gallon.


How far could you get with such a car? Well, the average gas tank is about 16 gallons (so says Yahoo Answers, the very epitome of reliability), so a tank of antilithium would get you 1.18 trillion miles. A lightyear is about 6 trillion miles (thanks, Wikipedia) so a one lightyear trip would require five refills and a drive to Alpha Centauri (the nearest star, 4.2 light years away) would require over 20 refills of antilithium.


There aren't many antilithium stations in interstellar space^{[citation needed]}, but let's suppose there were. Would this drive be worth it? The cost of antihydrogen is $62.5 trillion per gram, according to this. There aren't any estimates (Really! None at all! And this is the Web!) for the cost of antihelium, so I have to blatantly guess. Let's just say that antihelium is ten times as expensive, at $625 trillion per gram. A website implies that antilithium is a million times harder to make, so let's assume it's a million times as expensive. That comes out to $625 quintillion per gram. Going back to the last paragraph, it seems that we'd need 684,800 grams of antilithium to make the trip, so the cost of fuel would be $428 septillion. Let's just say that this is more money than Bill Gates currently has.^{[dubious--discuss]} Oh and, someone would still have to build a highway, since car's don't work well in empty space.^{[citation needed]}