# TrendingSideways

science, psychology, and culture shifts

Posts Tagged ‘relativity’

## The Theory of Relativity for Kids, Part 2 – The Twin Paradox

1 Comment, All Posts, by Carter Bowles.

Last week I wrote an intro to the theory of relativity for kids (and curious adults). I’ll be continuing this over the next several weeks. Click the link above to see the intro, or read ahead to learn more.

## The Theory of Relativity, For Kids

22 Comments, All Posts, by Carter Bowles.

So you want to understand the theory of relativity, and you’re a kid? No problem. Let’s get started.

(If you’re a parent looking for some activities to help teach your kid, consider ordering Albert Einstein and Relativity for Kids: His Life and Ideas with 21 Activities and Thought Experiments. And if you’re an adult who just wants to understand relativity, there’s no shame in reading on.)

## How Does Gravity “Escape” a Black Hole?

No Comments, All Posts, by Carter Bowles.

Black holes are often described as collapsed stars with such an intense gravitational pull that nothing can escape. This begs the question: “How does gravity ‘escape’ the black hole in the first place?”

## Did the LHC Catch a New Type of Matter: Color-Glass Condensate?

No Comments, All Posts, by Carter Bowles.

MIT physicists working at the LHC may have discovered a new kind of matter by accident. The existence of this type of matter, called “color-glass condensate,” was proposed shortly before the discovery.

## The Flow of Time Has Been Confirmed

No Comments, All Posts, by Carter Bowles.

Up until the the 1960s, physicists believed that time worked the same forward as it did backward. For example, in classical physics, if you reversed the momentum of every particle in the universe, the universe would look exactly like a tape being run in reverse.

This of course begs the question: if the laws of physics work the same way forward as they do backward, why does time flow forward and not the other way around?

A new paper hints at an answer. The forward flow of time may not be an illusion. At the very least, we can now be sure time has an “arrow.” The laws of physics work differently in reverse. Now we just need to figure out why.

## Superluminal Communication Testable Within a Few Years

No Comments, All Posts, by Carter Bowles.

Is it possible to send messages faster than the speed of light? A new theory could have us testing for an answer within just a few years.

The possibility of faster than light communication is loved by science fiction authors, and mostly loathed by the physics community, mainly because according to Einstein’s (very well tested) theory of relativity it ought to mean time travel is possible, which creates all kinds of unsightly logical paradoxes (among other things).

It is actually for precisely this reason that Einstein despised what quantum theory ended up being, despite his important role in its creation. Einstein and others mathematically demonstrated a phenomenon called quantum entanglement. This phenomenon allows two particles to communicate with one another instantaneously, apparently in complete violation of relativity.

## Converting Energy into Matter: What it Really Means

No Comments, All Posts, by Carter Bowles.

You are almost certainly familiar with the popular equation: E=mc^2, but do you know what it means? If you’ve read a pop science book every now and then, or paid attention in physics and chemistry classes, you may already know that it means mass and energy are equivalent. But this doesn’t necessarily mean what you think it does, either.

First off, we need to distinguish between mass and matter. Mass is a measurable quantity related to concepts like force and momentum. The more mass an object has, the more force it takes to accelerate it at the same pace.

Matter, at this point in our understanding of physics, isn’t necessarily as easy to define as we might think it should be. Matter isn’t necessarily solid (it can be liquid, solid, gas, or plasma), or even “tangible” (neutrinos are matter, but they pass through almost everything like a ghost).

## The Black Hole as a Creator? Dr. Caleb Scharf Explains

No Comments, All Posts, Featured, by Carter Bowles.

Black holes are a place where the universe goes to die. General relativity predicts that they carry you to the end of time and then deposit you inside the event horizon, where it becomes impossible to escape.

And yet Dr. Caleb Scharf, the Director of Astrobiology at Columbia University, wanted to tell me about a different side of black holes. Their intense gravitational fields are also a source of energy, and they may have played a part in the fact that our galaxy had the right ingredients for life.

## Friday Roundup: Stem Cells From Blood, Pregnancy Theory Challenged, Evidence of Gravity Waves

2 Comments, All Posts, by Carter Bowles.

Today we learn that scientists at Johns Hopkins found a way to turn blood cells back into stem cells. Meanwhile, a longstanding theory about human pregnancy faces a formidable challenger, and a revolutionary new material comes from a surprisingly common, and renewable, resource. Finally, scientists observe evidence of gravitational waves. That’s all ahead in today’s Friday Roundup.

## Cliff Pickover on the Beauty of Our Universe

No Comments, All Posts, Featured, by Carter Bowles.

I’m routinely surprised by how little interest most people seem to have in the fundamental forces of the universe. Perhaps it’s because textbooks suck all the life out of the subject matter, or because of a fundamental flaw in the educational system. To me, few things are more interesting.

Dr. Clifford Pickover shares this enthusiasm. He has written no less than 40 books and earned a strong reputation as a science writer. While he holds a PhD in molecular biology from Yale, not to mention 80 patents in computer tech, he believes in melding creativity with science and practices both Shaolin Kung Fu and the piano.

Pickover is clearly anything but average.

I had the opportunity to discuss his latest book with him, aptly named The Physics Book. As you’ll see, he knows how to bring the subject to life.