What is happening
Scientists have sent a satellite into space to meticulously test Einstein’s weak equivalence principle.
why does it matter
The weak equivalence principle is an integral part of general relativity, so these test results provide further support for the fundamental theory of our universe.
In 1916, Albert Einstein dared to state that Isaac Newton was wrong about gravity. No, he said, it’s not a mysterious force emanating from the Earth.
Instead, Einstein imagined that space and time are twisted into a multidimensional network, and the ligaments of this network are like unwrapped sections of paper. Bendable, moldable. It was believed that just because we exist within this kind of intangible network, our simple human bodies experience fake appearance Firmly hold us to the ground. We call that gravity.
(If it hurts your brain, don’t worry, here’s an article dedicated to breaking down that concept.)
While the genius mathematician referred to this puzzling idea as his theory of general relativity, a title that has stuck, peers called it “completely impractical and ridiculous”, a title that did not. Against all odds, Einstein’s mind-numbing idea has yet to falter. Its buildings remain true on both the smaller and inexplicably large scales. Experts have tried to punch holes in it again and again and again, but general relativity always prevails.
And on Wednesday, thanks to an ambitious satellite experiment, scientists announced, once again, that general relativity has proven to be a fundamental fact of our universe. The team performed what it called the “most accurate test” of one of the key aspects of general relativity, called the weak equivalence principle, with a task dubbed the microscope.
“I have worked on this topic for more than 20 years, and I realized that I had the opportunity to be the scientific instrument project manager and co-researcher on this mission,” said Manuel Rodriguez, a scientist at the French Space Laboratory. ONERA and author of a new study, published in the journal Physical Review Letters.
“It is very rare that such a remarkable result is left in the history of physics.”
A depiction of how Einstein’s relativity imagined the universe.
What is the principle of weak equivalence?
The weak equivalence principle is strange.
It pretty much says that all objects in a gravitational field should fall the same way when no other force affects them – I’m talking about external interference like wind, someone kicking an object, another object hitting it, you get an idea.
And yes, when I say all things, I mean all things. feather; piano; Basketball; you and me; Anything you can imagine, really, according to this principle, should fall exactly the same way.
The microscope project sent a satellite into Earth orbit containing two objects: a platinum ingot and a titanium ingot. “The choice was based on technical considerations,” Rodriguez said, such as whether the materials were easy and feasible to make in the lab.
But more importantly to understand the weak equivalence principle, or WEP, this alloy has exploded in Earth’s orbit because the material there is in our planet’s gravitational field with no other forces affecting it. Perfect for testing standards. Once the satellite reached space, researchers began testing, for years, whether the platinum bit and the titanium bit decreased In the same way while they were orbiting the earth.
They did – to a very precise degree.
“The most exciting part during the project was developing a tool and a task that no one had done before with this level of precision – a new world to explore,” Rodriguez said. “As pioneers of this new world, we expected at every moment to encounter phenomena we had never seen before because we were the first to enter.”
Capsule used during a microscope mission.
ZARM / Selig – ONERA 2013
If you are interested in the technical aspects, the results of the experiment showed that the acceleration of fall of one alloy differs from the other by no more than 1 part in 10^15. The researchers say that a difference beyond this quantity means a violation of the WEP by our current understanding of Einstein’s theory.
For the future, the team is working on a follow-up mission called Microscope 2, which Rodrigues says will test the weak equivalence principle 100 times better.
However, this may be as good as it will be for at least a decade or so, say the researchers.
Great, what does this mean to me?
In a way, the rigidity of general relativity is somewhat of a problem. This is because although it is a basic blueprint for understanding our universe, it is not Just Scheme.
We also have constructs like the Standard Model of particle physics, which explains how things like atoms and bosons work, and quantum mechanics, which explains things like electromagnetism and the uncertainty of existence.
But this is the warning.
Both concepts seem as unbreakable as general relativity, but they are incompatible with it. So… there must be something wrong. And this thing prevents us from creating a unified story of the physical universe. The Standard Model, for example, the famous cannot explain gravity, and general relativity does not really consider quantum phenomena. It’s a huge battle to be the ultimate theory.
Microscope team standing with satellite equipment, right.
ONERA / Rodriguez 2016
“Some theories predict a coupling between gravity and some electromagnetic parameters,” Rodriguez provided as an example. “This coupling does not exist in Einstein’s theory, which is why WEP exists.”
We find ourselves at a crossroads.
But the bright side is that the vast majority of scholars have considered all of these theories incomplete. So, if we can somehow find a way ending Of them — locating a new coupling, for example, Rodrigues says, or identifying a new particle to add to the Standard Model — might lead us to the missing pieces of the puzzle of our universe.
“It should be a revolution in physics,” Rodriguez said of breaking the WEP. “It would mean we found a new force, or maybe a new particle like the graviton – it’s the trophy in the world of physics.”