If, then.
Einstein was not sure if the universe was expanding, contracting or static. He famously had a constant he could use to change this:
"…Einstein’s cosmological constant, is a coefficient that Albert Einstein initially added to his field equations of general relativity.
Einstein introduced the constant in 1917 to counterbalance the effect of gravity and achieve a static universe, which was then assumed. Einstein’s cosmological constant was abandoned after Edwin Hubble confirmed that the universe was expanding."
He didn’t Hubble did, Einstein had trouble accepting it.
Hubble proved it but it was also in Einstein’s equations. He thought his equations should balance so he added a fudge factor. That fudge factor was the experimentally proved Hubble Constant. Without the fudge factor, the universe expands.
Einstein’s fudge factor was the Cosmological Constant, since revived as an explanation of the unexpected acceleration of the expansion of the universe. Hubble’s Constant is the current rate of expansion of the universe.
I thought that without the fudge factor the universe collapses?
Yes, possibly. It’s the same thing. Universe is expanding and depending on how fast and how much mass, it may keep expanding or reach a point and start contracting. Either way, it’s not static right now which the fudge factor was trying to artificially model.
Hubble’s and Lemaître’s mathematics is correct, but the physics is abominable.
Measuring red shift while observing stuff we see seems to get farther sway by the minute.
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Did Albert Einstein know about red shift?
Einstein died in 1955. Redshift observations started in 1912 but weren’t clear on what was happening or why, Friedmann et al’s calculations in 1922 probably raised the question in a serious context, and Hubble’s law was published in 1929. He knew about it, at least from the early '20s. Someone who read his letters or biography could probably narrow it down further.
Yep that’s not how science is done, but the real story is more interesting I think. It wasn’t Einstein so much as Hubble and Lemaître, but he did acknowledge the error that caused him to miss the expanding universe in his equations.
"This circumstance of an expanding universe is irritating " – Albert Einstein, 1929.
In every direction in the sky, there is a background fizz of light. It is all that remains of the most intense flare of energy ever emitted. To explain it, we must look back to 1929. At that time Edwin Hubble, an astronomer at Caltech, proved that the universe was much larger than anyone had expected and expanding in all directions. From this discovery, two competing explanations developed. The Steady State Theory and the Big Bang. The first allows the universe to create new matter as it expands. Matter just appears from some hidden and rather ghostly source. That permits the universe to look more or less the same as it does today, at least as far as galaxies go. The second treats the universe as a closed system. One that begins with a vast and concentrated supply of energy, which decays into lesser forms. Spreading out as it does. The Big Bang universe is an expanding bubble of space-time, with a few wisps of hydrogen and helium that form the stars. The origins of the Big Bang theory began before Hubble’s discovery. A Russian physicist, A. A. Friedmann had used Einstein’s general relativity to model an expanding universe. At this time, it was a purely theoretical exercise. No one realized then that our universe was expanding.
The rate at which the universe expands is known as the Hubble-Lemaître constant. That naming honours Georges Lemaître. In some ways he was the co-discoverer of the Big Bang. He was among the first to model Einstein’s theories of space and time across an entire universe. As a physicist, Catholic priest and astronomer, he had a clear perspective on this question. He had no problem with the idea of the universe having a unique origin for example. Both Einstein and others had learned that Relativity predicted an expanding universe. But at the time, there was no physical evidence of that. Einstein’s solution was to introduce an extra value to the equations. That balanced the universe’s expansion with an opposing force. For the moment, a stable universe seemed possible.
In the 1920s, astronomers were unsure whether our galaxy was the only structure in the universe. There was no astronomical distance scale. That might explain why most astronomers assumed a static universe. Lemaître was willing to explore a different option. He had seen the evidence from Erwin Hubble’s early observations at Mount Wilson Observatory in California. He published his theory in 1927. He estimated the speed of the expansion using those measurements. They proved that Spacetime was rapidly expanding, carrying along the rest of the physical universe.
Wherever astronomers pointed their telescopes every distant object was part of this rapid expansion. Lemaître understood that an expanding universe must have a tiny beginning. He called this origin point the cosmic atom, from which all matter emerged. Einstein rejected the significance of the new astronomical discoveries for some time. He maintained his belief in a static, unchanging cosmos until 1930, when he traveled halfway across the world from Berlin to Pasadena to see Hubble’s evidence in person. He examined Hubble’s photographs, looked through his telescopes, and declared himself fully persuaded.
He called the stabilizing term Lamda also known as the Cosmic Constant his “worst blunder” but actually it forms the foundation for our present understanding the effects of dark energy, the mysterious force driving the observed accelerated expansion of the universe.
The entire time I was reading I expected to to learn that in 1998, The Undertaker threw Mankind off Hell In A Cell, and plummeted 16 ft through an announcer’s table
That was Hubble who discovered cosmic expansion was a real thing. einstein believed in a static universe and made up a constant specifically to model a static universe in general relativity
He sat as a patent clerk and read everyone’s ideas. So he went with his concept after being exposed to these other ideas. I don’t believe it happened any other way. His time as a clear was critical to his peak mentality.
I really doubt anything so profound crossed his desk thst you could in any way say that it was responsible for his ideas. He might have been influenced slightly by things he saw but he just as easily could have had those ideas triggered by some other stimulus. His brain just worked differently, it allowed him to see the patterns and numerical relationships that no one else could. Give me one example of some technology from the early 1900s that was so paradigm shifting that it could have influenced relativity? I guarantee almost every patent he saw was trash.
Maph
Maff
Haven’t seen you in ages!
*Maphs
Lucky guess
Alternatively, maybe he’s wrong, but the math still works.
Everybody is wrong. He was just a lot less wrong than anyone had ever been up until that point.
check floating head physics
https://youtube.com/@mahesh_shenoy
he’s amazing at explaining those concepts with intuition and deriving the maths from nothing. 10/10 completely underrated.
and shift*
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If you think about it, it kind of has to be. If it wasn’t expanding, gravity would make it all fall together already.
Number get bigger. More number = more universe.
I’m pretty sure Einstein just copied Hubbles test results
