Toggle light / dark theme

Can black holes tunnel to white holes?

Tl;dr: Yes, but it’s unlikely.

If black holes attract your attention, white holes might blow your mind.

A white hole is a time-reversed black hole, an anti-collapse. While a black hole contains a region from which nothing can escape, a white hole contains a region to which nothing can fall in. Since the time-reversal of a solution of General Relativity is another solution, we know that white holes exist mathematically. But are they real?

‘Crowd Control,’ part 22: Spies in heaven

The final chapter in CNET’s historic “crowdsourced” sci-fi novel is out. You can read the whole thing here. Transhumanism is a large part of it (and a fictional version of my being President is in it too). This book was written by the participating public. This was a huge plus for the Transhumanist movement, as it meant transhumanism appeared many times on CNET as chapters were released (CNET is the world’s leading tech site in traffic):


In the finale of CNET’s historic crowdsourced sci-fi novel, the war on Earth is over, but the story of the multiverse may just be getting started.

Could the Big Bang have been more of a Big Bounce?

When the bang became a bounce.


How the universe began is one of the most brain-breaking questions you could possibly ask, and the Big Bang is probably the answer most people accept. But what if the infinitely dense point from which the entire universe burst forth wasn’t the beginning of everything, but merely the middle of an ongoing cycle? That’s the theory of the Big Bounce, which suggests that the universe regularly cycles through periods of expansion and contraction, meaning the Big Bang may have been preceded by an earlier universe collapsing in on itself. A new study details how this might be possible.

The idea of the Big Bounce has been bouncing around since 1922, but explaining just how the universe transitions between expanding and contracting has always been an issue. What’s to stop a universe just contracting into a point and collapsing completely? According to researchers from Imperial College London and the Perimeter Institute for Theoretical Physics in Canada, it may be the same quantum mechanics that prevent atoms from deteriorating into nothing.

In our universe as it currently is, there’s an asymmetry between the laws of the subatomic world and those that govern larger matter. Large-scale physics and quantum mechanics exist side-by-side now, but that doesn’t mean it’s always been the case: back when the universe was young and everything in it was tiny, quantum mechanics may have been the only set of laws in effect, an idea known as conformal symmetry. So the same processes that keep electrons from losing energy as they orbit the nucleus and destroying the atom may have prevented the universe from collapsing into oblivion.

Extra dimensions, gravitons, and tiny black holes

Why is gravity so much weaker than the other fundamental forces? A small fridge magnet is enough to create an electromagnetic force greater than the gravitational pull exerted by planet Earth. One possibility is that we don’t feel the full effect of gravity because part of it spreads to extra dimensions. Though it may sound like science fiction, if extra dimensions exist, they could explain why the universe is expanding faster than expected, and why gravity is weaker than the other forces of nature.

In our everyday lives, we experience three spatial dimensions, and a fourth dimension of time. How could there be more? Einstein’s general theory of relativity tells us that space can expand, contract, and bend. Now if one dimension were to contract to a size smaller than an atom, it would be hidden from our view. But if we could look on a small enough scale, that hidden dimension might become visible again. Imagine a person walking on a tightrope. She can only move backward and forward; but not left and right, nor up and down, so she only sees one dimension. Ants living on a much smaller scale could move around the cable, in what would appear like an extra dimension to the tightrope-walker.

A new look at the galaxy-shaping power of black holes

Data from a now-defunct X-ray satellite is providing new insights into the complex tug-of-war between galaxies, the hot plasma that surrounds them, and the giant black holes that lurk in their centres.

Launched from Japan on February 17, 2016, the Japanese space agency (JAXA) Hitomi X-ray Observatory functioned for just over a month before contact was lost and the craft disintegrated. But the data obtained during those few weeks was enough to paint a startling new picture of the dynamic forces at work within galaxies.

New research, published in the journal Nature today, reveals data that shows just how important the giant black holes in galactic centres are to the evolution of the galaxies as a whole.