HDE 226868‭

I've had a number of interesting conversations with people about how the cosmic microwave background (CMB) will evolve in the future. The CMB is the sea of photons left over from the epoch of recom...

0 answers  ·  posted 2y ago by HDE 226868‭  ·  edited 2y ago by HDE 226868‭

Neutrinos have extremely low masses, and it's quite easy for them to reach high energies and speeds. As such, it almost always makes sense to treat a neutrino as being relativistic. I've been doing...

1 answer  ·  posted 2y ago by HDE 226868‭  ·  last activity 2y ago by dmckee‭

The shell variant of a Dyson sphere consists of an artificially-made shell of material about 1 AU in radius encircling a star. The sphere captures most of the star's energy and stores it for future...

1 answer  ·  posted 2y ago by HDE 226868‭  ·  last activity 2y ago by celtschk‭

One way to achieve this would be to simply change the structure of Earth's magnetic field. At the moment, the field is that of a large magnetic dipole, with the field produced by the motion of flui...

posted 8y ago by HDE 226868‭  ·  edited 2y ago by HDE 226868‭

[science-based] almost certainly should be removed - I think we can safely assume that a site called Speculative Science is going to require science-based answers across the board. If an post's not...

posted 2y ago by HDE 226868‭

Before launching the site, we had a discussion on Codidact Meta about naming the category we currently called "Researched Q&A". Other possibilities we explored included "Hard science", our sta...

2 answers  ·  posted 2y ago by HDE 226868‭  ·  edited 2y ago by Monica Cellio‭

The behavior of strange matter is not well understood - least of all under the conditions we're used to on Earth! Most theoretical treatments focus on places in which strange matter is likely to be...

posted 3y ago by HDE 226868‭  ·  edited 2y ago by HDE 226868‭

The Earth would be broken into pieces if the total energy delivered by the impacts was comparable to the gravitational binding energy of the planet. Earth is a sphere, so its binding energy is $$U=...

posted 2y ago by HDE 226868‭  ·  last activity 2y ago by HDE 226868‭

Yeah, that's my fault. I wrote up an answer and posted it, but I deleted it shortly afterwards (and later undeleted it . . . and then redeleted it). I did so because I've been extremely active on S...

posted 2y ago by HDE 226868‭

I was the mod who deleted the comment - thanks for bringing this up. The main reason I deleted it was that I figured that the comment was primarily for the benefit of the poster, rather than the co...

posted 2y ago by HDE 226868‭  ·  edited 2y ago by HDE 226868‭

To accurately answer your question, you might need to use a stellar evolution code, either doing your own modeling or looking up existing data tables. I'd recommend the MESA code for the former app...

posted 4y ago by HDE 226868‭  ·  last activity 4y ago by HDE 226868‭

In most quantum field theories$^{\dagger}$, we have a quantity called the Lagrangian, from which we can derive information about the behavior of our system. It consists of a number of terms represe...

posted 3y ago by HDE 226868‭  ·  edited 2y ago by HDE 226868‭

Yes, if the orbit isn't circular. Seasons can definitely occur on a tidally locked planet. Just like normal planets, tidally-locked planets don't need to have perfectly circular orbits. This mean...

posted 2y ago by HDE 226868‭  ·  edited 2y ago by HDE 226868‭

A young B-type star (with a mass of about 10 M$_{\odot}$) is surrounded by a debris disk extending from about 2 AU to 1000 AU away. The disk has a mass of about 300 Earth masses - enough to form qu...

2 answers  ·  posted 8y ago by HDE 226868‭  ·  last activity 2mo ago by James McLellan‭

The Milky Way and Andromeda will collide a few billion years in the future. Stellar collisions will be rare because - as Douglas Adams put it - "Space is big. Really, really big." In the galactic d...

3 answers  ·  posted 7y ago by HDE 226868‭  ·  edited 2y ago by HDE 226868‭