# Why are so many objects in space shaped like discs?

It's one of the most consistent patterns in the unviverse. What causes it?

- Spinning discs are everywhere – just look at our solar system, the rings of Saturn, and all the spiral galaxies in the universe.
- Spinning discs are the result of two things: The force of gravity and a phenomenon in physics called the conservation of angular momentum.
- Gravity brings matter together; the closer the matter gets, the more it accelerates – much like an ice skater who spins faster and faster the closer their arms get to their body. Then, this spinning cloud collapses due to up and down and diagonal collisions that cancel each other out until the only motion they have in common is the spin – and voila: A flat disc.

# Mining the Moon

How can we use the resources that are already on the Moon to make human exploration of the satellite as economical as possible?

If you were transported to the Moon this very instant, you would surely and rapidly die. That's because there's no atmosphere, the surface temperature varies from a roasting 130 degrees Celsius (266 F) to a bone-chilling minus 170 C (minus 274 F). If the lack of air or horrific heat or cold don't kill you then micrometeorite bombardment or solar radiation will. By all accounts, the Moon is not a hospitable place to be.

- Time can change depending on how fast you're moving through space. Also, time can "flow" at different rates for different observers.
- Light doesn't experience time — it exists outside of time.
- We perceive space and time differently, but they may be woven together. For instance, they both balance each other out: If you are still, time goes by at a natural rate. However, if you move through space very fast, time begins to slow down.

# The missing 'puzzle' page of Einstein’s unified theory of everything found

Over 100 new pages of Einstein's writings, including long-lost calculations, have been made public.

- The Hebrew University makes public 110 new pages of Einstein's writings.
- Among the writings is a famously-missing page of calculations on the unified theory.
- Other papers by Einstein talk of politics and personal observations.

# The evolution of mathematics, from agriculture to quantum mechanics

Why is math the universal language? NASA's Michelle Thaller solves that one.

- Mathematics has snowballed from counting to 10 on our fingers, to calculus, to abstract concepts like imaginary numbers that move in 11 dimensions and predict particles physics.
- The math that led us down the rabbit hole of quantum mechanics is bizarre and while we can crunch the numbers, we can't really understand what they mean.
- If the math confirms that particles can move in 11 dimensions, is that a fundamental truth of the universe?

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