The History of the Universe Is Written on the Ocean Floor

“You can use sea sediments as a telescope to learn about the supernova, and conduct supernova archaeology,” says Brian Fields, an astrophysicist at the University of Illinois who was one of the first people to propose doing this. “You’re digging into the earth to look at the cosmic past.”

.. When looking for dead star remains, scientists use a radioactive isotope called iron-60, which supernovas churn out in vast quantities (Earthly sources produce only one-tenth as much).

.. the stardust would have taken about 100,000 years to shower Earth. Around the same interval, Earth experienced a sharp decline in global temperatures, and the onset of the Pleistocene ice ages. The cause of these climate changes is still under debate, but some anthropologists argue that the shift contributed to the evolution of human ancestors. The creep of glaciers was linked to a great drying throughout Africa, which caused forested ecosystems to become arid grasslands.

.. The closest one to go off next will be Betelgeuse, one of the night sky’s brightest, and a key fixture in the constellation Orion. It is about as big as the stars that Breitschwerdt studied, but twice as distant, and its violent ending will amount to little more than a spectacular light show here on Earth.

Are the Constants of Physics Constant?

So far, they seem to be—but nobody really understands why

.. Born was after a unifying theory to relate all the fundamental forces of nature. He also wanted a theory that would explain where these constants came from. Something, he said, to “explain the existence of the heavy, and light elementary particles and their definite mass quotient 1840.”
.. But the weird thing about such constants is that there is no theory to explain their existence. They are universal and they appear to be unchanging. So is the case with the masses of protons and electrons. But time and time again, they are validated through observation and experiment, not theory.
.. Paul Dirac, wondered in a Nature paper whether the constants were indeed constant if one were to look at the entire history of the cosmos. Measurements on earth are useful but it is a tiny blue dot in the vast universe. What Dirac asked decades ago is what physicists continue to ask today. Is it a constant everywhere in the universe? Why is it a constant? How constant?
.. The mass ratio, they write, varies less than 0.0005 percent, not enough to call it a change. This is based on telescope observations going as far as 12.4 billion years back in time when the universe was only 10 percent of its current age.
.. Even a small change of a few percent in the value of the ratio would mean a different universe. A smaller mass ratio could mean a wimpier proton, and possibly a weaker pull for the electrons orbiting the nucleus, leading to different kind of matter.
.. No theory in physics can explain the constant mass ratio, the steadfast shepherd of science. It just is, *shrug*.
.. The experimental search for a varying constant will likely continue as long as there is no theory to back its existence.