Some engines can operate at higher temperatures/pressures than the human body. On the other hand, vehicles have extra weight, possibly have different drag characteristics, etc. For "normal" speeds and loads, what would be the properties of a vehicle at a crossover point equal to the efficiency of an average human?

Also, if one lives above or below a road, sirens and other traffic noises often vary with the time of day, etc. The standard explanation is diffraction, but maybe others have additional angles or insights to lend.

I've heard (from a South African rugby player, surfer, and physicist) that some countries have TV aerials with different polarizations. Are there physical reasons for preferring one orientation over another (e.g., reflection or absorbtion properties of the environment, etc.), or is this simply a matter of taste? 

General science teachers often claim that black objects absorb all light and white objects reflect all light. To demonstrate, they may ask students to feel the difference between a locked black car and a white one parked outside on a hot day. While walking out to the parking lot to test this, one might see desiccated earthworms on a hot, whitish cement sidewalk.

Sometimes people paint a dining room dark red (which can usually be accomplished with one coat of paint). A later resident may have to apply multiple coats of white paint to undo any reddish tinge. The surface of a white car does feel cooler than a black one, but is the thickness of the white paint (along with other properties) comparable? Does anyone have  experience with the process of painting cars?

Some general science labs use Leslie Cubes, and they seem to indicate only minor thermal differences (i.e., single digit percentages) for the color (black or a white) of a cube. Cake mixes seem to recommend similar slight reductions in cooking temperature when using black baking pans (as oppsed to shiny ones). How much of a temperature difference is there for a person sitting in a black  or a white car, a black- or white-shingled house.

Does loose black clothing in hot climates really produce noticeable cooling air currents?

Following the recent spell of cold weather, I noticed that there are still piles of dirty snow with sand or grit (but not salt) in them, but all the clean snow has melted.

In the coldest parts of the world the temperature can be below -78 degrees C. which is the temperature at which carbon dioxide freezes. Would it be practical to remove the carbon dioxide from the atmosphere, at low cost, in these cold places, and so have a means of limiting the level of carbon dioxide in the the earth's atmophere?

Of all the CO2 taken in during a day, only some of it can be used with the remainder being exhaled.  Is there any way to characterize that amount as a very rough guide to understanding the consumption of CO2 by plants?+

According to me in older generations there were very less earth quakes when compared to the present situations

there were some estimations about earth quakes such that atleast there are 13-17 earth quakes happening month of which 2 of them are major i.e.,a rictor scale reading of 6-7.5

now a days you are able to notice that there are new types of earth quakes happening throughout the world such as TSUNAMI why is the change so . what made rapid increase in earth quakes level ?

even the concept of the 2012 dec 21 include earth quakes ,tsunamis. Is there any alternate to offend from an earth quake other than hiding beneath the tables and benches?