Snowball Earth: Mission to Planet Earth in the Distant Past

In this class, we've learned about our planet, the Earth, and about many other planetary bodies in our solar system. We've seen that there are many interesting similarities and differences between them. The Earth resides in the warm inner solar system, near the Sun, but Venus and Mercury are even hotter than the Earth. Most of the solar system is farther from the Sun than the Earth is, so we've learned about things like ice on Mars, on Europa, on Enceladus, etc..., and even about signs of liquid water beneath the surfaces of some of those bodies.

For this question, you're going to imagine you're a space alien living about 650 million years ago, on some other planetary body (like Mars or a moon of an outer planet), and you're studying the Earth.

Let's imagine this alien species has evolved much like humans have, and has senses similar to ours, and a level of intelligence like ours, and has developed science much like we have today.

So there you are - it's about 650 million years ago, and you're a space alien with human-like senses and intelligence, and a level of scientific and technological development like early 21st-century humans have. Just because you're a space alien, it doesn't mean you have super-duper advanced technology. You've got late-20th to early-21st century technology, if we're making a comparison to humans.

Now, here's the thing - 650 million years ago, the Earth was weird! It was going through a strange episode in its history called Snowball Earth. (In fact, there were more than one of these "snowball" episodes. The most recent one was about 650 million years ago. Complex multicellular life evolved on Earth about 540 million years ago.)

Scientists aren't sure if the Earth totally froze, with the oceans and continents completely covered with ice, but let's assume it did. Nothing but white everywhere. Like the ice planet Hoth from "The Empire Strikes Back". Kind of like the illustration in this article about Snowball Earth.

Method 2 - To get ALL of the possible points

Question: But what if... just what if... you just might be so gosh-darn smart, you can solve this problem without a space program! You can solve it with the technology of the late 1700s! Imagine you're sitting there listening to Hamilton - those people could have solved this problem!

How would they have done it? I wonder... hmm...

If you can figure out the low-tech, pre-space-age, could-have-been-done-200-years-ago method, you can write it in a few short paragraphs, like a medium-sized Discussion post

Your boss asked to analyze a system that initially contains 3,000 gallons of water that is contaminated with 53 lbs of arsenic. He wants you to reduce the concentration of the arsenic down to 10 mg/L, which is the standard that the US Environmental Protection requires for your company to be able to bottle and sell the water. You have a 1 hp pump that will allow you to move 17 gallons/minute of water into the well-mixed tank with the contaminated water. Unfortunately, the water you have coming in contains 3.5 mg/L of arsenic. An overflow valve releases water to a discharge at the same flowrate as the inlet to the tank.

Mohammed asked you to:

a) Identify the total amount of water you will have to pass through the tank to reach the standard in the tank using your pump, in gallons.

b) How long will it take to reach the final concentration before you can start to bottle and sell the water, in hours?

c) Predict what the concentration of arsenic is in the tank as a function of time, in mg/L.

After fermentation, a mixture of ethanol and water is sent to a small distillation column. At the top of the distillation column, a 95% ethanol solution at 65°C is produced at a flow rate of 3.5 kg/s. Your job is to design a double-pipe heat exchanger that will cool the 95% ethanol mixture to 40°C by using cooling water that is available at 10°C. Assume an outlet temperature of the cooling water of 55°C, and only use Schedule 40 pipe from the table below. Do not do viscosity corrections for heat transfer coefficients and the 95% ethanol solution will be pumped to the inside pipe. Assume that the heat capacity for the ethanol mixture is 2.55 kJ/kg.K and the heat capacity of the coolant is 4.18 kJ/kg.K. The density of the 95% ethanol solution is 0.804 g/mL Assume that the velocity of ethanol solution as 1 m/s as the initial guess. Check the accuracy of this calculation once you select the size of the pipe (the area should agree with the area required to achieve the desired heat transfer). The viscosity of the solution is given as 9.72 × 10–4 kg/(m · s) and the thermal conductivity is 0.175 W/(m · K).

1. Draw a schematic for the given system and define all the given information. List all assumptions. (5 points)
2. Find heat transfer required for the hot fluid. With this heat transfer required calculate the mass flow rate of coolant needed to achieve the desired outcome. (10 points)
3. Estimate the area of the pipe by assuming a velocity of 1 m/s and using the mass flowrate of ethanol solution. Find an estimated diameter. (5 points)
4. Use estimated values to find a pipe that meets the criteria using the table (schedule 40 is a requirement). (5 points)
5. With the chosen pipe, recalculate velocity for the inner pipe. (5 points)
6. Select a Schedule 40 pipe as the outer pipe and estimate the area of the annulus section and estimate the velocity of the coolant. (10 points)
7. Using the velocities find the Re number for each fluid and the corresponding convection coefficients. (10 points)
8. To finalize the design, we need the length of the pipes and number of bends. Limiting the length of the pipe to 6 m, calculate the surface areas for each of the pipes. With this areas and the corresponding convection coefficients, find the overall heat transfer coefficient, U. (10 points)
9. Determine the LMTD for your system. Use the relationship q=UA∆T_LMTD to find the necessary heat transfer area. Based on this, estimate the number of bends needed using the ratio of heat transfer area and surface area of the selected pipe for your design. (10 points)
10. What factors will be needed to provide a better design? (5 points)

In the Arc Gis software, state and briefly describe four functions of the basemap.

The Deborah number (De) is defined as follows:
De = relaxation time of the material / time scale of the process or experiment
When De<<1, the material may be described as being “liquid-like” in its response, and when
De>>1, the material may be described as “solid-like”. At intermediate values, the material may
be described as being viscoelastic, having a dual liquid (visco-) and solid (elastic) behavior.
(a) From this definition explain why at room temperature water and window glass are not
viscoelastic while a compound like silly putty is.
(b) How does the phenomenon of the glass transition temperature relate to viscoelasticity?
(c) Please give an example of a viscoelastic phenomenon that may occur during melt processing
of a polymer.

How are scientists trying to reduce impacts of black carbon?

Many people have done a reasonably good job conserving water, primarily by turning off their landscape irrigation and allowing their yards to dry up; others have not.

1. Your neighbor wants to conserve water, but does not want to stop watering altogether. They do want to try and keep their landscape green and healthy. What advice / suggestions would you offer your neighbor?

2. 2017 Update: With all of the rain we had the winter of 2017, and the snow pack at almost 180% of normal, do you think that the drought is over and we can go back to our normal water usage, or do you believe that this will be temporary, and we should continue to practice water efficiency and water conservation?

3. 2020 Update: How might the winter of 2019/2020 change your answer for question #2 above?

Around 650 million years ago, the Earth was covered from pole to pole with glaciers during a period referred to as Snowball Earth. Identify and describe a set of 3 realistic global scale feedback mechanisms that address the following:

a. A feedback mechanism that allowed the Earth to descend into a global glaciation

b. A feedback mechanism that kept the Earth in a permanent glaciation for millions of years

c. A feedback mechanism that allowed the Earth to escape from the glacial period to the warm period that followed.

how are Americans responding to mass media news coverage of COVID-19 and the Coronavirus pandemic?

Reasons for understanding petroleum as being of biogenic origin.

Please explain the "BIG FIVE" greatest mass extinctions and the results.

Then answer the questions: "Are mass extinctions a thing of the past? Why or Why Not?"

A sample contains 80% of radioactive Carbon ¹³C. Calculate the age of the sample if you knew that the half time of Carbon isotope is 5730 year. Radioactive decay follows first-order reaction kinetics.

Absolute or 100% ethanol is produced from a mixture of 95% ethanol and 5% water using the Keyes distillation process. A third component, benzene, is added to lower the volatility of the alcohol. Under these conditions, the overhead product is a constat-boiling mixture of 18.5% ethanol, 7.4% water and 74.1% benzene. Use the following data to calculate the volume of benzene that should be fed to the still in order to produce 250 litres of absolute ethanol: density of 100% ethanol = .785g/cm3 and density of benzene = .872 g/cm^3

1. What are some lethal ranges for pH and what effect do they have on aquatic organisms?

2. Describe how the Hudson River salinity compares to other major rivers in the U.S. (use the ppt unit of measurement and the chart in your lab to help answer this question)

3. What are some factors that can contribute to the turbidity of water?

4. After a heavy rainfall, would you expect phosphate levels in the Hudson River to increase or decrease relative to after a period of dry weather? Why?

5. Explain the process of eutrophication, and how elevated phosphate levels can lead to low dissolved oxygen.

6. Why is it important to test two different sites for a river or a body of water?

7. Besides the dissolved oxygen, temperature, salinity, pH, and turbidity, what else could you investigate to see how healthy a river is.

Anaerobic fermentation is carried in a bioreactor where glucose (C6H12O6) is digested to form the
products ethanol (C2H5OH) and propenoic acid (C2H3CO2H). The product stream is analyzed and
found to contain 96.5 mole % water, 1.34 mole % C2H5OH, 0.79 mole % C2H3CO2H, 1.12 mole
% CO2 and 0.25 mole % C6H12O6. Given the specific gravity of ethanol is 0.789.
a. Calculate the mass fraction of each compound and the average molecular weight of the
product stream mixture.
b. Determine the total mass and molar flow rates of the product stream if the production rate
of ethanol is 160 L/day

Mass balance