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Good point, let me correct that:

I found these which are advertised as 12 inches vertically when fully blown, making my original value an underestimate. If we go with a width, which we'll use as our diameter and continue to assume the balloon is a sphere, of 9.6 inches (found by opening this image in an image editor and getting ~175 pixels tall and ~140 pixels wide for the balloon. Assuming the balloon in the image and the fully inflated balloons we're using are roughly the same shape, we multiply 12 in by 140/175 to get the new diameter), the new volume is 7.591 L, or 7.591 g of lifting ability per balloon. Subtracting the balloons' mass of 3.2g (found from the first link) this gives us 4.391 g of lifting ability per balloon. Dividing 3750 g by this gives us 854.01 balloons.

The original and new answer are close, but that's more of a case of two wrongs making a right, not the original work being accurate.

tl;dr: we need to go back to 1987

Okay, lets assume Moore's law has held since the beginning of the computer age. I'm assuming 1945 as the starting point here, so that's 70 years. Moore's law states that processor calculation speed doubles every 18 months. That means we have 2^(0.67*70) = 1.3*10^14. So that's the speed of one processor today expressed in "original CPUs" (oCPUs).

According to this source, the number of computers in use today is about 2 billion, and has been developing exponentially. e^(x*70) = 2*10⁹ gives about x=0.306, so the function e^(0.306*x) approximates the increase in computers in use over time. To get the time when the total equivalent of installed processing power equals today's 1.3*10^14 oCPUs per real CPU we need to solve (e^(0.306*x))*(2^(0.67*x)) = 1.3*10^14 oCPUs. Wolfram Alpha gives us the solution x = 42.18..., or rounded to two places: x = 42. That means the time you're looking for is 42 years after 1945, or 1987.

The length of a DNA strand is approximately 1.5-3 metres per cell.

The DNA in one cell weighs approximately 6.5e-12 g (First answer).

1 g/(6.5e-12 g) = number of cells required to make up 1 g of DNA

= 1.5e11 cells.

1.5e11 cells * 2m per cell = 3e11 metres.

That's 300,000,000 kilometres, or approximately the distance from the Earth to the Sun and back.

I thought it would be a lot, but this seems ridiculous!

Well an average human has 4.7 liters of blood in their body while an olympic swimming pool contains 660,430 U.S. gallons so converting those gallons to liters results in 2540115.4 liters. Divide 2540115.4 by 4.7 and you get 540450.08 humans, but you can't have .08 of a human so you'd need 540,451 humans.

Edit: added a comma

> My final estimate would be once in 105 years

According to this source, it could "never happen in 100 years", which matches your claim of once in 105 years. ;-)

2.5 million liters/(4/3pi*(.1mm)^3 )*.73
That's the equation, and the answer is: 4.357*10^14 eggs, or about four hundred and thirty five trillion.

Bonus round: Google tells us that a human female can have up to 7 million eggs, and this place says 106 billion people have lived on earth. If there have been 53 billion women, then the human race has produced enough eggs to fill approximately 851.5 swimming pools. Which is gross.

Quick estimate at the end of a lecture I'm attending is:

(Annual Revenue/365/Price per meal) * ~800 Calories per meal

Calories per meal is a quick estimate of their nutritional facts, assuming a meal is a burger fries and a drink.

I assumed the price per meal is $7, I don't really know how much it is.

Comes out to about 23648071 calories I think.

http://finance.yahoo.com/q/is?s=MCD+Income+Statement&annual http://www.mcdonalds.com/us/en/full_menu_explorer.html

If the gravity well you're currently in ceases to exist, your kinetics start being dominated by the next most influential gravity well. In the case of the Earth-Moon system, that would be the Sun.

The Earth is orbiting the Sun at ~30km/s while the Earth is rotating at 460 m/s at the equator.

In the perfect scenario where we want to maximize our apoapsis (max distance from the Sun), the ideal scenario would be to perfectly add the rotational velocity to the orbital velocity, giving us a new periapsis tangential velocity of 30,465 m/s.

We can use this handy orbital velocity calculator to see how far from the Sun we could get. Plug in 1 AU for Distance at periapsis, 30,465m/s for Velocity at periapsis, and pick a reasonable Satellite mass (anything much less than the mass of the Sun, say 80kg), and you see the Distance of apoapsis is calculated to be ~1.1AU.

Mars orbits at 1.5AU, so we're not going to make it, unfortunately. Instead we'll be stuck in an elliptical orbit around the Sun for the next 5 billion years or so until the Sun enters its red giant phase and engulfs us and everything else left in the Earth's previous orbit.

(For what it's worth, the 1.1AU periapsis was much closer to Mars than I was expecting!)

Without knowing how your parents grew up (nutrition etc), if your doctor is correct and you only have 6 months left it's unlikely you will grow more than another 1/2 an inch.

https://www.omnicalculator.com/health/height

If you assume 100 conversion to energy (which occurs with fusion, but not so much with fission) using a spell of complete conversion, you're going to get: 14 ^13 Watts

By comparison, the sun puts out 3.86 ^26 watts a day, so not nearly as much as the sun, but it's going to be akin to the asteroid that destroyed most life on earth.

https://www.omnicalculator.com/physics/emc2

So, this thing is 1.3e8 km^(2). Mylar off Amazon costs roughly $1M/km^(2)... so it at those prices it would cost 130 trillion dollars to make.

In practice, I would estimate that amazon prices are probably roughly 10x what you would have to pay if you were producing it in bulk yourself... so it would only take around 20% of the world's economic output to produce.

Of course, then there's the question of getting 5 billion tons into orbit (assuming 1mil mylar).

Incidentally, the economic math neglects material scarcity. Given that world plastic production is roughly 300M tons, it might take a little longer to do.

>1 It takes about 12 to 13 minutes to melt an oversized ice cube on concrete in 109 degrees.

So it will take longer than 12 minutes to melt.

>2About 6 minutes before brain cells start to die. If a person has a cardiac arrest resuscitation has to begin within this time to be successful. The time may be prolonged if the body is cooled, for example by drowning in ice cold water.

>As mentioned, temperature (specifically metabolism) plays a very big role in how long you can go without oxygen, but as general guideline:

>* Heart: Needs constant oxygen * Brain: 4-6 min * Kidneys: +- 30 min * Muscles: +- 2-4 hours * GI Tract: +- 12 hours

And the max time you can go without air is about 6 minutes. So under normal circumstances: no.

You may be able to almost get it to work if you choked yourself on an ice cube, in ice water. At that point, even though you probably won't be able to sleep through it, you will probably require some medical attention.

EDIT: Grammar

A neat method.

Unfortunately, I couldn't get my hair to roll. Perhaps finger dryness or whatever issue.

Personally I'd just measure it with a ruler, but.. I realize that's not practical for most people.

since op has posted the dimensions of the box as 91, 111, 111

box vol = 91 x 111 x 111 cm3

dia of the brush with ref to https://www.amazon.com/YXQ-Copper-Plastic-Handle-Bristle/dp/B01M8GHDG1?th=1

17.5 x 1.2 x 2cm3 + 3.5 x 1 x 1 cm3

again assuming 80% fill 20,247 +/- 500

assuming 90%fill 22,500 +/- 500

The basic structure would be

• Estimate heat transfer coefficient of box (this is probably hard, depending on geometry and material)
• Assume inside of box is uniform temperature at 0C (because ice melting point, and we'll assume heat transfer within the box is fast compared to through the box). This will also assume that ice shape is irrelevant. It might as well be a pile of cubes.
• Assume outside of box is outdoor temperature
• Heat transferred = transfer coefficient * temperature difference * time
• Divide heat transferred by the specific heat of fusion of ice, and you have a required mass.

That said, I don't actually recommend doing it that way. I recommend just doing the experiment. I recommend the Elitech temperature data logger -- it's cheap and pretty simple. You connect it to a computer, set the data acquisition rate (e.g. 1 minute), and then when you're ready to deploy it, you hit the start button, toss it in the box. Come back later, retrieve it, plug it back into the computer, and you have a nice graph of temperature as a function of time. It can do insanely long acquisition sequences (three weeks a 1-minute resolution).

You can extrapolate to some extent from temperature -- if ice is 32F, and you get 6 hours at 62F, you should get around 3 hours at 92F. Or 6 hours if you double the ice loadout.

Oh, and you can use the temperature module to confirm that your outer edges are actually as cool as they should be. You want to avoid the case where it's cold enough by the ice block, but a few layers of food away it's actually 45 degrees.

Here's the longest road route I could find in the Northern Hemisphere (Alaska to Panama):

https://maps.google.com/maps?saddr=AK-3+S&daddr=Ruta+33&hl=en&sll=61.522695,-139.130859&sspn=25.1929,67.060547&geocode=FZRMvAMdWqML9w%3BFWzpgQAdZD8q-w&mra=dme&t=m&z=4

about 6,825 mi.

edit: There are probably some longer routes in Europe/Asia but my eyelids are drooping now.

Number of people in the world: 7.7 billion http://www.worldometers.info/world-population/

Average number of hairs on the human body: 5 million https://www.enotes.com/homework-help/how-many-hair-follicles-does-human-have-111383

7.7x10^9 * 5x10^6 = 38.5x10^15

Oh wow. I tried to calculate it, and using a 1,640 pound GE CF34-3A1 Turbofan engine and a 60 pound pilot, I can get 9.8m/s velocity with a third of a pound of fuel, it seems? I used this to calculate it.

To my understanding, to accelerate at 1G for an hour, I'd calculate it as trying to accelerate to a velocity of 9.80665/s x 60 x 60 = 35,303.94m/s? If so, it would take an initial weight of 3,444lbs.

Though, realistically, while the average acceleration would be 1G, it'd start out slower and get faster as fuel weight went down. The pilot may need to reduce the thrust towards the end.

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Sorry to ask, but is the above seem correct? I like to use these kinds of examples to help myself learn. Thank you again for all your help with this.

I think I may have it. Check me cause I prolly don't.

This is the calculator for the sag.

Some edits so these numbers are closer to what I want.

Box 1) I want 50 lbs of force applied to the line OR 222.5 N

Box 2) Cable distance 804.672m

Box 3) I rechecked the weight of my cable and came up with the correct weight. Over 804.672 m my cable weighs 465g. I then used this calculator to calculate the immersed weight of the cable to factor for my dense solution.

My cable has a radius of .04cm with a height of 80467.2cm SO a volume of 404.472cm3

This is then entered into immersed weight calculator. 465g is then entered into immersed weight calculator.

Then I enter my custom liquid into immersed calculator

Density 1.14g/cm3

This calculator then yields a result of the immersed weight of the cable in my custom liquid of 3.9g.

3.9g/804.672m = .00484g/m OR .00000484 kg/m Which is entered into box 3 of the original catenary curve calculator.

Box 4) 9.81 m/s2

Then I run the catenary curve calculator which yeilds a result of 0.01727 m

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Is this correct????

According to this calculator, lifting a 1 lb object would require about 37 standard 11-inch Helium balloons. If you add too many it'll just float away so if you're trying to get it to hover in mid-air you'll have a tough time balancing it.

good question i'm stumped.

I think it might be useful if it's counted as each book has a max quantity of 1. about 2.2 million unique books published a year around the world ...

I'd say about 20% of all books are captured in library's.... for example some books have 10 editions - but the library might only carry 2 of those editions.

http://en.wikipedia.org/wiki/Books_published_per_country_per_year#cite_note-2

http://www.worldometers.info/books/

You could try this book: https://www.amazon.com/Guesstimation-Solving-Worlds-Problems-Cocktail/dp/0691129495

The solutions strike me as kind of facile, but it at least has solutions at all, ya know?

Farm Tuff 4-Wheel Double Deck Push Cart, 24-Inch by 48-Inch, Green https://www.amazon.com/dp/B00EORGASQ/ref=cm_sw_r_cp_api_9zjRybYFG6DT9

Ok, any thoughts on this one? Certain death with that steering and those wheels or no?