Since we are all bragging about our special knowledge (scuba, aerospace) let me add that I have built powerful multi-stage vacuum pump systems (using different kinds of pumps at each stage) strong enough that the remaining air barely conducts electricity and glows when it does. I used a 9000v neon sign transformer as a poor mans pressure gage. When the pressure got low enough the 9000V would make it glow, sometimes in strange ways, bars and bands and things that I never really understood. When the vacuum got really good the glow went away, probably because there weren’t enough ionized air molecules left to conduct electricity. I was trying to get enough air out that electrons could travel freely, i.e. very fast. In there somewhere I also studied advanced thermodynamics which is where the gas laws describing this behavior comes from. Trust me! The gas laws are a better guide than intuition or gut feel when trying to predict what differences in air pressure will do, in a bag or elsewhere. And practical experience with extreme low pressure is even better.
LOL! This thread has really gotten in depth on the science surrounding a vacuum! 
Let me chime in as a Scuba Diver who in the past worked at an Aerospace Company (as this makes me really feel like I belong here! ) A steak - pretty much like a person - is not going to compress much under pressure! I’ve done a little free-diving, simply holding my breath as I dove to 65 feet or so. This is roughly two atmospheres, and while my lungs did collapse down quite a bit it was only the air compressing in them, not so much my “meatbag body”! I think we might see a steak compressed a bit if juices are squeezed out of it when the bag is put under vacuum, but honestly you’re not going to see the steak itself compressed worth mentioning.
@michihenning I respect your knowledge and esp. overall tech guy background (fellow long time techie myself!), but I think @chiara is right on track here as I think you’ll see when you rethink the scenario.
Yes, agree. It really depends on how soft/compressible the meat is. I’ve had issues with sausages deforming with my vacuum sealer. Soft meat, such as rib eye and salmon, also compress somewhat, as do soft cheeses. (I’ll not make the mistake of vacuum packing ripe brie again.)
I apologise for my combative tone. That was inappropriate and I’ll try not to let it happen again.
@Mirozen I stand corrected. 2 atmospheres trumps the max possible pressure of 1 atmosphere which is what you would get if the pressure in a bag was zero.
I didn’t mention that my vacuum pump experiment was a sealed glass tube with a glass tee in the middle going to the pumps through a non conductive hose. The 9000V connected to metal at the ends of the meter long glass tube, theoretically insulated from the rest of the system. One day I really learned about the electrical conductivity of near vacuum by touching a metal part of the fore pump thereby connecting myself to 9000V through the “conductive” vacuum. It was an experience. I was surprised it didn’t kill me or something even more painful but an electrician since told me that, especially at low current, 9000V can be less dangerous than 110V. Apparently 110V is a sweet spot which stops the heart, sort of a Goldilocks affect. Less voltage isn’t strong enough, it flutters a bit then picks up again. More voltage has the effect of causing the heart to jitter rapidly and then settle down. On the other hand since steak is no longer connected to a heart thus info probably isn’t key to this discussion.
@chiara. I don’t think Glass said the steak compressed. A pancake can have the same volume in a different shape.
If you shock the steak and it begins to moo…THAT’S when I’ll worry!
This thread is becoming fun and fanciful! I am pursuing only for amusement value, for all the nerds here.
@zencuke, I don’t think the steak would liquefy and ball-up on good ole planet Earth! It could liquify (sort of) if it somehow got chewed up by the pumps in your impressive vacuum setup (or possibly if subjected to really tremendous pressure, I guess). But having it ball up would require it to be fluid enough post-chewing (meh, possible, given high water content) and to be in a zero gravity environment. That last bit here is important, but don’t take my word for it! Tell you what: you try to achieve this by pumping the heck out of your bag. That will give me ample time to grind my steak super fine, and pester Elon Musk until he agrees to have it sent to orbit or outer space. We’ll see how that works out for both of us 
. Then we can do a SV cookout with proper steak. Last person who gets a steak to ball up using either of these two methods buys the steak.
@chiara Ah come on now! Cooking a steak isn’t exactly rocket science…oh wait…zero G vacuum balled steak…hey, maybe that IS rocket science!
Waaay off topic, but I can’t resist. A buddy of mine used to run the engine test lab at Aerojet Rocketdyne. He showed me this video just last weekend…
Very funny, and very apt, for all those of us who bragged about their scientific credentials 
I actually didn’t find it bragging. When someone has experience that applies to a discussion and notes it it’s not a brag, it’s just more info.
That’s a great clip, thanks for that! 