The 7 Biggest Unanswered Questions in Physics

If Isaac Newton suddenly popped out of a time machine, he’d be delighted to see how far physics had come. Things that were deeply mysterious a few centuries ago are now taught in freshman physics classes (the composition of stars is one good example).
Newton would be stunned to see enormous experiments like the Large Hadron Collider (LHC) in Switzerland — and possibly perturbed to learn that his theory of gravity had been superseded by one dreamed up by some fellow named Einstein. Quantum mechanics would probably strike him as bizarre, though today’s scientists feel the same way.
But once he was up to speed, Newton would no doubt applaud what modern physics has achieved — from the discovery of the nature of light in the 19th Century to determining the structure of the atom in the 20th Century to last year’s discovery of gravitational waves. And yet physicists today are the first to admit they don’t have all the answers. “There are basic facts about the universe that we’re ignorant of,” says Dr. Daniel Whiteson, a University of California physicist and the co-author of the new book "We Have No Idea: A Guide to the Unknown Universe."
What follows is a brief tour through seven of the biggest unsolved problems in physics. (If you’re wondering why head-scratchers like dark matter and dark energy aren’t on the list, it’s because they were in our earlier story on the Five Biggest Questions about the Universe.)
1. WHAT IS MATTER MADE OF?
We know matter is made up atoms, and atoms are made up of protons, neutrons, and electrons. And we know that protons and neutrons are made up of smaller particles known as quarks. Would probing deeper uncover particles even more fundamental? We don't know for sure.

We do have something called the Standard Model of particle physics, which is very good at explaining the interactions between subatomic particles. The Standard Model has also been used to predict the existence of previously unknown particles. The last particle to be found this way was the Higgs boson, which LHC researchers discovered in 2012.
But there’s a hitch.

“The Standard Model doesn’t explain everything,” says Dr. Don Lincoln, a particle physicist at Fermi National Accelerator Laboratory (Fermilab) near Chicago. “It doesn’t explain why the Higgs boson exists. It doesn’t explain in detail why the Higgs boson has the mass that it does.” In fact, the Higgs turned out to be a heck of a lot less massive than predicted — theory had held that it would be about “a quadrillion times heavier than it is,” says Lincoln.
The mysteries don’t end there. Atoms are known to be electrically neutral — the positive charge of the protons is cancelled out by the negative charge of the electrons — but as to why this is so, Lincoln says, “Nobody knows.”
2. WHY IS GRAVITY SO WEIRD?
No force is more familiar than gravity — it’s what keeps our feet on the ground, after all. And Einstein’s theory of general relativity gives a mathematical formulation for gravity, describing it a

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ANSWER THIS QUESTION PLEASE.
IF THE EARTH IS MOVING AROUND THE SUN AT 67, 000 MILES PER HOUR HOW COME WE DON'T FLY AWAY FROM THE SPACE STATION?.HOW COME SPACEWALKERS DON'T GET LEFT IN THE DUST? HOW DOES ANY THING KEEP UP WITH US IN ORBIT? HOW COME THIS INFORMATION IS NEVER MENTIONED DURING- BEFORE -AFTER ANY SPACE ENDEAVOURS?
OK I'LL WAIT