Image Credit : ESA/Hubble/NASA
Introduction to the Theory of Special Relativity
The understanding and now confirmation of Einstien’s Special and General theories of Relativity is of course all thanks, I should say mostly thanks, to Einstein. His one of a kind brain, as well as, many after, figured out the complexities that allow us to see BILLIONS of light years away from our home. In 1905, he told the world of that the laws of physics are the same for all accelerating observers, and that the speed of light in a vacuum was independent of the motion of all observers. Thus, the theory of special relativity was born.
So, his theory of special relativity, as stated above, says that the laws of physics are the same for all non-accelerating observers, and he showed that the speed of light within a vacuum is the same no matter the speed at which an observer travels states as I stated above, but as a result he found that space and time were not separate values but shared a powerful correlation and were interwoven into a single continuum known as space-time. Which a bit simpler conveyed says events that occur at the same time for one observer could occur at different times for another.
Theory of General Relativity
The theory created was a new foundation for which all physics and proposed new concepts of space and time could be built upon. Over the next approximately 10 years he felt certain he could work acceleration into his theorem and thus, introduced his theory of general relativity in 1915. The theory of general relativity in 1915 states that massive objects cause a distortion in the fabric of space-time, which is felt as what we know as none other, than gravity. You can think of this exampled through using a trampoline and a marble. If you were to push down the center of the trampoline and then release the marble racing around the trampoline, it would be pulled inward as it accelerated forward orbiting around as it was pulled towards the center. Exactly how gravity of planets pull at items that come near it.
Gravitational Lensing/waves
There are 2 ways we have been able to see and confirm Einstein was exactly right. They are whats known as:
- Gravitational Lensing
- Gravitational waves
Well, all of that information now discovered couldn’t exactly be proven quite like a biologist studying a sample of a cell under a microscope. Not fully anyway. Gravitational Lensing was first to show some truth to theories while we kept working our way toward ultimately being able to show full confirmation of these theories. Even if we were still stuck with only being able to use the first of the two tools we used to proves his theories correct would be great. That is because gravitational lensing is light that can be seen around a massive object, say a supermassive black hole, is bent, causing it to act as a lens for the things that lie behind it. As luck would have it, we have found that most galaxies at their centers have a black hole. These black holes masses are within 10% proportional to its galaxy’s total mass. Thus, the larger the galaxy, the larger the black hole and more of a gravitational lensing effect is produced. This allows scientist today to see objects stars, oddities, wonders and galaxies to list a few examples, that are actually behind amassive object in our line of sight. One of the best-known example of this is whats know as Einstein’s Cross:
Source
This particular quasar is approximately 8 billion light-years from Earth. It sits behind a galaxy that is 400 million light-years away from Earth. In the image taken, you see a total of 5 dots more or less. The four dots as I’ve so eloquently described around the center are of the quasar that’s behind the galaxy! in front, aka, the center dot. I apologize for just dropping such technical terminology describing the above image. 😄 The 4 dots appear around the center dot, the galaxy, like we see because the intense gravity due to the mass of the galaxy bends the light coming from the quasar around it. This has opened doors for us to study, collect and observe just an immense amount data that would not be possible if things were viewed as they are here on earth. If a solid colored material stands in your way, you will not see behind it without a different view advantage, say, by you moving in such a direction until it no longer obscures what we wanted to see. Here on Earth while orbiting around the sun, we are at the mercy of a very select set of view points due to the predictable and constants in our planetary rotation and orbit around our sun.
LIGO
The second and most recent data used to confirm Einstein was right are whats call gravitational waves. Something we summarized should be present if his theories are 100% theoretically correct.
Source
These are ripples sent through space-time when two black holes collide because as they accelerate towards each other they will eventually pull each other towards itself. So simply thinking of them instead of passing each other like cars on the highway, they will actually be pulled into a terminal orbital dance that ends with the two colliding. To prove the existence of gravitational waves, Project LIGO was dreamt up decades ago specifically to try and observe and thus prove the existence of gravitational ways.
Source
The project finally started observation for these in 2002 after decades of planning and funding. The initial first 8 years showed disappointing results, well actually, no results of the existence of gravitational waves. They decided in 2010, the facility would shutdown for an immense overhaul and upgrade. In mid September 2015 LIGO completed a 5-year overhaul that cost a total of $620 million US dollars. On September 18 2015, the now known as Advanced LIGO began its formal observation of the cosmos for gravitational waves. The instruments now being used were 4 times more powerful than the predecessors LIGO started with. In less than 6 months, on 11 February 2016, the LIGO Scientific Collaboration and Virgo Collaboration published a paper about the detection of gravitational waves. The paper was about the first confirmed detection of gravitation waves from a signal detected at 09.51 UTC on September 14 2015 from 2 black holes of both which were about 30 solar masses each, merging about 1.3 billion light-years from Earth. You are talking about an accomplishment of a lifetime that happened only really hours after the newly Advanced LIGO facility was formerly up and observing the cosmos.
In Conclusion
Einstein is not around to see his work confirmed, but I have no doubt he had any doubt what so ever in the plausibility of his work. He was a true one a kind mystery that laid down a new road for the physics community to follow and explore. Well, we can say 2 theories that a german immigrant thought up over a century ago were believed in enough to be studied, followed and experimented to the extent we can say confidently say we were not satisfied with just thinking he was mostly right. The great minds since have put in many hard hours out of curiosity and a drive to understand what may seem at the time incomprehensible, comprehensible. It took over a century from Theory to Confirmation, but if you ask me, thats shows we as a sentient being have a thirst for the unknown that will never be quenched as long as there are questions to be answered.
If you are interested in how exactly the Advanced LIGO works, here’s a great link to check out
Image Credit
https://phys.org/news/2016-02-ligo.html1
Sources:
https://www.space.com/17661-theory-general-relativity.html
https://www.space.com/40255-hubble-telescope-einstein-ring-photo.html
