How About That?
How About That?
I was asked on Twitter on behalf of a very curious four-year-old what was the fastest moon in the Solar System. And I need to admit that I was a bit stumped. Which moon moves the fastest around its planet? Well, the answer might surprise you. Or maybe not. My reasoning is that the bigger […]
Earth
“Everyone always wants to turn the earth in a black hole! Instead, COULD YOU turn it into a neutron star?”
Eclipse
I know why the moon goes red during a total eclipse. But why does it not go red until near totality? Phil, London This is actually a very interesting question, with an (unfortunately) unsatisfying answer. But let’s take a step back and clarify why the Moon goes red during an eclipse, for people w...
How About That?
In a previous post, I discussed how long the Earth would be able to survive without the Sun. We had to assume that our star would magically disappear into nothingness. My friend Gavin asked online: “Can we have a follow-up on no Sun and the effect on orbits?”
In just one minute, thanks to one of the best pop songs of all time, you can learn some amazing facts about Pluto and its moon Charon!
How About That?
The Sun is responsible for all life on Earth and most of our planet’s means of energy production depends on the Sun. We are told that without it we cannot survive, or at least told that we can’t survive for very long. My question is just that: how long would we survive? Our thought experiment […]
How About That?
Sometimes inspiration strikes in unusual ways at unusual times. I was tagged in a quote tweet where Prof Peter Coles states that as an astrophysicist he must contest Prince Harry’s statement that “the stars were aligned when he met Meghan.” Now, I’m currently on my honeymoon in New Zealand and we...
How About That?
A few years ago I filmed a vlog ranting about Astrology being nonsense and I’m now revisiting the subject, not because something has changed (it’s still bullshit), but because I think I understand my anger a bit better. A discussion arose in work concerning the most annoying unfounded beliefs tha...
Time Travel
I recently talked about how time travel to the past is unlikely to be possible. That came with the label that we haven’t found a law that tells us that it’s impossible just yet. We have hints, but no certainty. So what if time travel was suddenly possible? Who should be using it? For what […]
How About That?
Time is a curious dimension. Although we might be still in space, there’s no way for us to be still in time. And while we can explore every direction in space, time has a preferred direction: forward. We are constantly traveling through time, and for us we are going to the boring velocity of 1 […]
How About That?
One of the underlying ideas in Einstein’s general relativity is that for an observer, the acceleration due to gravity, or the acceleration due to thrust, are identical. This is a consequence of the equivalence principle. This phenomenon is the way to achieve artificial gravity in space. No specia...
How About That?
Space is big. The Voyager probe, launched in 1977 to explore Jupiter and Saturn, took 36 years to leave the Solar System. It is the furthest human object from us, and it is still in our neighbourhood. Even the radio waves we sent into space have barely reached a few hundred star systems, and they...