baggier t1_je7mc6p wrote

The prototype was a large sized drone powered by a conventional aviation fuel powered turbojet at speeds of about 200 km/h. The switch to hydrogen is theoretical, the hyperspeed (let alone supersonic) is just aspirational. And by aspirational I mean

  1. Raise lots of grants and venture capital
  2. Keep lots of scientists, engineers and management paid for many years
  3. Give up in about 10 years and move on to new project

baggier t1_jd2azh3 wrote

agrred. I am not sure that topical application will be totally effective as the bacteria can hide systemically, and it is not clear whether the enzyme can be administered say by injection without clearance and immune problems. Lots of things kill bacteria, (fire, acids etc) only a very few are useful in humans.


baggier t1_j9caxny wrote

Probably wrong, though cant get the original article due to paywall. This has been suggested before and is not needed, any autocatalytic process with a negative feedback loop (e.g. one enantiomer inhibiting production of the other or using the other as feedstock) will end up with just one enantiomer surviving.


baggier t1_j9c9ai7 wrote

Back in the day the key was weights. If two things combine to give a new substance that is heavier (say iron + oxygen to iron oxide) then it is obviously a compound. If a substance cleanly decomposes to two new substances, then the new substances are simpler and might be elements (say hydrogen peroxide to oxygen and water). After building up lots of these reaction it became clear that some things (e.g carbon) couldnt be decomposed into anything simpler and must be an element.


baggier t1_j2tab8w wrote

I would broadly agree except on the density bit. Tar is not much denser than water but the key attribute is the size of the molecules. Larger molecules have more area to interact with each other, resulting in more attraction and slower motion (e.g. higher viscosity). Tar molecules are about 10-20 times bigger than water.


baggier t1_iy2g9d1 wrote


baggier t1_itjvxjy wrote

To continue - there are two main types of drugs - first small molecules (aspirin, speed, phenacetin etc). These molecules are generally too small for the immune system to see and dont have enough "docking" sites for the immune molecules to latch on to. Many modern drugs are big (e.g. proteins such as artificial insulin) and they are quite likely to generate immune responses if they dont look like what the body expects. They have lots of molecular sites for the immune molecules to grab and recognize. Often these molecules are "pegylated" by the chemists, surrounded by nonimmunogenic polymers that sheild the large molecule from the immune system.