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Post by jandl100 on Apr 16, 2020 5:10:06 GMT
Yes, I've thought the same. Industry largely shut down, greatly reduced road traffic. Atmospheric pollution must be way down.
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Post by Firebottle on Apr 16, 2020 6:59:41 GMT
In a sentence is it possible to say why it is thought that the universe has 'missing' mass?
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Post by MartinT on Apr 16, 2020 7:31:48 GMT
It's related to the expansion of the universe calculations and accounting for missing mass.
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Post by jandl100 on Apr 16, 2020 8:19:45 GMT
In a sentence is it possible to say why it is thought that the universe has 'missing' mass? In a sentence .... galaxies are spinning way too fast, they should just fly apart given the mass of the stuff that can be seen; but they don't so lots of something extra is assumed to be there to give them enough gravity to hold them together - that something extra is called Dark Matter. Extra sentence - Similar for clusters of galaxies; a lot of extra mass needed to make them as stable as they are seen to be and to account for the motions of the individual galaxies. |
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Post by jandl100 on Apr 18, 2020 7:22:44 GMT
Another take on the video sequences when the proble on its way to the planet Mercury did a flyby of Earth.
"A compilation of about 200 images collected by the joint European-Japanese mission BepiColombo during its first – and only – flyby of Earth on 10 April 2020, a manoeuvre needed to adjust its trajectory en route to its destination, Mercury. The spacecraft, equipped with three 'selfie' cameras, captured a series of stunning images of our home planet as it closed in, approached, and finally departed. In this video, Earth first appears as a rotating marble from behind the spacecraft structure and high-gain antenna in the sequence captured on 9 April. Later, in the images shot just before closest approach, less than 13 000 km from Earth's surface, the planet appears in greater detail, with the outline of East Africa, the Arabian peninsula and India well in sight, between the spacecraft’s instrument boom on the left and its medium-gain antenna on the right. Finally, the sequence of images taken by BepiColombo as it moved away on 10 and 11 April show a crescent Earth shining against the cosmic darkness; towards the end of the video, the Moon also makes an appearance, visible as a tiny speck of light near the end of the spacecraft solar array.Full story: BepiColombo takes last snaps of Earth en route to Mercury
Credit:Images: ESA/BepiColombo/MTM, CC BY-SA 3.0 IGO Music: TV3 - CC BY-NC-ND 4.0 Lyrics author & melody composer: Stefano OrsiniMusic score: Angelo Coccia & Silvano Buogo"
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Post by jandl100 on Apr 18, 2020 7:45:58 GMT
In a sentence is it possible to say why it is thought that the universe has 'missing' mass? In a sentence .... galaxies are spinning way too fast, they should just fly apart given the mass of the stuff that can be seen; but they don't so lots of something extra is assumed to be there to give them enough gravity to hold them together - that something extra is called Dark Matter. Extra sentence - Similar for clusters of galaxies; a lot of extra mass needed to make them as stable as they are seen to be and to account for the motions of the individual galaxies. --- and a useful piece of additional info - the Dark Matter problem is fairly extreme; there needs to be 5 times as much dark matter as there is ordinary detectable matter in order to hold things together. So we haven't really got a clue atm what 85% of the matter in the universe is.  That's assuming the issue is mass and not a more fundamental misunderstanding of physics. |
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Post by jandl100 on Apr 21, 2020 9:56:02 GMT
It looks very much like a collison between two 125 mile wide objects in a star system 25 light years away has been observed. What was first assumed to be the discovery of a planet around the star Fomalhaut has not behaved as it should. The oberved planet was seen to slowly fade and then vanish - not usual behaviour for a planet! It's now believed the images were of an expanding cloud of dust and ice resulting from a collison between two large-asteroid sized objects. phys.org/news/2020-04-astronomers-planet.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletterArtist's impression of the bust-up.  |
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Post by user211 on Apr 21, 2020 17:01:13 GMT
Not an unreasonable assertion. It's basically a big game of Atari's Asteroids out there!
Big problem if we ever mange to get to one tenth or so of ljght speed. Hit something even tiny and you are probably done.
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Post by jandl100 on Apr 21, 2020 17:25:09 GMT
"Shields up, Mr Sulu"  |
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Post by MartinT on Apr 21, 2020 18:24:46 GMT
A smoke particle at 0.3C would create damage.
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Post by jandl100 on Apr 21, 2020 18:32:33 GMT
I wonder what happens at Warp Factor 4?
Is there dust in hyperspace?
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Post by user211 on Apr 21, 2020 22:10:00 GMT
Have a listen to THE MAN, Alcubierre himself.
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Post by jandl100 on Apr 22, 2020 8:22:12 GMT
that vid wasn't a waste of time - very informative
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Post by jandl100 on Apr 22, 2020 9:09:26 GMT
So we need negative mass... about a Jupiter-sized chunk, and a pre-laid Alcubiere Highway, and protection from intense gamma rays.
Looks like it would make an excellent planet-buster weapon as well.
Hmm. Maybe we need an alternative means of FTL travel.
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Post by MartinT on Apr 22, 2020 9:14:49 GMT
Maybe humanity has to grow up before being able to wield such power.
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Post by user211 on Apr 22, 2020 9:21:15 GMT
that vid wasn't a waste of time - very informative Glad to hear it. It's all pants anyway. What's basically happening is the programmers writing the simulation we are all living in (well, me at least) are just starting to flesh the universe out a bit more as they are bored. Consequently we can see a bit more of what's going on. But the cheap trick is to make FTL travel impossible so we can't explore the detail, and they don't have to work to hard. They actually aren't very good programmers so there's lots of bugs and inconsistencies that make it very hard to understand. Particularly at the quantum level, which is total bollocks.  Have you ever got into Nick Bostrom, Jerry? |
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Post by MartinT on Apr 22, 2020 9:33:08 GMT
Red pill / blue pill?
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Post by jandl100 on Apr 22, 2020 9:37:46 GMT
Yes, the modelling simplifications they are using in the simulation in which we live are quite obvious ... the speed of light limit is a great processing saving, so is the probabilistic nature of quantum mechanics. Anyway I'm obviously the main centre of interest of the simulation, the rest of you are just minor subroutines. |
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Post by MartinT on Apr 22, 2020 9:40:23 GMT
How dare you call me a subroutine, sir! I am a beautifully fleshed out, fully loaded dynamic link library.
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Post by jandl100 on Apr 22, 2020 9:42:25 GMT
Nick Bostrum, no, never heard of him
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