Home › Discovery Notes

Science Discovery Notes

My journal is for things as I learn them. This page is more like my messy notebook - cool facts, things I've observed, questions I still don't have answers to, and short summaries of stuff I've read.

Facts that stuck with me

A billion tonnes

A teaspoon of neutron star material would weigh about a billion tonnes on Earth - roughly a mountain.

600 million tonnes/sec

How much hydrogen the Sun fuses every single second.

10^15 gauss

A magnetar's magnetic field. Earth's is about 0.5 gauss.

Outshining a galaxy

For a few weeks a supernova can be brighter than its entire home galaxy of billions of stars.

2.5 million years old

The age of the light from the Andromeda galaxy by the time it reaches our eyes.

Made of star stuff

The iron in your blood and calcium in your bones were forged inside dead stars.

Observations from my backyard

Orion Nebula: Found it below Orion's belt with binoculars. It looks like a faint fuzzy smudge, but it's a stellar nursery with new stars forming inside. Best seen on a moonless night away from streetlights.

The Moon's terminator: The line between light and dark on the Moon is where shadows are longest, so craters look most dramatic there - not at full Moon like I expected.

Light pollution: I counted way more stars when we visited the countryside than I can see at home. It really made me notice how much city light hides the sky.

Questions I still have

  • What does matter actually look like inside a neutron star? Scientists aren't fully sure either.
  • Do all fast radio bursts come from magnetars, or only some of them?
  • If the universe is expanding, what is it expanding into? (I've read this question doesn't quite make sense, but I want to understand why.)
  • Could there be magnetars that have gone completely quiet and we'd never know?

I think having questions you can't answer yet is one of the best parts of science.

Mini research summaries

Summary: how a supernova actually explodes

A massive star's iron core can't make energy by fusion, so it collapses in under a second. The outer material falls in, hits the ultra-dense core, and bounces back as a shockwave. Tiny particles called neutrinos help blast the star apart. What's left is a neutron star or black hole, surrounded by an expanding cloud of new elements.

Summary: why magnetars are different from pulsars

Both are neutron stars. A pulsar shines using the energy of its spin. A magnetar shines using the energy stored in its magnetic field as that field slowly decays. The magnetar's field is roughly a thousand times stronger, which is why it can crack its own crust and fire off gamma rays.