stevenvh.net

# Science & technology

## Albert Einstein

When you ask people in the street to name a great scientist, chances are that most of them will say “Einstein”. I don't mind that. But when asked for another great scientist, many people will need some time to think. And that's something I do mind. If a person can't name another scientist than Einstein, he shouldn't name any scientist at all. What I mean is that Einstein was one of many scientists that shaped modern physics, and that ignoring those others is unjust, and it makes Einstein greater than he was.

### Standing on the shoulders of giants

Many people, among which many of Einstein's admirers, have an image of Einstein as a man who, sitting at his desk and completely on his own, came up with one of the greatest theories in physics. That image is wrong. Einstein knew what was going on in the world of physics, which in his day was a lot. For instance, William Kingdon Clifford (who died a few days before Einstein was born), in conjecturing that gravity may be caused by the Universe's geometry, laid out some of the bricks which would lead to the general theory of relativity. So did Hendrik Lorentz: his transformation formulas are crucial to spacetime behavior as described by Einstein. Furthermore it's worthwhile to mention Michael Faraday, James Clerk Maxwell, Henri Poincaré, Ernst Mach, Hermann Minkowski, and even Galileo Galilei, who was the first to come up with the concept of relativity.

The special theory of relativity owes its origins to Maxwell’s equations of the electromagnetic field.

Albert Einstein

### The Cosmological Constant

In Einstein's time it was accepted knowledge that the universe was static. The universe was eternal and fixed; it didn't either contract nor expand. But even Newtonian mechanics predicted that a static universe ultimately would collapse under the mutual gravity between galaxies, and Einstein's General Theory of Relativity didn't change this. That's why Einstein introduced a correcting term, the Cosmological Constant, which should counteract the gravity and thus prevent collapse.

Frankly, the Cosmological Constant was a terrible and unscientific construction, and later in his life Einstein rightly called it his “biggest blunder”. Look at it this way: let's say observations for a certain natural phenomenon give a value of 7. But your theory and your calculations result in a value of 6. What to do? Well, Einstein would fix it by adding “1” to the 6, so that $$6 + 1 = 7$$ It works! Isn't science great? How can we best describe the term “1”? “Magical” would be a good word, because Einstein couldn't explain this extra term, nor the value, only that it made his theory work. That's not science, that's tinkering.

#### “Right again, Einstein?”

Since Hubble in the 1920s we know the universe isn't static; it's expanding. Today we not only know it's expanding, but that it's expanding ever faster and faster. Cosmology doesn't have a theory which explains this effect, so it uses the name “Dark Energy” as a placeholder for it, which has to be filled in later. But Einstein aficionados dug up the Cosmological Constant saying it gives a perfect explanation for Dark Energy. Well, it doesn't. Einstein invented the Cosmological Constant to obtain a static universe, not an expanding one. Using my previous simplification it now appears that the value isn't “7”, but “9”. So with Einstein's term we get $$6 + 1 \stackrel{?}{=} 9$$ How wrong can you be? Einstein couldn't explain his Cosmological Constant for a static universe, let alone that he ever heard of an ever expanding universe. The only thing he knew was that he needed it. Actually, this is very much like Newton calling in God's hand to keep the planets' orbits stable.

Apparently some people's admiration and awe for the genius Einstein goes so far that they don't see that a blunder sometimes is just that: a blunder. To Clara Moskowitz and others: Einstein was a genius, but no more than that. Don't attribute to him the omniscience and infallibility of the gods.

### On religion

Many people seem to think that Einstein was religious. I even heard this as an argument by creationists: “See, even the greatest scientists believe in God and Creation.” For one thing, believing in God doesn't imply that you believe in the biblical Creation story. But not only didn't Einstein believe in the Genesis story, he wasn't religious at all.

In March 1954 Einstein received a letter from Joseph Dispentiere, an Italian immigrant who had worked as an experimental machinist in New Jersey. Dispentiere had declared himself an atheist and was disappointed by a news report which had cast Einstein as conventionally religious. Einstein replied two days later:

It was, of course, a lie what you read about my religious convictions, a lie which is being systematically repeated. I do not believe in a personal God and I have never denied this but have expressed it clearly. If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it.

The confusion is understandable. Einstein used to say things like “God doesn't play dice with the Universe”, but Einstein makes it clear that here “God” doesn't mean a personal God. The best way to interpret statements like this is to read “God” as “Nature”.

### On the atomic bomb

Many people seem to think that Einstein invented the atomic bomb. It's not exactly clear where this idea comes from, but the notion that mass and energy are equivalent may have something to do with it. That's the E = mc2, without a doubt the most famous equation in physics. The factor c2 is huge: it takes the speed of light, which is already high in itself, and then squares it. That's a huge number. So due to this high factor we see that a small mass m represents a huge amount of energy E. That's indeed the principle used in the atomic bomb.

But we can make a couple of notes here. First, several historians and scientists argue that E = mc2 was already mentioned by others before Einstein came up with it. The most notable is the Italian Olinto De Pretto, who published the equation in 1903, two years before Einstein did. De Pretto's brother was good friends with Beniamino Besso, who was related to a colleague of Einstein's, so Einstein may have known about De Pretto's work.

Secondly, the equation only says that mass is equivalent to energy, but it doesn't say how you can release the energy. That's the part the scientists who developed the bomb solved, not Einstein. As a matter of fact Einstein didn't even believe it was possible to convert mass to energy. He infamously claimed in 1932:

There is not the slightest indication that nuclear energy will ever be obtainable. It would mean the atom would have to be shattered at will.

Einstein was not involved in the development of the bomb.