PV Gap

Evelyn Said:

I need help picking an Engineering field for a project?

We Answered:

I would recommend Traffic Engineering. You could do a project on what times a busy intersection or stretch of road becomes congested and at what traffic flow rates/volumes, or how many people actually stop at STOP signs at different intersection types, or how many pedestrians cross against the light at a signalized intersection, or lots of other cool things that you could study outside in the field.

Jerry Said:

why is flying to space so expensive?

We Answered:

The simple answer: Conservation of energy laws = ~You don't get something for nothing." We have to accelerate objects to 11.2 km/second to achieve escape velocity from the Earth, and every extra gram requires more energy to achieve this. Once you begin to throw in humanoids, the equation becomes incredibly difficult. You have to keep them alive - can't have too many G's, you have to keep them from freezing, being irradiated, they have to breathe, eat, drink, they produce waste, not to mention psychological issues (weak humans). Every single one of these accommodations requires equipment to do so, again adding valuable weight we must get off of the ground. This doesn't even approach the issues we'll encounter once we get to where we're going (landing without dying, setting up shop, etc.). The math is one thing, the raw materials/resources are a completely different matter altogether.

John Said:

In terms of net energy gain, are biofuels more efficient than photovoltaics?

We Answered:

Nothing has energy gain, per se. Biofuels and photovoltaics both have energy output, but it is always less than the energy input.

A Solar array is expensive, but produces almost free power, but only when the sun is shining on the array. And that can vary depending on geography and weather.

Biofuels get their energy from the sun, but indirectly. They are very expensive to make, and usually diminish the world's food supply.