Comments by "David Elliott" (@davidelliott5843) on "Astrum" channel.

  1. Around 1750 AD (during the middle of a 400 years long cold period) we had CO2 at 180ppm. By 1950 CO2 had reached 200ppm but temperatures had warmed faster than the CO2 built up. Today we have 400ppm CO2 but temperatures, measured via ice core data, have hardly moved and have possibly got colder. CO2 does not seem to have the warming effect we are constantly told it has.
    33
  2. More likely “our galaxy”. There will be life elsewhere in the universe but sheer distances mean we can never meet. Not to mention the temporal issue. We are here before or after they were there.
    20
  3. Mars has an atmospheric of CO2 with just 1% of earth’s pressure all bathed in deadly ionising radiation and blasted by abrasive toxic dust. Humans cannot live there without space suits. We would need fully sealed cabins much like the space craft that took people to the planet. Hopefully the dust won’t destroy the seals. Hopefully the people won’t go barking mad. Hopefully the years of low gravity won’t permanently ruin their health.
    15
  4. This exactly why we have the space weapons treaties. But we deliberately don’t prevent anyone from flying satellites over “competitors” countries. Such flights are far too useful.
    11
  5. Billions of years ago, Earth and Mars both had rivers. However Mars is too small and no longer has useful air or any water.
    7
  6. Hot basalt on the moon will remain fluid far longer than on earth - there's little conductive cooling effect and we can see how it flooded into a smooth "sea" of dark rock. It could have settled around older peaks. Alternatively, less dense rocks might have literally floated to the surface. Is the "sea" deep enough for that?
    4
  7. Best of all the photon doesn’t exist. It’s just the smallest parcel of light that maths could dream up. I’m sure there’s a rent joke in there as well.
    3
  8. Be a booger if we knock a big metal rock onto a collision course with Earth.
    2
  9. Troll
    2
  10.  @Ewumm  Maybe a layer of graphene.
    2
  11. Volcanoes (cryo or thermal) need an energy source. Bearing in mind the Charon and Pluto have no relative motion what could be powering those volcanoes?
    2
  12. Did anyone know that Hubble main mirror is basically the same technology used on spy satellites and made by the company which makes spy satellite mirrors? Both happened to fit into the Space Shuttle because it’s load bay was built to carry big spy satellites. There’s no such thing as a coincidence.
    2
  13. The only way a spacecraft whacking an asteroid far further away than expected suggests the asteroid was a lot less dense than we thought.
    2
  14. Patrick Moore the founder member of Greenpeace tells us the current warming phase is simply part of a 1000 Year natural cycle. Data from Greenland ice cores show that we have approximately 500 years of alternating warm and cold. The Romans had it warm. We are currently on a warming trend. Interestingly, CO2 has followed the trend. More when it’s warm. Less when it’s cold.
    1
  15. In March 2018 UK had a Sudden Stratospheric Warming. It caused a period of cold easterly winds. Estuaries on the East side of southern England actually froze. Frozen sea is almost unheard of in UK. The last one was 1981.
    1
  16. This object came and went too fast to test any of the multitude theories. The nuttiest nut job idea is as unprovable (almost) as any other.
    1
  17. Water expands when it warms. Areas held down by mile thick ice sheets spring back causing adjacent areas to sink. (It’s happening in UK. That rebound takes thousands of years. The ice sheet rapidly melted 12000 years ago. An event that could not be caused by human CO2. So what did cause the sudden and very rapid melting of ice?
    1
  18.  @NexusGamingRadical  Technical term - Post-glacial rebound (aka isostatic rebound or crustal rebound) is land riding after the ice melted 12000 years ago. The north of UK is rising causing the south to sink. Google it.
    1
  19. People living on the Caspian Sea southern shore get a consistent dose of 250 mSv per year. They have no ill-effects and possibly a reduced rate of cancer. The international job related dose is just 20mSv. The people of Ramsar show that low dose radiation an be beneficial. That said their dose is probably where any beneficial effects swing into being dangerous.
    1
  20. Oxygen causes a blue sky. Mars has no free oxygen. If the planet ever had life it died billions of years ago as the atmosphere got literally blown away.
    1
  21. The object was tumbling so much that anyone inside would have been scrambled aeons ago. If it was an alien craft. Its contents were dead a VERY long time ago.
    1
  22. Why are the samples not put into tubes before being stored in the carousel? Oh silly me, that would be too expensive.
    1
  23. Faraday cages need to be conductive to work properly. A person at the same potential as the surroundings is safe. It's only when they gain a differential charge that a shock becomes risky.
    1
  24.  @human_isomer  All heavy elements are chemically toxic. Natural uranium is only slightly radioactive but if you were using enriched it could become a problem.
    1
  25.  @andretokayuk8100  Except much dust will get blown away from the explosion. Light photons at the levels made by a nuke have the power to blow dust away from the explosion. Under The Moon's low gravity and zero atmosphere that dust will circle for weeks. Much of it will fall back to where it came. Then there's the fallout. Radiation can be shielded against but radioactive particles will get carried on space suits and equipment and will contaminate the people using them.
    1
  26. Mars looks incredibly depressing. I think the biggest problems will be the mental health of colonialists. I mean why would anyone want to spend more than 1 day on Mars? It’s cold, toxic, bathed in radiation and everything is rusty.
    1
  27. Power will be problematic. Solar panels are 50%less effective on Mars and the abrasive regalith will etch the surface.
    1
  28. The equivalent weight of a few million cars (whatever that means) is frankly not a lot of water. If it’s used for anything other than life support it’s likely to be used up very rapidly. I cubic metre = 1 ton = 1 car (near enough). You can get that from one lake on earth.
    1
  29. Only one of the three rocket making billionaires can put people into orbit. Only one is building a satellite internet system. Only one regularly re-uses his rockets.
    1
  30. It's likely that Earth Venus and Mars all had life for many millions of years. Mars with no magnetic field lost its atmosphere and went cold. Venus turns to slowly to develop a core magneto so also has no significant magnetic field. It also has much more active core which boiled off the seas allowing UV and solar wind to blow away the hydrogen.
    1
  31. The point about ionising radiation is a bit simplistic. There are areas on Earth where people live normal lives despite high levels of background radiation. Ramsar in Iran sees 270 mSv. The world occupational limit is just 20 mSv
    1
  32. Birds were running the show until a big rock did for the big clever ones.
    1
  33. High level nuclear waste as in “spent” nuclear fuel has a half life of 30,000 years. It’s nasty stuff. That’s because today’s nuclear reactors extract less than 4% of the fissile energy. We have a reactor that will extract 99% of the fissile energy. There will be waste but, its half life is 30 years. All of the long life elements are fissioned into short life isotopes. That reactor is the British Moltex static salt “waste burner”. It’s undergoing homologation in Canada with the first reactor making power by 2030.
    1
  34. 1970s electronic components and integrated circuits were physically big enough to withstand radiation damage. Todays microelectronics would have failed long ago.
    1
  35. At ground level 200 watts per m sq cones directly from sunlight. 300 watts comes from the atmosphere. CO2 adds about 2 watts. The effect is too small to overcome Milancovic cycles.
    1
  36. I live in Devon (England’s South West. At midnight the sun is as far below the horizon as it will ever be jet in late June you can see the blue after sunset glow. I’ve not seen no Ti Lucent clouds this year but that glow shows how atmosphere refracts light into the night shadow.
    1
  37. We are told a black hole collapses to a singularity. Nobody asks why it needs to go that far. I believe the object simply has to be massive enough to prevent light escaping. The lump at its centre will be there. You just can’t ever escape its gravity. If you can actually get that fat during the life of the universe. Time stops at the speed of light. Gravity at the event horizon stops light so presumably it stops time as well.
    1
  38. Does matter ever cross the event horizon? Gravity powerful enough to stop light must also stop time. In which case anything that survives the tidal destruction would effectively stop on the event horizon. It’s time stops.
    1
  39. USA is (or was) spending 3% of the defence budget which itself is just 3% of the USA GDP. It’s pocket change. By the way it’s not a proxy war. It is incredibly stupid (1) because political weakness in US government gave Putin the feeling he could get away with it. (2) Putin was stupid to start the war at all.
    1
  40. IPCC exists to control atmospheric CO2 caused by humans. They are not allowed to consider any other options. CO2 has been considerably higher than today while global temperatures were lower. We also need to consider that CO2 really is plant food. The coldest of the last cold period was around 1750 (Little Ice Age 1300 AD to 1850 AD). CO2 dropped it always does when it’s cold and reached 180 parts per million (ppm). Photosynthesis stops at 150ppm. The levels increased gradually as world temperatures warmed up. By about 1950 we had 200ppm. Not a huge difference. The CO2 shot up after 1950 so today we have 400ppm. But temperatures have not accelerated. They are just following the upward trend that’s gone one for thousands of years.
    1
  41. Is gravity a very low frequency electromagnetic wave?
    1
  42. International law in fact does not exist. If a country wants to oppress its people or fly nuclear tipped rockets anywhere it likes there is no legal force to stop them. Think NK or it’s much bigger neighbour. Or the other big and nasty country that thinks it can do what it likes.
    1
  43. There’s no need to be upset. Video titles are done for the YouTube algorithm.
    1