How long would it take to travel to the nearest star?

Proxima Centauri, is our nearest star, about 4 light years away. A light year is the distance light travels in one year, or 9,460,730,472,581 kilometers. That's 9.46 trillion kilometers, or about 5.88 trillion miles. The fastest space ship we ever built was the Juno spacecraft, which in 2016 broke all speed records in space with a... Continue Reading →

Spaceships and Hollywood

Spoiler alert - in the future there never will be artificial gravity - astronauts won't be able to walk around in spaceships. In the movies most spaceships like the Starship Enterprise employ a convenient technology they call "artificial gravity" to overcome this weightlessness problem. In a few movies they even rotate parts of the ship,... Continue Reading →

Space Debris – A Dodging Problem

This is a no frill video (no audio) produced by scientists, to depict just how much junk "litter" we have floating around up in space, some of it going 35,000 miles per hour. Just something to think about.

If two ships are travelling side be side at some major fraction of the speed of light (e.g. 90%) and are, say, 100 yards apart, would they be able to see each other out the portholes?

Great question, and you see, that’s what we mean when we say everything is relative. Your “speed” is always relative to something else. If you don’t compare it to something else, you might as well be standing still. Relative to you, the other spaceship is standing still. You are both just floating there while Earth quickly moves... Continue Reading →

How close to a black hole (with 10 solar masses) must you be before time for you is dilated significantly, compared to your crew’s, 1 million km out?

A thought experiment: I was imagining a scenario where a spaceship tethered their compatriot and lowered him near the event horizon & then pulled him back towards the spaceship before being pulled into the black hole. Wouldn’t time go by quicker for him? Would there be a discrepancy in their ages? Not very far away... Continue Reading →

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