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Awesome link. Reminds me that one of my biggest gripes with movies is that when they show meteors (or whatever) entering Earth, it's never at realistic speeds.

Awesome link. Reminds me that one of my biggest gripes with movies is that when they show meteors (or whatever) entering Earth, it's never at realistic speeds. They're always super slow and floaty, hovering in the sky to menacing effect. Great, that's the artist's choice. But the real thing is so much scarier, like this footage! And it's still a fraction of the speed of an interstellar object.

marcosdumay 3y ago
On movies those are usually very large objects. Very large objects do hoover menacingly for a very long time before they finally appear to fall for a few seconds. The larger it is, the longer it will stay hoovering and only slowly growing in size.
- ericbarrett 3y ago
  Nah, even the big ones are shown sauntering through the atmosphere at maybe Mach 3, trailing smoke and flames like lit pitch. A city-sized asteroid wouldn't be more than a bright dot until the last seconds before entry, and at interstellar speeds it would take about three seconds to go from the vacuum of space to ground impact unless it had a very shallow vector.
  - pfdietz 3y ago
    At relativistic speeds it would take about 1 millisecond to go from LEO altitude to the ground.
    - buildbot 3y ago
      A relativistic asteroid would not be a good time for earth. Apparently according to gpt4 (so big grain of salt), a 1km asteroid going 0.9c is roughly 4.37×10^16 megatons of TNT worth of energy.
      - szundi 3y ago
        Or a grain of TNT
      - dylan604 3y ago
        that's one of those too big to comprehend type numbers. that's fine when talking about number of atoms, or the distances to another galaxy. trying to have my brain apply that to explosion just immediately goes to BSOD
        buildbot 3y ago
        Yeah same haha - for a slightly more relevant number, if every nuclear weapon yielded 50MT of TNT, the asteroid impact is approx 63 Billion times the entire worlds nuclear arsenal in terms of power.
        short_sells_poo 3y ago
        And that is still impossible to comprehend, so how about this, the Sun's energy output is about 10^10 megatons of tnt per second, so this impact would release 1 million second's worth of the Sun's output, or about 12 days. In other words, it would instantly vaporize the entire planet.
        buildbot 3y ago
        For the ultimate nerd snipe, how far would the light from that explosion be visible?
        dylan604 3y ago
        using what to "see"? naked eye? binocular aided? telescopes? also, seen by who/what? for the only known living things that could see it, it would be the last thing they did see. so maybe as far away as a couple of inches?
      - pineaux 3y ago
        This is in the correct ballpark. But 0.9c is crazy fast. [Expanse spoiler alert] I love how they use this mechanic for storytelling in "The Expanse". The rebels of the belt threaten earth by slinging rocks at it at really high speed. Seems a very realistic way of interplanetary war. Why not bend some fast moving rocks to your enemy?
- sushisource 3y ago
  >stay hoovering Hehe, I too love vacuuming.
  - dylan604 3y ago
    No, that's Hoovering. case sensitivity is important /s Edit: added /s for those unable
    - wongarsu 3y ago
      I've never seen anyone capitalize googling or astroturfing, though my dictionary seems to want to capitalize Xeroxing.
    - kwhitefoot 3y ago
      No one does that. Except perhaps the PR and legal departments of the Hoover company. I suppose you capitalise aspirin as well.
pfdietz 3y ago
The other problem with movies showing large meteors is how dim they are. In reality you would be blinded, even lethally burned, before the thing even hit the ground.
sdflhasjd 3y ago
Hollywood does slow explosions too. Its kind of a funny meta-anachronism when CGI uses the slow firey explosions that I suppose are inherited from the limitations of practical effects using gasoline deflagrations. YouTube has shown people real big explosions (Beirut, Tianjin, etc) and how vicious they are, but you rarely see a CGI shock wave. Rockets too, RPGs are fast but movies have them sauntering through the air.
- ajuc 3y ago
  I mean just look at laser beams in sci-fi :)
abecedarius 3y ago
Imagine if Don't Look Up had tried for a realistic comet impact. It could make a much greater artistic impact, the contrast to the surrealistic spin games up to that point.
kragen 3y ago
the chelyabinsk meteor was super slow and floaty, hovering in the sky to menacing effect (while glowing much brighter than the rising sun): https://youtu.be/gRrdSwhQhY0 https://youtu.be/gRrdSwhQhY0 however, that's because its trajectory was nearly horizontal rather than nearly vertical, so most of the people who saw it and were injured by it were tens of kilometers away, and it broke apart (exploded really) at 30 km up. it was initially traveling 19 km per second, 2½ times leo orbital speed. if you're traveling 19 km per second vertically instead of horizontally you only have 5 seconds from the von karman line (100km) until you make a crater or a tunguska 3 seconds from visibility to devastation still might be enough for hollywood dramatic flair https://en.wikipedia.org/wiki/Chelyabinsk_meteor https://en.wikipedia.org/wiki/Chelyabinsk_meteor

marcosdumay 3y ago

On movies those are usually very large objects. Very large objects do hoover menacingly for a very long time before they finally appear to fall for a few seconds. The larger it is, the longer it will stay hoovering and only slowly growing in size.

ericbarrett 3y ago
Nah, even the big ones are shown sauntering through the atmosphere at maybe Mach 3, trailing smoke and flames like lit pitch. A city-sized asteroid wouldn't be more than a bright dot until the last seconds before entry, and at interstellar speeds it would take about three seconds to go from the vacuum of space to ground impact unless it had a very shallow vector.
- pfdietz 3y ago
  At relativistic speeds it would take about 1 millisecond to go from LEO altitude to the ground.
  - buildbot 3y ago
    A relativistic asteroid would not be a good time for earth. Apparently according to gpt4 (so big grain of salt), a 1km asteroid going 0.9c is roughly 4.37×10^16 megatons of TNT worth of energy.
    - szundi 3y ago
      Or a grain of TNT
    - dylan604 3y ago
      that's one of those too big to comprehend type numbers. that's fine when talking about number of atoms, or the distances to another galaxy. trying to have my brain apply that to explosion just immediately goes to BSOD
      - buildbot 3y ago
        Yeah same haha - for a slightly more relevant number, if every nuclear weapon yielded 50MT of TNT, the asteroid impact is approx 63 Billion times the entire worlds nuclear arsenal in terms of power.
        short_sells_poo 3y ago
        And that is still impossible to comprehend, so how about this, the Sun's energy output is about 10^10 megatons of tnt per second, so this impact would release 1 million second's worth of the Sun's output, or about 12 days. In other words, it would instantly vaporize the entire planet.
        buildbot 3y ago
        For the ultimate nerd snipe, how far would the light from that explosion be visible?
        dylan604 3y ago
        using what to "see"? naked eye? binocular aided? telescopes? also, seen by who/what? for the only known living things that could see it, it would be the last thing they did see. so maybe as far away as a couple of inches?
    - pineaux 3y ago
      This is in the correct ballpark. But 0.9c is crazy fast. [Expanse spoiler alert] I love how they use this mechanic for storytelling in "The Expanse". The rebels of the belt threaten earth by slinging rocks at it at really high speed. Seems a very realistic way of interplanetary war. Why not bend some fast moving rocks to your enemy?
sushisource 3y ago
>stay hoovering Hehe, I too love vacuuming.
- dylan604 3y ago
  No, that's Hoovering. case sensitivity is important /s Edit: added /s for those unable
  - wongarsu 3y ago
    I've never seen anyone capitalize googling or astroturfing, though my dictionary seems to want to capitalize Xeroxing.
  - kwhitefoot 3y ago
    No one does that. Except perhaps the PR and legal departments of the Hoover company. I suppose you capitalise aspirin as well.

pfdietz 3y ago

The other problem with movies showing large meteors is how dim they are. In reality you would be blinded, even lethally burned, before the thing even hit the ground.

sdflhasjd 3y ago

Hollywood does slow explosions too. Its kind of a funny meta-anachronism when CGI uses the slow firey explosions that I suppose are inherited from the limitations of practical effects using gasoline deflagrations. YouTube has shown people real big explosions (Beirut, Tianjin, etc) and how vicious they are, but you rarely see a CGI shock wave. Rockets too, RPGs are fast but movies have them sauntering through the air.

ajuc 3y ago
I mean just look at laser beams in sci-fi :)

abecedarius 3y ago

Imagine if Don't Look Up had tried for a realistic comet impact. It could make a much greater artistic impact, the contrast to the surrealistic spin games up to that point.

kragen 3y ago

the chelyabinsk meteor was super slow and floaty, hovering in the sky to menacing effect (while glowing much brighter than the rising sun): https://youtu.be/gRrdSwhQhY0 https://youtu.be/gRrdSwhQhY0 however, that's because its trajectory was nearly horizontal rather than nearly vertical, so most of the people who saw it and were injured by it were tens of kilometers away, and it broke apart (exploded really) at 30 km up. it was initially traveling 19 km per second, 2½ times leo orbital speed. if you're traveling 19 km per second vertically instead of horizontally you only have 5 seconds from the von karman line (100km) until you make a crater or a tunguska 3 seconds from visibility to devastation still might be enough for hollywood dramatic flair https://en.wikipedia.org/wiki/Chelyabinsk_meteor https://en.wikipedia.org/wiki/Chelyabinsk_meteor