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“Imagination is more important than knowledge.” ― Albert Einstein
Knowledge versus imagination. Einstein spent the latter part of his life pursuing a “single, all encompassing theory of the universe.” He wanted to able to describe all of nature’s forces – to explain it all. He didn’t find it.
James Taylor sings in “Secret of Life”
Now the thing about time
Is that time isn’t really real.
It’s just your point of view,
How does it feel for you?
Einstein said he
Could never understand it all.
Planets spinning through space,
The smile upon your face,
Welcome to the human race.
That Einstein quote at the top of this article continues “…for knowledge is limited to all we now know and understand, while imagination embraces the entire world, and all there ever will be to know and understand.” Imagination is often the pathway to increasing knowledge.
It is interesting that astronomy experiments now might test an idea of Einstein’s that he proposed almost exactly a century ago. It has been a longstanding question of why the Universe is expanding at an accelerated rate. Calculations in a new study could help to explain whether dark energy, as required by Einstein’s theory of general relativity, or a revised theory of gravity are responsible.
Einstein wasn’t a big fan of a lot of the physics that came at the end of his life, and would probably not be a fan of string theory.
Brian Greene is a professor of mathematics and physics at Columbia University who is probably best-known to the public for his NOVA television specials. He is one of the best “explainers” of this deep science. He explains string theory and I can understand it – until he stops explaining it and I have to tell someone else what he meant. The idea of minuscule filaments of energy vibrating in eleven dimensions that make up the “fabric of space.. and create every particle and force in the universe” is not easy to understand or accept.
String theory fills in the gaps of Newtonian physics, especially regarding how gravity works, and Einstein’s Unification Theory depends on the existence of extra dimensions, which contain these filaments and some string theorists posit that there are at least eleven dimensions. For all of us used to living in four dimensions, that is tough to imagine.
James Gates is known for work on supersymmetry, supergravity, and superstring theory. When he was asked about Einstein’s statement that “imagination is more important than knowledge,” he said: “For a long time in my life, imagination was the world of play. It was reading about astronauts, and monsters, and traveling in galaxies, all of that kind of stuff, invaders from outer space on earth. That was all in the world of the imagination. On the other hand, reality is all about us. And it’s constraining, and it can be painful. But the knowledge we gain is critical for our species to survive.”
Brain Greene on string theory
I think it is pretty safe to assume that everyone has heard of Galileo Galilei. Not as well known is his eldest daughter.
Galileo was born on February 15, 1564, in Pisa, Italy. A mathematics professor, he made observations with implications for the future study of physics. He constructed a telescope (did not invent it) and made significant improvements to it. He supported the Copernican theory of a sun-centered solar system and so was accused twice of heresy by the Catholic church.
He had three children, but was closest to his eldest, Virginia. He saw her as much like himself in intellect, sensibility, and with an always-seeking spirit.
Virginia was born of his illicit affair with Marina Gamba of Venice. Her birth was in the summer of a new century – August 13, 1600.
That year was also when a Dominican friar, Giordano Bruno, who believed the Earth traveled around the Sun, was burned at the stake.
On her thirteenth birthday, Virginia entered a convent and remained there for the rest of her short life. She was devout but loved her father and remained in constant correspondence with him.
I learned about her when I read back in 1999 Galileo’s Daughter by Dava Sobel which used whatever surviving letters (never published in translation) between them as a major source. It is a good tale of that divide and connections between science and spiritual belief that still exists.
Virginia became Maria Celeste as a nun. We can surmise that Celeste might be a celestial nod to her father. In the convent, she was the apothecary – a kind of science of that time. She sent her father herbal treatments. She asked her father for financial help for the convent. She may have helped him prepare some manuscripts.
It is not really clear how father and daughter reconciled his heresy and her devotion. But they did. Love conquers all?
Galileo was not an atheist. He remained a Catholic and believed in the power of prayer.
Unfortunately, though letters from Maria Celeste were discovered among Galileo’s papers, his responses to her have been lost. Maria Celeste’s letters are published as Letters to father, translated and edited by Dava Sobel.
We remember Galileo mostly for the telescope, which he found out about in 1609. It was a Dutch gadget and initially known as a spyglass or eyeglass. It was curiosity that made faraway objects appear closer and they were being sold in Paris. Galileo saw it as a device of use in the military and promoted it as that to the Italian government.
He improved the design, as others were also doing in other countries, grinding and polishing lenses himself. The Venetian senate was so amazed and obsessed with using it to look for distant ships from bell towers of the city, they renewed his contract at the University of Padua for life, and Professor Galilei’s salary jumped to 1000 florins per year (a 500% raise from his starting pay).
That telescope cause a huge shift in the way we perceive the world we live in and the universe beyond or world.
Galileo used his improved telescope to make detailed drawings of the Moon’s phases, and he discovered 4 of Jupiter’s 67 moons (Io, Europa, Ganymede, and Callisto), though he considered them to be planets. In a 1610 letter, Galileo commented on them and said “I render infinite thanks to God for being so kind as to make me alone the first observer of marvels kept hidden in obscurity for all previous centuries.”
He reminds me of Charles Darwin in that both had a hard time with their discoveries knowing that this new knowledge would clash with existing religious beliefs. Galileo wrote a famous letter about science and religion and that conflict obviously concerned him – and his daughter, and probably some of you reading this today.
In 1947, eight years before his death, Einstein wrote to a friend that he could not seriously believe in quantum mechanics because “physics should represent a reality in time and space, free from spooky actions at a distance.”Albert Einstein came up with the phrase “spooky action at a distance” because he had a problem with the completeness of quantum mechanics, particularly as it conflicted with his own special theory of relativity.
This is most famously seen in the “EPR paradox” of 1935 named after its inventors Einstein, Boris Podolsky, and Nathan Rosen which concerns how a pair of particles are “strangely” linked.
The newer term for this is “entanglement,” which is when two particles are “so deeply linked that they share the same existence.”
That’s more physics than I can really grasp , and it involves mathematical relationships such as a wavefunction.
We think of space – be it ten feet between two people or thousands of miles – as the medium that separates things. Quantum entanglement makes you question that apparent truth. Entanglement means that quantum connections between two particles can persist even if the two particles are on opposite sides of the universe.
What Einstein found “spooky” was that when these entangled particles become widely separated in space, action upon one of them (such as measurement) immediately influences the other. Distance is irrelevant.
And Einstein found this impossible according to special relativity, so, quantum mechanics must be wrong, or at least incomplete, was his conclusion.
The paradox had a solution, but it came in the decade after Einstein’s death. A physicist at CERN, John Bell, in 1964 described entanglement as an entirely new kind of phenomenon, which he termed “nonlocal.”
What I find interesting about this, as it applies more to my non-physics world, is that Bell’s theory is more concerned with the transfer of information. Physicists are still experimenting on this theory, but it fits this information age we live in.
As Brain Greene said on a NOVA episode, quantum entanglement brings to mind voodoo, but the scientific evidence that it exists is overwhelming.
Einstein was trying at the end of his life to find a single theory that wrapped all of this and energy and time into a beautiful package. He didn’t find it. He would not be pleased that modern physicists reject the notion that quantum mechanics requires general relativity to be consistent.
This video was made at Ikeguchi Laboratory in Japan a few years ago and resurfaces online every once and awhile.
It shows 32 metronomes that are started, all out of sync. As the video progresses (it’s only 4 minutes, but you can jump a bit if you get anxious), they shift and then synchronize themselves.
Magic trick? Nope.
It’s that science that is magic – physics. The video shows that transfer of force can align the metronomes over time.
Transfer of force? You give a toy car a push. It rolls across the floor on its own. It hits another toy car halfway across the room with some force. Wait. How could it exert a force? The only reason it moved was because you pushed it.
After you pushed that first car, a force was transferred to the car. When it had that collision, it exerted a force on the second car. That force came from the hand that pushed it. Forces are transferred.
And yet, the metronomes syncing is still kind of magical. Most of the science I like best has some magic to it.
If non-science people have heard of one modern theory of physics, it is likely to be that of relativity. In 1905, Albert Einstein determined that the laws of physics are the same for all non-accelerating observers, and that the speed of light in a vacuum was independent of the motion of all observers. This was the theory of special relativity. Einstein then spent ten years trying to include acceleration in the theory and published his theory of general relativity in 1915. In it, he determined that massive objects cause a distortion in space-time, which is felt as gravity.
One hundred years later, Sarah Howe wrote a sonnet titled “Relativity” for a commission by Britain’s National Poetry Day. It was to be a poem on light. She wrote, paradoxically, about its absence. The poem is about black holes and is dedicated to Stephen Hawking. It begins:
When we wake up brushed by panic in the dark
our pupils grope for the shape of things we know.
That is the light we know in our world of gravity. She is also writing about light at the level of quantum physics where photons behave like particles and also as waves in a mysterious duality. Howe has said of the poem that she was also thinking about how scientist Galileo and poet Milton in their blindness “came to rely on other sorts of eyes.”
Last November was the 100th anniversary of Albert Einstein unveiling the key equations of general relativity, which he did in four lectures at the Prussian Academy of Sciences, and by the end of the month, he had arrived at the ten equations that physicists still use today.
One of his theories was of “spacetime.” Einstein’s theory viewed space and time not as two separate elements, but interwoven. A change in one produces an effect on the other. (His former professor, Hermann Minkowski actually came up with the space-time continuum but Einstein elaborated on it.
One of the parts of this that you may have heard of is that as the rate of speed goes up, the rate of time must go down and vice versa. For an object moving slowly through space, time is passing quickly and for an object moving at a very high rate of speed, time actually slows down. It is not something that we can observe firsthand, and since we don’t get to travel at anything close to the speed of light, we don’t “go back in time.”
But the theory has been tested many times in experiments sending the most accurate atomic clocks for orbits in rockets, and when they return to Earth the clocks on the rockets are just slightly behind their earthly counterparts.
He also theorized that light curves because gravity pulls at the fabric of spacetime. Einstein thought that curve should be visible during an eclipse, and in 1919, photographs of a solar eclipse proved that the deflection of the sunlight matched Einstein’s prediction.
Isaac Newton had said that gravity was a universal force always pulling on one body on another. We learned that in school and plenty of people know only that about gravity. Einstein argued that there was no “force” of gravity at all.
His concept of space and time is often compared to a stretched fabric or trampoline that can warp and bend because of the presence of massive objects, like our sun. Objects like Earth or us on it move as straight as they can, flowing through curved space-time.
If you are curious about how politics also shaped Einstein’s theory of general relativity, check out this article from nytimes.com
There were headlines this year about the discovery of gravitational waves. Gravitational waves are ripples in the curvature of spacetime. They propagate as waves, in the way we are used to seeing the rings propagate from the stone thrown into the water traveling outward from their source.
In the old physics of Isaac Newton, gravitational waves cannot exist – something to do with physical interactions propagating at infinite speed. But then in 1916, Mr. Einstein’s theory of general relativity said that gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation.
In the book Black Hole Blues and Other Songs from Outer Space, Janna Levin writes about them and the quest to record the soundtrack of our universe.
I like Levin’s scientific writing that a non-scientist can enjoy and understand. She is a theoretical astrophysicist and professor of physics and astronomy at Barnard College of Columbia University. I have read two of her earlier books, How the Universe Got Its Spots and, one of my favorites, A Madman Dreams of Turing Machines.
She writes about those dark black holes that science-fiction loves to use. These holes – so odd to think of nothing as something – sometimes collide. Those unilluminated collisions produce energy more powerful than any since the origin of the universe. The energy emanates as waves.
We can’t see these events. No telescope will ever record a collision. The evidence would be the sound of spacetime ringing.
Einstein predicted gravitational waves as part of his theory of curved spacetime. It has taken us a century to begin recording the first sounds of it from space.
I think this unseen aspect is rather wonderful, as in full of wonder. How strange to think that telescopes cannot see events earlier than about 380,000 years after the Big Bang, when the universe became transparent.
There are other theories. One is that it the gravitational influences of other universes.
Levin writes about 50 years of searching for these spacetime waves. The original searchers, Rai Weiss, Kip Thorne, and Ron Drever – have added hundreds of others and new massive instruments sensitive enough to detect a bit of sound from space.
In a conversation on edge.org, she says that:
“The effect of these gravitational waves is to squeeze and stretch space. If you were floating near these black holes, you would literally be squeezed and stretched. If you were close enough, you would feel the difference between the squeezing and stretching on your face or your feet. We’ve even conjectured that your eardrum could ring in response, like a resonant membrane, so that you would literally hear the wave, hear it even in the absence of a medium like air. Even though we think that empty space is silent, in these circumstances you would hear the black holes collide but you wouldn’t see them; it would happen in complete darkness. The two black holes would be completely dark, and your only evidence of their collision would be to hear the spacetime ringing.”
Can you imagine two black holes colliding, curving space and time around them? They are orbiting each other, moving curves, moving black holes, maxing out that cosmic speed limit of light and sucking in time, space, even information. I can imagine it, and yet not imagine it.