So what does the future hold for electricity? It’s unlikely that our dependence will do anything but increase, given the versatility, ubiquity, convenience, and cleanliness of electricity as a power source. Will the supplies of electricity keep up with our demands, will the electric grid be able to keep up with increasing demands and changing energy sources, will interruptions increase or decrease, will new electricity sources appear, and will the price be affordable for everyone? The answers depend on human innovation and our willingness to invest in the appropriate technologies and infrastructure.

Below is short clip where I discuss grid technologies, and why we’d like the grid to work better.  Take a look, and if you have any thoughts or questions on the topic, I will be hosting an IamA on Reddit Thursday, May 2, at 2:00pm EST, with researchers from our Grid Technologies Lab regarding the Future of Electricity.

I look forward to discussing the Future of Electricity with you!

- Jim (Stump the Scientist)

Tomorrow on the blog, Andrew Barnes, an applied mathematician, will share with you footage caught on the sPI Cam around how our researchers utilize Pi each day inside the labs. Andrew will also blog about a few mathematical vignettes of Pi, showing how Pi marks major milestones of human intellectual history from antiquity to the present.

But before you go, check out the clip below. As GE’s Stump the Scientist, I have answered many questions from our curious viewers in the social media world for quite some time. In honor of Pi Day, I thought it would be a great chance to turn the (circular) table and ask you a question! You will find my question at the end of the short clip below. And wait… I have more news.

Stump the Scientist is now on twitter to provide you with another outlet to ask me your most pressing scientific questions. We will continue to look at the questions submitted through GE’s Facebook page, as well as those submitted via @StumpScientist and select one to answer in detail through the Stump the Scientist video series! If you know the answer to my Pi related question, please tweet it to @StumpScientist from now until 1:59 p.m. tomorrow. I will review the answers submitted and tweet back to those who provide the best answers!

Happy Pi Day!

- Jim

Here’s what Chief Scientist Jim Bray had to say! (See video below text)

This question would “stump all scientists” for a definitive answer, and that is why this subject is grist for many science fiction books and movies. The question allows legitimate speculation but no definite answers yet. One of the reasons for this uncertainty is that, while we know how our computers work, we don’t know exactly how the human brain computes or even how it stores information (memories). Therefore, we don’t know exactly what problem we are up against when we try to equal or beat the brain with computer processors. Some scientists believe that the brain is a “Turing machine”, meaning that it does function like a computer processor, while others believe that it contains elements, such as quantum components, that make it basically different.

If the former opinion is true, then computer processors should be able to compete completely when they get complex enough, predicted by some to be in 10 -20 years, and the question of a computer becoming conscious may arise. Then all our science-fiction stories of human-like robots might come true. If the latter opinions are true, computers as we now know them may never be the equals of brains or “conscious”; some other type of machine may be required.  Already, for certain types of problems like playing chess, computers can beat the best humans. On the other hand, human brains still excel greatly at problems like pattern recognition, analysis of emotions, and creative thinking.

 Response from Chief Scientist Jim Bray:

Lino, You are correct that positive and negative electrical charges exist within matter everywhere. However, they are normally attached to each other by positive-negative electrical attraction at the lowest energy state, such as in atoms. Since they are in the lowest energy state (often called the ground state), you can’t get any energy out by forcing them to a lower energy state, which does not exist. Static electricity is caused by moving these electrical charges to some other location and therefore higher energy state, often by a mechanical motion. This is like charging a capacitor, as you mention. Then the charges can be returned to the original ground state by a release of static electricity (which is the motion of the charges), which is just the release of energy we added by moving the charges in the first place. This is not a way to make new energy but can be used to store a little usefully , as in capacitors. This is hard to harness and predict, other than in capacitors, because it usually occurs randomly, such as in the friction of walking across a carpet in dry room. The biggest example in nature is probably lightning, which is the release of the static electrical charge built up between the ground and the clouds by  the vertically moving air and water in a thunderstorm.

This week, GE’s facbook fan Eli asked, “has evidence of dark energy ever been discovered?

Response from Chief Scientist Jim Bray:

Yes, Eli, evidence of Dark Energy has been seen. In fact, it was this evidence that caused physicists to invent the term “Dark Energy”. In the standard model of the beginning of the universe, it “exploded” in its beginning in a “Big Bang” around 14 billion years ago. Since all the universe’s parts have gravity, physicists expected that the parts would attract each other as they flew apart from the initial Big Bang, and this gravitational attraction would cause the expansion to slow down over time. Physicists and astronomers can see the speed of expansion by studying the light from distant stars, which is shifted toward the red, with more shift the faster they are expanding away from us; this is called the Doppler shift. Imagine their surprise when they looked at the observed numbers and saw that the speed of expansion is increasing in recent times, not decreasing as expected from the effect of gravity. To explain this observation, physicists postulated a new force pervading all the universe called Dark Energy, which causes the objects in the universe to repel each other and therefore speed up their expansion away from each other. This theory is still somewhat speculative, and the details are still being worked out and checked; other ideas can still be the correct ones.

This week, GE’s facbook fan @Catherine asked, “If heat is molecules in motion, why do we feel cooler when we turn on a fan?” Check out the clip below to hear what our Chief Scientist had to say.

This week’s question: “why do atoms explode when you split them?”

Response from Chief Scientist Jim Bray

Not all atoms “explode” when you split them, but some do. Physicists call the splitting fission, and it is the heavy center (called the nucleus) of an atom that can fission. Physicists call those atoms that fission easily “fissile”, and uranium and plutonium are examples. Fissile materials are always big, heavy atoms; the light ones do not “explode” if fissioned. By “explode”, we mean that the atoms give off a lot of energy in some form when they fission. When a heavy atom’s nucleus fissions, it splits into 2 parts which are, of course, lighter. In fact, if we weigh the 2 parts and add the weights together, we get a smaller number than the weight of the original atom. This missing matter is turned into energy according to Einstein’s famous equation: E=mc2, where E is energy, m is the missing matter, and c is the speed of light. This energy is responsible for the “explosion”, which occurs in atomic bombs, for example. This energy release only occurs for heavy atoms because the lighter atoms are more stable, and so if we try to fission (split) light atoms, the do not have more stable atoms into which to split, and we won’t release any energy.

Jim

This week’s question: “In zero-gravity, do the laws of centrifugal force still apply?”

Response from Chief Scientist Jim Bray

Yes, the physical laws that govern mechanical forces (like centrifugal force) still apply in zero gravity. You are familiar with centrifugal force when you swing a weight around your head at the end of a string; you can feel the centrifugal force pull outward. In physics, we call this force a fictitious force, because the real force does not go outward, but it is the force of the string pulling the object inward that keeps it in a circle. We call that real force centripetal force, and it is equal and opposite to the fictitious centrifugal force. The relevant mechanical law, called Newton’s First Law, says that any object in motion will keep moving in a straight line if not disturbed by an outside force. The object moving at the end of the string is moving in a circle, not a straight line, and the force acting on it to make it move in a circle is the centripetal force from the string. This will happen whether in gravity or not. Gravity adds an additional force to the moving object which tries to pull it down. If you twirl the weighted string vertically, you will feel the pull stronger at the bottom of the circle than at the top, because gravity adds to the centripetal force the string must apply at the bottom of the circle and subtracts at the top. If I twirl the string horizontally, the string will apply equal force all the time, but the weight will travel closer to the ground in its circle.

Jim

This week’s question: Is wireless power transmission possible?

Response from Chief Scientist Jim Bray

Rohan, the answer is a definite “yes.”

Normally, we think of electric power as being carried by metal (copper) wires, and this is usually the case. However, little bit of power is carried wirelessly when we receive signals on our cellphones, TV antennas, radios, or wireless computers. This wireless power is carried by electromagnetic (EM) radiation (also called photons) from the antenna at the source, and it is imprinted with useful communication signals, which our receiving device amplifies and gives to us on a screen or in words. However, Rohan is probably thinking of providing a lot of power this way, for example for running motors. This can also be done, but it is a harder problem and is the object of current research to improve it (e.g., see Witricity). Just as in the cellphone case, the power is carried by EM radiation, but large power can only be carried efficiently a short distance, like a foot or so. The reason for the short distance is that the electric power must first be transformed to EM radiation at an antenna and then received by another antenna, where it is converted back into electricity for power. The EM radiation tends to spread out between the antennas, and so too much is lost if the antennas are too far apart. Some power is lost an any case, and so the wireless method will never be as efficient as a wire connection. However, the convenience of power transfer where wired connection is difficult (e.g., to vehicles or to hard-to-reach places) is the reason for the current work on this subject. We are likely to see more use of this in the future.

Jim

How is the build up of electricity in human body happening and what are the other objects that can have this same phenomena?

Response from Chief Scientist Jim Bray

Question from fan Nicolas Roux:

“How close are we to making nuclear fusion a reality?”

Response from Chief Scientist Jim Bray:

Nuclear fusion is the process whereby 2 lighter atoms combine (fuse) their nuclei to produce a heavier atom. This process often produces a lot of energy for lighter combining atoms, since some mass is converted to energy during the fusion process. We can say that nuclear fusion is certainly a reality now, since it provides the energy that causes all the stars shine; all stars are powered by fusion of light elements like hydrogen. It is also a reality here on earth, since it is the method by which thermonuclear weapons (H-bombs) work. So we now get to what we suppose Nicolas is asking: how close are we to making nuclear fusion a viable controlled power source for commercial power needs on earth?

This is a very hard problem because, in order to fuse the nuclei of atoms of a material, we must raise the temperature to many millions of degrees. There is no container for such temperatures, so physicists resort to using containing magnetic fields or quick energy inputs to try to raise the temperatures before the hot materials escape. The experiments and equipment are so complex and expensive that many nations have banded together to make a large experiment (using magnetic fields) called ITER in France. This experiment will not begin until around 2020 and will not produce commercial power. It will take a number of years after that to produce a plant to make commercial power, so we can guess that at least 25 more years will be needed. Another experiment in the US at Lawrence Livermore National Lab is producing fusion by quick energy input (by lasers) into materials. It is supposed to begin working this year, but it is also not going to produce any commercial power. 25 years might also be a good guess at how long it would take to commercialize that approach. So, in summary, no one knows for sure when fusion will be a reality for commercial power on earth. The problem is a hard one and the equipment is very expensive. The numbers I have given are just guesses.

Question from fan Natalie Armstrong:

“Why can gravity hold a human down, but not completely?”

Response from Chief Scientist Jim Bray:

Gravity holds everything down on earth, not just humans. When Natalie asks “but not completely”, I suppose she is referring to the fact that we can force humans and other things up for a while, but they usually fall back to the ground. The faster we force or throw things up, the longer it takes for gravity to slow them down and pull them back to earth; you can check that out just by throwing a ball up with various speeds. Another fact is that gravity get weaker as an object gets higher.

When you combine those 2 facts and think about it, it becomes reasonable that, if we throw something (including a human) up fast enough, gravity might not be strong enough to ever pull it back to earth. That is exactly what happens, and we call that speed “escape velocity”. On earth, escape velocity is about 25,000 miles/hour, which is why we don’t see it happen much. However, our rockets can achieve this, which is why we can put humans into space or put satellites into space such that they never return to earth.

Escape velocity is determined by the strength of gravity on a celestial body, so it would be a much smaller number on our moon but much larger on planet Jupiter.

Question from Facebook fan Zane Shirley-Howell:

How does matter hold itself together? Opposite charges of every atom should push apart.

Response from Chief Scientist Jim Bray:

Atoms are composed of a positively charged center, called the nucleus, surrounded by a cloud of negatively charge electrons. The first thing we should know is that opposite electrical charges attract each other, not repel; it is the same kind of charges that repel. So it is no surprise that the negatively charged electrons are attracted to the nucleus, which is oppositely charged, and the atom holds together.

When we look a little closer, there is a bit of a mystery: the nucleus gets its positive charge from several protons (in all cases but one), all with the electrical charge +1. The nucleus is very compact and occupies a very small amount of space in the atom’s center, and yet it does not come apart from the electrical repulsion of all the positively charged protons within it. The reason is that there is another force in nature within the nucleus called the “strong force”, and it acts at the small distances between all the particles in the nucleus to provide an attraction among them. The strong force is stronger than the electrical repulsion and so holds the nucleus together. So the atoms are stable.

At a larger scale, matter is made of atoms which are joined together chemically. Since the atoms are electrically neutral (having as many positive as negative charges), electrical repulsion is not a significant factor at these higher levels of aggregation.

Question from Facebook Fan Conor Crossey:

If space is expanding where did it start? Also what was there before the big bang?

Response from Chief Scientist Jim Bray:

The first question is: “If space is expanding where did it start?”. Indeed, all our astronomical observations tell us not only that space (the universe) is expanding, but that it appears to be expanding faster all the time. This was a relatively recent surprise to scientists and led to the proposal of “dark energy” to explain the increasing expansion rate. The answer to this question is probably best said: “nowhere in particular”. The concept of “where” assumes that there is a space, objects, or coordinate system, around us to which we can reference positions. This is easy to do in our universe because we can reference everything to the earth or to other objects such as stars. Now imagine that only you exist in a black void with nothing else around. How would you tell anyone your position? You could not, because there is nothing to which you could reference yourself. This is the problem with asking where space (the universe) started; there was nothing else around to provide the reference for “where”.

The second question is: “what was there before the big bang?”. The best answer is probably “no one knows” (you have stumped all scientists). Books have been written about this, but they are all speculation or opinion at this time. Some theories have proposed that our universe arose from events within a larger universe or from the rebound of the collapse of an earlier universe. Some people question the validity of the word “before” in the question, if time began with the big bang. We should also recognize that we can answer such questions only within the bounds of science, which is to say that the answer should have some observable, verifiable, testable consequences within our present universe and reality. If we propose answers which have no consequences or verifiability within our universe, then such answers belong to the realm of philosophy or religion, not science.

Michael Seidel sent in the following question:

If everything is in motion, and we are to believe Newton’s 3rd law to be true, what started the motion?

Response from Chief Scientist Jim Bray:

We can make this question hard or easy, depending on how we interpret it. The hypothesis “everything is in motion” is certainly approximately true, since, if we examine things around us closely enough, even seemingly stationary objects are composed of atoms which are moving because of thermal excitation (heat). For the reader, Newton’s 3^rd law says “for every action, there is an equal and opposite reaction”, and this means that the force needed to place anything into motion will also place into motion the thing which applied the force. So we can answer this question by saying that there are 4 forces (gravity, electromagnetism, weak, and strong) which act on all known matter and energy in the universe, and therefore it is natural that these combined forces will have caused “everything to be in motion”, since they act on everything. So the 4 forces started the motion, in the sense of Newton’s 3^rd law.

We can make the question harder philosophically by asking whether there is any net motion in the universe as a whole, combining all its parts, and how the 4 forces got started. While physics is theorizing about how the 4 forces arose from the “Big Bang”, we have no generally accepted answer. Such questions also require speculation about whether there is any other thing outside our (known) universe to act as a reference for motion, another unknown.

Question from Facebook fan Jason Burdorff:

Why is there more static electricity when there is cold weather? (or at least, why is it more noticeable?)

Response from Chief Scientist Jim Bray:

Static electricity refers to the separation of positive electrical charge (from the protons in atomic nuclei) from the negative electrical charges (from the electrons which surround all atoms). Normally, they exist next to each other in atoms such that everything is electrically neutral. However, some actions like friction (e.g., walking across a carpet, where shoes are sliding on the carpet) can separate these charges. Then, the extra charge on the shoes and person wearing them can discharge onto an uncharged object (like a doorknob), and we feel the small shock of “static electricity”.

This is more noticeable in cold weather because, in cold weather, the humidity is reduced in the air. Cold air contains less water than warm air, and we all have experienced the drier air indoors in the winter. It turns out that water molecules in the air speed up the discharge gradually of those things which have been electrically charged by static electricity. All things which are charged statically will eventually discharge, because that is their normal (lowest energy) state. However, in drier air, things retain their static charge longer, and we are more likely to have the time to notice the small shocks from the occasion discharges before the object discharge naturally.

Question submitted by GE Facebook fan Nakul Narayanan:

What is the difference between AC and DC power flow?

Response from Chief Scientist Jim Bray:

The difference between AC and DC power flow is denoted by the difference between its letters: A=alternating, and D=direct. C= current. First of all, the current C stands for the electric current in a wire, and this current consists of electrons that are being pushed through the wire by an electric field, also known as a voltage. “Power flow” means that the current carries power or energy to something (e.g., a computer, TV, motor, radio) to which the wire is attached. “Alternating” means that the current, or electrons, are being pushed back and forth by the voltage, while “direct” means that the electrons are being push only in one direction all the time by the voltage.

Why can both alternating and direct current give a power flow to something? You can consider an analogy. Think of holding a rope tightly in your hand. If someone pulls it though you hand in one direction, it will heat up your hand, maybe enough to burn you (“rope burn”). But also, if that person pulls the rope back and forth through your hand, it will also heat up and maybe burn your hand. Similarly, both AC and DC current can deliver power or energy to equipment.

In electrical engineering, we use both AC and DC power. Most of the electrical transmission that you see on outdoor power lines and in your home is AC because it has some advantages in manipulating it compared to DC. The frequency of alternation in the US is 60 cycles per second (called Hertz), but some other countries use 50 Hertz.

Question posted by Facebook user William Franco:
How do magnets work?

Response from Chief Scientist Jim Bray:

This is a “hot topic” at present in physics because the new CERN particle accelerator (the world’s most powerful “atom smasher”) is partly devoted to looking for this particle and is closing in on its whereabouts. Most of the physicists involved in this search think that they will have the answer (its existence and mass, or its non-existence) within a few months.

Physicists have created a “Standard Model” of all matter and energy in the universe (except for gravity and perhaps dark matter and dark energy). Most of the particles within this model have mass, but some do not (notably the photon, the particle of light). A major unsolved question is why most particles have mass, and how do they get mass. The chief theoretical answer that has been proposed for this question is: by their interaction with another very important particle within the model, which has not yet been seen. This proposed particle is the Higgs boson.

Since mass is such an important property of almost all things, you can now see why the Higgs is important. If it cannot be found or can be showed not to exist, the question of why things have mass will be unanswered, and some new theory will perhaps be required, one that might perhaps supplant the Standard Model. This would require a lot of revisions in physics which would be avoided by finding the Higgs.

Question posted by Facebook user Forrest Holt:
How do magnets work?

Response from Chief Scientist Jim Bray:

The answer is “by electricity”. Unless you already know a lot of physics, that answer, while short and sweet, will probably not explain much to you. So let’s go a little deeper.

All magnetism is caused by the flow of electric current (electricity).A broad class of magnets, called “electromagnets”, illustrates this. You can readily make a magnetic field around a wire by flowing an electric current through the wire. If you bundle a lot of wire together, such as in a coil of wire (like a solenoid), you can make a stronger electromagnet, and increasing the amount of electric current also increases the magnet’s strength.

We have to go a little deeper to explain the other class of magnets, permanent magnets (like the “bar” or “horseshoe” shaped materials). In these, the electric currents circle around each atom which compose the magnet. Electricity is compose of moving electrons, and electrons circle around all atoms. Not all atoms have electrons which circle in the proper manner to make a good magnet, but the atoms of permanent magnets (like iron) do. Each atom becomes a very small magnet, but when the very many atoms which make up the permanent magnet line up and cooperate, we get the familiar permanent magnet (which we might use to attach things to the refrigerator door). If the atoms do not line up, then we would say that the magnetic material is demagnetized.

UPDATE:
We received the following comment from one of our readers, Sasikanth Manipatruni, regarding Dr. Jim Bray’s response:

I do want to get some comment from you on permanent magnets. In reality, the Fe/Co/Ni permanent magnets show little orbital magnetic moment. And the contribution is mainly from the spin magnetic moment (one Bohr magenton per uncoupled spin). In-fact, when we do Landau-Lifshitz-Gilbert dynamics of a magnet, the magnetic moment of a single domain magnet is simply the number of unpaired electrons in the magnet multiplied by the value of Bohr magneton. Further confirmation of this is the spin torque effect when electrons with opposite spin injected into a magnet turn it.

So is it still fair to say magnetism is due to electricity ? The magnetic moment of the electron itself cannot be derived as a result of moving electrons forming an Ampere field. What I thought was that if we assumed a spinning electron, we get absurd values of the speed/angular velocity of electron.

Jim requested that we post the following clarification response:

Thank you for the excellent follow-up question. In answering these questions, I am often faced with the dilemma of how deep to go into the physics and still have an answer that is generally correct but understandable by the general public who are not trained in physics. You are quite correct in your observations. My simple answer of “by electricity” is still correct, since the property you point out belongs to the electron, the quantum unit of (most) electricity.

The electronic magnetism in permanent magnets is indeed (as you say), caused by combining both the orbital and spin components of the electron, in varying ways depending on the precise material. Furthermore (as you note), the electron spin magnetic moment cannot be calculated classically by any actual classical spin of the charge cloud of the electron; it is a fully quantum mechanical property. Attempts to do it classically fail by approximately a factor 2. The excellent fully quantum mechanical theory of electromagnetism, called QED (quantum electrodynamics), does allow us to calculate this spin magnetic moment as accurately as we wish. In my original answer, I lumped all these properties into “motion” of the electron around an atom without going into the quantum theory.

Of course, it is possible to go even deeper into the physics of magnetism; e.g., paramagnetism, diamagnetism, antiferromagnetism. The nucleus also has a magnetic moment, and it is small enough compared to the electron that we can neglect it in discussions of most magnets, but it is vital for important fields like MRI and NMR.

Magnetism is a very broad and deep topic in physics. Your follow-up points out some of this additional depth.

Thanks, as always for everyone’s great interest and questions!

This week’s question came from Omer Saeed and asked, “Why a free falling object is weightless?”

Chief Scientist Jim Bray responded by video.  Check it out!