For those who dream of living in a world with alternate realities, such as for example a place where one could be in two different places at the same time, new research suggests that our universe and its physical laws may not be the only ideal ones for life to exist. Could you think of a few occasions in which time travel or simultaneously occupying two spaces would be incredibly fabulous? I know I can…

Some physicists argue that our universe seems quite “fine tuned” for life as we know it. If any of the fundamental forces of nature: the Strong, the Electromagnetic, the Weak and Gravity would have been slightly stronger or weaker we simply couldn’t exist. The chemical reactions and conditions needed for human life, they argue, are only possible in a universe with the specific constants of nature that prevail in ours.

The Strong Nuclear force is responsible for binding quarks into protons and neutrons and these into atomic nuclei, so it is essentially the reason why matter exists. The Electromagnetic force gives us light, atoms and chemical bonds; whereas Gravity makes matter coalesce into galaxies, stars and planets. And we know that we humans are entirely made up of material that comes from stars. So without stars or atoms or light we just simply couldn’t live. Finally, without the Weak force it would be hard for our sun to give us energy to sustain life and for complex chemical reactions to take place.

Nevertheless, Alejandro Jenkins and Gilad Perez suggest that congenial universes can exist where these forces of nature are different, including the case where the Weak Force is zero. Perhaps -without this last Force- other pathways exist that allow for the creation of the elements. Having just seen the movie Avatar, I am inspired to think of many different possibilities of life out there. It is clear that the fantastic alien ecosystem in the film where magnetic fields can levitate mountains and connecting to tree roots transmits energy through electrochemical signals is not the only possible alternate universe.

If you had to design your own world, what constants would you pick? I for example would chose to have different gravitational fields in different areas so that when I go out to a party my weight would be cut in half and I could fit into my old slim dress. I personally would love to experience weightlessness and why not, fly as I’m cooking at home or train for those up-in-the-air Salsa dancing moves. Wouldn’t that be fun?

Though it is difficult to determine the histories of universes with physical parameters different from our own, researchers keep investigating what else is out there. One way to do this is by studying the “cosmological constant” which represents the amount of energy living in empty space as predicted by Quantum Mechanics and Einstein’s Theory of General Relativity. If the magnitude of this constant were a tiny itsy bit different, space would either expand too quickly for planets to form or collapse in a “big crunch” seconds after it came into existence. A deviation in even the 100th decimal place would lead to a disaster. Thus, it is extraordinary that our universe managed to find the perfect balance.

Perhaps the Large Hadron Collider at CERN near Geneva hopes to answer some of the questions related to possible different universes. Perhaps there are extra dimensions in our universe beyond the four known ones (3 spatial and one temporal). Only time will tell…

Credit: Scientific American January 2010

References and Resources:

http://www.scientificamerican.com/article.cfm?id=looking-for-life-in-the-multiverse

http://space.mit.edu/home/tegmark/crazy.html

http://physlink.com/Education/essay_weinberg.cfm

http://www.scientificamerican.com/article.cfm?id=parallel-universes-level

Not all science is done in labs. In fact, most of us are scientists around our house every day without even realizing it. Step into the kitchen for example. You don’t have to channel Rachael Ray if you want to be Mrs. Wizard — even the most simple culinary tasks are chock-full of science! The academics call this Molecular Gastronomy. But I call it Chemistry in the Kitchen.

Let’s say you want to bake a cake. Even if you use a mix out of a box, guess what, you’re running a number of science experiments! Step 1: As you add the water, egg and oil to the powdered mix you are creating what is called an emulsion — though you call it batter. Other examples of emulsions in the kitchen are mayonnaise and butter. An emulsion is a stable combination of two liquids that normally do not mix. Oil and water are famously difficult to combine, as you probably already know from the phrase “they’re like oil and water” or from endlessly shaking up your salad dressing. But, while salad dressing separates into two layers unless constantly shaken, the oil and water you add to your cake mix form a batter. Why? Well the secret ingredient — the emulsifier — is the egg.

Egg yolk contains molecules called lecithins. These molecules are rod-shaped and each end has a different property — kind of like a magnet. One end of the magnet is hydrophilic — it attracts water — while the other is hydrophobic — it repels water. The lecithins in the egg yolk pull the batter together: hydrophobic ends grab the oil; hydrophilic sides grab the water. The emulsifying egg coaxes these two stubborn liquids together into a stable batter. And there you have it: oil and water together at last, with the help of one little egg.

Ok, Step 2: time to mix. The directions on the box tell you to beat your batter for 2-3 minutes after the ingredients are combined, much longer than you might think. Why? Well, mixing is one form of leavening  — the process that changes your cake from a dense batter to the light and fluffy treat that comes out of the oven. Leavening works by creating gas-filled bubbles in the batter — these small gaps cause the cake to expand, and rise up in the pan. Think of a piece of cake or bread: look closely and you’ll notice that much of what you’re eating is empty space. Creating these spaces is what leavening is all about.

Mixing your cake batter is a form of mechanical leavening; other examples include creaming, beating, stirring and kneading. What you are really doing during those 2-3 minutes is physically adding air molecules to the batter. Think about how you stir a bowl of hot soup to cool it down; the motion of swirling the soup with your spoon adds air to the hot liquid. By beating your batter, you are doing the same thing: adding air molecules that will expand in the oven and create the gaps of fluffiness. If you like your cake lighter, beat it a little bit more; if you like a denser cake, beat it a little bit less. You’re the scientist, after all!

Though you aren’t adding them, your cake mix also contains chemical leaveners. You probably have some chemical leaveners in your kitchen, but you call them baking powder and baking soda. Chemical leaveners are used because they release carbon dioxide when they combine with moisture and heat. So your cake rises due to bubbles of air created mechanically and bubbles of carbon dioxide produced chemically. No wonder it is so fluffy and delicious!

Step 3:  time to bake. The instructions on the box suggest different cooking times for different baking dishes. Why? Well, heat moves through solids when atoms vibrate against each other and exchange electrons, in a process called conduction. Metals are good conductors because the electrons in their atoms are easily transferred — loose, in a way — so heat moves faster through metal than through, say, wood. Because metal conducts so well, putting your cake in a metal pan will allow the heat from the oven to move more quickly through the pan to the batter, so you can cook it for less time than in a glass or ceramic dish.

Because heat moves through conduction, each heated-up molecule transfers heat to the one next to it. So, the outside of your cake will be cooked first while the center is the last to receive the vibrations. That’s why you check the center of the cake to see if it’s done. Conductive heat transfer creates texture and heat gradients in the food you cook: think of a seared steak with a juicy pink center. Do you like your cake slightly crispy on the outside and softer in the middle? Experiment with the concept of conductive heat transfer until you find the temperature, material and baking time to create your perfect cake.

Congratulations kitchen chemists — you’ve not only baked a delicious cake but dropped some major science on the way. And now for the best experiment of all: bon appétit!