[Bonus] Galactic Navigation, People Born on Mars, Jumping Off Pluto | Q&A 303
Could we find a way to Earth from another part of a galaxy? Would people born on Mars grow taller to adopt to lower gravity? Can you jump off the surface of Pluto? And in our free bonus question on Patreon, what would happen if dark energy is disproved? All this and more in this Q&A.
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Comments (20)
I think the Pioneers plaques showed a map of the pulsars near our solar system, to show the aliens where we are.
MTG?! SIGNED ALPHAS. Just when you think this guy can’t get any cooler…
Hah, the cool part is that I played the game when it was a prototype, with Richard Garfield. :-)
I don't see why being taller and thinner while living on a low gravity world would provide an evolutionary advantage. I am not saying there couldn't be such an advantage, just that I don't know what it would be. Taller men do seem to have an evolutionary advantage in that women seem to find tall men more attractive, but I don't know why that advantage (if it exists) would be more pronounced on a lower gravity planet. All that said, people would probably be slightly taller on Mars than on Earth, but not necessarily because of evolution. Astronauts on the ISS tend to experience an increase in height of about 3% (roughly 2 inches for a 6-foot person) because their spines relax in microgravity. Astronauts return to their previous height within a few months of returning to Earth. Presumably, living with 40% of Earth's gravity might cause only 40% as much spinal compression. However, I am not an orthopedist, so that presumption might be wrong.
That seems to be the trope in sci-fi, but I wonder which recessive genes will rise to the challenge if we live on other worlds for a long time.
An article in Guide to Space a couple of days ago was about a majority of observed galaxies rotating in the same direction. That was presumably based on the difference in red shift of the light from one side the galaxy to the other. Is there any way to determine whether the dark matter around a galaxy is rotating, and if it is, whether it's in the same direction as the normal matter?
In theory, you'd be looking for different red-shifting on opposite sides of the dark matter due to frame dragging. But that's beyond the ability of current instruments. Astronomers just assume that the galaxy is embedded within a larger dark matter blob and they're rotating together.
Hi Fraser, I just read another article on Guide To Space talking about a galaxy that should not exist and I have a question. The article said this galaxy has metals in it. Just like here in our backyard, stars are forming from the bits of stars that came before them and gas clouds. My question is, wouldn’t it be possible that there is still supernova remnants and gas clouds all through the universe then as there is now?? Thanks for everything and congratulations on the new website!
There could still be regions which are more primordial in composition than the rest of the Universe, if they were cut off enough. There have been some discoveries of regions that appear similar to conditions during the first generation of stars in the Universe.
What are your thoughts on the string theory version of the multiple universes' causing the 'big bang'. As far as the possible fact the universe may not have started from a singularity and that the CMB is like the inprint of the two universes touching, the universe bounces away from each other and then attracts back to each other? What are the points for and against this theory?
I'm just a journalist, I don't have opinions about this kind of thing. Some string theories propose this idea as a way to explain the Big Bang, and others reject it. We'll need more evidence.
What are those three cards?
Throne of Bone, Hurloon Minotaur and Wooden Sphere.
Plugging Einstein@Home, come on guys, with the massive budget cuts scientists could really use the help with crunching numbers 🖥️
Are they still operating?
I understand that pulsars are directional. Does this not mean that detecting the same pulsars we see from Earth at other locations in the Galaxy would be a matter of luck and therefore pulsar-based navigation might not in practice be feasible? [I also posted this on the Youtube. Sorry!]
They're not directional, the pulsar rotates so its beam completes a circle hundreds of times a second. You can see it from any direction.
I had the same thought 🤔
Is it better if I keep watching these on YouTube for the views?
Nope, this is the best place.