If you somehow got rid of your rest mass to move at the speed of causality, two things would happen: first, you'd experience no time; second, you'd instantly crash into your destination and die in a rather energetic way. That's the neat thing about photons; from a photon's POV time and distance do not exist. A photon, from its POV, is emitted and absorbed at the same time in the same place.
Aside from the fact that anything with mass cannot travel at the speed of light… Lots of fun things happen as you approach the speed of light. There’s an excellent mostly-hard sci fi novel called Tau Zero that explores this concept in depth and, despite being older, is worth the read.
(1) Time dilation (the universe and you have different clocks).
(2) blueshifting of objects in front of you. At 0.95c, basically all visible starlight in front of you has been blueshifted into ionizing radiation. Fun fun.
(3) shape distortion. You become more needle-shaped – getting very long and skinny, as observed by the rest of the universe.
(4) you become a nuke. At .99c if you run into anything, your kinetic energy related explosion would be roughly 6x the Tsar Bomba (largest nuke ever detonated) for each kg of mass. Or, put another way, each kg of your mass would impact with the energy of 3kg of antimatter contacting 3kg of matter. Boom.
Sci fi always overlooks the last one. Near light speed combat is basically firing buckets of sand at planets and blowing them up.
Speaking of sci fi, Kim Stanley Robinson’s 2312 does a really good job of incorporating the existential dread and lurking horror of weaponized orbital mechanics.
The time thing is interesting, but I feel like no one talks much about the appearance of passing objects. That is, I wonder how the image of a passing celestial object might distort due to length contraction and any other effects. I’m still trying to understand that. This article seems pretty digestible, so far.
I love this line, "...is an asteroid-sized moon orbiting a few thousand miles (or kilometers) above the Martian surface..." A few thousand miles...or kilometers, we don't care, pick your favorite.
Starlink is causing problems, but it seems to me that this image was made in bad faith to oversell the case. The caption says it’s a combination of 29 separate exposures, but if those exposures were combined properly, you wouldn’t see the satellites (median combination does wonders, and there are more sophisticated techniques which do even better). Some streaks start at one chip edge and extend to another chip edge, without continuity across the focal plane. So it’s not at all clear just how this image was created. And why on earth is it not flat-fielded? Maybe this is just really sloppy image processing, but even amateurs can do far better than this, leaving the final combination with no satellites at all.
Our navy terrorizes most of the world. The US Army just figured out Class A uniforms. There is no reason why the Bundeswehr should outshine us in uniform design. It’s a tailoring gap we must overcome before we can conquer ze world. So you have nothing to worry about, except coming up with better comments.
It’s not a secret, just hard for amateurs to do. No doubt states with space monitoring equipment always knew. He just did it with a camera in his backyard and his laptop.
Also, he’s Finnish.
Amateur observations of the spaceplane indicate it is flying in a highly elliptical orbit ranging between 201 and 24,133 miles in altitude (323 and 38,838 kilometers). The orbit is inclined 59.1 degrees to the equator.
This is not far off the predictions from the hobbyist tracking community before the launch in December. At that time, enthusiasts used information about the Falcon Heavy’s launch trajectory and drop zones for the rocket’s core booster and upper stage to estimate the orbit it would reach with the X-37B spaceplane.
Salad is good for you, generally speaking, so growing fresh greens in orbit seems like a winning way for space farers to stay healthy. New research suggests that as nutritious as space salad might be, it could pose something of a risk to astronauts.
The problem is growing leafy plants like lettuce and spinach in space can come with a side dish of bacteria, according to a new study from a team at the University of Delaware. In tests on plants grown in simulated microgravity, they were shown to actually be more susceptible than normal to the Salmonella enterica pathogen.
Sounds like not a big problem at all. Seems like they'll just have to use appropriate cleaning methods. Even in the worst case scenario they would probably just have to use food irradiation.
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