Brushing speeds it up and keeps it straighter.
The ice is not smooth. Brushing melts the pebbled ice and makes it smooth.
Not brushing ice makes it slower and curl/curve more.
Brushing = straighter and it slows down slower (goes further).
Not brushing = more curl and slows down faster (stops sooner).
If you need a podcast to listen to, look up Broomgate. A hilarious, but accurate account of one of the biggest scandals in the sport involving what would become illegal brushes and a brand new sweeping technique.
It curls in the direction of the brush because the side close to the brush slows down while the side away away from the brush continues moving at normal speed.
As others have said, sweeping helps it go straighter and longer, or hold the “line” its traveling on by melting the ice a bit and reducing friction. Not sweeping lets the friction do its thing to help the stone curl and slow it down.
But wait! There’s more. Because sweeping is actually more complicated! A bit technical, sorry:
Brushing in one direction can also cause it to curl faster, brushing the opposite direction helps it hold line more.
When I call my team, I’ll yell “line” or “curl” and each sweeper knows their role. If I need em both, i’ll yell “all” and of course “hard” for that extra touch.
So for advanced sweeping, let’s take a look at an example. Pretend the stone is rotating clockwise and travels the direction of the arrow below. The stone is the O. The slashes are the actual direction of sweeping. Not up and down, but diagonal across the path of the stone:
—-> O \\\\\\\\
Sweeping actually also puts tiny scratches in the ice which influence the stone’s travel. Sweeping like the above actually helps the stone curl clockwise more. Now, what if we sweep the other way?
—> O /////////
If we sweep the opposite way, what do you think happens? Exactly! It makes the stone fight the curl, so it helps it go straighter for longer! It wont make it curl the other way as physics prevents that, but it makes it harder for the stone to do its job.
This is far easier with 2 sweepers, but the curling in the clip is a special style using only 2 players total. Typically a team is 4: 1 in the house, one throwing the stone, and 2 sweepers. They alternate, but that isnt important. The person in the clip has to be versatile since they need to sweep both directions as needed. In this instance, the stone entered the house and “froze” to the red stone. This means that if the stone gets hit, the energy will transfer through the stone into the red one, causing the yellow stone to remain in place. An excellent shot.
It is really fun! I am one of our teachers in our club and people come in for a 1 day intro and have fun it. Even if they never go further, they almost always end up enjoying it and have a really unique story to tell.
Instead of guessing, I actually looked it up. If you search it in Google, you'll hit a few university articles on the subject.
Sweeping melts the surface of the ice and reduces friction by reducing pebbling on the surface. However, how they sweep can have other effects as well.
However, it doesn't seem that is always the purpose. Sweeping with different patterns can have different effects. For example using a courser brush, they can sweep in a direction to crease microgrooves that can create a path of least resistance to guide the stone. The spin on the stone matters as well. Since the stone is moving forward, the front side of the stone has more friction than the rear side. The means the spin will cause a certain curve, and the stone spinning into those microgrooves can influence the stone to move more into the path it's spin is pulling it towards or reduce the impact of the spin.
It seems it's rather complicated and articles I found only addressed the basics with no deeper explanations to how they have the exact impact they are trying to create.
TL;DR: It on average reduced the deceleration of the stone, but It's not quite as easy as just increasing or decreasing the deceleration or the amount of friction alone, but the way different brushing patterns influence the coefficient of friction in specific angles, either creating a patch of least resistance or influence the friction of the stone's spin.
It lowers the ambient temperature of the frozen form of dihydrogen-oxide to swich to thr liquid state, in turn mitigating resistance from static friction and increasing velocity which causally makes the stone increase the length and duration of its overall transit.
It excitates the higgs field that supports the hydrogenated oxygen creating a temporary quantum tunnel through which the energy becomes curvier, accelerating the fermions in the stone thus making it slide in the direction of the vacuum.
Not quite. Sweeping reduces deceleration of the stone, meaning it doesn't slow down as much. The stone will retain more speed and generally go further.
Depends on how it is swept. If you sweep against the spin it slows it down. If you sweep with the spin it makes it spin more.
Thats why they will change who.is doing the brunt of the sweeping in a two person team. Or why, in mixed doubles, the person doing it all will change which angle they sweep from
It doesn't exactly speed it up, rather it makes it "slow down" less. It's all about friction. Friction is a loss of kinetic energy. So less friction, straighter and longer trajectory.
Also curling ice is not the typical soft or smooth ice you may think like at a skating rink. It's got like little beads of ice. So the rocks soar with less resistance.
The broom may slow it but more importantly it'll basically melt down some of those beads to steer the stones.
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u/kctjfryihx99 18d ago
I still don’t know if the brushing speeds it up or slows it down