Fermi Questions Marathon

[quizbowl]

I live in Michigan.
Michigan is probably about 3% of the United States's landmass, and the United States is probably around 5%-8% of the world's landmass, so the answer is -3.

What fraction of a human's mass is DNA?

A human is about 70 kg, and we have... tens of grams? hundreds of grams? worth of DNA, so -3.

How long (days) would it take to bicycle from New York to San Francisco via Chicago, assuming you're biking only during the day?

Should probably take about 3E3 miles to do the whole juggernaut. Assuming that you bike for ten hours a day (saving the rest for sleep and personal duties) and at about 2E1 miles per hour, you'd get 2E2 miles/day. Divide it out and you'd get 1.5E2 days.

How many nanometers will a single erythrocyte travel in 24 hours (assuming no apoptotic pathways)?
(and, unrelated, 1000 posts )

[Phenylethylamine]

How long (days) would it take to bicycle from New York to San Francisco via Chicago, assuming you're biking only during the day?

Should probably take about 3E3 miles to do the whole juggernaut. Assuming that you bike for ten hours a day (saving the rest for sleep and personal duties) and at about 2E1 miles per hour, you'd get 2E2 miles/day. Divide it out and you'd get 1.5E2 days.

Your division is wrong: 3E3/2E2 is 1.5E1, not 1.5E2. And that's low. I think your speed estimate is quite high (i.e., it is possible to bike at 20 mph, but you'd never average 20 mph – more like 10 or 12), so you should've gotten more like 3E1 (which technically doesn't change your final answer, but still).

In reality, of course, it would take about twice that, because most cyclists can't bike ten hours a day for thirty consecutive days. I'm actually planning a bike ride across the country next summer (with this organization that does builds for Habitat for Humanity along the way), and it'll be roughly 72 days, with ten or twelve days in there that don't involve any biking, just working on build sites or relaxing... so I think a more realistic estimate would be 60, because ten hours a day is only doable so many times in a row.

[JTMess]

A red blood cell travels a complete circuit around the body in about a minute. I will estimate that the loop travelled by major veins and arteries around the human body is 6 meters. This means that red blood cell travel 6 m/s, or ~5E5 meters in 24 hours. 5E5 meters= 5E12 nm.

What is the mass (kg) of all celestial bodies in the Milky Way Galaxy?

Since this forum was getting a little slow, I decided to add a really tough question in the hope that someone would take a shot at it. Good luck!

[anepictimelord]

A red blood cell travels a complete circuit around the body in about a minute. I will estimate that the loop travelled by major veins and arteries around the human body is 6 meters. This means that red blood cell travel 6 m/s, or ~5E5 meters in 24 hours. 5E5 meters= 5E12 nm.

What is the mass (kg) of all celestial bodies in the Milky Way Galaxy?

Since this forum was getting a little slow, I decided to add a really tough question in the hope that someone would take a shot at it. Good luck!

black holes will make up the majority and the black whole at the center of the Milky Way is E5 suns and our sun is E30 kilos. that makes the supermassive black hole E37 kilos. That black hole is probably not 1/100th the mass of the Milky way so lets say 1/10. that puts the number at E38 kilos.

You and your partner are converted to pure energy. this energy is spread out evenly throughout the earths surface. How many Joules does each square meter receive"?

[Schrodingerscat]

Two people will be roughly 100 kilograms. E=Mc^2, so 9E20 Joules of energy. The earth is a sphere of 6 million square meters. If I am remembering my geometry, SA=4pi*r^2, so 8*36E12, 300E12, 3E14 square meters. Thus 3E6 joules per square meter. Fermi answer: 6.

How many joules of light is sent into the sky from electrical lighting every night in the United States?

[hyun314]

How many fermi questions are there?

[hmcginny]

very early on Angstrom asked a question that no one answered: "How much energy is lost to sound in a flight from NY to LA?", and at the time I had no idea how to answer it and it had been bugging me for a while, but in studying for sounds I found the amount of sound energy in watts released by certain instruments. A full orchestra releases 67 watts, and planes are louder than that, but not 10 times as loud, so E2 watts. That flight would take around 6 hours, so thats 2E4 seconds, or 2E6 Joules of energy released.

The average lightbulb is like E2 watts, there are E8 households in the US, each with E1 lightbulbs on for 5 hours or so that we would consider "night". So thats E11 watts from lightbulbs times the ~2E4 seconds that they are on for, giving us E15 joules released.

How many fermi questions are there? Well, each team in science olympiad has probably written at least E2 in the years that this has been an event. Some probably haven't written any, so that outweighs those of us that have written E3, so lets say olympiad alone has led to E5 questions. All of the order of magnitude classes at colleges are a whole bunch more, so lets say there are probably E7 fermi questions ever written.

If an asteroid hits the earth and 10% of its mass is evenly distributed across the earth at a rate of .2 Tg/Pm^2 (Teragrams per petameter squared), how massive was the original asteroid in kg? I'll give you a hint, the asteroid is not a normal mass.

[anepictimelord]

heres one. How many golden rectangles make up all the d20 dice ever made?

[Bogoradwee]

heres one. How many golden rectangles make up all the d20 dice ever made?

well unless I don't understand your question, couldn't the answer be 0? You didn't specify the units of the golden rectangle, and from I know of it, it just has to have a certain ratio to it on its sides. Also, how deep would it be? The ratio only has to do with two sides, so there's no z axis. Please correct me if I'm wrong.

[anepictimelord]

heres one. How many golden rectangles make up all the d20 dice ever made?

well unless I don't understand your question, couldn't the answer be 0? You didn't specify the units of the golden rectangle, and from I know of it, it just has to have a certain ratio to it on its sides. Also, how deep would it be? The ratio only has to do with two sides, so there's no z axis. Please correct me if I'm wrong.

A D20's vertices can be made with 3 golden rectangles. a golden rectangle is a rectangle with sides in the golden ratio, or phi. in the platonic solids the golden ratio can be found